title: Patterns of presentation of malaria in a tertiary care institute in Saudi Arabia.
abstract: OBJECTIVE
  The occurrence of malaria in a non-endemic area is an exceptional event. Review of clinical experience at the King Faisal Specialist Hospital & Research Centre (a tertiary medical centre located in a non-endemic area) demonstrated a relatively frequent infection rate among patients. We therefore examined circumstances that could contribute to the high rate of occurrence observed.
  
  
  METHODS
  We retrieved archived blood smears of patients diagnosed with malaria from the records of the Hematology Section of King Faisal Specialist Hospital & Research Centre, Riyadh, Kingdom of Saudi Arabia, followed by a review of the clinical records to extract demographic data, clinical presentations including history of proximate blood transfusion, and travel to, or residence in, areas endemic for malaria.
  
  
  RESULTS
  There were 217 patients diagnosed with malaria between 1978 and 1999, (1398 to 1419 Hejira calendar) resulting in an average yearly frequency of 9.86 cases. Males were 2.6 times more frequently affected than females (p<0.001). The majority of patients were infected through natural means, either by residence in endemic areas (N=83) or by travel to one (N=90). A significant minority, 44 (20.3%), became infected through blood transfusion. The majority of blood transfusion-induced malaria occurred in patients who were immunocompromised for various reasons, mostly related to dysfunction of the hematopoietic system or to major surgical insult. The most frequently implicated organism was Plasmodium falciparum, accounting for 74.2% of cases, whilst Plasmodium vivax accounted for 25.4%.
  
  
  CONCLUSIONS
  We demonstrate that patients presenting with malaria are more likely to be males who have been exposed during travel to endemic areas or through blood transfusion. In all cases, Plasmodium falciparum is the most likely organism to be implicated.
authors.affiliation: Department of Pathology and Laboratory Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Al-Hassan
authors.forename: George T
authors.initials: GT
authors.lastname: Roberts
mesh_terms: D001803:Blood Transfusion; D019353:Endemic Diseases; D005260:Female; D006766:Hospitals, County; D006801:Humans; D015994:Incidence; D016778:Malaria, Falciparum / Q000175:diagnosis / Q000453:epidemiology*; D016780:Malaria, Vivax / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D011336:Probability; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D012529:Saudi Arabia / Q000453:epidemiology; D017678:Sex Distribution; D014195:Travel