Taken from
Quarterly Newsletter from the National Centre for Disease Control (NCDC) Volume 4, Issue 3, July-Sept, 2015
http://nicd.nic.in/writereaddata/lin...5277865388.pdf
Recent Surge of Influenza A H1N1 cases and deaths in India and report of death audit in Maharashtra
The influenza virus is notable for its unique ability to cause recurrent
epidemics and global pandemics. Genetic re-assortments in the influenza virus
cause fast and unpredictable antigenic changes in important immune targets
leading to recurrent epidemics of febrile respiratory disease every 1 to 3 years. In
2009, pandemic Influenza A (H1N1) was the most commonly circulating strain of
influenza virus globally with more than 214 countries reporting laboratory
confirmed cases and over 18,449 deaths reported to WHO as on 1st August 2010.
During current year, India experienced increase in Influenza cases especially Influenza A
H1N1. A total 40,770 cases and 2702 deaths of laboratory confirmed Influenza A H1N1 was
reported (data till 4th Oct 2015).
The rising trend of the cases was observed from the 2nd week of 2015, which continued to
peak till 8th week of 2015 and started to decline during week 18. A total of 35,767 cases &
2218 deaths were reported during the spurt from 2nd week to 18th week. Maximum cases
were reported during the month of February (Fig. 1). The States most affected during the
initial spurt (week 2- week 18) were Rajasthan, Gujarat, Maharashtra, Delhi, Karnataka,
Telangana & Madhya Pradesh.
The cases started increasing again since July 2015 following a decline after the spurt in the
months of Feb ? May 2015. The States of Maharashtra and Kerala were affected initially
with increasing trend of cases & deaths from July. Other states like Gujarat, Karnataka,
Telangana, Madhya Pradesh & Goa have shown a rising trend during the second spurt
(29th week to 39 week) i.e. since August and September 2015 (Fig. 1).
Concerned about the situation the Directorate General of Health Services, Govt. of India
deployed a central teams with the objective to carry out epidemiological investigation to
suggest recommendations for containment in coming season. This report is based on the
key findings of the central team visiting Maharashtra in August to conduct a record based
study of patients admitted in various healthcare institutions to identify risk factors.
In Maharashtra, data was collected from the records available at State Surveillance Unit,
IDSP, Pune, National Institute of Virology, Pune, along with three tertiary care hospitals in
Mumbai and Pune and one diagnostic laboratory centre (Private Laboratory) in Mumbai.
Data was collected from both government and private sector establishments Data was
collected for the recent 50 deaths which includes deaths between periods of 30.7.2015 to
23.9.2015. The team also held discussions with the microbiologist as well as physicians and
programme officers during the visits.
Figure 2 shows the number of cases increasing again since
July 2015 following a decline after the spurt in the months of
Feb ? May 2015 seen across India. Majority of the districts
have reported deaths. It was also observed that Nasik,
Kolhapur, Satara, Sangli were the newer districts reporting
deaths as compared to the last spurt of H1N1 in Maharashtra.
The case fatality rate for the current increase in cases is lower than that witnessed during
preceding months of April, May & June. This shows increasing testing due to awareness
during spurt increased the denominator of positive cases during seasonal spurt.
Maximum deaths were reported from private hospitals (57%) as compared to government
hospitals (43%).
Table 2 shows positivity rates from the various laboratories records. The positivity from the SRL
diagnostic laboratories is nearly 48 % which is higher than the other laboratories.
The team reviewed the death records of recent 50 deaths to identify possible epidemiological
risk factors for mortality.
Age wise distribution of the cases shows maximum proportion of deaths in the age group
of 15-50 yrs age group followed by 30% and 18% among the 50-65yrs & >65yrs age groups
respectively. More young adults were affected compared to older age individuals.
Fifty six percent of deaths were in males as compared to 44% in females. Sixty four percent
of deaths were from urban areas. Symptomatically, fever & cough (60%) was most common
presentation followed by the fever, cough & breathlessness together i.e. (54%) cases.
Maximum deaths were from Mumbai, 15 (30 %), followed by Pune, 7(14%) and Thane, 14
(14%).
Fifty nine percent deaths were associated with co- morbidities (n=49). Diabetes (36%)
was the most common co-morbidity observed followed by coronary heart disease (18%),
respiratory diseases (16%), neurological diseases (8%) and obesity (8%) (Figure 3).
Out of 50
deaths, 2 (4%) were pregnant women of which one was 36 weeks pregnant while for other
period of gestation was not mentioned. Four (8%) deaths were associated with co infection
which includes dengue, malaria, tuberculosis and leptospirosis each.
Association of co-morbidity and age wise distribution
shows that as age increases the association with the co
morbidity increases (Table 3). Nearly 80 % of death
among the age group more than 50 yrs had an
associated co-morbidity.
It was also observed that
nearly 65 % of deaths among the age group 15-50
years had no association with co-morbidity. Comorbidity
appears to increase the risk of mortality among the influenza A H1N1 cases.
Death amongst young adults (without co morbidity) could be due to delayed presentation to
the hospital, transportation delayed or inadequate facility at the treating hospital.
Fifty seven percent of fatal cases had reported to the health facility between 3-7 days of
onset of symptoms while 10 (21.3%) had reported to the health facility after 7 days of onset
of symptoms. Only 5 (10.8%) had started treatment within 48 hrs of onset of symptoms.
21 (42%) & 9 (18%) of deaths occurred within 48 hrs & after 7 days of hospitalization
respectively (Figure 3).
Based on the above findings the team recommended that all patient with diabetes/ co
morbid conditions to be referred to tertiary care centre or specialist as early as possible.
Strict categorization for sample testing specially at private labs needs to be followed as well
as revisiting the private accredited labs for quality testing. Early reporting to health facility
could be improved by increasing awareness among the community as well as health care
worker.
H1N1 hospitals treating such a patient be well equipped
(ventilator management) and train physician in critical care
to initiate early and appropriate treatment.
Initiation of Oseltamivir as earliest after onset of
symptoms so as to decrease the severity of the cases
especially high risk groups as well as halting the
transmission in the community.
Our study reinforces the need to identify and target highrisk
groups for interventions, such as information on
immunization, early medical advice and use of antiviral
medications, as cost of testing is much higher than cost of
vaccination if calculated for each individual as the
positivity reported by Private labs is very high. Further
analytical studies need to be carried out for understanding
the profile of all respiratory viruses causing influenza like illness and severe acute respiratory
infections as well as risk factors between survival and deaths due to influenza A H1N1.
(Contributed by: Drs Prabha Arora, Amol Patil -NCDC, Neeraj Gupta- Safdarjung
Hospital as part of field investigation team; Drs Ranjeet Prasad, Pradeep
Khasnobis as part of H1N1 data analysis team at CSU, IDSP)
