Isolation of recent variant influenza types A(H3N2), A (H1N1) & B strains in Pune, India

Area of Science:

• Virology
• Epidemiology
• Public Health

Background:

• Continuous surveillance for influenza is crucial for monitoring viral circulation and identifying new strains.
• Pune, India, conducted influenza surveillance in 2000 to understand local influenza epidemiology.

Purpose of the Study:

• To investigate influenza virus strains circulating in Pune, India, during the 2000 surveillance period.
• To identify and characterize isolated influenza virus types and subtypes.

Main Methods:

• Throat/nasal swab specimens were collected from 293 patients with influenza-like illness.
• Specimens were inoculated into Madin-Darby Canine Kidney (MDCK) cell culture for virus isolation.
• Isolated influenza strains were identified using serological and/or molecular methods.

Main Results:

• Influenza A(H3N2), A(H1N1), and Type B strains were isolated.
• Identified strains were similar to A/Sydney/05/97(H3N2), A/New Caledonia/20/99(H1N1), and B/Sichuan/379/99.
• A/New Caledonia/20/99 (H1N1) and B/Sichuan/379/99 represented new variant strains for Pune.
• A(H1N1) strains were isolated in Pune in 2000 after a 10-year absence.

Conclusions:

• The study documented the circulation of specific influenza A and B strains in Pune during 2000.
• The emergence of new variant strains highlights the dynamic nature of influenza virus evolution.
• The re-emergence of A(H1N1) after a decade warrants continued influenza surveillance and preparedness.