Bartonella rochalimae and Other Bartonella spp. in Fleas, Chile

the exact tissue type of each sample, only that tonsils, adenoids, or both combined could be present, the 5.5% rate we found was about one third the rate found in tonsil lymphocytes and about one tenth the rate found in adenoid lymphocytes. A seasonal effect may contribute to the large discrepancies found in HBoV prevalences. Apparently, viruses can persist in tonsillar tissue well after the symptomatic phase of illness. In children with no signs of acute respiratory infection, Drago et al. (7) reported that 45.5% of samples contained viral nucleic acid. Depending on the duration of persistence, asymptomatic children, sampled shortly after the season of the virus in question, would be more likely to have detectable virus in their tonsillar tissue. The Longtin et al. study samples were collected from December through April; our study samples were collected from June through September. If HBoV is seasonal, as has been suggested (3), it may have been circulating in the target population before samples were taken and persisted only in tonsillar tissues. Thus, if tonsillar tissue from asymptomatic children was obtained within the persistence period after the HBoV season, samples would be HBoV positive; those obtained shortly after the persistence period would have a much lower rate. Differences in patient age in the 3 studies may also have contributed to the different rates observed. The Longtin et al. group was substantially younger (median age 23 months) than the Lu et al. group (median age 5 years) or our group (median age 5.9 years). Preliminary seroepidemiology reports indicate the presence of HBoV antibodies in >50% of children 2–3 years of age (8,9). The detection of HBoV in the tonsillar tissues we tested showed a higher rate of infection than would be expected in an asymptomatic population. However, the rate was far lower than that previously reported for tonsillar tissues (1,4). Nathalie Clément,1 Gino Battaglioli, Ryan L. Jensen,2 Bruce C. Schnepp,2 Philip R. Johnson,2 Kirsten St. George, and R. Michael Linden3 Author affiliations: Mount Sinai School of Medicine, New York, New York, USA (N. Clément, R.M. Linden); Wadsworth Center, Albany, New York, USA (G. Battaglioli, K. St. George); and Nationwide Children’s Hospital, Columbus, Ohio, USA (R.L. Jensen, B.C. Schnepp, P.R. Johnson)