Scientists in the USA are looking to use “gene chip technology” to reduce or contain drug resistance to malaria, an increasing problem globally but particularly in Southeast Asia.
The goal is to “see resistance as it is emerging, respond in real time and modify strategies to save a drug, such as protecting it with new formulations and combinations tailored to the specific location of emergence,” said the lead researcher, Michael Ferdig. “We now have markers for emerging resistance and new hypotheses that we will use to track down the resistance mechanism.”
Genetic markers or “signposts” are any alteration in the DNA that helps to identify the presence of a specific disease.
Artemisinin is a natural plant product that represents the first-line treatment for malaria, after resistance to chloroquine, an antimalarial previously widely used, forced treatment to change in the early 1970s. Growing resistance to artemisinin in the greater Mekong sub-region - including Cambodia, the southern provinces of China, Lao, Myanmar, Thailand and Viet Nam - means treatment is taking longer to clear parasites.
“Southeast Asia, and in particular western Cambodia, is the region where all resistances in [the parasite] plasmodium falciparum have emerged,” said Francois Nosten, director of the Shoklo Malaria Research Unit along the Thai-Myanmar border, a region which has reported longer treatment times in the past eight years for patients taking artemisinin-based drugs to cure malaria.
However, experts warn that gene chip technology is years away from practical application.
“The gene chip is only at the stage of being developed and not there yet,” said Nosten. “Several groups are competing to find the molecular markers of resistance to artemisinin, but it will take several years before something is usable in the field and we do not have this time to waste.”
According to the World Health Organization, four out 10 people globally who are at risk of becoming infected with malaria live in Southeast Asia.
Migration from highly endemic malarial areas, counterfeit anti-malarial drugs, and the misuse of artemisinin have all contributed to worsening drug resistance, says the agency.