Prabda Praphasiri

and 8 more

Background: Adults with cardiopulmonary conditions are at increased risk for complications from influenza and respiratory syncytial virus (RSV) infection, but few data are available from middle-income countries. Methods: Using data from a prospective cohort study of influenza vaccine effectiveness among community-dwelling Thai adults aged ≥65 years, we estimated and compared the incidence of influenza and RSV in those with and without cardiopulmonary conditions. During May 2015-May 2017, older adults in a rural province in Thailand were followed weekly with year-round surveillance for acute respiratory illness (ARI), defined broadly as new onset or worsening of cough with or without fever, and hospitalized ARI. When ill, nasal self-swabs and/or nasopharyngeal swabs were collected for reverse-transcription polymerase chain reaction testing. We used Poisson regression to calculate incidence rate ratios (IRR), adjusting for age, sex, past healthcare-seeking behavior, weekly influenza activity, and influenza vaccination. Results: Overall, 3,220 adults with a median age of 71 years (IQR 68-76) were enrolled; 1,324 (41.1%) were male; and 313 (9.7%) had ≥1 underlying cardio-pulmonary condition, most commonly chronic obstructive pulmonary disease (131; 41.2%) or asthma (73; 23.3%). Compared to those without, participants with cardiopulmonary conditions had higher incidences of ARI, influenza, and RSV (Adjusted IRR: 1.83, 95% CI 1.63-2.05; 1.84, 95% CI 1.05-3.23; 2.02, 95% CI 1.10-3.72, respectively). Conclusion: Our findings show that older adults in rural Thailand with cardiopulmonary conditions have increased rates of ARI, influenza, and RSV infections, and support efforts to ensure this population has access to influenza vaccines and other respiratory illness prevention measures.

Joshua Mott

and 4 more

Global influenza virus circulation declined and has been below traditional seasonal levels during the COVID-19 pandemic.1-3 We reviewed WHO influenza surveillance outputs from May 1-December 31, 2020 (epidemiologic weeks 18-53) from tropical Asian countries. For each country we report influenza surveillance specimens tested, and the percentage positive for influenza, by type and subtype. We compared current data to historical data from 2015-2019 in order to place the current season in historical context. Twelve included countries tested 17,407 surveillance specimens, with 592 (3.4%) testing positive for influenza viruses. From April 27-July 26, 2020 (epidemiologic weeks 18-30), specimens tested decreased from an average of 14,102 per year in 2015-2019 to 3,969 (71.9% decrease) and influenza positivity from 22% to <1%. During weeks 31-53, specimens tested decreased from an average of 24,782 per year in 2015-2019 to 13,438 (45.8% decrease) and influenza positivity from 18% to 4%. In six countries that maintained testing of surveillance specimens for >90% of weeks, influenza circulation was unseasonably low, or absent, during weeks 18-30, 2020. However, during weeks 31-53, the percentage of surveillance specimens testing positive for influenza approached or reached positivity rates of 2015-2019 in Bangladesh and Cambodia; and increased but remained lower than historical positivity in Lao PDR and Viet Nam. The data presented here are a reminder that the low levels of influenza circulation in the northern hemisphere in summer 2020 may not necessarily persist into the upcoming influenza season, and influenza surveillance and prevention strategies should continue as planned and not be delayed.