Inexpensive blood test for major parasitic diseases

Dec 5 2005

The National Reference Centre for Parasitology (NRCP), based at the MUHC, is developing a comprehensive and inexpensive blood safety test that will allow clinicians to check for all major parasitic diseases in patients' blood.

The test, which is currently in final stages of development, will also improve the safety of blood transfusions, which are one of the ways that parasitic conditions are spread. The new test will lead to an increase in the number of blood samples checked for parasites, and improve turnaround time--a critical issue in life and death cases.

"Anyone can be bitten by an insect while on holiday and unknowingly contract a parasitic disease," says Dr. Momar Ndao, Laboratory Director of the NRCP. "For example, people with Chagas disease--caused by a parasite transmitted through the bite of the South American assassin bug--can remain symptomless for 2-3 decades, while the parasites slowly invade the body's organs." Conditions like the South American Chagas disease can then be transmitted to others through blood transfusions, which is particularly dangerous to immunocompromized people who often require transfusions.

Routine testing of donated blood for diseases like HIV and hepatitis saves many lives each year, but parasitic conditions often avoid detection because tests to identify them are often complex and expensive, and hence conducted in only a few specialist laboratories in the world. The NRCP is one of only two laboratories in North America, capable of conducting tests for rare parasitic conditions. "We have an incredible workload," notes Dr. Ndao. "Each year we conduct approximately 6,000 tests on 17 different diseases." Dr. Ndao and colleague Dr. Brian Ward--Chief of Infectious Diseases at the MUHC and Medical Director of the NRCP--receive samples for analysis from all over the world, and demand for testing has increased by 270% over the past decade.

Dr. Ndao knows that every blood sample he tests could represent another life saved--the new blood safety test under development represents a way to provide the expertise of the NRCP to the world. With funding from Health Canada (NML/PHAC) and the Canadian Institutes of Health Research (CIHR), the NRCP blood safety test will allow clinicians to instantly establish whether blood is parasite-free. "The test covers all the major parasitic diseases, from protozoan parasites (Malaria) to helminthes (Fasciola)," says Dr. Ndao. "It's like a mini NRCP lab in every package."