Spectrum of H1N1 influenza infection in Indian children: A tertiary centre experience

Objective: To study the clinical profile, severity, outcome and risk factors for H1N1 influenza infection in children < 18 years. Method: Children <18 years admitted to the Paediatric Department of our hospital and confirmed to have H1N1pdm2009 influenza infection from December 2016 to November 2017 were included. We reviewed the case sheets of the study population and captured the required data. Illness was classified as mild, progressive or severe illness and treated as per CDC guidelines. Outcome measures analysed included - mortality, duration of ICU / hospital stay, need for oxygen supplementation or assistive ventilation. Results: Our study involved analysis of 31 children. We found clustering of cases from 1-5 years accounting for 56% with no sex predilection. We observed a bimodal seasonal peak in incidence of infection from December to February (32%) and June to August (42%). Malnutrition was most common risk factor affecting 15/31 (48.4%) children followed by pre-existing medical illness 10/31 (30%). Risk stratification done as per CDC recommended guidelines showed the majority of the children (64.5%) manifesting as mild illness. Chest x-ray showed bilateral non-homogeneous peri-hilar opacities with air bronchogram in 19 (61%) children. Seven (22%) children required admission to ICU, 6 (20%) required oxygen therapy and 1 required noninvasive ventilation. Two children had developed hypotension requiring inotropes. No mortality was observed in the current study. Conclusions: H1N1 Influenza is still causing significant morbidity among children, especially in those with malnutrition and preexisting medical illness.