Gene drives are a promising tool for malaria control - how can we tell they actually work?

Transcript

Gene drives are a promising new tool for malaria control. They involve releasing genetically modified mosquitoes into the wild – mosquitoes engineered to halt the parasites from developing inside the insects, or that cause the mosquitoes to die. These GM mosquitoes are then released into new habitats. Over time and across multiple generations, the gene drive spreads, reducing malaria transmission. That’s the theory. But one fundamental question remains: how can we tell they actually work? Experts say there are three distinct measures of gene drive efficacy. First, smaller-scale trials of releases should emphasize genetic efficacy, measuring the spread and frequency of the gene drive across time and space. Then, examine entomological efficacy by measuring the density of mosquitoes or the number of parasites they carry. Finally, consider the epidemiological data, by measuring the number of malaria cases in the areas where the gene drive has been released. This approach aims to ensure that the ‘causal pathway’ of gene drives effectively reduces cases and deaths.

Source

Considerations for first field trials of low-threshold gene drive for malaria vector control

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.

Temperature, rainfall, and humidity determine malaria transmission - but climate change is altering each one of those variables. What might this mean for cases of the disease?

With Alex Eapen, from the ICMR (Indian Council of Medical Research) in Chennai, India.

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 compare the temperature of mosquito breeding spots with a decade early to examine its impact on malaria transmission.

Transcript

The effects of climate change on malaria are becoming clearer. Anopheles stephensi – an urban form of the malaria mosquito – is changing its geography, moving from Southeast Asia to parts of Africa and India. To investigate the link between temperature and malaria, between 2021 and 2022 researchers in Chennai, India placed data loggers that recorded temperature – and the daily range of temperature - in both indoor and outdoor settings. They took those measurements and compared them to ten years earlier, from 2012 to 2013. The daily temperature range of indoor asbestos structures increased from 4.3 to 12.6 degrees Celsius — compared to a marginal increase in other structures. Importantly, an increase in temperature was associated with a decrease in the incubation period – that's the time it takes for the parasite to develop in the mosquito. With invasive mosquito species entering new areas, combined with the shorter time it takes to transmit, it's becoming more clear that rising temperatures will lead to an increase in malaria cases in certain areas – and that preparation will be key.

Source

Impact of climate change on temperature variations and extrinsic incubation period of malaria parasites in Chennai, India: implications for its disease transmission potential

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.

A single protein helps malaria parasites develop in the blood and cause disease symptoms. Could inhibiting this essential protein help curb the spread of disease?

With Abhishek Kanyal and Krishanpal Karmodiya.

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 poorly studied malaria protein could serve as a key drug target to help combat the growing problem of resistance.

Transcript

A poorly studied malaria protein – Plasmodium falciparum histone deacetylase 1 – could serve as a key drug target to help combat the growing problem of resistance. The protein helps regulate the ‘intraerythrocytic’ stage of the parasite: a 48-hour cycle in which the parasite invades, replicates, and bursts free from red blood cells, causing disease symptoms. By making this protein fluorescent, researchers found that it is associated with a range of major biological functions that help the parasite progress through this stage, particularly during the ‘trophozoite’ (or mature) stage. When PfHDAC1 was overexpressed, the number of malaria parasites increased – along with the expression of other genes responsible for parasite development. Dihydroartemisinin—a key antimalarial drug—ordinarily interferes with these biological processes, but overexpression of the protein leads to reduced sensitivity and resistance. This research reveals more about the parasite lifecycle in the human body and suggests a new drug target against it.

Source

PfHDAC1 is an essential regulator of P. falciparum asexual proliferation and host cell invasion genes with a dynamic genomic occupancy responsive to artemisinin stress

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 sickle cell disease can be a blessing and a curse. And why we need equity in genomic research and to diversify the genomes we sequence.

With Ambroise Wonkam (Johns Hopkins University).

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 is one of humanity’s oldest diseases – and one with which we have evolved.

Transcript

Malaria is one of humanity’s oldest diseases – and one with which we have evolved. Over time, it’s put selective pressure on our genome to respond better to its infection. Sickle cell disease is one example. It causes a defect in hemoglobin – transforming red blood cells into a banana or sickle shape – reducing the amount of oxygen transported to the body’s cells. The mutation has been around for more than 20,000 years – and is thought to originate near present-day Cameroon. But in one of the many evolutionary twists, under the right conditions, sickle cell disease can protect humans from malaria, because it makes it harder for malaria parasites to infect red blood cells. Possessing one copy is an asset, providing resistance to severe malaria, but if two copies of the mutation appear, it is a liability, leading to premature death. The evolutionary relationship between malaria endemicity and sickle cell disease is evident geographically. This complex, genetic legacy is the focus of an upcoming talk by Ambroise Wonkam at the Johns Hopkins Malaria Research Institute’s World Malaria Day symposium on April 25th.

Source

Evolutionary history of sickle-cell mutation: implications for global genetic medicine

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.

On the steps of Capitol Hill, we meet the scientists bringing their scientific battle against malaria into the world of political advocacy. They join a 100+ group of advocates lobbying their members of Congress to fund critical interventions against malaria – becoming ‘malaria champions’ as well.

We ask:

• Why have they decided to join the world of political advocacy?

• How are they using their expertise to strengthen the champion’s efforts?

• What scientific message do they have to share?

With David Sullivan (Johns Hopkins University), Tracey Lamb and Jenna Reed (University of Utah) and Louisa Messenger (University of Las Nevas Nevada)

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.