Malaria species positivity rates among symptomatic individuals across regions of differing transmission intensities in Mainland Tanzania.

BACKGROUND

Recent data indicate that non-Plasmodium falciparum species may be more prevalent than thought in sub-Saharan Africa. Although Plasmodium malariae, Plasmodium ovale spp., and Plasmodium vivax are less severe than P. falciparum, treatment and control are more challenging, and their geographic distributions are not well characterized.

METHODS

We randomly selected 3,284 of 12,845 samples collected from cross-sectional surveys in 100 health facilities across ten regions of Mainland Tanzania and performed quantitative real-time PCR to determine presence and parasitemia of each malaria species.

RESULTS

P. falciparum was most prevalent, but P. malariae and P. ovale were found in all but one region, with high levels (>5%) of P. ovale in seven regions. The highest P. malariae positivity rate was 4.5% in Mara and eight regions had positivity rates ≥1%. We only detected three P. vivax infections, all in Kilimanjaro. While most non-falciparum malaria-positive samples were co-infected with P. falciparum, 23.6% (n = 13/55) of P. malariae and 14.7% (n = 24/163) of P. ovale spp. were mono-infections.

CONCLUSIONS

P. falciparum remains by far the largest threat, but our data indicate that malaria elimination efforts in Tanzania will require increased surveillance and improved understanding of the biology of non-falciparum species.

Informations de copyright

© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.