Pregnant women with their infants are considered at higher risk for
influenza-associated complications, and the WHO recommends influenza
vaccination during pregnancy to protect them, including their infants
(0-6 months). There are limited data on the influenza burden among
pregnant women and their infants (0-6 months), and there is no routine
influenza vaccination in Bangladesh. Five annual cohorts (2013-2017) of
pregnant women were enrolled from 8 sub-districts of Bangladesh before
the influenza season (May-September); contacted weekly to identify new
onset of influenza-like illness (ILI) (subjective or measured fever and
cough) and acute respiratory illness (ARI) (at least two of: cough,
rhinorrhea, or difficulty breathing) among their infants from birth to 6
months of age. We collected nasopharyngeal swabs from ILI and ARI cases,
tested by rRT-PCR for influenza virus (including types and subtypes) and
estimated influenza incidence (95% CI) /10,000 pregnancy-months or
infant-months, respectively. We enrolled 9,020 pregnant women, followed
for 26,709 pregnancy-months and detected 1,241 ILI episodes. We also
followed 8,963 infants for 51,518 infant-months and identified 5,116 ARI
episodes. Influenza positivity was 23% for ILI and 3% for ARI cases.
The overall incidence (2013-2017) of influenza among pregnant women was
158.5/10,000 pregnancy-months (95% CI: 141.4-177.6), and that among
infants was 21.9/10,000 infant-months (95% CI: 18.2-26.5). Although the
data was collected more than five years ago, as the only baseline data,
our findings illustrate evidence of influenza burden among pregnant
women and infants (0-6 months) which may support preventive policy
decisions in Bangladesh.