Researchers at Singapore’s Nanyang Technological University, lead by Dr. Zbynek Bozdech have discovered the mechanism by which the malaria parasite is developing resistance to key front-line drugs used for its treatment, such as artemisinin.
Malaria is caused by a parasite, Plasmodium which is transmitted to humans via the bites of infected mosquitoes. They infect red blood cells causing symptoms such as fever and vomitting and if left untreated, could prove fatal. In 2013, an estimated 198 million cases of malaria were reported worldwide, with an estimated 584,000 deaths. One of the key intervention strategies to control malaria include artemisinin-based combination therapies and indoor residual spraying with insecticide to control the mosquitoes carrying the parasite.However, there is an emerging parasite resistance to artemisinin and if the mechanism by which the parasite is developing drug resistance is not understood, there could be a rise in global malaria mortality.
In a breakthrough research finding, published in the leading journal Science, NTU Associate Professor Zbynek Bozdech along with his international research team from 11 different countries, have analyzed 1,000 malaria samples taken from patients in the area of Greater Mekong subregion using the cost-effective microarray technique. In recent years, almost all the parasites had developed resistance to artemisinin in the Greater Mekong subregion consisting of Cambodia, Laos, Myanmar, Thailand and Vietnam. This is different from the malaria parasites in African countries, where only one to three per cent of them had mutated and drug resistance has not yet been detected. The clinical data from the 1000 samples was correlated with functional genomics results, to determine how the parasite protects itself against Artemsinin.
NTU research fellow, Dr Sachel Mok, the first author of the scientific paper, said they found the malaria parasite’s two major ways by which it becomes resistant to Artemisinin.
“First, the malaria parasite increased its capacity to repair the damage caused by the anti-malarial drug which gives it a higher chance of survival.”
“Second, because the drug is more effective against the parasite at its later stage of its development, the parasite slowed down its growth so it could survive longer in the younger stages.”
“Using methods like gene expression analysis, we linked these two phenomena to a gene named K13, which was previously suggested to be associated with drug resistance but it was not clear how.”
With this new knowledge, doctors will be able to design new strategies for drug treatments, particularly when deciding which cocktail of drugs will work better with Artemisinin to better treat patients.Their scientific paper involved 31 scientists from 11 countries such as. Thailand, Vietnam, Cambodia, Myanmar, and Laos; with notable partners such as Oxford University in the UK; the University of Maryland, School of Medicine, from United States; as well assistance from the World Health Organisation (WHO).
The published article can be read at: