Lessons learnt from the Indian H1N1 (swine flu) epidemic: Predictors of outcome based on epidemiological and clinical profile

Abstract

Introduction:Influenza A (H1N1) virus has caused serious respiratory illness (swine flu) and death over the years. The first confirmed case of swine flu H1N1 in India was documented in May 2009, but huge numbers of cases were reported thereafter. In 2015, swine flu outbreak in India had led to significant morbidity and mortality.Objective:to study details of swine flu patients admitted in a rural tertiary care center in western India in 2015 and to identify predictors of mortality.Methodology:Retrospective data of swine flu cases admitted at a tertiary care teaching hospital in 2015 and their outcome as either cured or expired was recorded.Result:Out of 65 confirmed cases of severe swine flu that required hospitalization, 40(61%) were male. 55 of 65 (84.61%) patients [mean (SD) age: 50(15)] were cured while 10 patients [mean (SD) age 51(15)] expired. Overall mean (SD) age was 50.23(15) years with average (SD) days of hospitalization were 6.32(3.3) days. The commonest symptoms were cough (100%) followed by throat pain (96.9%), common-cold, fever (93.8%), and breathlessness (83.1%). 40% of patients needed non invasive ventilator support while 16.9% patient required invasive ventilator. Mean temperature on presentation was (99.96’F), RR (25.89/min), SpO2 on room air was 82.06%. Average White Blood Cells were 8274/mm3 with neutrophils were 79.58%. Mean procalcitonin was 0.83 ng/ml. It was found through univariate analysis that sputum production (P = 0.013), chest pain (P = 0.04), Respiratory Rate (P = 0.013), SpO2 on presentation at room air (P = 0.001), Days of non invasive ventilator (P = 0.001), intubation and invasive ventilator (P = 0.001) were statistically significantly associated with outcome but through multivariate analysis it was revealed that only requirement of intubation (invasive ventilator) was significantly predicting mortality(Odds ratio=234) (P = 0.0001).Conclusion:Requirement of intubation was associated with poor outcome.