An outbreak of acute eosinophilic myositis attributed to human Sarcocystisparasitism

Seven members of a 15-man U.S. military team that had operated in rural Mal aysia developed an acute illness consisting of fever, myalgias, bronchospas m, nesting pruritic rashes, transient lymphadenopathy, and subcutaneous nod ules associated with eosinophilia, elevated erythrocyte sedimentation rate, and elevated levels of muscle creatinine kinase. Sarcocysts of an unidenti fied Sarcocystis species were found in skeletal muscle biopsies of the inde x case. Albendazole ameliorated symptoms in the index case; however, his sy mptoms persisted far more than 5 years. Symptoms in 5 other men were mild t o moderate and self-limited, and 1 team member with laboratory abnormalitie s was asymptomatic. Of 8 team members tested for antibody to Sarcocystis, 6 were positive; of 4 with the eosinophilic myositis syndrome who were teste d, all were positive. We attribute this outbreak of eosinophilic myositis t o accidental tissue parasitism by Sarcocystis.