HBoVs in the absence of other enteric pathogens were seen in 46% of the HBoV-positive samples, and more frequently in the controls, 50.3% vs 40.9% in cases. No significant difference in HBoV load was observed between cases and controls, or between the samples positive for HBoV alone or in the presence of other pathogens. Previous studies have investigated the relationships between viral load and disease severity [33, 34, 35, 36, 37] . In respiratory infections significantly higher HBoV loads were seen in samples collected from children positive for HBoV alone than in those from children with co-infections. In respiratory infections also, viral loads .10 4 were associated with disease, whereas loads ,10 4 were associated with asymptomatic children [33, 38] . This lead to the suggestion that higher viral loads are indicative of a causative role of HBoV in respiratory infections [33, 38] . However, Brieu et al [38] found no significant correlation between viral load and clinical symptoms or disease severity.