Analyzing the clinical profile of swine flu/influenza A H1N1 infection in central India: a retrospective study.

Recently, India reported an increase in swine flu (influenza A H1N1) activity. There are limited studies on epidemiology of swine flu in Indian context. This study aims to analyze clinical and epidemiological profile of suspected swine flu cases in central India. 171 cases were included in a hospital based, observational, descriptive study conducted from December 2014 to April 2015. Demographics, clinical presentation and outcome of positive and negative cases were compared. Data was analyzed using STATA software. Distribution by age, sex and residence was found similar (p > 0.05) in positive and negative cases. Cough (89%), fever (85%) and throat irritation (51%) were chief complaints (avg. duration = 4.9 days). History of travel, history of contact with swine flu cases (p = 0.002) and history of visiting crowded places (p = 0.098) was reported considerably in higher proportion in positive cases as compared to negative cases. There were 14 deaths and they occurred significantly in younger age among positive cases as compared to negatives (Mean ± SD: 34 ± 2.8 vs 47 ± 8.4 years). Case fatality ratio (CFR) in positive cases showing history of travel, contact with swine flu cases, requiring invasive ventilator support and >3 X-ray zones involvement were significantly higher. Outbreak in later part of winter, high case fatality and younger population is more affected. In this study, swine flu infection and outbreaks started later in the year Hospital stay and CFR were increased. Understanding the swine flu infection, changing clinical presentation of swine flu and formulate new strategies for its prevention and management.