Diagnostic dilemma in coinfection.

: A Fifteen years girl belonging to a low socioeconomic status was admitted with peritonsillar abscess caused by methicillin resistant Staphylococcus aureus (MRSA), high fever, diarrhoea and septicaemic shock. Initial blood cultures and widal test, stool cultures and routine stool examination were non-contributory to the diagnosis. A bone marrow culture in the second week confirmed the diagnosis of Salmonella typhi infection. Examination of a fresh stool sample showed cysts of Entamoeba histolytica. She was treated with ciprofloxacin, metronidazole, augmentin and ceftriaxone. She had no clinical evidence of immunosuppression prior to this episode and her HIV test was negative. This case report highlights the presence of community acquired MRSA infection causing perititonsillar abscess, and the diagnostic dilemma of fever and diarrhoea due to coinfection with Salmonella typhi and Entamobea histolytica.