United States Centers for Disease Control and Prevention support for influenza surveillance, 2013–2021 Aide apportée par les Centers for Disease Control and Prevention des États-Unis d'Amérique dans la surveillance des grippes, 2013–2021 Apoyo de los Centros para el Control y la Prevención de Enfermedades de Estados Unidos a la vigilancia de la gripe, 2013-2021 دعم المراكز الأمريكية لمكافحة الأمراض والوقاية منها لمراقبة الإنفلونزا، 2013 إلى 2021 美国疾病控制和预防中心 2013-2021 年间对流感监测的支持 Поддержка эпиднадзора за гриппом в 2013–2021 гг. со стороны центров США по контролю и профилактике заболеваний

ABSTRACT

Objective To assess the stability of improvements in global respiratory virus surveillance in countries supported by the United States Centers for Disease Control and Prevention (CDC) after reductions in CDC funding and with the stress of the coronavirus disease 2019 (COVID-19) pandemic. Methods We assessed whether national influenza surveillance systems of CDC-funded countries (i) continued to analyse as many specimens between 2013 and 2021;(ii) participated in activities of the World Health Organization’s (WHO) Global Influenza Surveillance and Response System;(iii) tested enough specimens to detect rare events or signals of unusual activity;and (iv) demonstrated stability before and during the COVID-19 pandemic. We used CDC budget records and data from the WHO Global Influenza Surveillance and Response System. Findings While CDC reduced per-country influenza funding by about 75% over 10 years, the number of specimens tested annually remained stable (mean 2261). Reporting varied substantially by country and transmission zone. Countries funded by CDC accounted for 71% (range 61–75%) of specimens included in WHO consultations on the composition of influenza virus vaccines. In 2019, only eight of the 17 transmission zones sent enough specimens to WHO collaborating centres before the vaccine composition meeting to reliably identify antigenic variants. Conclusion Great progress has been made in the global understanding of influenza trends and seasonality. To optimize surveillance to identify atypical influenza viruses, and to integrate molecular testing, sequencing and reporting of severe acute respiratory syndrome coronavirus 2 into existing systems, funding must continue to support these efforts.