In sub-Saharan Africa, mothers often carry their babies on their backs in colorful cotton wraps called lesu. Could treating these wraps with insecticide help prevent malaria? Dr. Ross Boyce discusses a groundbreaking study in Uganda showing that permethrin-treated wraps significantly reduce malaria in infants – and further, what this could mean for protecting the youngest and most vulnerable children from this often fatal disease.

A new study in rural western Uganda finds that treating baby-carrying cloths, or lesu, with an insecticide with modest repellent effect significantly reduces malaria infections in young children.

Transcript

In many parts of sub-Saharan Africa, mothers carry their young children on their backs in colorful cotton wraps called lesu. Could treating these cloths with insecticide reduce malaria transmission?

A study published in the New England Journal of Medicine explored this question in rural western Uganda, where malaria is transmitted year-round. Researchers enrolled 400 mothers with children aged six to 18 months.

Using a blinded randomized placebo-controlled trial design, half received lesu treated with permethrin, a commonly-used insecticide. The other half received untreated cloths. All participants also received insecticide-treated bed nets.

Every two weeks for 24 weeks, the mothers and children visited local health centers to check for fever and undergo malaria testing. The results were striking: children carried in permethrin-treated lesu represented 66% fewer malaria cases – 0.73 cases per 100 people compared with 2.13 in the control group.

The findings suggest that insecticide-treated lesu – much like treated bed nets – could offer an effective new tool particuarly against outdoor biting for a highly vulnerable population - children under 5 years of age - in sub-Saharan Africa.

Source

Permethrin-Treated Baby Wraps for the Prevention of Malaria [NEJM]

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.

Too much can kill the mosquito — too little can also kill it. But the right amount can strengthen the mosquito's defenses and stop malaria transmission. Today, the Goldilocks dose. Emma Camacho shares how a natural compound called L-DOPA strengthens mosquitoes' defenses at just the right concentration, revealing a new way to block malaria transmission.

Feeding mosquitoes L-DOPA can either strengthen their defences against malaria or shorten their lifespan — showing that in vector control, the dose makes the difference

Transcript

As with all medicine, the dose determines whether something helps or harms.

Researchers recently looked at a substance commonly found in mosquito habitats that might form part of their diet. It's called L-3-4-dihydroxyphenylalanine, or L-DOPA. Mosquitoes use it as a source of melanin.

At low doses – up to a concentration of 2% – L-DOPA was toxic to mosquitoes and reduced the number of malaria parasites they carry in a dose-dependent manner. At higher doses, toxicity was stronger and the mosquitoes' rates of survival decreased, demonstrating what's known as a biphasic dose response.

These findings offer two potential strategies for L-DOPA in malaria control. Low doses fed to mosquitoes in water could improve their defences against the parasite, thereby reducing onward transmission to humans. Higher doses could be used to kill mosquitoes or reduce their life span, particularly if used in a sugar bait.

These strategies align with the need for cost-effective, sustainable and eco-friendly vector control methods. For L-DOPA, it all comes down to the dose.

Source

Dietary L-3,4-dihydroxyphenylalanine (L-DOPA) augments cuticular melanization in Anopheles mosquitos reducing their lifespan and malaria burden

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.

How do you turn vast amounts of genetic data into actionable insight – efficiently and accurately? Professor Bryan Greenhouse of UCSF discusses a series of "hackathons" at the Johns Hopkins Malaria Research Institute (JHMRI) that bring together scientists from around the world to tackle one of the biggest challenges in malaria research: analyzing parasite genetics. By developing open-source tools, workflows, and training resources, these collaborations are making cutting-edge analysis more accessible to labs and public health programs everywhere.

In Kwale, Kenya, where bed nets alone can't stop malaria, researchers are testing ivermectin – a drug long used to treat parasitic infections – as a new way to kill mosquitoes. Trials show a 26% drop in malaria cases and added benefits against other mosquito-borne diseases, suggesting ivermectin could be a scalable, community-driven tool in the fight against insecticide resistance.

With Carlos Chaccour (researcher at the Navarra Center for International Development) and Joseph Mwangangi (scientist at KEMRI)

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.

A new study in Kenya shows that mass drug administration of ivermectin safely reduced malaria cases by 26%, offering a promising supplement to insecticide-based prevention.

Transcript

Bed nets and insecticides are commonly used to prevent malaria transmission. But insecticide resistance is making those tools less effective.

There's a growing interest in ivermectin, an antiparasitic drug normally used to treat neglected tropical diseases such as river blindness or scabies, that is also capable of killing the Anopheles mosquitoes that transmit malaria.

In a new study in the New England Journal of Medicine, researchers from ISGlobal, an institute in Barcelona, investigated whether ivermectin given to at-risk populations en masse – in a policy of 'mass drug administration' – might supplement the use of insecticides to reduce malaria transmission.

In Kwale, a coastal county in Kenya where malaria is present year-round, nearly twenty-nine thousand people took part.

Half were given ivermectin at 400μg per kilogram of bodyweight. The other half were given 400mg of albendazole, not an antimalarial drug, but an anti-worming drug comparable to ivermectin.

Each group took the drug once a month for three months. The study looked at both the efficacy and safety of the two interventions.

Both drugs proved safe, but ivermectin had a greater impact, leading to a 26% reduction in malaria cases – higher than the 20% efficacy benchmark set by the World Health Organization.

Source

Source: Ivermectin to Control Malaria — A Cluster-Randomized Trial [NEJM]

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.

Focusing on patients in Mali, researchers examine why some children develop life-threatening complications like cerebral malaria or severe malarial anemia.

With Mark Travassos (University of Maryland School of Medicine), Mahamadou Ali Thera (University of Science Techniques and Technologies of Bamako), and Rafal Sobota (Northwestern University).

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.