The number of malaria cases in Cambodia plummeted by more than 50 percent in 2016, compared to 2015, though experts and recent research findings suggest the emergence and spread of artemisinin-resistant malaria parasites in the Greater Mekong subregion represents a “serious threat” in the elimination of the disease.

The Ministry of Health’s National Malaria Centre yesterday released its 2016 malaria figures, which show a 54 percent drop in cases. In 2016, the Kingdom recorded a total of 23,627 cases, compared to 51,262 in 2015.

The number of deaths also dipped to only one, compared with 10 the previous year. That figure represents a sharp decrease over the past five years, down from 112,057 cases and 93 fatalities in 2011.

National Malaria Centre director Huy Rekol did not respond to multiple requests for comment yesterday, though the statement said officials attributed the decrease in both cases and fatalities to better prevention efforts, and more knowledge about the mosquito-borne illness among villagers in hot spots.

Professor François Nosten, director of the Shoklo Malaria Research Unit, a field station for tropical medicine faculty at Mahidol University in Bangkok, said it’s “good news” that the number of malaria cases in Cambodia is going down, but that’s typical when there’s an increase in control by instituting better detection and treatment.

“However, it is only hiding, and will come back as soon as resistance is established,” he said. “This has already happened in the past … The priority should be to rapidly eliminate malaria rather than just controlling it.”

In Cambodia, just shy of 60 percent of malaria cases involve the parasite plasmodium falciparum, which first emerged in the Kingdom in 2008, and is resistant to the most potent anti-malaria drugs, according to a 2016 WHO report.

Dr Luciano Tuseo, head of the malaria program at WHO Cambodia, said last year’s introduction of a new combination of drugs – Artesunate-Mefloquine, or ASMQ – which followed the failure of Dihydroartemisinin-Piperaquine, or DHA-PIP, could have a played a role in the drop in cases.

The DHA-PIP failure rate in Cambodia ranges between 10 to 50 percent, he said. Though, for the moment, there hasn’t been any ASMQ drug failure, he said.

“Cambodia’s Ministry of Health, [the] malaria program and its partners, including the main donors … are really engaged to eliminate malaria P falciparum before 2020,” he said.

However, a study published last week in The Lancet, a UK-based medical journal, said the emergence and geographic spread of artemisinin-resistant P falciparum lineage – which is outcompeting other malaria parasites in the Greater Mekong subregion – “represents a serious threat to global malaria control and aspirations to eliminate malaria”.

“We hope this evidence will be used to reemphasise the urgency of malaria elimination in the Asia-region before falciparum malaria becomes close to untreatable,” the researchers said in a statement. `