Arjen Dondorp | |
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Born | Adrianus Mattheus Dondorp September 1963 (age 60–61) Utrecht, Netherlands |
Education | University of Amsterdam |
Occupation | Intensivist |
Known for | Pathophysiology and treatment of severe malaria, antimalarial drug resistance and development of intensive care practice |
Adrianus Mattheus Dondorp (born September 1963) is a Dutch intensivist, infectious diseases physician, and head of the Mahidol Oxford Tropical Medicine Research Unit in Bangkok. He is best known for his research in severe falciparum malaria, a disease that requires intensive care in hospital. He chairs the World Health Organization Technical Expert Group on antimalarial medication drug resistance and containment.
Born in Utrecht, The Netherlands, Dondorp studied medicine at the University of Amsterdam between 1982 and 1986, achieving a 'doctoral' in medicine, 'with distinction'. [1]
He became interested in blood flow properties (rheology) whilst he was a medical student and had found that 'red cell deformability' was extraordinarily reduced in falciparum malaria in returning Dutch travellers, an observation which was to steer him towards studies in the pathophysiologygy of malaria. [2]
By 1999, he was registered as physician in infectious diseases, when he also completed a PhD in the pathophysiology of severe falciparum malaria, with special reference to ‘red cell deformability’. [2] This research included clinical analyses completed in Thailand (1995-1996) and Kenya (1997-1998). [1]
A year later he was registered as intensive care physician at Department of Intensive Care Medicine, Academic Medical Centre, Amsterdam, the Netherlands. Since 2001, Dondorp has continued his research as Deputy Director and Head of Malaria Research, Mahidol-Oxford Research Unit (MORU), Bangkok, Thailand. [1] [3]
Dondorp's foremost research interests have focused attention on the pathophysiology and treatment of severe malaria, antimalarial drug resistance and development of intensive care practice in low income countries. [4]
"The main reason you become so ill from severe malaria is that the red blood cells harbouring the parasite become very sticky and adhere to the walls of the smallest blood vessels in all the vital organs, such as the brain, kidney and lung vasculature. This blocks normal circulation and can be fatal." - Dondorp [5]
Findings from his clinical studies of the small blood vessels (microcirculation) in patients with severe malaria have revealed that red cells become rigid and lose ability to change shape. [5] They lose their flexibility to pass through blood vessels that are smaller in diameter than the red cells. This rigidity impairs blood flow through the small blood vessels. Dondorp's team demonstrated this impairment of microcirculatory flow due to red cell rigidity in severe malaria. [4] [6]
A strong prognostic significance was also found to be the amount of plasma PfHRP2, a protein released by the sequestrated parasite. This protein contributes to the metabolic acidosis seen in people with severe malaria. His team, however, demonstrated resistance of Plasmodium falciparum to artemisinins in Western Cambodia. New treatments would have to be found to contain efforts against this serious threat to global malaria control. [4]
He has highlighted that resistance to artemisinin and piperaquine is a genuine worry, and should malaria become untreatable, would be a significant threat to controlling the spread of malaria from South East Asia to Africa, which is therefore a "race against time". [5] [6]
Artesunate is recommended by the World Health Organization (WHO) in preference to quinidine for the treatment of severe malaria and has been used worldwide for many years. Artesunate is in the class of medications known as artemisinins, which are derivatives from sweet wormwood ( Artemisia annua ). [7]
Dondorp hopes to make best use of the wide range of expertise in the Technical Expert Group on Antimalarial Drug Resistance. They advise, design and execute programmes for the WHO on aspects of containing artemisinin resistance. [2]
Malaria is a mosquito-borne infectious disease that affects vertebrates. Human malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin 10 to 15 days after being bitten by an infected Anopheles mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria.
Antimalarial medications or simply antimalarials are a type of antiparasitic chemical agent, often naturally derived, that can be used to treat or to prevent malaria, in the latter case, most often aiming at two susceptible target groups, young children and pregnant women. As of 2018, modern treatments, including for severe malaria, continued to depend on therapies deriving historically from quinine and artesunate, both parenteral (injectable) drugs, expanding from there into the many classes of available modern drugs. Incidence and distribution of the disease is expected to remain high, globally, for many years to come; moreover, known antimalarial drugs have repeatedly been observed to elicit resistance in the malaria parasite—including for combination therapies featuring artemisinin, a drug of last resort, where resistance has now been observed in Southeast Asia. As such, the needs for new antimalarial agents and new strategies of treatment remain important priorities in tropical medicine. As well, despite very positive outcomes from many modern treatments, serious side effects can impact some individuals taking standard doses.
Plasmodium is a genus of unicellular eukaryotes that are obligate parasites of vertebrates and insects. The life cycles of Plasmodium species involve development in a blood-feeding insect host which then injects parasites into a vertebrate host during a blood meal. Parasites grow within a vertebrate body tissue before entering the bloodstream to infect red blood cells. The ensuing destruction of host red blood cells can result in malaria. During this infection, some parasites are picked up by a blood-feeding insect, continuing the life cycle.
Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans. The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. It is responsible for around 50% of all malaria cases. P. falciparum is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer and is classified as a Group 2A (probable) carcinogen.
Artemisia annua, also known as sweet wormwood, sweet annie, sweet sagewort, annual mugwort or annual wormwood, is a common type of wormwood native to temperate Asia, but naturalized in many countries including scattered parts of North America.
