Swine-origin influenza A (H1N1) in Indian children

Background: Swine-origin influenza A H1N1 (S-OIV) has not been systematically studied in Indian children. Objectives: To study the clinical characteristics, morbidity and mortality pattern in children with S-OIV infection. Methods: This prospective study was conducted during the 'containment phase' of the pandemic in New Delhi from 10 June to 5 August 2009. All children suspected of being infected by S-OIV were admitted to the isolation wards and clinically evaluated according to WHO guidelines. Nasal and throat swabs were collected immediately for real-time reverse transcriptase polymerase chain reaction (RT-PCR). Haemoglobin, total leucocyte and platelet counts and chest radiography were undertaken in all patients. Those who tested positive for S-OIV infection were treated with oseltamivir for 5 days in isolation wards. Results: Thirty-seven children fulfilled the inclusion criteria. Twenty-one tested positive for S-OIV by RT-PCR and 16 tested negative. Comparison of the clinical characteristics of the two groups showed that duration of cough was longer in children with S-OIV (p < 0.03). Total leucocyte and lymphocyte counts were significantly less in the S-OIV group (p < 0.001 and < 0.02, respectively). Oseltamivir-related gastritis was seen in 38% of children. All improved and were discharged. Conclusion: S-OIV infection in Indian children had features similar to those of seasonal influenza. Lymphopenia is an important feature of S-OIV.