Mycoplasma pneumoniae and health outcomes in children with asthma

Background Acute infections with Mycoplasma pneumoniae (Mp) have been associated with worsening asthma in children. Mp can be present in the respiratory tract for extended periods; it is unknown whether the long-term persistence of Mp in the respiratory tract affects long-term asthma control. Objective To determine the effect of Mp on asthma control. Methods We enrolled 31 pediatric subjects 3 to 10 years of age with persistent asthma who completed up to 8 visits over a 24-month period. We detected Mp by antigen capture and polymerase chain reaction. Primary outcome measurements included symptom scores, quality of life, medication scores, oral corticosteroid use, health care usage, school absences, and exhaled breath condensate pH. Results Low levels of Mp community-acquired respiratory distress syndrome toxin were detected in 20 subjects (64.5%) at enrollment. Subjects with Mp positivity at a given visit had a .579 probability of remaining Mp positive at the subsequent visit, whereas those with Mp negativity had a .348 probability of becoming Mp positive at the following visit. The incidence of Mp overall was higher in the spring and summer months. Overall, we found no significant relation between the detection of Mp and worse outcome measurements at the same visit or at subsequent visits. Conclusion The long-term persistence of Mp in the respiratory tract is common in children with asthma. However, the detection of Mp was not associated significantly with worse asthma symptoms, quality of life, health care usage, school absences, or exhaled breath condensate pH in this pediatric asthma cohort.