A two wave comparison of clinical and epidemiological characteristics of 2009 pandemic Influenza A (H1N1) in hospitalized pediatric patients of Saurashtra region, India

Abstract

Objective: To study and compare clinical and epidemiological characteristics of pediatric patients hospitalized with 2009 pandemic Influenza A (H1N1) infection during two waves. Materials and Methods: From September 2009 to February 2011, 62 children were admitted in pediatric ward of the hospitals during 1 st wave and 55 during 2 nd wave, infected with 2009 Influenza A (H1N1) virus in Rajkot city. Real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) testing was used to confirm infection. The clinico-epidemiological features of the disease were closely compared and monitored. Results: First wave reported median age of 2.5 years, which was 2 years during second wave in positive cases. The median duration of diagnosis of infection was reported 5 days after onset of illness, and 7-day median time for hospital stay in both the waves. Majority of patients reported with cough and fever. Total 16.1% patients during 1 st wave and 27.3% in 2 nd wave reported some underlying condition. All admitted patients received oseltamivir drug, but only 9.7% (1 st season) and 12.7% (2 nd season) cases received it within 2 days of onset of illness. In both seasons, more than one-fourth (29.0%) of admitted patients expired. Pneumonia was reported in 97.1% patients (1 st wave) and in 60.0% (2 nd wave) with chest radiography. Conclusion: Influenza A (H1N1)-related illness affects children, including infants with survival of about 71% patients during both waves. The median time from the onset of illness to diagnosis was 5 days. Delayed referral, presence of any coexisting condition, pneumonia and receiving corticosteroid treatment were associated with severe Influenza A (H1N1).