One hundred children
hospitalized for wheezing under 2 years of age were enrolled in 1992-1993. The
children were prospectively followed-up; 87 of them attended the control visit
3 years after hospitalization and 82 at the age of 6 to 8 years in 1999.
Nasopharyngeal
aspirates were obtained on admission in all cases, and in 2000, frozen samples
were available in 81 cases for rhinovirus, enterovirus and coronavirus
detection by PCR. RSV was found in 22 cases, and the presence of RSV was
associated with a low risk for later asthma (1). Rhinovirus was identified in
27(33%), enterovirus in 10(12%), and coronavirus no children. The mean age was
14 months in rhinovirus-positive and 9 months in rhinovirus-negative cases.
The presence of
asthma was assessed at the control visits by similar criteria. Three
doctor-diagnosed wheezing episodes were demanded, and at least one of them must
have been observed during the preceding 12 months. Asthma was present in
39(48%) and 27(33%) children at the two follow-up visits; among them, 17 (44%, p=0.070)
and 16 (59%, p=0.003) belonged to the original rhinovirus group. No association
was found between enteroviral infections and later asthma.
Rhinovirus was the
most common virus associated with wheezing in early childhood and carried a significant risk for asthma at
school age. In the present study, the risk was 2.4-fold compared to the other
than rhinovirus induced wheezing, being partly explained by the different age
distributions.
1) Reijonen T, et al. Pediatrics 2000; 106 (December).