A Nosocomial Outbreak of Malaria Associated With Contaminated Catheters and Contrast Medium of a Computed Tomographic Scanner

Abstract

AbstractObjective:To identify the risk factors associated with an unexpected outbreak of malaria that occurred among seven patients in a general teaching hospital in Taipei in October 1995.Design:A three-stage case-control study was conducted to identify risk factors.Patients:We identified all 7 patients who were diagnosed as malaria cases and 69 controls from those undergoing computed tomography (CT) examination.Methods:Malaria was diagnosed by demonstrating the presence ofPlasmodium falciparumon either thick or thin blood smears. Clinical characteristics and exposure information were collected from medical records and patient interviews.Results:The index case was infected by malaria when he visited Nigeria in early September and was diagnosed when he was hospitalized in hospital A in October. Among 10 patients examined with the Imatron scanner after the index case, all 6 who were injected with contrast medium were infected, but none of 4 examined without contrast medium were infected (P=.005).Conclusions:This nosocomial outbreak of malaria was most likely due to transmission via a contaminated catheter and contrast medium used for CT scanning. Use of disposable catheters may avoid such nosocomial outbreaks in the future.