Plasmodium vivax and Plasmodium falciparum mixed infections in human and mosquito hosts: The impact of multi-species infection on parasite densities and transmission to mosquitoes

What the report says

PLOS Neglected Tropical Diseases published an uncorrected proof on July 24, 2026, examining how mixed malaria infections involving Plasmodium vivax and Plasmodium falciparum behave in people and in mosquitoes in Ethiopia. The study, led by W. Chali and colleagues, focused on patients recruited at four Ethiopian health facilities, comparing 284 P. vivax-only infections, 150 P. falciparum-only infections and 77 mixed infections.

According to the article, researchers used qPCR testing to measure parasite levels and gametocytes — the parasite stage that infects mosquitoes — in blood samples. They also used direct membrane feeding assays to test whether mosquitoes became infected after feeding, with species confirmed by quantitative PCR. The study found that P. falciparum gametocyte carriage was lower in mixed infections than in single-species P. falciparum infections, and densities among carriers were also reduced. For P. vivax, gametocyte prevalence was similar in mixed and single-species cases, even though asexual parasite density was lower in mixed infections.

The authors reported that mixed infections still transmitted efficiently to mosquitoes. Among mixed-infection carriers tested in feeding experiments, 56.3% transmitted both parasite species, and in some cases both species were found in individual mosquitoes. The study also found that species-specific gametocyte density remained linked to mosquito infection rates, without evidence that the other parasite species changed that relationship.

The findings matter because mixed P. vivax–P. falciparum infections can be missed by routine diagnosis, the authors noted, while still helping sustain malaria transmission. The paper says all data and code are available on GitHub, and the authors declared no competing interests.