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  • #31
    Dengue virus is an under-recognised causative agent of acute encephalitis syndrome (AES): Results from a four year AES surveillance study of Japanese encephalitis in selected states of IndiaDengue virus is an under-recognised causative

    Vasanthapuram RaviCorrespondence information about the author Vasanthapuram Ravi
    , Shafeeq Keeran Shahul Hameed
    , Anita Desai
    , Reeta Subramaniam Mani
    , Vijayalakshmi Reddy
    , Anoop Velayudhan
    , Ravi Yadav
    , Amita Jain
    , Lahari Saikia
    , A.K. Borthakur
    , Daiji Gogoi Mohan
    , Bhaswati Bhandopadhyay
    , Nemai Bhattacharya
    , Akshay Chandra Dhariwal
    , Prafulla Kumar Sen
    , Srinivasan Venkatesh
    , Jagdish Prasad
    , Kayla Laserson
    , Padmini SrikantiahEmail the author Padmini Srikantiah

    Open Access
    DOI: https://doi.org/10.1016/j.ijid.2019.01.008

    Article Info




    Highlights

    • Dengue virus is one amongst the three most common agents identified in AES.
    • Existing surveillance for acute encephalitis syndrome (AES) does not include routine testing for dengue.
    • Dengue accounts for 5% of AES cases in India especially in the absence of laboratory evidence for other pathogens tested.
    • Testing for dengue in AES cases must be included in routine surveillance.


    Abstract

    Background

    Acute encephalitis syndrome (AES) surveillance in India has indicated that Japanese encephalitis virus (JEV) accounts for 5-35% of AES cases annually; the etiology remains unknown in the remaining cases. We implemented comprehensive AES surveillance to identify other etiological agents of AES, with emphasis on dengue virus.


    Methods

    Serum and cerebrospinal fluid (CSF) specimens were collected from patients enrolled prospectively in AES surveillance from 2014-2017 at selected sites of three high burden states of India. All samples were initially tested for JEV IgM. Specimens negative for JEV by serology were tested for IgM to scrub typhus, dengue virus (DEN), and West Nile virus; all JEV IgM-negative CSF samples were tested by PCR for S.pneumoniae, N.meningitidis, H.influenzae, herpes simplex virus type 1, enteroviruses and DEN.


    Results

    Of 10,107 AES patients, an etiology could be established in 49.2% of patients including JEV (16%), scrub typus (16%) and DEN (5.2%) as the top three agents. Amongst the DEN positive cases (359/6892), seven (2%) were positive only for dengue virus RNA: one in serum and six in CSF.


    Conclusion

    Amongst the pathogens identified, dengue accounted for 5% of all AES cases and was one of the three common etiological agents. These results underscore the importance of including dengue virus in routine testing of AES cases.


    Keywords:

    Acute encephalitis syndrome, etiological agents, dengue, India



    https://www.ijidonline.com/article/S...019-0/fulltext
    Twitter: @RonanKelly13
    The views expressed are mine alone and do not represent the views of my employer or any other person or organization.

    Comment


    • #32
      ORIGINAL ARTICLE
      Year : 2017 | Volume : 30 | Issue : 6 | Page : 317-320
      Status and trend of acute encephalitis syndrome and Japanese encephalitis in Bihar, India

      Praveen Kumar1, PM Pisudde2, PP Sarthi1, MP Sharma3, VR Keshri4
      1 Centre for Environmental Sciences, Central University of South Bihar, Patna, Bihar, India
      2 Department of Community Medicine, ESIC Medical College, Sanat Nagar, Hyderabad, India
      3 State Programme Officer (Malaria), Chief Malaria Office, Patna, Bihar, India
      4 Maternal Health Specialist, Bihar Technical Support Programme, Care India, Patna, Bihar, India
      Date of Web Publication 16-Aug-2018
      Correspondence Address:
      P M Pisudde
      Department of Community Medicine, ESIC Medical College, Sanat Nagar, Hyderabad
      India
      Source of Support: None, Conflict of Interest: None
      DOI: 10.4103/0970-258X.239070
      Abstract
      Background. Acute encephalitis syndrome (AES) is a clinical condition, of which the most common cause is Japanese encephalitis (JE). Though there is deficiency of data on AES and JE from Bihar, the state ranks third in the reporting of JE cases after Uttar Pradesh and Assam. We aimed to assess the status and trends of AES and JE cases in Bihar and to know the status of the disease in the districts.
      Methods. We collected monthly epidemiological data for AES and JE for the period 2009–2014.
      Results. A total of 4400 cases (733 cases/year) with an average case fatality rate (CFR) of 30% for AES for the entire study period. A total of 396 cases of JE were reported with approximately 14% CFR. The disease peaks were during the start and end of the Indian summer and monsoon months for AES and JE, respectively. Districts such as Patna, Jehanabad, Nawada, Gaya and East Champaran reported the maximum number of AES and JE cases with annual incidence rates of 4.7–25.0 and 0.546–1.78 per 100 000 population, respectively.
      Conclusion. Since 2009, the incidence of AES and JE cases has been increasing in Bihar.
      How to cite this article:
      Kumar P, Pisudde P M, Sarthi P P, Sharma M P, Keshri V R. Status and trend of acute encephalitis syndrome and Japanese encephalitis in Bihar, India. Natl Med J India 2017;30:317-20
      How to cite this URL:
      Kumar P, Pisudde P M, Sarthi P P, Sharma M P, Keshri V R. Status and trend of acute encephalitis syndrome and Japanese encephalitis in Bihar, India. Natl Med J India [serial online] 2017 [cited 2019 Jun 19];30:317-20. Available from: http://www.nmji.in/text.asp?2017/30/6/317/239070


      Introduction

      Acute encephalitis syndrome (AES) is a multifactorial clinical condition, the most common cause being Japanese encephalitis (JE). JE is a vector-borne viral disease caused by the JE virus of group B arbovirus (Flavivirus) and is transmitted to humans by the Culicine mosquito. JE affects the central nervous system (CNS), and can cause serious complications and death. The case fatality rate (CFR) is high and those who survive may suffer from neurological sequelae such as convulsions, episodic headache, autonomic disturbance, abnormal behaviour, mood disorder, intellectual deficit, paresis, incoordination of movements, jerky limb movements, speech disorder, cranial nerve palsy, gaze palsy, parkinsonian features, impaired hearing, etc.[1] An estimated 25% of affected children die from the disease, and among those who survive, 30%–40% suffer from physical and mental impairment. Children suffer the highest attack rate due to lack of cumulative immunity from natural infections.[2] JE was first recognized in Japan in 1924. Since the late 1960s, the extent of epidemics in Japan and China has steadily declined. It is estimated that 3 billion people are at risk, and the disease has spread to new territories.[3]

      According to WHO, JE is endemic in large parts of the Asia and Pacific regions, especially in the South Asian and Western Pacific regions. According to WHO statistics, 3187 cases of JE were reported in 2013 from all over the world; of these, 42% were from countries in the South-East Asia region, and of these 80% were from India.[4] According to a systematic review by Campbell in 2011, India falls in the medium-to-high incidence areas with an expanding vaccination programme and shares its place with Sri Lanka, Thailand and Vietnam. The population of these endemic areas is about 538.1 million.[5] A fatality rate of 3 0%–50% has been attributed to JE in southern and eastern Asia.[6]

      The first case of JE was reported in India in 1955 from Vellore, Tamil Nadu and the first major outbreak was reported in 1973 from Burdwan district of West Bengal. Since then, in India, AES and JE have been reported from 171 districts of 19 states. In India, the JE virus has been isolated from more than 15 species of mosquitos belonging to genera Culex, Aedes and Anopheles; Culex tritaeniorhynchus and Culex vishnui are considered the main vectors.[7] A major outbreak of JE was reported from eastern Uttar Pradesh (UP) during 2005 with more than 6000 cases and 1500 deaths. This led to the introduction of the JE vaccine in endemic areas. Bihar, which is adjacent to eastern UP, has also reported a rise in the number of patients with AES and JE with periodic epidemics in some districts, including Muzaffarpur district.[8]

      The outbreaks of JE in Gorakhpur and Basti divisions in eastern UP during 2005, led to the development of surveillance guidelines for AES and JE by the National Vector Borne Disease Control Programme (NVBDCP). These guidelines required JE to be reported as an AES and after confirmation from the sentinel sites, a line-list of JE cases needed to be drawn and sent in prescribed formats.[9]

      There is deficiency of data on AES and JE from Bihar. We aimed to ascertain the status and trends of AES and JE in Bihar to suggest measures for prevention and control.

