Epidemiology and clinical outcome of H1N1 in Gujarat from July 2009 to March 2010.

ABSTRACT

OBJECTIVE: Epidemiology and clinical outcome of H1N1 in Gujarat from July 2009 to March 2010. METHODS AND MATERIALS This retrospective descriptive study analyses the month wise distribution of suspected as well as confirmed cases of H1N1 with their outcomes in the state of Gujarat from the month of July 2009 to March 4th 2010. The study included only those who were falling in Category C according to the national guidelines. Besides the government hospitals, the data also have been sought from all the private hospitals suspecting and treating swine flu cases. The patients are classified according to age, gender, location, approach to either government or private hospital, duration of symptoms on admission, associated co morbid conditions, the final outcome, duration of death after symptoms and the district wise distribution of sale of Oseltamivir. The incidence ratio for cases and deaths per 10 lakh population is calculated and compared with other states. RESULTS: 28760 patients attended the swine flu ward and the OPD. Out of 5532 suspected severe (Category C) cases, 1486 cases were confirmed positive with positivity ratio of 26.8%. 28% of all suspected and 37.9% of all positive were seen during the month of January. 64.9% cases were seen amongst the young age group of 13 to 45 years. 55.6% cases were seen in men and maximum cases (336) and deaths (54) were seen in Ahmedabad district. Oseltamivir was started after 5 days in 52% of cases. 297 had expired with an overall Case Fatality Rate of 19.9%. Maximum deaths were seen in young age group (13-45 years) with case fatality rate of 19.6%. 41% patients succumbing to disease were referred from Private to government hospitals and overall 35% cases had expired between 1 and 24 hour of admission. 69% patients did not have history of comorbid illness/condition. Gujarat ranked 5th in Case Incidence Rate per 10 lakh population while ranked second in Death Rate per 10 lakh population. CONCLUSION: The incidence and mortality from H1N1 in the state was significantly higher in young, more during the winter months. The case fatality rate in Gujarat is higher than rest of the world, the reason being a selection bias created by the categorization of the patients into category A, B and C as only category C patients were admitted and observed. The sale of Oseltamivir after liberalization of sale of the drug has greatly increased.