Years of investment in influenza surveillance in Bangladesh has established a robust system that was capable of detecting a surge in co-circulating influenza A(H3N2) at a time when resources were primarily focused on tackling COVID-19.

Bangladesh has two sentinel surveillance platforms for monitoring influenza and severe respiratory diseases. These are jointly governed by the Institute of Epidemiology, Disease Control and Research and the International Centre for Diarrhoeal Disease Research. Both have benefited from long-standing investment from the Pandemic Influenza Preparedness Framework Partnership Contribution (PIP PC).

During the COVID-19 pandemic, these influenza surveillance systems were re-purposed to also monitor SARS-CoV-2. The surveillance focus during the pandemic was necessarily on the new SARS-CoV-2 virus. Yet the system still managed to detect an acute surge in influenza A(H3N2) cases in mid to late 2020 (during epidemiological weeks 35 to 45).

During those ten weeks, 245 cases of influenza {influenza A(H3N2)} were detected among 1588 collected samples of SARI and ILI by laboratory investigation. The government of Bangladesh used information and analysis from the laboratory and surveillance network to design and launch effective measures to manage the outbreak. As a result of these measures, coupled with the public health and social measures applied for containing COVID-19, influenza A(H3N2) cases gradually started decreasing from early October 2020. Later, selected specimens from the outbreak were sent to the WHO collaborating centre at the US Centres for Disease Control in Atlanta, United States to inform the WHO’s bi-annual vaccine composition meeting.