Myositis Caused by Trachipleistophora hominis in a Person With Human Immunodeficiency Virus: The First Case in Thailand

Background To date, cases of extraintestinal microsporidiosis have been increasingly reported in both otherwise healthy and immunocompromised individuals. Among them, microsporidial myositis is very rare. To the best of our knowledge, this is the first report of microsporidial myositis caused by Trachipleistophora hominis in a patient with human immunodeficiency virus (HIV) in Thailand. Case report A Thai man with HIV presented with fever and muscle pain at both anterior thighs and left arm for 3 months. Muscle biopsy was performed, and pathology exhibited neutrophil infiltration and focal aggregations of microsporidial spores. The 18S ribosomal RNA sequence revealed the species of this microsporidium as T hominis, and albendazole of 800mg/day was initiated. He gradually improved, and was discharged home 6 weeks after hospitalization. Conclusions To the best of our knowledge, this is the first report of microsporidial myositis caused by Trachipleistophora hominis in a person with HIV in Thailand.