A team of international researchers from the London School of Hygiene & Tropical Medicine (LSHTM), Australia, Eritrea and WHO has uncovered new evidence that malaria parasites in Eritrea are developing resistance to common treatments and becoming harder to detect with widely used diagnostic tests. 

The study, published in The Lancet Regional Health, highlights a concerning trend that could impact malaria control efforts in the region.

By analysing malaria samples from patients across Eritrea, the researchers identified genetic mutations that allow certain malaria strains to evade rapid diagnostic tests (RDTs) and resist treatment with artesunate-amodiaquine, a frontline antimalarial drug. 

Notably, the study found that 11.9% of samples contained the pfk13 Arg622Ile mutation, which has been linked to partial resistance to artemisinin-based therapies. This mutation was more prevalent in parasites that also had deletions in the pfhrp2 and pfhrp3 genes—key markers that rapid tests rely on to detect malaria. These findings suggest that drug resistance and diagnostic escape may be working together to drive the spread of these difficult-to-treat malaria strains.

Eritrea was the first African country to stop using HRP2-based RDTs after discovering that genetic changes in malaria parasites were causing false-negative test results. It was also the first country in Africa to report the pfk13 Arg622Ile mutation, marking a significant milestone in the fight against drug-resistant malaria.

Associate Professor Dr Khalid Bashir said: “This study highlights a concerning combination of drug resistance and diagnostic escape in malaria parasites in Eritrea, emphasising the urgent need for enhanced surveillance and alternative diagnostic and treatment tools in Africa. As resistance to both detection and treatment spreads, timely data and adaptive strategies will be crucial to safeguard progress in malaria control. Strengthening regional collaborations, such as WHO HANMAT network, increasing investment in the surveillance of biological threats and integrating genomic monitoring can help detect emerging threats early and guide policy decisions.”

The researchers noted limitations of the study including the fact it relied on previously collected samples and may not fully reflect Eritrea’s current malaria landscape. They emphasise the need for ongoing surveillance to track the spread of resistant malaria strains and adapt control strategies accordingly.

The research was funded by the Wellcome Trust ISSF and the US Department of Defence Armed Forces Health Surveillance Division.