Paired serum samples from six children with mild to fatal myocarditis have been studied in the microimmunofluorescence test for antibodies against Chlamydia trachomatis. Two patients with other known causes of myocarditis had no antibodies. The other four patients each had C trachomatis antibody. Two had high titer rises, and two with onset one to three months before the first serum sample was taken had level antibody titers. The study of serum from myocarditis patients was unplanned; they were part of a group of paired serum samples from children that had been submitted to the laboratory for viral diagnostic studies during a 16-month period. While the association of C trachomatis antibody with myocarditis was unexpected, it is consistent with the known etiologic role of C psittaci in myocarditis and the widening spectrum of systemic diseases caused by C trachomatis. Since Chlamydia can be treated with antibiotics, the possible etiologic association with myocarditis has important therapeutic ramifications.
Grayston JT, Mordhorst CH, Wang S. Childhood Myocarditis Associated With Chlamydia trachomatis Infection. JAMA. 1981;246(24):2823–2827. doi:10.1001/jama.1981.03320240031020