High frequency of human bocavirus 1 DNA in infants and adults with lower acute respiratory infection.

Human bocavirus (HBoV) is a parvovirus with a possible aetiological role in respiratory disease that is currently under investigation. We detected HBoV1 in children and adults hospitalized with acute disease of the lower respiratory tract. HBoV genome was detected by PCR in nasopharyngeal swabs collected from 75 patients aged 0-89 years during 2010. HBoV was found in 17/75 (22.7 %) patients, 64.7 % of them infants younger than 1 year old and 29.4 % adults older than 30 years [the bimodal age distribution among HBoV-positive (HBoV(+)) patients was statistically significant, P<0.001]. Of all HBoV(+) cases, 35.3 % were co-infected; all co-infections occurred in children (≤13 years old) and 83.3 % of them were HBoV-respiratory syncytial virus (RSV) co-infections. Among infants younger than 1 year, 50 % HBoV(+) specimens were co-infected, all of them with RSV. The rate of co-infection in infants was significantly higher compared to the frequency of co-infection in the whole cohort (P = 0.003). The results suggest that HBoV1 is involved in acute respiratory disease. Interplay between HBoV1 and RSV cannot be discarded as a cause of elevated percentages of co-detections in infants.