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Malaria Telediagnosis

Malaria Telediagnosis CDC uses the Internet to assist remote laboratories in the microscopic diagnosis of malaria…	Stephanie Johnston and Henry Bishop of CDC's Division of Parasitic Diseases discuss telediagnosis images received through the Internet.

Blaine Mathison at his telediagnosis station at the Arizona State Laboratory. The view through the microscope is shown on the computer monitor. Images can be captured by the digital camera mounted on the microscope. The images are stored in the computer and sent by email to CDC.

The best way to find out whether a patient who is suspected of having malaria actually has the disease is to look for malaria parasites in the patient’s blood. To do this, laboratory workers collect a blood specimen from the patient, spread some of the blood on a glass slide (to make a thick smear and a thin smear), stain the slide, and examine it under a microscope for the presence of malaria parasites. This procedure can be life-saving because it helps in the diagnosis of a potentially fatal disease. However microscopic examination for malaria requires skills and experience that are not always available in all laboratories. For example, in the United States malaria is rare and often laboratory workers are not sufficiently familiar with its microscopic diagnosis.

CDC offers telediagnosis to better assist laboratory workers in diagnosis of malaria and other parasitic diseases. When U.S. and international laboratories are not sure about what they see when searching for malaria parasites on a slide, they can e-mail CDC images of the suspected parasites. In a period ranging from a few minutes to a few hours, experts at CDC’s Division of Parasitic Diseases (DPD) review the images and discuss the findings with the submitting laboratory by email or by telephone. Such contact not only allows almost “real time” diagnosis but also offers an opportunity for training in microscopic diagnosis.

CDC, through the National Food Safety Initiative, has provided 47 public health laboratories in the United States, and a laboratory in Guatemala (CDC-Medical Entomology Research and Training Unit) with funding to acquire the equipment needed for telediagnosis. This includes a digital camera that can be attached to a microscope and a computer with Internet access. More than 250 telediagnosis requests have been received in the last 3 years, with an increasing trend during that period . Public health laboratories and clinical laboratories are the primary users (213 submissions), although submissions from international laboratories (39) are on the rise.

Images of malaria parasites submitted to CDC for telediagnosis: (clockwise from top left) Plasmodium falciparum (from the Missouri State Public Health Laboratory), P. vivax (Connecticut Public Health Laboratory), P. ovale (Ohio Bureau of Public Health Laboratories), and P. malariae (Wisconsin State Laboratory of Hygiene). The images show red blood cells, some of which are infected with malaria parasites. The number of parasites, their appearance, and the resulting change in appearance of the infected red blood cells are used to determine the type (species) of the infecting malaria parasites

Telediagnosis is a component of the DPDx Project, a program to strengthen the laboratory diagnosis of parasitic diseases. Supported through National Food Safety Initiative funding, DPDx offers a Web site on parasitology diagnosis, a monthly case-study listserv, CD products, and continuing education training for laboratory workers.

Laboratories interested in participating in DPDx activities (including telediagnosis) should contact dpdx@cdc.gov.

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