University of Wits scientists artificially inject mosquitoes with human malaria to promote treatment

Vector refers to an organism that carries and spreads an infectious disease, just as mosquitoes produce malaria.

Lead fertilizers are chemical compounds that show promise as a treatment for disease and may lead to the development of a new drug.

Antiplasmodial lead fertilizers are the ones that fight parasites of the genus Plasmodium, which is the parasite that infects mosquitoes and causes malaria in humans.

The findings of the study were published in Nature Communication on January 11, 2021, at a time when the incidence of malaria usually ends after the holiday season.

INFECTION MOSQUITO RESULTS CENTER

Professor Lizette Koekemoer, co-director of WRIM and Chair of SARChI at the National Research Foundation in Medical Entomology and Control, and an honorary member of the Center for Emerging Zoonotic and Parasitic Diseases, was a National Institute for Mobile Diseases, co-author of the paper.

Koekemoer and her team at WRIM established a specialized mosquito infection center in the Faculty of Health Sciences at the University of Wits, where the mosquito transmission inhibition tests took place.

“The WRIM infection center is the only facility in South Africa and the southern African region that can infect mosquitoes with a human malaria parasite,” says Koekemoer. “The infection center provided the high level of knowledge required to capture mosquitoes by the human malaria parasite, Plasmodium falciparum, and allowed this specific study to be conducted.”

ISSUES CURATING TO COMBAT TRANSMISSION

Drugs are used to control human malaria but resistance to these drugs is developing rapidly. Moreover, the drugs usually target only one stage of the life cycle of the parasite and are not good candidates for inhibition of transmission.

To expand drug suitability for malaria eradication strategies, drugs must be chemotype-capable [a chemically distinct entity in a plant or microorganism] which blocks both human-to-mosquito transmission and human-to-human mosquito transmission.

Koekemoer, with WRIM colleagues and co-authors Erica Erlank, Luisa Nardini, Nelius Venter, Sonja Lauterbach, Belinda Bezuidenhout, and Theresa Coetzer performed specific experiments to measure the reduction of mosquito infestation as well as the “killing effect”. [endectocide effect] in the vectors.

The scientists scribbled 400 of the chemical compounds found in the “Pandemic Response Box”, provided by Medicines for Malaria Venture (MMV), to identify the most effective fertilizers across the parasite’s life stages. which usually occurs in the human population.

The Pandemic response box contains 400 different molecules similar to drugs that are active against bacteria, viruses or fungi. It is available free of charge as long as researchers share data derived from research on the molecules in the box with the public within 2 years of its creation.

The fertilizers that showed a positive effect on gametocytes at a late stage (those that circulate in the blood and were transferred to a mosquito when feeding on an infected person) were evaluated for their ability to inhibit cross-linking. sent.

Mosquitoes were given infected blood that was treated either with or without the fertilizer. After eight to 10 days, the intestines swell [stomach] they were removed and the number of parasites (called oocysts) was counted and compared to those mosquitoes that received only untreated infectious blood food.

TAKING A SPARK

Mass drug administration (MDA) is the administration of antimalarial drugs to target the parasite reservoir in humans, without testing whether these individuals carry the malaria-causing parasite.

The World Health Organization (WHO) recommends MDA for the eradication of Plasmodium falciparum malaria discs. However, the effort and expense required to implement MDA on a large scale is prohibitive.

Identifying the potential fertilizers for MDA is among the biggest obstacles to overcome and is therefore an intensive research development line.

Taking advantage of the scarce skills and knowledge available in various research centers such as the WRIM, this study was published in Nature Communication established the first screening of pipes in South Africa.

This opens the door for effective and rapid additional chemical screening to help eradicate malaria.

A ‘TOIRT TARGETS TRANSMISSION ZERO

While there were still 229 million malaria cases in 2019 and 409 000 deaths during this period (compared to some 88 million reported Covid-19 cases), the successes of reducing malaria cases over the past two decades has encouraged many countries to commit to abolishing dispersal altogether.

To date, the WHO has declared 38 countries and regions free of malaria. In southern Africa, eight countries – including South Africa – have eradicated malaria as a policy goal.

However, there are a number of challenges regarding progress towards elimination of transmission and the urgent need for new drugs and insecticides to counteract drug development in the parasite and the vector.

The WRIM and similar studies are innovative approaches. However, it is still a long way between the lab and fieldwork. But the first steps were taken.

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