Human metapneumovirus and other respiratory viral infections during pregnancy and birth, Nepal

Human metapneumovirus (HMPV) is a respiratory virus that can cause severe lower respiratory tract disease and even death, primarily in young children. The incidence and characteristics of HMPV have not been well described in pregnant women. As part of a trial of maternal influenza immunization in rural southern Nepal, we conducted prospective, longitudinal, home-based active surveillance for febrile respiratory illness during pregnancy through 6 months postpartum. During 2011–2014, HMPV was detected in 55 of 3,693 women (16.4 cases/1,000 person-years). Twenty-five women were infected with HMPV during pregnancy, compared with 98 pregnant women who contracted rhinovirus and 7 who contracted respiratory syncytial virus. Women with HMPV during pregnancy had an increased risk of giving birth to infants who were small for gestational age. An intervention to reduce HMPV febrile respiratory illness in pregnant women may have the potential to decrease risk of adverse birth outcomes in developing countries.