Plasmodium falciparum gametocyte density and infectivity in peripheral blood and skin tissue of naturally infected parasite carriers in Burkina Faso

Creators

Bousema, Teun
Meibalan, Elamaran
Barry, Aissata
Gibbins, Matthew
Awandu, Shehu
Meerstein-Kessel, Lisette
Achar, Fiona
Bopp, Selina
Moxon, Christopher
Diarra, Amidou
Debe, Siaka
Ouedraogo, Nicolas
Barry-Some, Ines
Badoum, Emilie
Fagnima, Traore
Lanke, Kjerstin
Goncalves, Bronner
Bradley, John
Wirth, Dyann
Drakeley, Chris
Guelbeogo, Wamdaogo
Tiono, Alfred
Marti, Matthias
Gibbins, Matthew P
Achcar, Fiona
Ouédraogo, Nicolas
Badoum, Emilie S
Fagnima, Traoré
Gonçalves, Bronner P
Guelbeogo, Wamdaogo Moussa
Tiono, Alfred B

Description

Background

Plasmodium falciparum transmission depends on mature gametocytes that can be ingested by mosquitoes taking a blood meal on human skin. Although gametocyte skin sequestration has long been hypothesized as important contributor to efficient malaria transmission, this has never been formally tested.

Methods

In naturally infected gametocyte carriers from Burkina Faso, we assessed infectivity to mosquitoes by direct skin feeding and membrane feeding. We directly quantified male and female gametocytes and asexual parasites in finger-prick and venous blood samples, skin biopsy samples, and in of mosquitoes that fed on venous blood or directly on skin. Gametocytes were visualized in skin tissue with confocal microscopy.

Results

Although more mosquitoes became infected when feeding directly on skin then when feeding on venous blood (odds ratio, 2.01; 95% confidence interval, 1.21–3.33; P = .007), concentrations of gametocytes were not higher in the subdermal skin vasculature than in other blood compartments; only sparse gametocytes were observed in skin tissue.

Discussion

Our data strongly suggest that there is no significant skin sequestration of P. falciparum gametocytes. Gametocyte densities in peripheral blood are thus informative for predicting onward transmission potential to mosquitoes and can be used to target and monitor malaria elimination initiatives.