Transmission-blocking Immunity in Malaria
Plasmodium Gametocytes and Infectivity
Plasmodium gametocytes develop from asexual parasites and are the only parasite life-stage infective to mosquitoes. The likelihood of onward transmission to mosquitoes and the proportion of mosquitoes that are infected by a gametocyte carrier is positively associated with gametocyte density (Churcher et al. 2013; Da et al. 2015; Kiattibutr et al. 2017). In P. vivax, gametocyte generation begins early during infection with gametocytes appearing in the bloodstream 2–3 days after the first asexual parasites and typically disappearing within 3 days after asexual infections are cleared (Bousema and Drakeley 2011). As a consequence, P. vivax gametocyte density is strongly associated with total parasite density (Koepfli et al. 2015; McCarthy et al. 2013; Tadesse et al. 2018), and there is a strong positive association between total parasite density and the likelihood that mosquitoes become infected when feeding on an infected individual (Kiattibutr et...
- Beshir KB, et al. Residual Plasmodium falciparum parasitemia in Kenyan children after artemisinin-combination therapy is associated with increased transmission to mosquitoes and parasite recurrence. J Infect Dis. 2013;208:2017–24. https://doi.org/10.1093/infdis/jit431.CrossRefPubMedCentralPubMedGoogle Scholar
- Da DF, et al. Experimental study of the relationship between Plasmodium gametocyte density and infection success in mosquitoes; implications for the evaluation of malaria transmission-reducing interventions. Exp Parasitol. 2015;149:74–83. https://doi.org/10.1016/j.exppara.2014.12.010.CrossRefPubMedGoogle Scholar
- Ouedraogo, AL, et al. Modeling the impact of Plasmodium falciparum sexual stage immunity on the composition and dynamics of the human infectious reservoir for malaria in natural settings. Under Rev. (In preparation)Google Scholar
- Reuling IJ, et al. A randomized feasibility trial comparing four antimalarial drug regimens to induce Plasmodium falciparum gametocytemia in the controlled human malaria infection model. Elife. 2018;7: e31549. https//doi.org/10.7554/eLife.31549.
- Stone, WJ, et al. Unravelling the immune signature of Plasmodium falciparum transmission reducing immunity. Nat Commun. 2018;9:558. https://doi.org/10.1038/s41467-017-02646-2.
- Tadesse FG, et al. The relative contribution of symptomatic and asymptomatic Plasmodium vivax and Plasmodium falciparum infections to the infectious reservoir in a low-endemic setting in Ethiopia. Clin Infect Dis. 2018. https://doi.org/10.1093/cid/cix1123.