Human bocavirus and acute wheezing in children.
BACKGROUND
Human bocavirus is a newly discovered parvovirus. It has been detected primarily in children with acute lower respiratory tract infection, but its occurrence, clinical profile, and role as a causative agent of respiratory tract disease are not clear.


METHODS
We investigated the presence of human bocavirus by quantitative polymerase chain reaction of nasopharyngeal aspirate specimens and selected serum samples obtained from 259 children (median age, 1.6 years) who had been hospitalized for acute expiratory wheezing. The samples were analyzed for 16 respiratory viruses by polymerase chain reaction, virus culture, antigen detection, and serological assays.


RESULTS
At least 1 potential etiologic agent was detected in 95% of children, and >1 agent was detected in 34% of children. Human bocavirus was detected in 49 children (19%). A large proportion of the cases were mixed infections with other viruses, but human bocavirus was the only virus detected in 12 children (5%). High viral loads of human bocavirus were noted mainly in the absence of other viral agents, suggesting a causative role for acute wheezing. In addition, infections that had uncertain clinical relevance and low viral loads were prevalent. Human bocavirus DNA was frequently detected in serum specimens obtained from patients with acute wheezing, suggesting systemic infection.


CONCLUSIONS
Human bocavirus is prevalent among children with acute wheezing and can cause systemic infection. Results suggest a model for bocavirus infection in which high viral loads are potentially associated with respiratory symptoms and low viral loads indicate asymptomatic shedding. Therefore, quantitative polymerase chain reaction analysis may be important for additional studies of human bocavirus.
Allander
Tobias
T
Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden. tobias.allander@karolinska.se
Jartti
Tuomas
T
Gupta
Shawon
S
Niesters
Hubert G M
HG
Lehtinen
Pasi
P
Osterback
Riikka
R
Vuorinen
Tytti
T
Waris
Matti
M
Bjerkner
Annelie
A
Tiveljung-Lindell
Annika
A
van den Hoogen
Bernadette G
BG
Hyypiä
Timo
T
Ruuskanen
Olli
O
D000208:Acute Disease; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001483:Base Sequence; D052660:Bocavirus / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D005387:Finland; D005500:Follow-Up Studies; D006760:Hospitalization; D006801:Humans; D007223:Infant; D008297:Male; D008969:Molecular Sequence Data; D010322:Parvoviridae Infections / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D012135:Respiratory Sounds; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018570:Risk Assessment; D012720:Severity of Illness Index
D000305:Adrenal Cortex Hormones; D004279:DNA, Viral