      Methods

      The Bihar plain is divided into two unequal halves by the river Ganga which flows from west to east. With a population of 10.38 crore (103.8 million), 17% of the state population is in the 0–6 years age group. The literacy rate of Bihar is 63.8% and decadal growth is 25%. Bihar, consisting of 38 districts, is a complex state for healthcare services in terms of resources and accessibility.[10]

      The NVBDCP follows the case definition of JE based on a syndromic approach. Epidemiological surveillance is done for AES, and suspected JE cases are reported as follows: ‘Clinically, a case of AES is defined as a person of any age, at any time of year with the acute onset of fever and a change in mental status (including symptoms such as confusion, disorientation, coma, or inability to talk) and/or new onset of seizures (excluding simple febrile seizures). Other early clinical findings may include an increase in irritability, somnolence or abnormal behaviour greater than that seen with usual febrile illness.’ Continuous surveillance of the disease is done through the Integrated Disease Surveillance Project (IDSP).[11] JE surveillance aims to identify patients with AES and subsequently confirm JE virus infection using IgM ELISA (enzyme-linked immunosorbent assay).[2] Laboratory confirmation of suspected cases of JE is done at identified sentinel laboratories, where the preferred test for diagnosis of JE is the IgM Capture ELISA. The samples are initially processed in district sentinel laboratories. Samples are then sent for confirmation to designated national laboratories.[12]

      The cases are reported by health workers to district health authorities. In-charge nodal officers from the district regularly visit facilities reporting AES cases for validation of the reported data. At the state level, reports are received from the districts according to the status of the disease, i.e. daily reports during outbreaks, weekly reports during the transmission period and monthly reports in the inter-epidemic period. The districts are monitored for regular reporting. The data are then merged at the state level, collated and immediately transmitted through specified proformas.[12] We collected the monthly epidemiological data of AES and JE for the period 2009–2014. We accessed the data with permission from the state health authorities.

      We estimated the trends of AES and JE cases, burden of AES and JE in terms of morbidity and mortality, annual incidence rate (number of cases per 100 000 population) and CFR (proportion of deaths against the total number of cases reported per year).

      Results

      A total of 4400 cases of AES were reported between 2009 and 2014, an average of 733 cases per year. There were 1309 deaths reported with an average CFR of about 3 0%. There were 396 cases of JE and 56 deaths during the study period [Table 1]. The CFR for confirmed JE cases was about 14%.
      Table 1: Annual rates for acute encephalitis syndrome and Japanese encephalitis in Bihar (2009–2014)

      Click here to view

      From 2009 to 2014, AES cases started to appear in April–May, reached a peak during June and declined from October [Figure 1]. A similar pattern is seen each year. Two peaks are seen, one in June and another in September and October. The maximum number of cases and the highest peak was in 2014. The trend of JE (confirmed) cases over the years mirrored the trend in AES cases [Figure 2].
      Figure 1: Trend of acute encephalitis syndrome cases from 2009 to 2014 in Bihar

      Click here to view
      Figure 2: Trend of Japanese encephalitis (confirmed) cases from 2009 to 2014 in Bihar

      Click here to view

      The districts of Patna, Nalanda, Jehenabad, Nawada, Gaya, Aurangabad, Vaishali, Muzaffarpur, Sheohar and East Champaran had the highest annual incidence rate (4.7–25 per 100 000 population) for AES [Figure 3]. District such as Saran, Siwan, Bhojpur, Buxar, West Champaran, Jamui and Sitamarhi had a lower annual incidence rate of 2.2 to 4.73 per 100 000 population and fall in the third quartile. Districts such as Kaimur, Darbhanga, Madhubani and others were in the first quartile and added little to the pool of AES cases.
      Figure 3: A map showing district-wise distribution in Bihar of cases with acute encephalitis syndrome according to the annual incidence rate (per 100 000 population)

      Click here to view

      The districts of Patna, Jehenabad, Nawada, Gaya, Lakhisarai, Gopalganj, Siwan, East Champaran and West Champaran have annual incidence rate of JE ranging from 0.546 to 1.78 per 100 000 population, which falls in the fourth quartile. Kaimur, Rohtas, Vaishali, Sheohar, Begusarai, Munger, Supaul, Araria, Purnia, Katihar and Kishanganj did not report any cases of JE. However, Aurangabad, Arwal, Bhojpur, Buxar, Saran, Nalanda, Khagaria and Banka were in the third quartile [Figure 4].
      Figure 4: A map showing district-wise distribution in Bihar of Japanese encephalitis (confirmed) cases according to the annual incidence rate (per 100 000 population)

      Click here to view

      Discussion

      We collected data from 2009 to 2014 and observed that year on year the reporting of AES and confirmed JE cases increased. This could be due to strengthening of the surveillance system by the NVBDCP. The average CFR was 30% in AES and 13% in confirmed cases of JE. The CFR ranged from 5.3% to 34.8% for AES. A CFR of 20%–36% was reported in another study from Bihar in 2013.[8] However, a study from UP by Kakkar et al.,[13] which analysed two years' data from a tertiary care centre found that the CFR for AES ranged from 18% to 19.8%; less than that in our study. Another study that compared CFR at different times found it to be 31.5% in 1978 during an outbreak, 34.5% in 1985 and 31.5% in 1988, and declined to 24.9% in 2005. This was possibly due to improvement in the management of cases with JE.[14] A study between 1978 and 2007 of over 100 000 AES cases showed a CFR of almost 33% from 13 different states.[15] In Nepal, which is adjoining Bihar, the overall mortality of JE varied from 9.8% in 2000 to 20.9% in 2003;[16] similar to our study.

      The AES cases had a seasonal distribution—beginning in the months of April and May and peaking in June. The cases started to decline from October. A similar pattern was seen in confirmed cases of JE. Most previous studies too reported epidemics between May and October, and mostly from the northern and eastern parts of India.[17] In UP, the reported JE cases between 1998 and 2007 were sporadic in June and peaked in September before declining. Seasonal peaks of cases of JE have occurred during July to October, coinciding with the rainy and post-rainy seasons. The onset of winter brings a decline in the cases of JE.[10] In Nepal, cases of AES and JE started a little earlier, in April–May, and reached a peak during late August to early September, and then declined.[16] Saxena et al. studied the trend of AES cases and suggested that JE was increasing in northern India, which may result in larger epidemics in the future.[18] In India, Karnataka has been reported to have two epidemics each year, a severe form from April to July and a milder one from September to December along with the rest of India.[15] In Tamil Nadu, of 561 AES cases reported during a study, JE was confirmed in 4.9% with an increasing trend from 4.1% in 2007 to 5.3% in 2009.[19] The minimum reported incidence in a tropical setting for all ages was 6.34 per 100 000 population.[20] Districts of Patna, Nalanda, Jehenabad, Nawada, Gaya, Aurangabad, Vaishali, Muzaffarpur, Sheohar and East Champaran had the maximum number of cases of AES cases with an annual incidence ranging from 4.7 to 24.8 per 100 000 population. Dinesh et al.[21] and Mishra et al.[8],[22]have also reported a similar distribution of cases.

      Conclusions

      With all districts reporting cases of AES and JE, the disease is endemic in Bihar. The cases of AES start appearing in April and reach a peak in June and then decline. There is another peak of JE cases in October. The CFR of AES and JE ranges from 5% to 35% in Bihar. The annual incidence rate of AES ranges from 0.05 to 25 per 100 000 population with all districts reporting cases. Confirmed cases of JE have an annual incidence ranging from 0 to 2 per 100 000 population and 75% of the districts report cases of JE. The reporting and surveillance mechanism needs to be strengthened in all the districts of the state. Private practitioners who participate less in surveillance activities need to be encouraged to do so especially for cases of AES. Intense information, education and communication (IEC) activities must be started at the village level to increase participation from the community and to improve the long-term passive surveillance. Hence, there is a need to intensify efforts for prevention and control during April–June.

