Misdiagnosis of an imported case of malaria caused by Plasmodium falciparum.

An unusual case of malaria presented with gastroenteritis and bloody diarrhoea in a 46-year-old male. The patient was a non-Saudi resident of Makkah, Saudi Arabia. Fever was not the presenting complaint, and the patient had not experienced any chills or sweating. He gave history of recent travel to Pakistan. Initial laboratory investigations showed anemia, thrombocytopenia, normal liver function, and negative blood film for malaria. His widal, Brucella, and dengue serology was negative. Endoscopic examination showed gastroenteritis. On the fifth day of admission, a sexual form of Plasmodium falciparum on peripheral smear was reported by chance. Malaria was misdiagnosed because of initial negative blood film which may have been due to false microscopy or a long period between exposures and positive blood film. We concluded that a repeat blood film for malaria at 12- to 24-hour intervals for 48 to 72 hours is cost effective when a patient has recently travelled to an endemic area.