Incidence and clinical features of hospitalization because of respiratory syncytial virus lower respiratory illness among children less than two years of age in a rural Asian setting

Background. Lower respiratory illness is the leading cause of child death in the developing world. Despite this few reports on respiratory syncytial virus (RSV) lower respiratory illness disease burden exist from rural areas of the developing world, and none exist for Indonesia. Methods. We evaluated children living in any of 83 villages on Lombok Island, Indonesia who were ≤2 years of age when hospitalized for severe lower respiratory illness during 2000 and 2001. All hospitals on Lombok were included in the evaluation. We obtained the number of births and deaths that occurred within the study villages and time frame, allowing for incidence determination. Results. Of 2677 children hospitalized for severe lower respiratory illness whose RSV status was determined, 23% had a positive test; this percentage varied from 50% at the end of the rainy season to 0% shortly before the start of the rainy season. Among children ≤2 years of age, the confirmed and estimated incidences of severe RSV lower respiratory illness hospitalization were 10 and 14 per 1000 child-years, respectively; values for children <1 year of age were 17 and 25 per 1000 child-years. The confirmed casefatality percentage among RSV-positive cases was 1.9%; however, 84% of children who died were dead before RSV status could be determined, suggesting the actual case fatality percentage was higher. Conclusions. Lombok has a large burden of severe childhood RSV lower respiratory illness, and death occurs frequently. Novel RSV vaccines thus could have a substantial positive impact on lower respiratory illness morbidity and mortality.