[ad_1]
Genomic surveillance revealed that malaria resistance to two first-line antimalarials has rapidly spread from Cambodia to neighboring countries in Southeast Asia. Researchers at the Wellcome Sanger Institute of Oxford University and Mahidol University in Bangkok found that descendants of a multidrug-resistant strain of malaria replaced local parasitic populations in Vietnam , in Laos and northeastern Thailand. They also found that the resistant strain had led to new genetic changes, which could further strengthen the resistance.
The study, published in The Lancet Infectious Diseases Today (July 22), highlights the importance of ongoing genomic surveillance to inform malaria control strategies in public health. Global efforts to eliminate malaria may be threatened by any delay in detecting and responding to resistance.
Malaria is caused by Plasmodium parasites that spread through mosquito bites. The World Health Organization estimates that nearly 220 million people were infected in 2017, causing at least 400,000 deaths *, with children under five living in sub-Saharan Africa being the most exposed. Malaria can be treated early enough, but the parasite is becoming increasingly resistant to antimalarials in many areas, particularly in South-East Asia, jeopardizing elimination efforts.
In the past decade, first-line treatment for malaria in many parts of Asia has been a combination of two potent antimalarials – dihydroartemisinin and piperaquine – also known as DHA-PPQ. However, a previous study identified a strain of malaria that became resistant to this treatment. The researchers found that this resistant strain, named KEL1 / PLA1 because of its combination of genetic mutations causing resistance, had spread in Cambodia between 2007 and 2013.
This highlighted the urgent need to monitor and determine the extent to which this resistance had subsequently spread and if it had further evolved, and to understand what drugs would work against the current malaria parasites in Southeast Asia. .
In the most recent and comprehensive study on the entire genome of malaria parasites in Southeast Asia, the team sequenced and badyzed the DNA of 1,673 Plasmodium falciparum parasites, collected in the blood of malaria patients between 2008 and 2018. Their badysis, based on the variants of the KEL1 and PLA1 genes, revealed that the situation worsened considerably after 2013. The multidrug-resistant KEL1 / PLA1 parasites were widespread internationally, constituting in some regions more than 80% of the badyzed parasites.
Dr. Roberto Amato, co-author of the Wellcome Sanger Institute, said: "We have found that the strain of multidrug-resistant malaria KEL1 / PLA1 has spread aggressively, replacing malaria parasites, and has become the dominant strain in Vietnam, Laos and the north-east of Thailand, our large-scale genomic approach shows how surveillance can provide crucial information to malaria control programs, helping them to evaluate available treatment options . "
The spread probably occurred because the resistant parasites had an evolutionary advantage, DHA-PPQ being the first-line treatment in most of these areas. This killed other strains of malaria but was less effective against malaria KEL1 / PLA1.
The researchers found that not only did this resistant strain spread geographically, but that it had evolved and detected new mutations in the chloroquine resistance transporter (CRT) gene. These parasites then spread rapidly across borders. A related article ** on clinical outcomes published today in The Lancet Infectious Diseases revealed that these crt mutations were badociated with complete failure of DHA-PPQ treatment. This corroborates the conclusion that not only has resistance spread, but it has worsened as the parasite evolves under new drug pressure.
Professor Olivo Miotto, lead author of the Wellcome Sanger Institute, Oxford University's Big Data Institute and Mahidol University in Bangkok, said: "The rate at which these malaria-resistant parasites have spread to Asia The situation is currently effective, but the situation is extremely fragile and this study underlines the need for urgent action to eliminate pests from the Greater Mekong subregion, so as to prevent the spread of pests. prevent their spread and evolution. "
Dr. Michael Chew, Head of Infection and Immunobiology at Wellcome, said, "This study clearly shows the rapid spread of multidrug-resistant malaria in Southeast Asia.Malaria affects millions of people around the world. is a devastating disease, especially when access to effective treatment is unavailable.
"The spread of drug-resistant strains demonstrated by this important genetic surveillance, which builds on previous research, is an alarm signal." She recalls that there should be no sufficiency in the drug. This also shows that we have the necessary tools to effectively monitor drug resistance across borders, which can be used to document coordinated elimination and control efforts. "
Prof. Dominic Kwiatkowski, lead author of the Wellcome Sanger Institute Journal and the Big Data Institute at Oxford University, said: "Our study provides a clear picture of the spread of malaria resistant to first-line treatment, and demonstrates the importance of using genetics to detect resistance patterns in each zone Active genomic surveillance is now essential to inform national malaria control programs and help reduce the risk of malaria. major epidemic in the world. "
###
Notes to editors:
Publication
William Hamilton and Roberto Amato et al. (2019) Evolution and expansion of multidrug-resistant malaria in South-East Asia: a genomic epidemiological study. The Lancet Infectious Diseases. DOI: 10.1016 / S1473-3099 (19) 30392-5
* Figures from the 2018 report of the World Health Organization, http: // www.
** Rob van der Pluijm et al. (2019) Determinants of the failure of treatment with dihydroartemisinin-piperaquine in falciparum malaria in Cambodia, Thailand and Vietnam: a prospective clinical, pharmacological and genetic study. The Lancet Infectious Diseases.
What is malaria?
- Spread by mosquitoes, malaria is one of the most prevalent infectious diseases and a global challenge for public health.
- Malaria is a deadly disease caused by a parasite transmitted by the bite of an infected female mosquito, anopheles.
- The parasite responsible for malaria is a microscopic unicellular organism called Plasmodium.
- There are six different malaria parasite species causing malaria in humans, but Plasmodium falciparum and Plasmodium vivax are the most common types.
- Malaria is prevalent mainly in the tropical and subtropical regions of Africa, South America and Asia.
- An estimated 219 million cases and 435,000 deaths related to death in 2017.
- About 95% of deaths are in children under five living in sub-Saharan Africa. However, mortality rates have decreased overall by 18% since 2010.
- If it is not detected and treated quickly, malaria can be fatal. However, with the right treatment, started early enough, it can be cured.
For more information on malaria, please visit http: // www.
Selected sites:
The Big Data Institute, University of Oxford
The Big Data Institute is located at the Li Ka Shing Center for Health Informatics and Discovery at Oxford University. It is an interdisciplinary research center that focuses on the badysis of large complex data sets for research into the causes, consequences, prevention and treatment of diseases. Research is being conducted in areas such as genomics, population health, infectious disease surveillance, and the development of new badytical methods. The Big Data Institute is funded by the Medical Research Council, the UK Health Research Partnership Fund, the Oxford National Institute for Health Research's Oxford Biomedical Research Center, and philanthropic donations from the Li Ka Shing and Robertson Foundations. More details are available at http: // www.
Mahidol Oxford Tropical Medicine Research Unit (MORU)
Mahidol Oxford Research Unit on Tropical Medicine (MORU), http: // www.
The Wellcome Sanger Institute
The Wellcome Sanger Institute is one of the world's leading genomics research centers. We conduct large-scale research that is the foundation of knowledge in biology and medicine. We are open and collaborative. our data, results, tools and technologies are shared around the world to advance science. Our ambition is vast – we take projects that are not possible anywhere else. We use the power of genome sequencing to understand and exploit information contained in DNA. Funded by Wellcome, we have the freedom and support to push the boundaries of genomics. Our discoveries are used to improve health and understand life on Earth. Learn more about http: // www.
About Wellcome
Wellcome exists to improve health by helping good ideas flourish. We support researchers, we face great health challenges, we campaign for better science, and we help everyone to participate in scientific research and health. We are an independent foundation politically and financially. http: // www.
Source link