      Conflicts of interest. None



      References
      1. Baruah HC, Biswas D, Patgiri D, Mahanta J. Clinical outcome and neurological sequelae in serologically confirmed cases of Japanese encephalitis patients in Assam, India. Indian Pediatr 2002;39:1143-8.
      2. Ministry of Health and Family Welfare. National Programme for Prevention and Control of Japanese Encephalitis/Acute Encephalitis Syndrome, Operational Guidelines. New Delhi:National Vector Borne Disease Control Programme, Directorate General of Health Services, Ministry of Health and Family Welfare; 2014.
      3. Erlanger TE, Weiss S, Keiser J, Utzinger J, Wiedenmayer K. Past, present, and future of Japanese encephalitis. Emer Infect Dis2009;15:1-7.
      4. World Health Statistics 2015. Geneva:World Health Organization; 2015.
      5. Campbell G, Hills S, Fischer M, Jacobson J, Hoke C, Hombach J, et al. Estimated global incidence of Japanese encephalitis: A systematic review. Bull World Health Organ 2011;89:766-74.
      6. Tiwari S, Singh RK, Tiwari R, Dhole TN. Japanese encephalitis: A review of the Indian perspective. Braz J Infect Dis 2012;16:564-73.
      7. National Institute of Virology. Japanese encephalitis. New Delhi:Indian Council of Medical Research. Available at www.icmr.nic.in/pinstitute/niv/JAPANESE%20ENCEPHALITIS.pdf (accessed on 15 Jul 2017).
      8. Mishra R. Epidemiological report on acute encephalitis syndrome (AES)/Japanese encephalitis (JE) outbreak in Bihar and planning perspectives for its control. Am J Health Res 2014;2:404-10.
      9. Guidelines: Clinical management of acute encephalitis syndrome including Japanese encephalitis. New Delhi:National Vector Borne Disease Control Programme, Directorate General of Health Services, Ministry of Health and Family Welfare; 2009.
      10. Government of Bihar. State profile. Updated 16 Jul 2016. Available at http://gov.bih.nic.in/Profile/default.htm (accessed on 16 Jul 2016).
      11. Ministry of Health and Family Welfare, Government of India. Integrated Disease Surveillance Program. New Delhi:National Centre for Disease Control, Directorate General of Health Services. Available at http://idsp.nic.in/index4.php?lang=1...d=313&lid=1592 (accessed on 16 Jul 2017).
      12. Directorate of National Vector Borne Diseases Control Programme. Guidelines for surveillance of acute encephalitis syndrome (with special reference to Japanese encephalitis). New Delhi:National Vector Borne Diseases Control Programme, Directorate General of Health Services, Ministry of Health and Family Welfare; 2006.
      13. Kakkar M, Rogawski ET, Abbas SS, Chaturvedi S, Dhole TN, Hossain SS, et al. Acute encephalitis syndrome surveillance, Kushinagar district, Uttar Pradesh, India, 2011-2012. Emerg Infect Dis 2013;19:1361-7.
      14. Kumari R, Joshi PL. A review of Japanese encephalitis in Uttar Pradesh, India. WHO South-East Asia J Public Health 2012; 1:374-95.
      15. Kelly R. Acute encephalitis syndrome outbreaks in India—An ongoing puzzle. Sydney : School of Public Health and Community Medicine; Oct 2014. Available at https://sphcm.med.unsw.edu.au/infect...ongoing-puzzle (accessed on 15 Jul 2017).
      16. Bhatta LR, Wierzba T, Joshi AB, Banjara MR. Status and trend of Japanese encephalitis epidemics in Nepal: A five-year retrospective review. J Nepal Health Res Counc Dec 2008. Available at http://jnhrc.com.np/index.php/jnhrc/article/view/75 (accessed on 4 Jul 2017).
      17. Joshi R, Kalantri SP, Reingold A, Colford JM. Changing landscape of acute encephalitis syndrome in India: A systematic review. Natl Med J India 2012;25: 212-20.
      18. Saxena SK, Mishra N, Saxena R, Singh M, Mathur A. Trend of Japanese encephalitis in North India: Evidence from thirty-eight acute encephalitis cases and appraisal of niceties. J Infect Dev Ctries 2009;3:517-30.
      19. Gunasekaran P, Kaveri K, Arunagiri K, Mohana S, Kiruba R, Kumar VS, et al. Japanese encephalitis in Tamil Nadu (2007–2009). Indian J Med Res 2012;135: 680-2.
      20. Jmor F, Emsley HCA, Fischer M, Solomon T, Lewthwaite P. The incidence of acute encephalitis syndrome in western industrialised and tropical countries. Virol J 2008;5:134.
      21. Dinesh DS, Pandey K, Das VNR, Topno RK, Kesari S, Kumar V, et al. Possible factors causing acute encephalitis syndrome outbreak in Bihar, India. Int J Curr Microbiol App Sci 2013;2:531-8.
      22. Mishra R. Annual communicable disease surveillance report 2013, Bihar. Patna:Integrated disease surveillance project, State health society, Bihar; 2013.
      Figures
      [Figure 1], [Figure 2], [Figure 3], [Figure 4]

      Tables
      [Table 1]
      http://www.nmji.in/article.asp?issn=...0;aulast=Kumar
      Twitter: @RonanKelly13
      The views expressed are mine alone and do not represent the views of my employer or any other person or organization.

      Comment


      • #33
        Original Research Article https://doi.org/10.20546/ijcmas.2018.712.414
        Chandipura Virus Recognized among AES for the First Time
        in Bihar, India
        Diwakar Singh Dinesh1
        *
        #
        , Roshan Kamal Topno1#
        , Krishna Pandey1
        , Rishikesh Kumar1
        ,
        Ganesh Chandra Sahoo1
        , Maneesh Kumar1
        , Banke Bihari Singh2
        ,
        Wakil Paswan2
        and Pradeep Das1
        1
        Indian Council of Medical Research- Rajendra Memorial Research Institute of Medical
        Sciences, Agamkuan, Patna-800007, India
        2
        Anugrah Narayan Magadh Memorial Medical College and Hospital Gaya, Bihar, India
        #*Authors contributed equally
        *Corresponding author

        A B S T R A C T

        The epidemic outbreak of Acute Encephalitis Syndrome (AES) was continuing specially
        from 2014 onwards and taking toll of pediatric age group distributed in different blocks of
        Gaya district of Bihar, India. In an extensive survey during outbreak (2016), a case of high
        fever history was diagnosed having Chandipura virus out of 24 acute fever cases admitted
        at Anugrah Narayan Memorial Magadh Medical College and Hospital (ANMMMCH)
        Gaya. Off which nine cases were from Gaya district. The age group of affected cases was
        1-15 years. Male were affected more than females (M:F::55.5:44.4). Records of death were
        found five. Patients were suffering from acute-onset of fever with change in mental status
        (including symptoms such as confusion, disorientation, coma, or inability to talk) and often
        with new onset of seizures. All were diagnosed as equivocal JE by IgM ELISA except one.
        It was the first case report from Bihar, India. The treatment was only based on sign and
        symptoms. AES is a seasonal and major health problem of Bihar coming every year. This
        study has disclosed one of the reasons of AES in Bihar.
        ...
        https://www.ijcmas.com/7-12-2018/Diw...%20et%20al.pdf
        Twitter: @RonanKelly13
        The views expressed are mine alone and do not represent the views of my employer or any other person or organization.

        Comment


        • #34
          Dengue virus is an under-recognised causative agent of acute encephalitis syndrome (AES): Results from a four year AES surveillance study of Japanese encephalitis in selected states of India

          Author links open overlay panelRaviVasanthapurama

          Shafeeq KeeranShahul HameedaAnitaDesaiaReeta SubramaniamManiaVijayalakshmiReddyaAnoopVelayudhanbRaviYadavaAmitaJaincLahariSaikiadA.K.BorthakurdDaiji GogoiMohaneBhaswatiBandyopadhyayfNemaiBhattacharyafAkshay ChandraDhariwalgPrabir KumarSengSrinivasVenkateshhJagdishPrasadiKaylaLasersonbPadminiSrikantiahb




          Show more
          https://doi.org/10.1016/j.ijid.2019.01.008Get rights and content
          Under a Creative Commons license
          open access


          Highlights

          • Dengue virus is one of the three most common agents identified in AES.
          • Existing surveillance for acute encephalitis syndrome (AES) does not include routine testing for dengue.
          • Dengue accounts for 5% of AES cases in India especially in the absence of laboratory evidence for other pathogens tested.
          • Testing for dengue in AES cases must be included in routine surveillance.



          Abstract

          Background

          Acute encephalitis syndrome (AES) surveillance in India has indicated that Japanese encephalitis virus (JEV) accounts for 5-35% of AES cases annually; the etiology remains unknown in the remaining cases. We implemented comprehensive AES surveillance to identify other etiological agents of AES, with emphasis on dengue virus.

          Methods

          Serum and cerebrospinal fluid (CSF) specimens were collected from patients enrolled prospectively in AES surveillance from 2014-2017 at selected sites of three high burden states of India. All samples were initially tested for JEV IgM. Specimens negative for JEV by serology were tested for IgM to scrub typhus, dengue virus (DEN), and West Nile virus; all JEV IgM-negative CSF samples were tested by PCR for S. pneumoniae, N. meningitidis, H. influenzae, herpes simplex virus type 1, enteroviruses and DEN.

          Results

          Of 10,107 AES patients, an etiology could be established in 49.2% of patients including JEV (16%), scrub typhus (16%) and DEN (5.2%) as the top three agents. Amongst the DEN positive cases (359/6892), seven (2%) were positive only for dengue virus RNA: one in serum and six in CSF.

          Conclusion

          Amongst the pathogens identified, dengue accounted for 5% of all AES cases and was one of the three common etiological agents. These results underscore the importance of including dengue virus in routine testing of AES cases.


