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Volume 39, Number 1, February 2006

The significance of a rapid cold hemagglutination test for detecting mycoplasma infections in children with asthma exacerbation


Ya-Ting Chang, Yao-Hsu Yang, Bor-Luen Chiang
Department of Pediatrics, Taiwan Adventist Hospital, Taipei; and Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan

Received: May 27, 2005    Revised: August 18, 2005    Accepted: August 26, 2005   

 

Corresponding author:

Bor-Luen Chiang, Department of Pediatrics, National Taiwan University Hospital, Fl. 7, No. 7, Chung-Shan S. Road, Taipei 100, Taiwan. E-mail: gicmbor@ha.mc.ntu.edu.tw This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

 



 

Background and purpose: 

Mycoplasma pneumoniae infection is a frequent cause of community-acquired respiratory infections in children and adults. However, standardized, rapid, specific methods for its diagnosis are lacking. The relationship between M. pneumoniae infection and asthma exacerbation has been recently discussed in the literature. We investigated the accuracy of rapid detection of mycoplasma infection by cold hemagglutination test compared to conventional enzyme immunoassays. The clinical characteristics of mycoplasma infection seen during emergent visits in asthmatic children were reviewed.

 



 

Methods:

We retrospectively reviewed medical records of patients with asthma exacerbation visiting the Department of Pediatric Emergency, National Taiwan University Hospital, over a 12-month period. Subjects 2-18 years of age diagnosed with asthma at our outpatient clinic were included in this study. Patients with immunodeficiency, congenital anomalies, neurological diseases and irregular follow-up were excluded.

 



 

Results:

A total of 269 children (174 males and 95 females) with a mean (± standard deviation) age of 6.15 ± 3.08 years were included. The prevalence of asthma exacerbation in regular follow-up patients was 13.4%, and as many as 19.6% of cases (74/378 person-times) required hospitalization. Asthma attacks were most prevalent during December. 126 patients had both rapid cold hemagglutination testing and mycoplasma immunoglobulin M titers determined using acute blood samples drawn in the emergency room; 46 (36.5%) of these patients demonstrated mycoplasma infection. Sensitivity and specificity of the rapid cold hemagglutination test was 78.3% and 41.3%, respectively. The positive predictive value was 43.4%. Comparison of patients with or without mycoplasma infection revealed no differences in gender, age, chest X-ray findings, and most symptoms/signs and laboratory data, except that more signs of fever and auscultatory rales were seen in the non-mycoplasma infection group.

 



 

Conclusion:

Mycoplasma infections could be an exacerbating factor for asthma, and the rapid cold hemagglutination test should not be a guideline for prescribing macrolides in the emergency room.

 



 

Key words:

Asthma, bacterial antigens, hemagglutination tests, immunoenzyme techniques, Mycoplasma pneumoniae



 



 

J Microbiol Immunol Infect 2006;39:28-32.