Epidemiology of respiratory syncytial virus in children ≤2 years of age hospitalized with lower respiratory tract infections in the Russian Federation: a prospective, multicenter study

BACKGROUND Respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infections among infants and young children, and is responsible for an estimated four million deaths per year globally. A monthly injection of palivizumab has been used for prophylaxis of serious RSV infections among high-risk children in 71 countries since 1998 and approval for use in the Russian Federation was obtained in February 2010. A recommendation for RSV prophylaxis in the Russian Federation would require knowledge of the prevalence and seasonality of RSV in that country. METHODS In a prospective, multicenter, epidemiological study of the prevalence, seasonality, and peak occurrence of RSV infection, children aged ≤2 years hospitalized for lower respiratory tract infections in three regions of the Russian Federation, from September 2008 through April 2009, were screened and tested for RSV using rapid immunochromatography of nasopharyngeal lavage. For subjects who were tested positive, hospitalization data were collected. RESULTS Of 519 children aged ≤2 years enrolled from September 11, 2008 through April 26, 2009, 197 tested positive for RSV (38.0%, 95% CI: 33.8, 42.3). The onset of the 2008-2009 RSV season in the Russian Federation occurred in late October 2008, similar to what is observed in other northern temperate zones. Peak activity occurred in early April 2009, when 62% of children enrolled tested positive for RSV. CONCLUSION The prevalence of serious RSV infections in the Russian Federation is similar to the prevalence previously identified in other temperate zones of the northern hemisphere. The seasonality of disease shifted towards early spring, with peak activity later in the season, within a range reported in other countries. These data provide further evidence of serious RSV infection in children in the Russian Federation, as well as guidance for timing of seasonal RSV prophylaxis, especially among individuals at high risk for serious RSV infection.