          Keywords

          Acute encephalitis syndrome
          Etiological agents
          Dengue
          India


          Introduction

          Dengue (DEN) is a mosquito-borne viral disease caused by any one of the four dengue virus (DENV) serotypes. It is the second most common mosquito-borne disease affecting humans after malaria (World Health Organization, 2009). Approximately 4 billion people are at risk of the disease, and annually there are an estimated 100 million cases of symptomatic dengue (Bhatt et al., 2013). Reported case-fatality rates of severe DEN range from 0.2% to 5% (World Health Organization, 2009). Population growth, urbanization, deterioration of mosquito-control programmes, and an increase in air travel and trade have contributed to the emergence and geographical spread of the disease over past decades (Guzmán and Kouri, 2002). While the great majority of DEN cases are self-limited febrile illnesses, central nervous system (CNS) involvement following DENV infection has been increasingly recognized in the past decade (Solomon et al., 2000, Misra et al., 2006, Jackson et al., 2008, Carod-Artal et al., 2013). In addition to immune-mediated syndromes and DEN muscle dysfunction, reported neurological complications of DENV infection have also included dengue encephalopathy and encephalitis (Solomon et al., 2000, Misra et al., 2006, Jackson et al., 2008, Carod-Artal et al., 2013).
          Acute encephalitis syndrome (AES) is a major public health problem in India and annually several thousands of cases are reported to the National Vector Borne Disease Control Program (NVBDCP) of India, the nodal agency responsible for AES surveillance in India. According to NVBDCP surveillance guidelines (NVBDCP, 2006), all reported AES cases should be tested for IgM antibodies to Japanese encephalitis virus (JEV); those that are negative for JEV IgM are reported to have an unknown etiology (“AES-unknown”). Annually, JEV accounts for approximately 10–15% of AES in India, and the majority of cases are classified as “AES-unknown.” With the goal of enhancing existing AES surveillance, we systematically investigated additional etiologies of AES in three high burden states of India through an expanded testing strategy designed to detect recognized etiologies of AES other than JEV, including DEN. Here we present the results from our large-scale study with special focus on DENV as a causative agent of AES.
          Materials and methods

          Study design

          In 2014, we initiated a tiered laboratory-based enhanced AES surveillance project in six district hospitals in three states of India: Uttar Pradesh, West Bengal, and Assam. Sites were selected after standardized assessment of district laboratory capacity and were linked with one of four designated state-level referral laboratories. Between 2014 and 2017, the network expanded to a total of 19 district sites and five referral microbiology laboratories.
          Surveillance criteria and enrollment

          All patients admitted to the participating district hospitals who fulfilled the 2006 NVBDCP case definition of AES were included in the study. As per the NVBDCP criteria (2006), AES is defined as “a person of any age during, at any time of the year presenting with acute onset of fever and change in mental status (including symptoms such as confusion, disorientation, coma or inability to talk) and/or new onset of seizures (excluding simple febrile seizures)”. Project staff at each district hospital site worked with clinical staff to identify AES patients. Demographic data collected included age stratification (<1, 1–5yrs, 6–10 yrs, 11–15 yrs and >15 yrs) and gender. Clinical data collected included presence or absence of seizures, final outcome, and CSF cell count. Consistent with NVBDCP’s guidelines, serum and/or CSF were collected from each patient at the treating clinician’s discretion and submitted to the district hospital laboratory for analysis.
          AES standard diagnostic testing algorithm

          Beginning in 2014, a uniform laboratory testing algorithm was adopted to detect etiologies other than JEV. In accordance with standard NVBDCP guidelines, patient serum and CSF specimens were initially tested for the presence of JEV IgM by ELISA (National Institute of Virology JEV IgM ELISA kit, Pune, India) at the district hospital laboratory. Positive results were communicated immediately to respective district hospital clinicians. Specimens that were negative for JEV IgM were transported within 2–3 days of collection to the designated referral laboratory where serum specimens were tested for IgM antibodies to DENV (DENV IgM kit; National Institute of Virology, Pune, India). In addition to DEN, serum specimens were also tested for Orientia tsutsugamushi (scrub typhus IgM; Inbios IgM, USA), and West Nile virus (WNV IgM; Inbios, USA) by ELISA, and CSF specimens negative for JEV IgM antibodies were tested by real-time PCR for the presence of nucleic acid of Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, herpes simplex virus type 1(HSV-1) and enteroviruses, as described elsewhere (Centers for Disease Control and Prevention, 2016, Gudza-Mugabe et al., 2015, Piqueur et al., 2009, Ramamurthy et al., 2011). In January 2017, simultaneous serum-based ELISA testing for JEV, DENV and scrub typhus was initiated at the district hospital laboratories, in addition to assessment for JEV IgM in CSF. Further, starting in January 2017, two additional assays were added to the testing algorithm. Along with DENV IgM testing, DEN NS1 antigen detection in serum by ELISA (n = 1405) and testing for Zika, DENV, and CHIKV RNA using the CDC, Atlanta, USA, Trioplex PCR (n = 822; 708 CSF and 114 sera) was performed in all referral laboratories of the network. Among the various tests carried out for DEN in serum, the IgM ELISA was given preference, followed by NS1 ELISA, followed by PCR, subject to availability of sufficient volume of sample.
          In accordance with NVBDCP guidelines, detection of JEV IgM in serum or CSF was considered evidence of confirmed JE. Additionally, detection of DENV RNA in serum or CSF was also considered confirmatory evidence of DENV infection, even when other pathogens were detected. Detection of IgM antibodies to DENV in serum in the setting of negative results to all other pathogens or detection of DEN NS1 antigen in serum samples were considered evidence of probable DENV infection. In each of the other serum assays (scrub typhus, WNV), detection of IgM antibodies to a specific pathogen in the setting of negative results to all other pathogens was also considered as evidence of probable infection. Similarly, detection of nucleic acid in CSF for any one of the other pathogens tested, in the setting of negative results to all other pathogens, was also considered evidence of confirmed infection. For the current analysis, multiple infections were not included.
          Quality assurance in laboratory testing

          To ensure quality of laboratory results obtained across the network, the National Institute of Mental Health and Neuro Sciences (NIMHANS) provided annual hands-on training to all participating district and referral laboratories. In addition, each laboratory was assessed annually with a proficiency panel consisting of 5–10 coded positive and negative clinical samples for each pathogen in the algorithm. A proficiency score of >80% was required for continued participation in the network.
          Statistical analysis

          The data were analyzed using SPSS Version 23 and the Chi-squared test was used to compare age, gender, clinical features and outcomes between JEV and DEN positive AES cases. A p value of <0.05 was considered statistically significant.
          Ethics

          The study was approved by the institutional review boards of NIMHANS. The CDC Center for Global Health Associate Director for Science reviewed the protocol and determined that CDC was not engaged.
          Results

          Between 2014 and 2017, a total of 10,107 patients were enrolled in this study. Serum samples were available from 2123 (31%) patients, CSF samples were available from 252 (4%) patients, and both serum and CSF were available from 4517(65%) patients. Of note, 691/10,107 (6.8%) patients were positive for more than one pathogen and excluded from analysis. Irrespective of the tests used (molecular or serology), exclusive positives were considered positive in absence of evidence for other pathogens. Exclusive positives in DEN diagnostic tests (ELISA or PCRs) were combined for analysis purpose.
          Amongst the 10,107 patients, an etiological agent was identified in 49.2% using both immunoassays and molecular assays in serum and/or CSF (Ravi et al., 2019). Of 10,107 patients, JEV was identified as the etiological agent in 1658 patients (16%) based on the NVBDCP guidelines of detection of JEV-IgM in serum and/or CSF samples. Among 8449 JEV-IgM negative patients, 6892 (82%) were tested for DENV (6511 by DEN IgM ELISA, 1405 by DEN NS1 ELISA and 822 by PCR; 708 CSF and 114 serum- Table 1). In the remaining 1557 patients, DEN testing could not be carried out due to lack of adequate quantity of sample. Overall, DEN was detected in 5.2% (359/6892) of evaluated AES patients. Of these 359 patients, 280 (78%) were positive for DEN IgM in serum samples, 72 (20%) were positive for DEN NS1 antigen in serum and 7 (2%) were positive for DENV RNA by PCR (1 in serum and 6 in CSF) (Table 2). None of the six CSF samples showed presence of RBCs on microscopic examination and none of them had a WBC count of more than 100 cells/cu.mm. In 3/6 CSF PCR positive cases that had a corresponding serum sample available, all three serum samples were negative for DENV RNA and NS1 antigen. No other tests were positive for these 359 cases and for the purpose of analysis, the probable and confirmed cases were combined. The year-wise proportion of cases with evidence of DENV infection among the AES cases was similar across the three states (4-6%) during the study period except in 2015, when there was a threefold increase (14%) observed in West Bengal (Figure 1).
          Table 1. Details of samples that were subjected to various dengue tests.
          6511 None tested
          1405 None tested
          114 708
          a IgM ELISA and NS1 ELISA kits used were licensed for diagnostic use only on serum samples and hence these tests were not used for testing the CSF samples.

          Table 2. Annual distribution of dengue positive AES cases in Assam, Uttar Pradesh and West Bengal.
          2/152 (1.3%) 14/273 (5.1%) 1/78 (1.3%) 17/503 (3.4%)
          12/268 (4.5%) 15/294 (5.1%) 21/145 (14.5%) 48/707
          (6.8%)
          63/1093 (5.8%) 29/713 (4.0%) 4/108 (3.7%) 96/1914 (5.0%)
          82/1723 (4.8%) 75/1297 (5.8%) 41/748 (5.5%) 198/3768 (5.2%)
          159/3236 (4.9%) 133/2577 (5.2%) 67/1079 (6.2%) 359/6892a (5.2%)
          a Amongst the 359 cases with laboratory evidence of DENV infection, 353 (98%) were positive by immunoassays; 280 (80%0 were positive for DEN IgM in serum samples, 72 (18%) were positive for DEN NS1 antigen in serum and 7 (2%) were positive for DENV RNA by PCR (1 in serum and 6 in CSF). Note: 18/72 DEN NS1 positive samples were also positive for DEN IgM in serum and 1/7 samples positive for DEN RNA in serum was also positive for DEN NS1 and IgM.

