Blastocystosis: a new disease in the acquired immunodeficiency syndrome?

The protozoon Blastocystis hominis may cause episodes of diarrhoea with abdominal pain, tenesmus, fever and eosinophilia. We have observed 5 cases of blastocystosis in male subjects with symptomatic HIV infection. All patients had a complete response to metronidazole. This report confirms that Blastocystis hominis may be responsible for HIV-related diarrhoea.