A newly identified parvovirus appears to cause lower respiratory tract infections in children, a team of scientists in Sweden and Singapore reported.
They detected the virus—provisionally named human bocavirus (HBoV)—through a rapid new system for large-scale molecular virus screening of clinical samples without the need for cultures and with minimal hands-on effort. Their method should make it feasible to systematically explore all viruses that affect humans, including unidentified ones, reported Tobias Allander, M.D., of Karolinska University Hospital, Stockholm, and his associates (Proc. Natl. Acad. Sci. USA 2005;102:12891–6).
To assess HBoV's clinical effects, the investigators screened culture-negative nasopharyngeal aspirate samples from 266 pediatric patients and 112 adults seen in clinics. Seven samples from infants and children were positive for HBoV. A subsequent retrospective study of all 540 aspirates available from the pediatric infectious diseases ward at the hospital found HBoV in 17 patients (3%), and 14 of these had no other viruses present. HBoV is the likely cause of the respiratory distress and fever in these patients, the investigators concluded.
Seven of the 14 patients underwent chest x-ray, and results showed interstitial bilateral infiltrates in 6 patients.
Approximately 250,000 infants and young children are hospitalized each year in the United States for lower respiratory tract infection, and no etiologic agent is found in 12%–39% of cases.
The virus screening system that detected HBoV employs host DNA depletion, random polymerase chain reaction amplification, large-scale sequencing, and bioinformatics.