Frequent and Prolonged Shedding of Bocavirus in Young Children Attending Daycare

Background. Little is known about human bocavirus (HBoV) persistence and shedding and the association between HBoV detection and the onset and resolution of respiratory symptoms. Methods. We performed HBoV testing on nasal swab samples from a prospective, longitudinal study of respiratory illness in 119 children who attended daycare. Results. HBoV was detected in 70 children (59%) and in 106 (33%) of the 318 cases of illness. Another virus was detected in 76 (72%) of 106 HBoV-positive cases. Extended and intermittent shedding was observed, with consistent HBoV detection documented for up to 75 days. HBoV was detected in 20 (44%) of 45 asymptomatic enrollment samples, and HBoV prevalence and viral load did not differ significantly between children with and children without symptoms at enrollment. HBoV-positive illnesses were longer than HBoV-negative illnesses (odds ratio for duration of symptoms 17 days, 2.44; 95% confidence interval, 1.41-4.22), and illnesses with HBoV load >= 4 log 10 copies/mL required a visit to a health care provider more often than did HBoV-negative illnesses (odds ratio, 1.64; 95% confidence interval, 1.02-2.64). Conclusion. HBoV was more common in illnesses with greater severity. However, detection of HBoV was not associated with the presence of respiratory illness or with specific respiratory symptoms in this prospective study of infants and toddlers attending daycare centers.