“In 2014, the most recent year for which data are available, about 438,000 people died from malaria worldwide,” said Liwang Cui, professor of entomology, Penn State, and the project’s principal investigator. “And that’s just a tiny fraction of the people who were diagnosed with malaria that year — 214 million people contracted the disease.”
Cui noted that Southeast Asia accounts for 7 percent of global malaria deaths, and the majority of these cases occur along the borders of these countries. Recently, he added, the six Greater Mekong Subregion (GMS) countries — Cambodia, China’s Yunnan Province, Lao People’s Democratic Republic, Myanmar, Thailand and Vietnam — have committed to eliminating malaria by 2030 in all countries of the GMS.
Among the many projects they will pursue with their grant, Cui and his colleagues — which includes Jetsumon Sattabongkot, faculty of science, Mahidol University, Thailand — will continue to use molecular diagnostic tools to conduct malaria surveillance and to identify transmission hotspots and risk factors for malaria infection, as well as evaluate the effectiveness of current treatment regimens, along the borders of three countries within the GMS — China, Myanmar and Thailand.
The researchers will also examine how environmental changes affect disease transmission, and whether changes in mosquito biting behaviors — for example, outdoor/indoor biting — have a genetic basis. In addition, they will use genetic techniques to examine resistance to several commonly-used insecticides among the major vector mosquitoes, and they will track the spread of resistance to other sites.
“Our previous work has found that the mortality rates of the Anopheles sinensis mosquitoes from both central and southwestern China were all below 90 percent for the five insecticides tested — deltamethrin, permethrin, DDT, malathion and bendiocarb — suggesting that they [the mosquitos] were all resistant to pyrethroids, organophosphates, carbamates and organochlorines,” said Cui.
According to Cui, fake drugs to treat malaria are often sold in the border regions of Southeast Asia. As part of their project, he and his colleagues will investigate the extent of this problem using a special diagnostic tool they developed.
“Many migrants, due to illegal immigration status, often actively avoid contact with the authorities and seek malaria treatment at private sectors and small drug vendors,” he said. “As a result, border areas represent the biggest market for counterfeit and substandard antimalarial drugs.”
The team already has made many advances in these areas and the new funding from the NIH‘s National Institute of Allergy and Infectious Diseases will enable them to continue this work.
“We will use innovative molecular and genomic technologies to reveal the underlying mechanisms needed to design integrated, targeted control measures that attack the roots of the malaria problem,” said Cui. “By strategically selecting three countries in this region with drastically different malaria epidemiologies, we expect that the findings of these studies will benefit the entire malaria community.”
Other researchers of this consortium include Jason Rasgon and Renze Li at Penn State; Daibin Zhong at the University of California, Irvine; Jetsumon Sattabongkot, Jaranit Kaewkungwal, Saranath Lawpoolsri at Mahidol University; Myat Phone Kyaw, Myo Min, Than Naing Soe at Myanmar Medical Association; Yaming Cao at China Medical University; Baomin Wang at China Agricultural University; and Zhaoqing Yang Kunming Medical University.