Influenza virus infections among a sample of hospital attendees in Ragama, Sri Lanka.

Abstract

OBJECTIVES: This study was carried out to define the types of influenza viruses circulating among humans and to understand the seasonality of influenza virus activity. Such information is essential for deciding on influenza vaccination strategy and on the appropriate time for delivering influenza vaccination, if such a vaccination policy was decided to be a priority. METHOD: During the period July 2003 - August 2004, 300 nasopharyngeal aspirates (NPA) were obtained from a systematic sample of patients reported to Out-patient Department, Colombo North Teaching Hospital, Ragama with