[ad_1]
The fight against the parasites responsible for malaria proves delicate in Southeast Asia. The researchers said a fast-changing variant of falciparum malaria was resistant to essential drugs.
This has led to "alarming failure rates in Cambodia, Thailand and Vietnam" for DHA-piperaquine, one of the world's most important drugs for malaria control.
The discovery was documented by the University of Oxford researchers in a study published today in The Lancet Infectious Diseases.
Study authors say that DHA-piperaquine should no longer be used to treat P. falciparum malaria Cambodia, Vietnam and northeast of Thailand because it is inefficient and will actually help to increase malaria transmission.
TThe researchers want urgent action to eradicate falciparum malaria from the Greater Mekong subregion to prevent a local increase of several resistant strains and spread them to other parts of Asia and Africa. Africa and to avoid a possible global health emergency.
Spread of resistance
"Resistance to our antimalarial drugs is worsening and spreading Eastern subregion of Greater Mekong,"A co-author of the study, Sir Nick White, professor at the University of Oxford.
"We urgently need to eliminate malaria in this region and act now to prevent the spread of these multidrug-resistant parasites to other parts of Asia and sub-Saharan Africa. When resistance to previous antimalarial drugs arose in Southeast Asia and spread to Africa, millions of children died. "
Deaths due to malaria declined significantly after the introduction in the late 1990s of artemisinin-based combination therapy (ACT), which combines artemisinin, the most common drug. effective against malaria, to another anti-malaria such as piperaquine.
However, in 2014, the Follow-up study of artemisinin resistance (TRAC) reported in the New England Journal of Medicine (NEJM) that artemisinin resistance to Plasmodium falciparum – the most deadly form of parasite causing malaria and most prevalent in Africa and Asia – was widespread throughout the world. Greater Mekong Subregion.
Since then, global progress against malaria has stalled.
In fact, the number of cases worldwide has steadily increased over the last three years, with An estimated 219 million cases of malaria (compared with 217 million in 2016) and 435,000 deaths from malaria in 2017. children under five in sub-Saharan Africa, according to the WHO Report on Malaria in the World 2018.
Professor Arjen Dondorp, co-author of the study and deputy director of the Bangkok-based Mahidol Oxford (MORU) Tropical Medicine Research Unit, said: "DHA-piperaquine has failed and should no longer be used to treat P. falciparum malaria in the eastern Greater Greater Mekong Subregion. It provides ineffective treatment to the patient and thus contributes to increased malaria transmission.
"It has immediate importance for public health, so we thought we should not wait to report it before the release of our full report. TRAC II results later this year, "he said.
DHA-piperaquine is a drug used in artemisinin-based combination therapy on the WHO list of essential drugs. It is used to treat P. falciparum and vivax malaria in Africa and Asia, as well as large-scale pilot programs to eliminate malaria in the Greater Mekong subregion.
The researchers said that although resistance to artemisinin in Africa was still reported, they wanted to eliminate these highly drug-resistant falciparum parasites in Southeast Asia in order to preserve the efficacy of DHA-piperaquine and other ACTs in Africa and elsewhere in Asia. prevent a global health emergency.
"Cradle of drug resistance"
"Southeast Asia is the cradle of antimalarial drug resistance. We need to eliminate falciparum malaria before it becomes impossible to treat in the Greater Mekong subregion and elsewhere in Asia, "said Dr. Rob van der Pluijm, co-author of the study and coordinator of TRAC II.
"This is the third time that the falciparum parasite has developed widespread resistance to antimalarials: first, chloroquine and sulphadoxine-pyrimethamine appeared and spread in the 1960s and 1970s, and resistance has now appeared to artemisinin-based and ACT-based drugs. We must get rid of these pests once and for all," he said.
In an accompanying document in The Lancet Infectious DiseasesResearchers at the Wellcome Sanger Institute report that the P. falciparum strain that became resistant to DHA-piperaquine, which they call KEL1 / PLA1, has evolved and widespread in recent years after its discovery in Cambodia.
The parasites have mutated and produced an even higher level of resistance, allowing them to spread across the Greater Mekong subregion.
"Genetic surveillance data show that resistant falciparum parasites are evolving, developing new mutations that make them more fit and resilient, allowing them to spread regionally and support whole populations of parasites." ."Said the University of Oxford Prof Olivo Miotto, co-author of the study and senior researcher in computer science at MORU.
"We must act quickly so that the situation does not worsen. "
Source link
