Early studies showed that Respiratory Syncytial Virus (RSV) was the main trigger of wheezing in infants. New evidences indicated that rhinovirus (RV) may play a significant role in the development of asthma.
Objectives:
To investigate the role of RV infection in the episode of recurrent wheezing in young children (5 years and younger) by case-control study. The clinical features and duration of symptoms were analyzed according to the result of the follow-up in 4 weeks.
Methods:
Children with recurrent wheezing during attack and children without wheezing were included in this study. Specimen of nasopharyngeal aspirates were obtained for detection of virus. RV, Human metapneumovirus (hMP), Bocavirus (hBoV) were tested by reverse transcription-polymerase chain reaction. RSV, parainfluenza viruses type Ⅰ, Ⅱ, Ⅲ, influenza virus A, B and adenoviruses (ADV) was confirmed by detection of viral antigens via fluoroimmunoassay. Counting of white blood cells, severity of disease was accessed in the first visit. Duration of symptoms and interval between episodes were recorded in the 4 weeks follow-up.
Results:
Nasopharyngeal aspirates were collected from 109 recurrent wheezing children and 70 non-wheezing children. Compared with control group, the wheezing children were higher positive rate for total detective virus (53.2% vs15.7%, χ2=25.3, P<0.01), RV (31.2% vs 12.9%, χ2=7.9, P=0.005) and RSV（19.3% vs 4.3%, χ2=8.2, P=0.004). The positive rates of RV was higher in toddler wheezing than infant wheezing group （44.8% vs 20.0%, χ2=6.0, P=0.015). The EOS count was 0.38 (0.12-0.57) *10^9/ L in RV-positive wheezing children, which was much higher than that in other virus-positive cases 0.21 (0.07-0.38) *10^9/ L (U=252, P=0.04). Compared with other virus-positive cases, RV-positive wheezing children have higher LYMP and WBC counts (P<0.05). There was no different between virus-negative and virus-positive cases in the symptoms of wheezing, coughing and nasal in from of 4 weeks follow-up. (P>0.05).
Conclusions:
High in of respiratory virus is found in children with wheezing exacerbation. RV is the most important pathogen in recurrent wheezing patients. The RV induced wheezing is associated with high level of EOS, LYMP and WBC counts. It implies RV may associated with atopy and immunoreaction. The clinical symptom is not different between RV and other virus infection in short time.