Amebic prostatitis.

A man with persistent prostatitis despite antibiotic therapy was found to have amebas compatible with Entamoeba histolytica in his urine after prostatic massage. Two indirect hemagglutination titers for E histolytica were negative. The patient had a prompt response to metronidazole therapy. Prostatitis due to amebic infection should be considered in patients who do not respond symptomatically to standard antibiotic therapy.