NEW YORK (Reuters Health) - Human bocavirus (HBoV) is associated with
respiratory tract infections, especially in infants and young children,
according to two reports in the November 1st issue of The Journal of
Human bocavirus is a recently discovered parvovirus that has been
frequently detected among diagnostic respiratory samples, but its role
in respiratory tract infections remains unclear.
In the first study, Dr. Peter Simmonds from University of Edinburgh,
Scotland, and colleagues screened diagnostic respiratory samples for
HBoV to investigate its involvement in respiratory disease.
HBoV was the third most frequently detected virus in the viral
screening of 924 respiratory samples (most of which were from infants
and young children), the authors report, after respiratory syncytial
virus and adenovirus.
HBoV was most commonly detected in samples in which other respiratory
viruses were present, the results indicate.
Detection of HBoV was most prevalent in December and January, the
researchers note, and infections were almost completely confined to
infants and young children. Its association with respiratory disease was
similar to that of respiratory syncytial virus.
In the second study, Dr. Jeffrey S. Kahn and colleagues from Yale
University School of Medicine, New Haven, Connecticut screened
respiratory samples that were negative for other respiratory viruses for
the presence of HBoV. The samples were obtained from children with or
without respiratory symptoms.
Twenty-two (5.2%) of 425 samples tested positive for HBoV, the authors
report, but none of 96 respiratory specimens from asymptomatic children
tested positive for the virus.
Symptoms experienced by HBoV-positive children included rhinorrhea in
90%, fever in 70%, cough in 70%, and wheezing in 50%, the investigators
A minority (30%) of infected children had hypoxia, the report
indicates. In the 17 children who had X-rays performed, 12 had abnormal
"Our data suggest that HBoV is an etiological agent responsible for
both upper and lower respiratory tract disease in infants and young
children," the authors conclude. "Additional studies are required to
completely define the epidemiological profile of this newly recognized
"The most important contribution of (these studies) is that, for the
first time, a substantial number of individuals without respiratory
symptoms were included as controls, and HBoV either was not found or was
found very infrequently in this group of individuals," writes Dr.
Kenneth McIntosh from Children's Hospital Boston, Boston, in a related
"Finding, in two studies, a zero or very low incidence among control
infants of the same age, sampled over the same time period in the same
hospitals, is a huge advance, because it provides a statistical
association of the virus with disease," Dr. McIntosh concludes. "It does
not, however, prove causality, although it adds important corroborative
"The list of what we do not know is much longer than the list of what
we do know," Dr. McIntosh adds.