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Source: http://timesofindia.indiatimes.com/n...ow/5007132.cms
Report points to new strain of chikungunya virus
Govind Kamat Maad, TNN 14 September 2009, 05:35am IST
MARGAO: A research paper 'Emerging Infectious Diseases', published by the Centre for Disease Control and Prevention, Atlanta, USA, has indicated that the strain of the chikungunya virus that caused the 2006 epidemic in India, including parts of Goa, is a new strain belonging to the novel Central/East African genotype. What has raised concern among the medical fraternity in Goa is that this strain was responsible for a few deaths in Kerala after chikungunya-affected patients developed complications like meningo-encephalitis and severe hepatitis.
Deputy director, national vector borne diseases control programme, directorate of health services, Dipak Kabadi, when contacted, affirmed that the current outbreak in parts of Sanguem and Canacona is a "continuation of the 2006 epidemic" that saw several cases detected in Vasco and Margao. However, no tests have been conducted to determine the strain of the current virus outbreak. Sources told TOI that the blood samples of suspected cases are tested for the presence of antigens to the virus based on which the cases are declared as positive or negative.
The research paper, authored by Harendra S Chahar, Preeti Bharaj, Lalit Dar, Randeep Guleria, Sushil Kabra and Shobha Broor, all affiliated to the All India Institute of Medical Sciences, New Delhi, mentions the occurrence of chikungunya and dengue virus in India and reveals that the isolate of the chikungunya virus found in Goa in 2006 has been identified as a new sequence of the virus. In a phylogenetic analysis, the Goa isolate has been named as GOA018 with a genetic bank (GenBank) accession number EF187902.
Dr Jagadish Kakodkar, associate professor, preventive and social medicine, Goa Medical College and Hospital, Bambolim said that the possibility of the strain belonging to the novel genotype could not be ruled out. "In order to ascertain if the current chikungunya virus is the same as the 2006 epidemic, what is required is availability of facilities for viral isolation and for conducting tests like RT-PCR (reverse transcription - polymerase chain reaction) and IFA (immuno-fluorescence assay), which help in the detection of the strain/mutation of the virus. None of these facilities are available in Goa and samples are required to be sent to either National Institute of Communicable Diseases, Delhi or National Institute of Virology, Pune."
When asked why samples were not being sent to Delhi or Pune, Dr Kabadi spoke at length over the rapid diagnostic tests for chikungunya being conducted at GMC's microbiology department and stressed that "chikungunya is not known to cause deaths". "The procedure for conducting these rapid diagnostic tests have been streamlined as the tests are now conducted using test kits supplied by NIV, Pune. I am aware of some deaths in Kerala during the 2006 outbreak, but they were not directly linked to chikungunya. Death occurred in patients because of some complications in their condition and not because of chikungunya. I see no reason why the samples need to be sent to the NIV, Pune to detect the genetic variation of the virus," Dr Kabadi averred.
Asked to explain what significance the study holds for the current outbreak in Goa, Dr Kakodkar said: "Chikungunya virus is an alpha virus having many strains like, for example, Asian genotype, Central/East African genotype, West African genotype. The study shows that the 2006 epidemic in India was because of the Central/East African strain which appears to have replaced the relatively uncomplicated Asian genotype. What's significant is that until April 2006, there were no documentation of deaths in any of the medical journals, but after the chikungunya epidemic, deaths were reported in India. As many as 125 deaths were reported in Kerala, majority of the cases from Alapurzha district. Some of the unusual features during that epidemic, observed in some cases, were complications of the brain like meningo-encephalitis and also severe hepatitis, besides mother-child transmission was documented and deaths reported."
Report points to new strain of chikungunya virus
Govind Kamat Maad, TNN 14 September 2009, 05:35am IST
MARGAO: A research paper 'Emerging Infectious Diseases', published by the Centre for Disease Control and Prevention, Atlanta, USA, has indicated that the strain of the chikungunya virus that caused the 2006 epidemic in India, including parts of Goa, is a new strain belonging to the novel Central/East African genotype. What has raised concern among the medical fraternity in Goa is that this strain was responsible for a few deaths in Kerala after chikungunya-affected patients developed complications like meningo-encephalitis and severe hepatitis.
Deputy director, national vector borne diseases control programme, directorate of health services, Dipak Kabadi, when contacted, affirmed that the current outbreak in parts of Sanguem and Canacona is a "continuation of the 2006 epidemic" that saw several cases detected in Vasco and Margao. However, no tests have been conducted to determine the strain of the current virus outbreak. Sources told TOI that the blood samples of suspected cases are tested for the presence of antigens to the virus based on which the cases are declared as positive or negative.
The research paper, authored by Harendra S Chahar, Preeti Bharaj, Lalit Dar, Randeep Guleria, Sushil Kabra and Shobha Broor, all affiliated to the All India Institute of Medical Sciences, New Delhi, mentions the occurrence of chikungunya and dengue virus in India and reveals that the isolate of the chikungunya virus found in Goa in 2006 has been identified as a new sequence of the virus. In a phylogenetic analysis, the Goa isolate has been named as GOA018 with a genetic bank (GenBank) accession number EF187902.
Dr Jagadish Kakodkar, associate professor, preventive and social medicine, Goa Medical College and Hospital, Bambolim said that the possibility of the strain belonging to the novel genotype could not be ruled out. "In order to ascertain if the current chikungunya virus is the same as the 2006 epidemic, what is required is availability of facilities for viral isolation and for conducting tests like RT-PCR (reverse transcription - polymerase chain reaction) and IFA (immuno-fluorescence assay), which help in the detection of the strain/mutation of the virus. None of these facilities are available in Goa and samples are required to be sent to either National Institute of Communicable Diseases, Delhi or National Institute of Virology, Pune."
When asked why samples were not being sent to Delhi or Pune, Dr Kabadi spoke at length over the rapid diagnostic tests for chikungunya being conducted at GMC's microbiology department and stressed that "chikungunya is not known to cause deaths". "The procedure for conducting these rapid diagnostic tests have been streamlined as the tests are now conducted using test kits supplied by NIV, Pune. I am aware of some deaths in Kerala during the 2006 outbreak, but they were not directly linked to chikungunya. Death occurred in patients because of some complications in their condition and not because of chikungunya. I see no reason why the samples need to be sent to the NIV, Pune to detect the genetic variation of the virus," Dr Kabadi averred.
Asked to explain what significance the study holds for the current outbreak in Goa, Dr Kakodkar said: "Chikungunya virus is an alpha virus having many strains like, for example, Asian genotype, Central/East African genotype, West African genotype. The study shows that the 2006 epidemic in India was because of the Central/East African strain which appears to have replaced the relatively uncomplicated Asian genotype. What's significant is that until April 2006, there were no documentation of deaths in any of the medical journals, but after the chikungunya epidemic, deaths were reported in India. As many as 125 deaths were reported in Kerala, majority of the cases from Alapurzha district. Some of the unusual features during that epidemic, observed in some cases, were complications of the brain like meningo-encephalitis and also severe hepatitis, besides mother-child transmission was documented and deaths reported."