Epidemiological and entomological studies of malaria transmission in Tibati, Adamawa region of Cameroon 6 years following the introduction of long-lasting insecticide nets

Parasites & Vectors

Maurice Marcel Sandeu¹  Jean-Claude Toto²  Parfait Awono-Ambene²  Lawrence Ayong³  Lionel Brice Feufack-Donfack⁴  Sandrine Eveline Nsango⁵  Carole Else Eboumbou Moukoko⁵  Aline Gaelle Bouopda Tuedom⁵  Elangwe Milo Sarah-Matio⁶  Christelle Maffo Ngou⁶  Isabelle Morlais⁶  Luc Marcel Abate⁷  Albert Ngano Bayibéki⁸ 

[1] Department of Medical Entomology, Centre for Research in Infectious Diseases, 13591, Yaounde, Cameroon;Department of Microbiology and Infectious Diseases, School of Veterinary Medicine and Sciences, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon;Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaounde, Cameroon;Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon;Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon;CNRS UPR 9022, Inserm U 963, Université de Strasbourg, 2, allée Konrad Roentgen, 67084, Strasbourg Cedex, France;Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon;Faculté de Médecine et des Sciences Pharmaceutiques de l’Université de Douala (FMSP–UD), BP 2701, Douala, Cameroon;Service de Paludisme du Centre Pasteur Cameroun, BP 1274, Yaounde, Cameroon;UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394, Montpellier, France;UMR MIVEGEC, IRD, CNRS, Université de Montpellier, Institut de Recherche pour le Développement, 911 avenue Agropolis, 34394, Montpellier, France;Université Catholique d’Afrique Centrale, BP 1110, Yaoundé-Campus Messa, Yaounde, Cameroon;

关键词: Malaria;    Plasmodium vivax;    Anopheles coluzzii;    Epidemiology;    Entomology;    Cameroon;   

DOI  :  10.1186/s13071-021-04745-y

来源: Springer

【 摘 要 】

BackgroundMalaria remains a serious public health problem in Cameroon. Implementation of control interventions requires prior knowledge of the local epidemiological situation. Here we report the results of epidemiological and entomological surveys carried out in Tibati, Adamawa Region, Cameroon, an area where malaria transmission is seasonal, 6 years after the introduction of long-lasting insecticidal bed nets.MethodsCross-sectional studies were carried out in July 2015 and 2017 in Tibati. Thick blood smears and dried blood spots were collected from asymptomatic and symptomatic individuals in the community and at health centers, respectively, and used for the molecular diagnosis of Plasmodium species. Adult mosquitoes were collected by indoor residual spraying and identified morphologically and molecularly. The infection status of Plasmodium spp. was determined by quantitative PCR, and positivity of PCR-positive samples was confirmed by Sanger sequencing.ResultsOverall malaria prevalence in our study population was 55.0% (752/1367) and Plasmodium falciparum was the most prevalent parasite species (94.3%), followed by P. malariae (17.7%) and P. ovale (0.8%); 92 (12.7%) infections were mixed infections. Infection parameters varied according to clinical status (symptomatic/asymptomatic) and age of the sampled population and the collection sites. Infection prevalence was higher in asymptomatic carriers (60.8%), but asexual and sexual parasite densities were lower. Prevalence and intensity of infection decreased with age in both the symptomatic and asymptomatic groups. Heterogeneity in infections was observed at the neighborhood level, revealing hotspots of transmission. Among the 592 Anopheles mosquitoes collected, 212 (35.8%) were An. gambiae, 172 (29.1%) were An. coluzzii and 208 (35.1%) were An. funestus (s.s.). A total of 26 (4.39%) mosquito specimens were infected by Plasmodium sp. and the three Anopheles mosquitoes transmitted Plasmodium at equal efficiency. Surprisingly, we found an An. coluzzii specimen infected by Plasmodium vivax, which confirms circulation of this species in Cameroon. The positivity of all 26 PCR-positive Plasmodium-infected mosquitoes was successively confirmed by sequencing analysis.ConclusionOur study presents the baseline malaria parasite burden in Tibati, Adamawa Region, Cameroon. Our results highlight the high malaria endemicity in the area, and hotspots of disease transmission are identified. Parasitological indices suggest low bednet usage and that implementation of control interventions in the area is needed to reduce malaria burden. We also report for the first time a mosquito vector with naturally acquired P. vivax infection in Cameroon.Graphical Abstract

【 授权许可】

CC BY