Trends of Influenza A Virus Infection in Paediatric Patients

Abstract

Objectives: Influenza A virus infection causes significant morbidity and mortality worldwide. India continues to have Influenza A (H1N1) pdm09 positivity in patients, especially in Rajasthan. We studied the epidemiological profile of influenza A infection in paediatric patients presenting with Influenza like Illness (ILI) / Acute Respiratory Infections(ARI), during the period 2014-2016.

Methods:Throat or nasopharyngeal swab samples were collected in viral transport medium (VTM) from 1315 patients with ILI in 0-5 years age group, attending paediatric Hospital and transported to the laboratory. Samples were tested for influenza A, its subtypes, and for H275Y mutation as per recommended real-time RT-PCR protocols.

Result:Among 1315 patients 227 (17.2%) were positive for Influenza A, out of which  7.1%  were Influenza A H3N2 and 10.1% were (H1N1) pdm09 positive. Among the positive patients 129(9.7 %) were males of which 55(4.2 %) were positive for Influenza A H3N2, and 74(5.6 %) for Influenza A (H1N1) pdm09. A totalof 98(7.5%) femaleswere positive for Influenza A,of which39(3%) were positive for H3N2 and 59(4.5%) for H1N1 pdm09. The positivity was higher in winter months. All 60 Influenza A (H1N1) pdm09 positive samples were negative forH275Y mutation.

Conclusions: Both, H3N2 and (H1N1) pdm09 subtypes of Influenza A are prevalent in our area; prevalence is higher during the winter season, especially in males. All 60 Influenza A (H1N1) pdm09 positive samples were negative for H275Y mutation. This epidemiological information can be helpful in planning vaccine strategies and for prevention and control of infection and for proper treatment of patients.