          Figure 1. Seasonality of AES cases in relation to JE and dengue seropositivity in selected sites of Assam, Uttar Pradesh and West Bengal over a three-year period (2015–2017).

          The proportion of children with evidence of DENV infection (31%) between 1-5 years of age was significantly higher (p = 0.00007) compared to those positive for JEV (19%) (Table 3). On the other hand, the proportion of patients with JEV (42%) >15 years of age was significantly higher (p = 0.016) compared to those with evidence of DENV infection (32%). The gender distribution was similar between those with evidence of DENV infection (206/359; 58%) and JEV positive AES cases (973/1658; 59%). Clinical presentation with seizures was common in patients with evidence of DENV infection (60%) and JEV (60%) positive AES patients (p = 0.66; Table 4. The mortality and recovery patterns in patients with evidence of DENV infection revealed that 29 (10%) died and the majority of the patients with evidence of DENV infection (73%) recovered from the illness by the time of hospital discharge (Table 4). In contrast, 254 (19%) of JEV-positive AES cases died, and 770 (58%) recovered from illness.
          Table 3. Age and gender distribution of JE and dengue-positive AES cases.
          27 (2%) 10 (3%) χ2 = 1.86, p = 0.172
          304 (19%) 111 (31%) χ22 = 15.57, p = 0.000079
          405 (25%) 82 (23%) χ2 = .528, p = 0.467
          184 (12%) 39 (11%) χ2 = 0.074, p = 0.779
          670 (42%) 113 (32%) χ2 = 5.732, p = 0.016
          973 (61%) 206 (58%) χ2 = 0.32, p = 0.582
          * χ2− Chi-Square test was used to determine significance. p = <0.05 was considered statistically significant.

          Table 4. Clinical features and outcomes of JE and dengue positive AES cases.
          923 (60%) 192 (60%) χ2 =0 .045, p = 0.831
          JE (n = 1329) Dengue (n = 280)
          254 (19.1%) 29 (10.4%) χ2 = 9.016, p = 0.002
          770 (57.9%) 205 (73.2%) χ2 = 5.22, p = 0.02
          15 (1.1%) 1 (0.4%) χ2 = 1.37, p = 0.24
          290 (21.8%) 45 (16.1%) χ2 = 3.13, p = 0.07
          a LAMA = Left against medical advice.
          * χ2− Chi-Square test was used to determine significance. p = <0.05 was considered statistically significant.


          CSF cell counts were recorded in 122/359 (34%) of the patients with evidence of DENV infection. Of these, 36% (44/122) had a normal cell count of 0-5 cells/cu.mm (Table 5). Of the remaining 64% (78/122), the cell count was between 6-100 cells/cu.mm in 53% (64/122) and beyond 100 cell/cu.mm in 16% of cases (13/122). This was not significantly different from the cell counts recorded among JEV positive AES patients (p = 0.93; Table 5).
          Table 5. CSF cell count range in JE and dengue positive AES cases.
          155 (36%) 44 (36%) χ2 = .003, p = 0.955
          216 (51%) 65 (53%) χ2 = .072, p = 0.787
          54 (13%) 13 (11%) χ2 = .292, p = 0.588
          * χ2− Chi-Square test was used to determine significance. p = <0.05 was considered statistically significant.


          Seasonality

          The majority of AES cases were reported between June and December of each year, in the post monsoon season (Figure 1). While AES cases positive for JE showed a distinct peak in June–July of every year, cases with evidence of DENV infection exhibited a cyclical pattern throughout the year and the geographic distribution and seasonality showed this pattern over the three-year period of this study.
          Discussion

          This is the first large scale study carried out to identify etiology of AES in India. Amongst the 49% of AES patients in whom an etiological agent was identified, JEV, scrub typhus and DENV accounted for over 88%. These overall results are being communicated in a separate manuscript elsewhere (Ravi et al., 2019). In this report we underscore the importance of identifying DENV as an etiological agent in AES cases, especially when it is not traditionally considered as a neurotropic virus. The association of DENV infection with neurological abnormalities was first described from Thailand by Sanguansermsri et al. (1976) in a patient presenting with encephalopathy. Since then, neurological involvement has been increasingly reported in DENV infection in the past two decades across Asia and South America (Thisyakorn et al., 1999, Cam et al., 2001, Chokephaibulkit et al., 2001, García-Rivera et al., 2003, Malavige et al., 2007, Kumar et al., 2008, Agarwal et al., 2009, Sundaram et al., 2010, Tan et al., 2010, Araújo et al., 2012, Koshy et al., 2012, Rao et al., 2013). Although there are several reports of neurological manifestations in DENV infection from India, most of them have been limited to small case series and were not designed to address the prevalence of DENV infection among AES cases (Misra et al., 2006, Kumar et al., 2008, Agarwal et al., 2009, Varatharaj, 2010, Sundaram et al., 2010, Verma and Varatharaj, 2011, Verma et al., 2011, Koshy et al., 2012, Rao et al., 2013). This large-scale prospective investigation on etiology of acute encephalitis syndrome employed a standardized WHO case definition of AES and an algorithmic approach to laboratory testing. The results indicate that 5.2% of AES cases had evidence of acute DENV infection.
          One of the major challenges in attributing DENV as an etiological agent of AES has been the lack of a standardized case definition (Varatharaj, 2010, Soares and Puccioni-Sohler, 2011, Soares et al., 2011). In 2009, although WHO released new DEN guidelines and a new case classification, which included CNS involvement in the definition of severe disease, specific clinical/laboratory criteria for DEN encephalitis or DEN encephalopathy were not provided (World Health Organization, 2009). Furthermore, these two terms are used quite interchangeably in the literature. Another major challenge has been the lack of availability of validated serological methods for detection of DEN IgM/NS1 antigen in CSF. In short, the only available practical test for confirming neuroinvasion of DENV for public health purposes has been the detection of DENV nucleic acid in CSF. Consequently, in the absence of clear clinical/laboratory criteria for defining neurological involvement in DENV infection, investigators have largely relied on clinical signs coupled with CSF abnormalities and serological/molecular evidence of recent DENV infection (DEN IgM antibodies and/or NS1 antigen in serum and detection of DENV nucleic acid in CSF and/or serum) as an indicator of DENV infection (Solomon et al., 2000). Amongst the 359 AES patients with evidence of DENV infection in the present study, six patients (2%) were exclusively positive for dengue virus RNA in the CSF indicating the presence of virus in CNS. Absence of RBCs and a WBC count of less than 100 cells/cu.mm in these six samples suggests that these are not traumatic CSF taps. Detection of DEN NS1 antigen in serum, which is considered as definitive evidence of systemic DENV infection was possible in 20% of DEN positive AES patients. Although not considered definitive evidence, detection of DENV-specific IgM antibodies in the serum of AES patients in the absence of laboratory evidence of other pathogens strongly suggests DENV infection was associated with the clinical and neurological presentation observed in these patients. Although the clinical manifestations of AES cases with evidence of DENV infection are not readily distinguishable from JEV, there was a striking difference in mortality and recovery noted between confirmed JEV and AES with evidence of DENV infection. Therefore, routine testing for DENV should be instituted, which can help to guide clinical therapy (which might include a different approach to clinical monitoring of platelets, and management of IV fluids in DEN cases) to reduce associated morbidity/mortality, and better understand burden of disease.
          Though there was an increase in the number of patients with evidence of DENV infection in the post- monsoon period, these cases were detected year-round in contrast to JE cases, which showed a distinct peak during the months of June–July of every year. This was not expected, as in India, DEN is still primarily considered to be a seasonal post—monsoon epidemic illness. This finding emphasizes the need to suspect DEN as an etiological agent of AES throughout the year. The year-round detection of DEN may reflect the changing global epidemiological trends where increasing globalization, urbanization and population growth has resulted in transmission of DEN in most endemic countries of the tropical and sub-tropical region (Murray et al., 2013).
          This study had two limitations. First, it was not designed to address the question of what proportion of laboratory-confirmed DEN patients had neurological manifestations such as DEN encephalitis/encephalopathy. Rather, we focused on trying to understand the proportion of AES cases that were associated with DENV infection. Second, while we were able to capture data on clinical outcomes and mortality, our surveillance system did not permit the detailed collection of platelet counts among AES, or specifically DEN patients. Poor outcomes in some proportion of DEN patients might have been related to hemorrhagic complications. With the institution of routine DENV testing among AES patients, further evaluation, including monitoring of platelet counts, could be supported, and potentially contribute to improved outcomes.
          In conclusion, the findings of this study have major implications for AES surveillance in India where DENV is at present not considered as a possible etiological agent of AES especially when samples are negative for all other pathogens. It is in this context that the findings of this study underscore the need for incorporating routine serological testing for DENV into the national AES testing algorithm.

