Identification of Rickettsiae, Uganda and Djibouti

1508 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 13, No. 10, October 2007 originally designed to identify infl uenza and relied on fever for specimen collection. Our retrospective selection criteria refl ected the classic initial manifestations of infl uenza (1,4), and thus could have missed nonfebrile cases. Second, the study was not designed to refl ect age distribution of children with respiratory infection, but rather those with fever and who had adequate amounts of available sera. This feature potentially biases toward older children. Third, data describe only 1 year, and patterns of illness may differ in other years. Fourth, acute infection was determined by serologic analysis. Previous studies in Bangladesh reported nutrition-related impaired immune responsiveness (10). Thus, some infl uenza-infected children who showed a nondetectable immune response may not have been included. These fi ndings indicate that infl uenza and other respiratory viruses contribute to pediatric febrile illness in urban Bangladesh. They also justify prospective surveillance to better defi ne epidemiology and clinical fi ndings associated with these viruses.