Ontario case study suggests misuse of drug therapies increases risk of malaria infection
Public Health Ontario public health laboratories identify 200 positive malaria smears annually
Sept. 23, 2010, Toronto — Travellers are returning to Ontario with malaria because drug therapies to prevent and treat the mosquito-borne disease are being misused, says a medical microbiologist with the Public Health Ontario (PHO).
Dr. Dylan Pillai said the misuse of anti-malarial drugs, including artemisinin, the best available malaria drug, is partly to blame. The result is less effective prevention and treatment strategies and the possible emergence and spread of drug-resistant strains of malaria.
The findings of his case study were published recently in the journal Emerging Infectious Diseases and can be found here: http://www.cdc.gov/eid/content/16/10/1608.html
“Infectious disease researchers at PHO are committed to working with public health partners to generate world-class information that supports the effective use of anti-malarial drugs,” said Dr. Pillai. “The result is better knowledge that drives the development of anti-malarial health strategies and supports the well-being of Ontarians and people around the world.”
Efforts are now underway to co-ordinate PHO laboratory surveillance and research with partners in France, the U.K., and the U.S. through the Worldwide Antimalarial Resistance Network (WWARN).
Malaria causes millions of deaths annually with the largest burden of disease in sub-Saharan Africa. But Ontario’s diverse population means travellers and recent immigrants visiting friends and relatives back home are at risk if they don’t take proper precautions.
“Some travellers do not seek medical advice prior to visiting regions around the world where malaria is common,” said Dr. Pillai. “This greatly increases their risk of contracting the disease.”
Symptoms of malaria can include headache, fever, chills, sweating, nausea, vomiting and, if left untreated, can lead to death, especially in the case of P. falciparum malaria.
Dr. Pillai said artemisinin is best used in combination with a longer-acting partner drug to guarantee its effectiveness.
The World Health Organization has requested fixed-dose combinations of artemisinin — a single pill containing two or more drugs.
He said artemisinin should not be used on its own to treat malaria and should not be used at all as a preventive medication.
“This research at PHO has important implications for travellers’ health, surveillance of drug-resistant malaria, and global public health policy as it relates to access to important anti-malarial medications,” said Dr. Pillai.
Meanwhile, the issue of artemisinin-resistant malaria will take centre-stage next month as some of the world’s leading malaria researchers gather in Toronto for the Gairdner Global Health Symposium on Oct. 27, sponsored in part by PHO.