          Acknowledgements

          The authors thank all the clinicians, project coordinators, laboratory co-coordinators and laboratory technicians of the various study sites for their help in data collection, specimen collection and transport, testing and timely reporting of results to the clinicians and the state and national program officials. We also thank the state health authorities especially the surveillance officers of UP, Assam, and West Bengal for all their support in the implementation of the study at various sites. The excellent support and valuable inputs provided by the Directorate of Health Services, Ministry of Health and Family Welfare, Government of India for carrying out this study is also gratefully acknowledged.
          Funding

          This study was funded by the Centers for Disease Control, USA under the CDC Cooperative Agreement Grant No. 1U01GH001168. This article is part of a supplement entitled ‘Dengue Fever in India’ which is sponsored by the Department of Biotechnology, Government of India and collated by the and collated by the Translational Health and Science and Technology Institute.
          Conflict of interst

          None declared.


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          • #35
            h/t tetano
            Acute Encephalitis Syndrome with an Unusual Diagnosis

            Mili Thomas, DCH, DNB, Kamala Swarnam, MD, DCH, Gopika Sekhar Remadevi, DCH, DNB, A Marthanda Pillai, MS (Neuro), MNAMS, FRCS

            Journal of Tropical Pediatrics, fmz058, https://doi.org/10.1093/tropej/fmz058

            Published:
            25 August 2019









            Abstract

            Four-year old boy was admitted with acute onset of fever with seizures and altered sensorium. His mother had history of contact with influenza A H1N1 virus (H1N1) infection. Blood counts, electrolytes, blood sugar and ammonia were normal. Liver enzymes were mildly elevated. CSF study showed elevated protein, normal sugar and no pleocytosis. Cerebrospinal fluid (CSF) viral panel was negative. Magnetic resonance imaging brain was suggestive of acute necrotizing encephalopathy. His throat swab and sputum polymerase chain reaction was positive for H1N1. He was managed with ventilation, intravenous steroids and other supportive measures. At discharge his sensorium improved but had neurological sequelae. We are presenting this case as this is a very rare complication of H1N1 infection with high rate of mortality. Early supportive measures and steroids/intravenous immunoglobulin may save the patient.
            acute encephalitis syndrome, necrotising encephalopathy, H1N1, influenza
            Topic:
            Issue Section:
            Case Report

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            Twitter: @RonanKelly13
            The views expressed are mine alone and do not represent the views of my employer or any other person or organization.

            Comment


            • #36
              Status and trend of acute encephalitis syndrome and
              Japanese encephalitis in Bihar, India
              PRAVEEN KUMAR, P.M. PISUDDE, P.P. SARTHI, M.P. SHARMA, V.R. KESHRI
              ABSTRACT
              Background.
              Acute encephalitis syndrome (AES) is a
              clinical condition, of which the most common cause is
              Japanese encephalitis (JE). Though there is deficiency of data
              on AES and JE from Bihar, the state ranks third in the reporting
              of JE cases after Uttar Pradesh and Assam. We aimed to assess
              the status and trends of AES and JE cases in Bihar and to know
              the status of the disease in the districts.
              Methods.
              We collected monthly epidemiological data for
              AES and JE for the period 2009–2014.
              Results.
              A total of 4400 cases (733 cases/year) with an
              average case fatality rate (CFR) of 30% for AES for the entire
              study period. A total of 396 cases of JE were reported with
              approximately 14% CFR. The disease peaks were during the
              start and end of the Indian summer and monsoon months for
              AES and JE, respectively. Districts such as Patna, Jehanabad,
              Nawada, Gaya and East Champaran reported the maximum
              number of AES and JE cases with annual incidence rates of 4.7–
              25.0 and 0.546–1.78 per 100 000 population, respectively.
              Conclusion.
              Since 2009, the incidence of AES and JE
              cases has been increasing in Bihar.
              Natl Med J India 2017;30:317–20
              INTRODUCTION
              Acute encephalitis syndrome (AES) is a multifactorial clinical
              condition, the most common cause being Japanese encephalitis
              (JE). JE is a vector-borne viral disease caused by the JE virus of
              group B arbovirus (Flavivirus) and is transmitted to humans by the
              Culicine mosquito. JE affects the central nervous system (CNS),
              and can cause serious complications and death. The case fatality
              rate (CFR) is high and those who survive may suffer from
              neurological sequelae such as convulsions, episodic headache,
              autonomic disturbance, abnormal behaviour, mood disorder,
              intellectual deficit, paresis, incoordination of movements, jerky
              limb movements, speech disorder, cranial nerve palsy, gaze palsy,
              parkinsonian features, impaired hearing, etc.1 An estimated 25%
              of affected children die from the disease, and among those who
              survive, 30%–40% suffer from physical and mental impairment.
              Children suffer the highest attack rate due to lack of cumulative
              immunity from natural infections.2 JE was first recognized in
              Japan in 1924. Since the late 1960s, the extent of epidemics in
              Japan and China has steadily declined. It is estimated that 3 billion
              people are at risk, and the disease has spread to new territories.3
              According to WHO, JE is endemic in large parts of the Asia
              and Pacific regions, especially in the South Asian and Western
              Pacific regions. According to WHO statistics, 3187 cases of JE
              were reported in 2013 from all over the world; of these, 42% were
              from countries in the South-East Asia region, and of these 80%
              were from India.4 According to a systematic review by Campbell
              in 2011, India falls in the medium-to-high incidence areas with an
              expanding vaccination programme and shares its place with Sri
              Lanka, Thailand and Vietnam. The population of these endemic
              areas is about 538.1 million.5 A fatality rate of 30%–50% has been
              attributed to JE in southern and eastern Asia.6
              The first case of JE was reported in India in 1955 from Vellore,
              Tamil Nadu and the first major outbreak was reported in 1973
              from Burdwan district of West Bengal. Since then, in India, AES
              and JE have been reported from 171 districts of 19 states. In India,
              the JE virus has been isolated from more than 15 species of
              mosquitos belonging to genera Culex, Aedes and Anopheles;
              Culex tritaeniorhynchus and Culex vishnui are considered the
              main vectors.7 A major outbreak of JE was reported from eastern
              Uttar Pradesh (UP) during 2005 with more than 6000 cases and
              1500 deaths. This led to the introduction of the JE vaccine in
              endemic areas. Bihar, which is adjacent to eastern UP, has also
              reported a rise in the number of patients with AES and JE with
              periodic epidemics in some districts, including Muzaffarpur
              district.8
              The outbreaks of JE in Gorakhpur and Basti divisions in
              eastern UP during 2005, led to the development of surveillance
              guidelines for AES and JE by the National Vector Borne Disease
              Control Programme (NVBDCP). These guidelines required JE to
              be reported as an AES and after confirmation from the sentinel
              sites, a line-list of JE cases needed to be drawn and sent in
              prescribed formats.9
              There is deficiency of data on AES and JE from Bihar. We
              aimed to ascertain the status and trends of AES and JE in Bihar to
              suggest measures for prevention and control.
              METHODS
              The Bihar plain is divided into two unequal halves by the river
              Ganga which flows from west to east. With a population of 10.38
              crore (103.8 million), 17% of the state population is in the 0–6
              years age group. The literacy rate of Bihar is 63.8% and decadal
              THE NATIONAL MEDICAL JOURNAL OF INDIA VOL. 30, NO. 6, 2017
              [Downloaded free from http://www.nmji.in on Thursday, November 1, 2018, IP: 157.35.239.90]
              318 THE NATIONAL MEDICAL JOURNAL OF INDIA VOL. 30, NO. 6, 2017
              growth is 25%. Bihar, consisting of 38 districts, is a complex state
              for healthcare services in terms of resources and accessibility.10
              The NVBDCP follows the case definition of JE based on a
              syndromic approach. Epidemiological surveillance is done for
              AES, and suspected JE cases are reported as follows: ‘Clinically,
              a case of AES is defined as a person of any age, at any time of year
              with the acute onset of fever and a change in mental status
              (including symptoms such as confusion, disorientation, coma, or
              inability to talk) and/or new onset of seizures (excluding simple
              febrile seizures). Other early clinical findings may include an
              increase in irritability, somnolence or abnormal behaviour greater
              than that seen with usual febrile illness.’ Continuous surveillance
              of the disease is done through the Integrated Disease Surveillance
              Project (IDSP).11 JE surveillance aims to identify patients with
              AES and subsequently confirm JE virus infection using IgM
              ELISA (enzyme-linked immunosorbent assay).2 Laboratory
              confirmation of suspected cases of JE is done at identified sentinel
              laboratories, where the preferred test for diagnosis of JE is the IgM
              Capture ELISA. The samples are initially processed in district
              sentinel laboratories. Samples are then sent for confirmation to
              designated national laboratories.12
              The cases are reported by health workers to district health
              authorities. In-charge nodal officers from the district regularly
              visit facilities reporting AES cases for validation of the reported
              data. At the state level, reports are received from the districts
              according to the status of the disease, i.e. daily reports during
              outbreaks, weekly reports during the transmission period and
              monthly reports in the inter-epidemic period. The districts are
              monitored for regular reporting. The data are then merged at the
              state level, collated and immediately transmitted through specified
              proformas.12 We collected the monthly epidemiological data of
              AES and JE for the period 2009–2014. We accessed the data with
              permission from the state health authorities.
              We estimated the trends of AES and JE cases, burden of AES
              and JE in terms of morbidity and mortality, annual incidence rate
              (number of cases per 100 000 population) and CFR (proportion of
              deaths against the total number of cases reported per year).
              RESULTS
              A total of 4400 cases of AES were reported between 2009 and
              2014, an average of 733 cases per year. There were 1309 deaths
              reported with an average CFR of about 30%. There were 396 cases
              of JE and 56 deaths during the study period (Table I). The CFR for
              confirmed JE cases was about 14%.
              From 2009 to 2014, AES cases started to appear in April–May,
              reached a peak during June and declined from October (Fig. 1). A
              similar pattern is seen each year. Two peaks are seen, one in June
              and another in September and October. The maximum number of
              cases and the highest peak was in 2014. The trend of JE (confirmed)
              cases over the years mirrored the trend in AES cases (Fig. 2).
              The districts of Patna, Nalanda, Jehenabad, Nawada, Gaya,
              Aurangabad, Vaishali, Muzaffarpur, Sheohar and East Champaran
              had the highest annual incidence rate (4.7–25 per 100 000 popu-
              lation) for AES (Fig. 3). District such as Saran, Siwan, Bhojpur,
              Buxar, West Champaran, Jamui and Sitamarhi had a lower annual
              incidence rate of 2.2 to 4.73 per 100 000 population and fall in the
              third quartile. Districts such as Kaimur, Darbhanga, Madhubani
              and others were in the first quartile and added little to the pool of
              AES cases.
              The districts of Patna, Jehenabad, Nawada, Gaya, Lakhisarai,
              Gopalganj, Siwan, East Champaran and West Champaran have
              annual incidence rate of JE ranging from 0.546 to 1.78 per 100 000
              ...
              https://www.researchgate.net/publica...ihar_India#pf3
              Twitter: @RonanKelly13
              The views expressed are mine alone and do not represent the views of my employer or any other person or organization.