Artemisinin and its semisynthetic derivatives are a group of drugs used in the treatment of malaria due to Plasmodium falciparum. It was discovered in 1972 by Tu Youyou, who shared the 2015 Nobel Prize in Physiology or Medicine for her discovery. Artemisinin-based combination therapies (ACTs) are now standard treatment worldwide for P. falciparum malaria as well as malaria due to other species of Plasmodium. Artemisinin is extracted from the plant Artemisia annua a herb employed in Chinese traditional medicine. A precursor compound can be produced using a genetically engineered yeast, which is much more efficient than using the plant.
Artemether is a medication used for the treatment of malaria. The injectable form is specifically used for severe malaria rather than quinine. In adults, it may not be as effective as artesunate. It is given by injection in a muscle. It is also available by mouth in combination with lumefantrine, known as artemether/lumefantrine.
Artesunate (AS) is a medication used to treat malaria. The intravenous form is preferred to quinine for severe malaria. Often it is used as part of combination therapy, such as artesunate plus mefloquine. It is not used for the prevention of malaria. Artesunate can be given by injection into a vein, injection into a muscle, by mouth, and by rectum.
Plasmodium knowlesi is a parasite that causes malaria in humans and other primates. It is found throughout Southeast Asia, and is the most common cause of human malaria in Malaysia. Like other Plasmodium species, P. knowlesi has a life cycle that requires infection of both a mosquito and a warm-blooded host. While the natural warm-blooded hosts of P. knowlesi are likely various Old World monkeys, humans can be infected by P. knowlesi if they are fed upon by infected mosquitoes. P. knowlesi is a eukaryote in the phylum Apicomplexa, genus Plasmodium, and subgenus Plasmodium. It is most closely related to the human parasite Plasmodium vivax as well as other Plasmodium species that infect non-human primates.
Dihydroartemisinin is a drug used to treat malaria. Dihydroartemisinin is the active metabolite of all artemisinin compounds and is also available as a drug in itself. It is a semi-synthetic derivative of artemisinin and is widely used as an intermediate in the preparation of other artemisinin-derived antimalarial drugs. It is sold commercially in combination with piperaquine and has been shown to be equivalent to artemether/lumefantrine.
Amodiaquine (ADQ) is a medication used to treat malaria, including Plasmodium falciparum malaria when uncomplicated. It is recommended to be given with artesunate to reduce the risk of resistance. Due to the risk of rare but serious side effects, it is not generally recommended to prevent malaria. Though, the World Health Organization (WHO) in 2013 recommended use for seasonal preventive in children at high risk in combination with sulfadoxine and pyrimethamine.
Pyronaridine is an antimalarial drug. It was first made in 1970 and has been in clinical use in China since the 1980s.
Piperaquine is an antiparasitic drug used in combination with dihydroartemisinin to treat malaria. Piperaquine was developed under the Chinese National Malaria Elimination Programme in the 1960s and was adopted throughout China as a replacement for the structurally similar antimalarial drug chloroquine. Due to widespread parasite resistance to piperaquine, the drug fell out of use as a monotherapy, and is instead used as a partner drug for artemisinin combination therapy. Piperaquine kills parasites by disrupting the detoxification of host heme.
Project 523 is a code name for a 1967 secret military project of the People's Republic of China to find antimalarial medications. Named after the date the project launched, 23 May, it addressed malaria, an important threat in the Vietnam War. At the behest of Ho Chi Minh, Prime Minister of North Vietnam, Zhou Enlai, the Premier of the People's Republic of China, convinced Mao Zedong, Chairman of the Chinese Communist Party, to start the mass project "to keep [the] allies' troops combat-ready", as the meeting minutes put it. More than 500 Chinese scientists were recruited. The project was divided into three streams. The one for investigating traditional Chinese medicine discovered and led to the development of a class of new antimalarial drugs called artemisinins. Launched during and lasting throughout the Cultural Revolution, Project 523 was officially terminated in 1981.
Pregnancy-associated malaria (PAM) or placental malaria is a presentation of the common illness that is particularly life-threatening to both mother and developing fetus. PAM is caused primarily by infection with Plasmodium falciparum, the most dangerous of the four species of malaria-causing parasites that infect humans. During pregnancy, a woman faces a much higher risk of contracting malaria and of associated complications. Prevention and treatment of malaria are essential components of prenatal care in areas where the parasite is endemic – tropical and subtropical geographic areas. Placental malaria has also been demonstrated to occur in animal models, including in rodent and non-human primate models.
Piperaquine/dihydroartemisinin (DHA/PPQ), sold under the brand name Eurartesim among others, is a fixed dose combination medication used in the treatment of malaria. It is a combination of piperaquine and dihydroartemisinin. Specifically it is used for malaria of the P. falciparum and P. vivax types. It is taken by mouth.
Artesunate/pyronaridine, sold under the brand name Pyramax, is a fixed-dose combination medication for the treatment of malaria. It can be used for malaria of both the P. falciparum and P. vivax types. It combines artesunate and pyronaridine. It is taken by mouth.
Liu Xu was a Chinese pharmaceutical chemist known for the discovery of artesunate, a novel antimalarial drug. The discovery of artesunate solves the problem that artemisinin is nearly insoluble in water. Artesunate can be given by intravenous injection, intramuscular injection, by mouth, and by rectum.
Sanjeev Krishna,, is a British physician and parasitologist whose research focuses on affordable diagnosis and treatment of diseases such as COVID-19, malaria, Ebola, African trypanosomiasis, leishmaniasis, and colorectal cancer. Krishna is Professor of Medicine and Molecular Parasitology at St George's, University of London and St George's Hospital.
David A. Fidock, is the CS Hamish Young Professor of Microbiology and Immunology and Professor of Medical Sciences at Columbia University Irving Medical Center in Manhattan.