One of the main ways of controlling malaria is to reduce mosquito populations through insecticides. But the mosquitoes are developing resistance, making most insecticides less effective. What if the answer lies beneath our feet?

Transcript

One of the main ways of controlling malaria is to reduce mosquito populations through insecticides. But the mosquitoes are developing resistance, making most insecticides less effective. We need new vector control interventions – what if the answer lies beneath our feet? Researchers from the Dimopoulos Group at the Johns Hopkins Malaria Research Institute have turned to an unexpected source of inspiration—soil. They’ve produced a natural biopesticide, derived from a type of bacteria found in soil called Chromobacterium. When you deliver this biopesticide through a sugar bait – which lures the mosquitoes to feed on it – it kills the mosquitoes, regardless of their resistance to insecticides. Additionally, at non-lethal doses, Chromobacterium can enhance the effectiveness of other insecticides, acting as a synergist, as well as making mosquitoes incapable of finding a human to feed on. These findings were first demonstrated in the lab, but have now been confirmed in enclosed field trials in Burkina Faso. It's hoped that this naturally-occurring insecticide could support vector control efforts to curb disease transmission.

Source

Chromobacterium biopesticide overcomes insecticide resistance in malaria vector mosquitoes (Science)

About The Podcast

The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.

The prevention of malaria depends upon multiple layers of interventions that work together to reduce cases and deaths. But what makes someone decide to sleep under a bed net, or apply an insecticidal cream? What makes one person take up more interventions than another? How influential are government-accredited health experts versus friends and family?

With András Vörös, an Associate Professor in Quantitative Methods at the University of Birmingham and Elisa Bellotti, a Senior Lecturer in Sociology at the University of Manchester.

About The Podcast

The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.

Malaria prevention depends on the adoption of multiple behaviors – like sleeping under a bednet and wearing clothes that cover the skin. Researchers find that conversations with people in one’s own social circle are the strongest factors that influence behavior uptake.

Transcript

Malaria prevention depends on the adoption of multiple behaviors – like sleeping under a bednet and wearing clothes that cover the skin – to reduce exposure to infectious mosquitoes. Theories of ‘social influence’ are often used to explain the uptake of single behaviors, in which an individual's relationship to others explains their adoption of certain behaviors. Yet, to better understand the uptake of different malaria prevention behaviors in a broader context, researchers looked beyond just social ties to consider the influence of behavior carry-over: where an individual who already adopts one prevention behavior is more likely to adopt another. Researchers applied this multi-level social network analysis to structured interviews from 10 villages in Northeast India, all conducted at a single point in time. They found that network exposure – talking to someone in your network who adopts a certain behavior – was the most important and consistent factor in explaining behavior uptake. This was more influential than individual behavior carry-over (which had no effect), existing village behavior patterns, or ties with health workers (which had minimal effect). This reinforces the importance of social discussion as the most significant factor in determining behavior uptake.

Source

A multilevel social network approach to studying multiple disease-prevention behaviors (Nature Scientific Reports)

About The Podcast

The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.

Today, the discovery of antibodies targeting a new region of the malaria parasite that could serve as a promising target for drugs and vaccines.

Scientists discover new antibodies - a promising target for clinical exploration.

Transcript

The currently licenced malaria vaccines and monoclonal antibodies all target a well-known region of the same malaria protein. That protein – the circumsporozoite protein, commonly known as CSP – covers the surface of the parasite as it enters the human skin through a mosquito bite. By targeting CSP, the vaccines aim to stop each malaria parasite in its tracks. But what about other proteins on the sporozoite - the parasite form injected into the blood by the mosquito - or other regions of the CSP protein? In a recent study, scientists screened plasma from malaria-infected individuals for immune responses against sporozoites. Many had developed antibodies against these well-known regions of CSP, but some had developed antibodies targeting a different region of the sporozoite surface. Out of ten new antibodies isolated from these individuals, several were functional – inhibiting the development of later parasite stages that occur in the liver and preventing sporozoite infection in a mouse model of malaria. However, they were targeting a different region of CSP that was only uncovered after processing by the sporozoite. This new region – called pGlu-CSP – is, the authors say, a site of vulnerability and a promising target for future clinical exploration.

Source

Protective antibodies target cryptic epitope unmasked by cleavage of malaria sporozoite protein (Science)

About The Podcast

The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.

We focus on drug resistance and the troubling news that the frontline drug against malaria, artemisinin, is failing due to resistant parasites in severe cases of malaria, and how the collective efforts of drug development – and the data produced – could be used to build an AI chatbot capable of predicting resistance before it strikes.

With Robert Opoka and Elizabeth Winzeler.

About The Podcast

The Johns Hopkins Malaria Minute is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.

Researchers search for ways to predict antimalarial drug resistance and identify more effective drug combinations.

Transcript

The front-line treatment for malaria is typically a combination of drugs called artemisinin-based combination therapy. Resistance to treatment has already been reported in mild cases of malaria, but now, for the first time, it’s also being reported in severe cases of malaria. Severe malaria cases are more likely to end in a fatal outcome, so drug resistance in these scenarios poses a risk to human life. To try and stay one step ahead of resistance, researchers tested compounds and combed through publications to identify 118 compounds active against over 700 parasite clones to see how the parasites evolve under pressure, and to identify mutations in the parasite genome likely to be associated with drug resistance. They confirmed that Plasmodium falciparum – the deadliest and most prevalent species of the malaria parasite – evolves relatively easily, with mutations that affect the drug’s mechanism of action and which move through the population. The hope is that this dataset of drug resistance markers could provide an ‘early warning system’ – to predict drug resistance in the field and to identify a more effective drug combination.

Source

Artemisinin Partial Resistance in Ugandan Children With Complicated Malaria (JAMA)

Systematic in vitro evolution in Plasmodium falciparum reveals key determinants of drug resistance (Science)

About The Podcast

The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.

The World Health Organization has today released its annual World Malaria Report. Here are the takeaways.

Transcript

The World Health Organization has today released its annual World Malaria Report. Here are the takeaways. Since the turn of the century, the global malaria community has averted over 2.2 billion malaria cases and 12.7 million deaths, with over a million deaths prevented in 2023 alone. Yet, despite significant progress, major gaps remain. In 2023, there were 263 million malaria cases globally, up 11 million from the year before, and nearly the same number of deaths. This means we’re off course against key WHO targets, with the case rate amongst at-risk populations three times higher than hoped, and a funding gap of over $4bn. It’s hoped that a ‘Big Push’ of political and capital commitment could accelerate efforts against the disease, help overcome drug and insecticide resistance, and improve access to new bed nets, drugs, and vaccines. But, as ever, this is dependent on funding, political will, and as this year’s report notes, a special focus on equity. There’s a need to disaggregate data to reveal the nuances of malaria transmission and understand how the disease intersects with gender equality, health equity and human rights.

Source

World malaria report 2024

About The Podcast

The Johns Hopkins Malaria Minute podcast is produced by the Johns Hopkins Malaria Research Institute to highlight impactful malaria research and to share it with the global community.