              Comment


              • #37
                Volume 26, Number 1—January 2020

                Dispatch

                Distribution of Japanese Encephalitis Virus, Japan and Southeast Asia, 2016–2018

                On This Page
                The Study
                Conclusions
                Suggested Citation
                Figures
                Figure
                Tables
                Table
                Downloads
                Appendix
                RIS [TXT - 2 KB]
                Article Metrics
                Metric Details
                Ryusei Kuwata1, Shun Torii1, Hiroshi Shimoda, Supriyono, Thanmaporn Phichitraslip, Noppadol Prasertsincharoen, Hitoshi Takemae, Reu Caesar James Taga Bautista, Valeen Drex Bendette Mendio Ebora, Jose Alexander Cabiling Abella, Alan Payot Dargantes, Upik Kesumawati Hadi, Agus Setiyono, Emmanuel Tugbang Baltazar, Luzviminda Tadeja Simborio, Srihadi Agungpriyono, Sathaporn Jittapalapong, Worawut Rerkamnuaychoke, Eiichi Hondo, and Ken Maeda2Comments to Author
                Author affiliations: Yamaguchi University, Yamaguchi, Japan (R. Kuwata, S. Torii, H. Shimoda, Supriyono, K. Maeda); Kasetsart University, Bangkok, Thailand (T. Phichitraslip, N. Prasertsincharoen, S. Jittapalapong); Nagoya University, Nagoya, Japan (H. Takemae, E. Hondo); Central Mindanao University, Musuan, the Philippines (R.C.J.T. Bautista, V.D.B.M. Ebora, J.A.C. Abella, A.P. Dargantes, E.T. Baltazar, L.T. Simborio); Bogor Agricultural University, Bogor, Indonesia (U.K. Hadi, A. Setiyono, S. Agungpriyono); Rajamangala University of Technology, Chonburi, Thailand (W. Rerkamnuaychoke)

                Suggested citation for this article Abstract

                During 2016–2018, we conducted surveillance for Japanese encephalitis virus (JEV) in mosquitoes and pigs in Japan, Thailand, the Philippines, and Indonesia. Phylogenetic analyses demonstrated that our isolates (genotypes Ia, Ib, III, IV) were related to JEV isolates obtained from the same regions many years ago. Indigenous JEV strains persist in Asia.

                The locations of epidemics of arthropodborne viruses (arboviruses) are strongly associated with the distribution of their vectors. In general, the distribution of arboviruses can expand through the dispersal, transfer, and migration of their vector arthropods and reservoir animals. Mosquitoes transmit a variety of viral pathogens (e.g., dengue, Zika, and chikungunya viruses) and have caused a number of arboviral epidemics throughout the world (1). Japanese encephalitis virus (JEV; family Flaviviridae, genus Flavivirus) is a mosquitoborne arbovirus that causes a severe form of encephalitis in humans. JEV is distributed across most of Asia, the western Pacific, and northern Australia (2). The World Health Organization has estimated that the annual number of Japanese encephalitis cases worldwide exceeds 60,000 (2). JEV is transmitted primarily by mosquitoes of the Culex vishnui subgroup, principally Cx. tritaeniorhynchus Giles; pigs and wading ardeid birds, such as egrets and herons, are known to be the major amplifying hosts (3).

                On the basis of their genome sequences, JEVs are classified into 5 genotypes (4). JEV genotype I (GI), which has been further classified into subgenotypes GIa and GIb, and JEV GIII are the dominant lineages and have been detected widely throughout Asia. JEV GII is the third-most common lineage and has been found in Indonesia, Singapore, South Korea, Malaysia, and Australia. JEV GIV and GV are rare lineages; only a few viruses of these genotypes have been isolated from Indonesia, Malaysia, and China as of October 2019. Over the past 30 years, JEV GIa has displaced GIII as the dominant lineage in many countries of Asia (5). Although the origin and spreading pattern of JEV genotypes across the world has been investigated in some reports (6,7), the exact mechanisms of JEV genotype shift remain unclear.
                The Study

                To study the epidemiology of arbovirus infection, we, an international team of researchers in Japan, Thailand, the Philippines, and Indonesia, conducted arbovirus surveillance in our respective countries during 2016–2018 with the support of our governments. In each country, we collected mosquitoes in and around cattle or pig housing using sweeping nets and aspirators. We collected mosquitoes that had digested blood in their midguts. We identified their species and sorted them into pools, which we used for virus isolation. We also collected serum samples from pigs and wild boars from each country to use for virus isolation.

                We passed homogenized mosquito or serum samples through 0.45-μm filters (Corning Inc., https://www.corning.comExternal Link) and inoculated filtrates onto monolayers of 3 culture cell lines (mammalian cell lines Vero9013 and BHK-21 and mosquito cell line C6/36). We assessed cytopathic effect (CPE) daily and collected supernatants from cells that exhibited CPE. If we observed no CPE, we passaged the cells 5 times for 7 days each, after which, if virus was present, CPE should have become apparent. We extracted RNA from culture supernatants using the QIAamp Viral RNA Mini Kit (QIAGEN, https://www.qiagen.comExternal Link) and subjected the resulting RNA to reverse transcription PCR (RT-PCR) using the QIAGEN One-Step RT-PCR Kit and 2 universal flavivirus-specific primer sets (MAMD and cFD2 or FU2 and cFD3) (8,9) to screen for flaviviruses. To determine genome sequences, we used the QIAGEN One-Step RT-PCR Kit, TaKaRa LA RT-PCR Kit version 2.1 (Takara Bio, https://www.takarabio.comExternal Link), and Invitrogen 5′ RACE System for Rapid Amplification of cDNA Ends version 2.0 (https://www.thermofisher.comExternal Link) as needed in combination with several JEV-specific primers (Appendix Table 1).

                Of 945 pig serum samples, we selected 56 candidate samples for virus isolation on the basis of their RT-PCR results with the MAMD and cFD2 primers, and from these samples, we obtained the full or partial genome sequences of 5 JEV isolates (Appendix Table 2). Out of a total of 22,277 mosquitoes comprising >16 species, we obtained the full or partial genome sequences of only 2 JEV isolates (Appendix Table 3). Overall, we obtained the full-genome sequence of 4 of the 7 JEV isolates and the partial genome sequence (envelope gene) of the remaining 3 isolates (DDBJ accession nos. LC461956–62; Table).

                A preliminary study we performed showed that many pigs in these countries possessed antibodies against JEV (K. Maeda, unpub. data). We found that JEV was more often isolated from serum samples from JEV antibody–negative pigs in farms where JEV seroprevalence was low. Because JEV isolation seems to be difficult in endemic regions, we suggest selecting younger pigs, which are less likely to be JEV antibody positive, for virus isolation studies to increase the chances of success.


