High Prevalence of Polyclonal Plasmodium falciparum Infections and Association with Poor IgG Antibody Responses in a Hyper-Endemic Area in Cameroon.

Autor:	Biabi MFAB; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biochemistry, Faculty of Science, University of Douala, Douala BP 2701, Cameroon., Fogang B; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon., Essangui E; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon., Maloba F; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon., Donkeu C; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon., Keumoe R; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon., Cheteug G; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Medical Laboratory Sciences, Faculty of Science, University of Buea, Buea BP 63, Cameroon., Magoudjou N; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biochemistry, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon., Slam C; Department of Pathology, School of Medicine, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA., Kemleu S; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon., Efange N; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biochemistry, Faculty of Science, University of Buea, Buea BP 63, Cameroon., Perraut R; Centre Pasteur du Cameroun Annex, Garoua BP 921, Cameroon., Nsango SE; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon., Eboumbou Moukoko CE; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.; Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala BP 2701, Cameroon., Assam JPA; Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon., Etoa FX; Department of Microbiology, Faculty of Science, University of Yaounde I, Yaounde BP 812, Cameroon., Lamb T; Department of Pathology, School of Medicine, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA., Ayong L; Malaria Research Unit, Centre Pasteur du Cameroun, Yaounde BP 1274, Cameroon.
Jazyk:	angličtina
Zdroj:	Tropical medicine and infectious disease [Trop Med Infect Dis] 2023 Jul 29; Vol. 8 (8). Date of Electronic Publication: 2023 Jul 29.
DOI:	10.3390/tropicalmed8080390
Abstrakt:	Malaria remains a major public health problem worldwide, with eradication efforts thwarted by drug and insecticide resistance and the lack of a broadly effective malaria vaccine. In continuously exposed communities, polyclonal infections are thought to reduce the risk of severe disease and promote the establishment of asymptomatic infections. We sought to investigate the relationship between the complexity of P. falciparum infection and underlying host adaptive immune responses in an area with a high prevalence of asymptomatic parasitaemia in Cameroon. A cross-sectional study of 353 individuals aged 2 to 86 years (median age = 16 years) was conducted in five villages in the Centre Region of Cameroon. Plasmodium falciparum infection was detected by multiplex nested PCR in 316 samples, of which 278 were successfully genotyped. Of these, 60.1% (167/278) were polyclonal infections, the majority (80.2%) of which were from asymptomatic carriers. Host-parasite factors associated with polyclonal infection in the study population included peripheral blood parasite density, participant age and village of residence. The number of parasite clones per infected sample increased significantly with parasite density (r = 0.3912, p < 0.0001) but decreased with participant age (r = -0.4860, p < 0.0001). Parasitaemia and the number of clones per sample correlated negatively with total plasma levels of IgG antibodies to three highly reactive P. falciparum antigens (MSP-1p19, MSP-3 and EBA175) and two soluble antigen extracts (merozoite and mixed stage antigens). Surprisingly, we observed no association between the frequency of polyclonal infection and susceptibility to clinical disease as assessed by the recent occurrence of malarial symptoms or duration since the previous fever episode. Overall, the data indicate that in areas with the high perennial transmission of P. falciparum , parasite polyclonality is dependent on underlying host antibody responses, with the majority of polyclonal infections occurring in persons with low levels of protective anti-plasmodial antibodies.
Databáze:	MEDLINE
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