Evidence Against Mycoplasma pneumonia as An Etiologic Agent of Kawasaki Disease

Background: The etiology of Kawasaki Disease (KD) remains unknown. The majority of KD patients present with a history of, or concurrent respiratory symptoms. Isolated case reports of Mycoplasma pneumoniae (Mp) associated with KD have been reported. Since Mp can cause mucous membrane disease (eye and mouth lesions), rash, and fevers, it remains a possible etiological agent for KD. Objective: To evaluate the prevalence of Mp identified in the upper respiratory tract of patients admitted with a diagnosis of KD. Methods: All KD patients admitted to Children’s Hospital Colorado (CHCO) over a 14 month period (Feb 2013 - Mar 2014) who had a nasopharyngeal wash (NPW) submitted for diagnostic testing were included in the study. Mp PCR was performed using the Film Array Respiratory Panel (BioFire Diagnostics, Salt Lake, City, UT). Furthermore, a CDC investigated pediatric outbreak of Mp in our community afforded the opportunity to investigate an epidemiological association between Mp and KD by comparing the incidence of KD to the incidence of Mp positive respiratory samples from Jan 2013 - May 2014. Results: Forty-seven (65%) of 72 KD patients had a NPW submitted and tested for Mp. None of these 47 patients tested positive for Mp. During 2013 - 2014 there was no correlation between the overall incidence of Mp positive respiratory samples and the incidence of KD. Conclusions: Our data do not support the hypothesis that Mp is an etiological agent of KD. Although unlikely, this study does not exclude the possibility that another Mycoplasma species could be involved in the pathogenesis of KD.