                Figure. Maximum-likelihood phylogeny of JEV isolates, Japan and Southeast Asia, 2016–2018 (circles), and reference isolates constructed on the basis of the envelope gene sequence (1,500 nt). A) Genotype Ia (GIa); B) genotype...

                The 2 JEV isolates we recovered in Japan, JEV/MQ/Yamaguchi/803/2016 and JEV/MQ/Yamaguchi/804/2016, were GIa and not GIII. In a phylogenetic analysis, these viruses clustered with JEV isolates recovered from Japan (in 2013 and 2009), China (in 2007), and South Korea (in 2010) (Figure, panel A). The 2 viruses collected in Japan in 2016 were most closely related to viruses recovered in 2013 from the same site that had been sampled in our previous study (10), suggesting that this strain has been maintained in the Yamaguchi area of Japan since at least 2013.

                The JEV isolate we obtained from Thailand, JEV/sw/Thailand/185/2017, was GIb and clustered with other JEV isolates detected in Thailand during 1985–2005 (11), as well as isolates from Myanmar in 2010, Cambodia in 2014 and 2015, and Singapore in 2014 (Figure, panel B). Thus, these JEVs have been maintained in Thailand and other parts of the southern peninsula of continental Asia for >30 years.

                JEV is distributed extensively throughout the Philippines (12). However, only 3 JEV GIII isolates from the Philippines (which were obtained from pigs during 1984–1986) were available for genetic analysis. Our 2 Philippines-derived JEV isolates, JEV/sw/Mindanao/K3/2018 and JEV/sw/Mindanao/K4/2018, clustered with these isolates (Figure, panel C). Our 2 Indonesia JEV isolates, JEV/sw/Bali/93/2017 and JEV/sw/Bali/94/2017, were obtained from the island of Bali, where a JEV vaccination program began in March 2018 (13). These JEV isolates clustered with other Indonesia isolates obtained in the 1980s (Figure, panel C) (14).

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                Conclusions

                In summary, our phylogenetic analysis revealed that the JEV isolates we obtained from Japan were GIa, the isolate from Thailand was GIb, the isolates from the Philippines were GIII, and the isolates from Indonesia were GIV (Figure, panels A–D; Appendix Figure). These results indicated that JEV GIII and GIV are still active and being maintained in parts of Asia.

                Our data demonstrate that a number of the JEV isolates we obtained in select countries of Southeast Asia during 2016–2018 were phylogenetically related to isolates reported in the same country in the 1980s, suggesting that some JEV strains have been maintained in their corresponding regions. Contrary to our expectation, the JEV transmission cycle seems to have been maintained indigenously. JEV strains are presumed to be transferred between JEV endemic regions by movement of arthropod vectors and bird reservoirs. Nonetheless, we infer that fixation of an invading JEV strain into a new region is difficult unless the new strain possesses properties advantageous for virus growth and expansion (15). However, the genotype shift from GIII to GIa has occurred in East Asia since the 1990s, indicating that GIa must have had some sort of growth advantage over GIII that permitted its spreading to and expansion in these countries. Our findings that JEV strain invasion in Asia is infrequent could assist in public health decision-making regarding vaccine formulation and campaign strategies.

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                Dr. Kuwata is a microbiologist at Yamaguchi University, Yamaguchi, Japan. His research interests are epidemiology and vectorborne diseases.

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                Acknowledgment

                This work was supported in part by grants-in-aid from the following funders: the Japanese Ministry of Health, Labour, and Welfare (grant no. H30-shokuhin-ippan-004); Ministry of Education, Culture, Sports, Science, and Technology and Japan Society for the Promotion of Science through the KAKENHI program (grant nos. JP15H05262 and JP15K19084); Japan Agency for Medical Research and Development through the Asia Project; and Department of Science and Technology–Philippine Council for Health Research and Development.

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                References

                1. Arrigo NC, Weaver SC, Calisher CH. The taxonomy of arboviruses. In: Vasilakis N, Gubler DJ, editors. Arboviruses: molecular biology, evolution and control. Poole, UK: Caister Academic Press; 2016. p. 9–29.
                2. Campbell GL, Hills SL, Fischer M, Jacobson JA, Hoke CH, Hombach JM, et al. Estimated global incidence of Japanese encephalitis: a systematic review. Bull World Health Organ. 2011;89:766–74, 774A–774E. DOIExternal LinkPubMedExternal Link
                3. Samy AM, Alkishe AA, Thomas SM, Wang L, Zhang W. Mapping the potential distributions of etiological agent, vectors, and reservoirs of Japanese Encephalitis in Asia and Australia. Acta Trop. 2018;188:108–17. DOIExternal LinkPubMedExternal Link
                4. Nabeshima T, Morita K. Phylogeographic analysis of the migration of Japanese encephalitis virus in Asia. Future Virol. 2010;5:343–54. DOIExternal Link
                5. Nga PT, del Carmen Parquet M, Cuong VD, Ma SP, Hasebe F, Inoue S, et al. Shift in Japanese encephalitis virus (JEV) genotype circulating in northern Vietnam: implications for frequent introductions of JEV from Southeast Asia to East Asia. J Gen Virol. 2004;85:1625–31. DOIExternal LinkPubMedExternal Link
                6. Han N, Adams J, Chen P, Guo ZY, Zhong XF, Fang W, et al. Comparison of genotypes I and III in Japanese encephalitis virus reveals distinct differences in their genetic and host diversity. J Virol. 2014;88:11469–79. DOIExternal LinkPubMedExternal Link
                7. Gao X, Liu H, Li X, Fu S, Cao L, Shao N, et al. Changing geographic distribution of Japanese encephalitis virus genotypes, 1935–2017. Vector Borne Zoonotic Dis. 2019;19:35–44. DOIExternal LinkPubMedExternal Link
                8. Kuno G, Chang GJ, Tsuchiya KR, Karabatsos N, Cropp CB. Phylogeny of the genus Flavivirus. J Virol. 1998;72:73–83.PubMedExternal Link
                9. Scaramozzino N, Crance JM, Jouan A, DeBriel DA, Stoll F, Garin D. Comparison of flavivirus universal primer pairs and development of a rapid, highly sensitive heminested reverse transcription-PCR assay for detection of flaviviruses targeted to a conserved region of the NS5 gene sequences. J Clin Microbiol. 2001;39:1922–7. DOIExternal LinkPubMedExternal Link
                10. Kuwata R, Sugiyama H, Yonemitsu K, Van Dung N, Terada Y, Taniguchi M, et al. Isolation of Japanese encephalitis virus and a novel insect-specific flavivirus from mosquitoes collected in a cowshed in Japan. Arch Virol. 2015;160:2151–9. DOIExternal LinkPubMedExternal Link
                11. Nitatpattana N, Dubot-Pérès A, Gouilh MA, Souris M, Barbazan P, Yoksan S, et al. Change in Japanese encephalitis virus distribution, Thailand. Emerg Infect Dis. 2008;14:1762–5. DOIExternal LinkPubMedExternal Link
                12. Lopez AL, Aldaba JG, Roque VG Jr, Tandoc AO III, Sy AK, Espino FE, et al. Epidemiology of Japanese encephalitis in the Philippines: a systematic review. PLoS Negl Trop Dis. 2015;9:e0003630. DOIExternal LinkPubMedExternal Link
                13. Im J, Balasubramanian R, Yastini NW, Suwarba IGN, Andayani AR, Bura V, et al. Protecting children against Japanese encephalitis in Bali, Indonesia. Lancet. 2018;391:2500–1. DOIExternal LinkPubMedExternal Link
                14. Garjito TA, Widiarti , Anggraeni YM, Alfiah S, Tunggul Satoto TB, Farchanny A, et al. Japanese encephalitis in Indonesia: An update on epidemiology and transmission ecology. Acta Trop. 2018;187:240–7. DOIExternal LinkPubMedExternal Link
                15. Obara M, Yamauchi T, Watanabe M, Hasegawa S, Ueda Y, Matsuno K, et al. Continuity and change of Japanese encephalitis virus in Toyama Prefecture, Japan. Am J Trop Med Hyg. 2011;84:695–708. DOIExternal LinkPubMedExternal Link

                Top Figure

                Table


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                Suggested citation for this article: Kuwata R, Torii S, Shimoda H, Supriyono, Phichitraslip T, Prasertsincharoen N, et al. Distribution of Japanese encephalitis virus, Japan and Southeast Asia, 2016–2018. Emerg Infect Dis. 2020 Jan [date cited]. https://doi.org/10.3201/eid2601.190235

                DOI: 10.3201/eid2601.190235

                Original Publication Date: 11/21/2019

                1These authors contributed equally to this article.

                2Current affiliation: National Institute of Infectious Diseases, Tokyo, Japan.

                Table of Contents – Volume 26, Number 1—January 2020
                https://wwwnc.cdc.gov/eid/article/26/1/19-0235_article
                Twitter: @RonanKelly13
                The views expressed are mine alone and do not represent the views of my employer or any other person or organization.

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