Tanzania’s malaria landscape includes newly identified vectors and parasites

Researchers from the Ifakara Health Institute and the Wellcome Sanger Institute investigated malaria-carrying mosquitoes and parasites across 25 districts of Tanzania between 2020 and 2023.

The team collected over 71,000 mosquitoes and used a DNA sequencing technique called ANOSPP to identify species more accurately than traditional methods. They discovered two mosquito species new to Tanzania, Anopheles funestus-like and Anopheles longipalpis Type C, and found that current methods misidentify mosquitoes about 6 percent of the time.

The study also revealed five Plasmodium parasite species, including the expected Plasmodium falciparum and, surprisingly, Plasmodium caprae, which primarily infects goats. This marks the first time P. caprae has been found in Tanzania and in Anopheles arabiensis mosquitoes globally, raising questions about the potential for transmission between animals and humans.

Researchers also found that districts with higher malaria rates tend to have a greater overlap of the three main vector species, Anopheles arabiensis, Anopheles funestus sensu stricto, and Anopheles gambiae sensu stricto. These findings suggest Tanzania’s malaria control strategies may need to consider a wider range of mosquito species than previously thought, as some undetected species may still transmit the disease.

The researchers recommend integrating ANOSPP into routine surveillance to improve accuracy and uncover previously missed parasites, like those that require different treatment than P. falciparum.