Zhao J, Takamura M, Yamaoka A, Odajima Y, Iikura Y

Capital Institute of Pediatrics, Beijing, China

Showa University School of Medicine, Tokyo, Japan


Objective: To determine how many percent of asthma exacerbation caused by respiratory virus infections and to examine a relationship of eosinophils change and asthma episode.

Method: The respiratory syncytial virus (RSV), influenza A virus and adenovirus antigens of sputum were tested by rapid enzyme immunoassay and eosinophils in sputum were counted of 64 children suffered from asthma attack from Oct 1999 to Mar 2000.

Result: Virus was detected from 44% patients. RSV and influenza A virus was 27% and 17%, respectively. No adenovirus was detected. RSV infected children were younger (3.850.83 years old) than Influenza A virus infected patients (5.231.34 years old). 82% patients in RSV group and 36% patients in influenza A virus group were in moderate and serve asthma episodes (p<0.05). In RSV infected children, sputum eosinophil count was higher in the severe group, and younger patients had more eosinophils in their sputum than older (p<0.05). No similar results were found in influenza A virus patients.

Conclusion: the results indicate that, compared with influenza A virus induced asthma attack, RSV infection was more likely to be associated with asthma exacerbation in infants and younger children, with more severe state. The increased sputum eosinophils may be responsible of parts of these.