1. Estimation of malaria transmission from humans to mosquitoes in two neighbouring villages in south Cameroon: evaluation and comparison of several indices
- Author
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L.C. Gouagna, Christian Boudin, Innocent Safeukui, Sarah Bonnet, Richard Paul, Jean-Yves Meunier, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), Institut de Recherche pour le Développement (IRD), Ecologie des Systèmes Vectoriels, Institut Pasteur [Paris] (IP), Université de Yaoundé I, Biochimie et Biologie Moléculaire des Insectes, and This project was supported by research funds from IRD (ex-ORSTOM), WHO (ID No. 970781), OCEAC, and fellowships to S. Bonnet (MRT, IRD, CANAM and Pasteur-Weizmann Foundation).
- Subjects
Male ,Veterinary medicine ,Rural Health ,Disease Vectors ,law.invention ,law ,MESH: Child ,Epidemiology ,Prevalence ,MESH: Animals ,Cameroon ,Malaria, Falciparum ,Child ,TRANSMISSION HOMME VECTEUR ,MESH: Immunity ,MESH: Plasmodium falciparum ,MESH: Aged ,Plasmodium falciparum gametocyte ,[SDV.MHEP.ME]Life Sciences [q-bio]/Human health and pathology/Emerging diseases ,MESH: Middle Aged ,biology ,MESH: Malaria, Falciparum ,MESH: Infant, Newborn ,transmission ,General Medicine ,Middle Aged ,MESH: Infant ,PREVALENCE ,Infectious Diseases ,Transmission (mechanics) ,Child, Preschool ,MOUSTIQUE ,epidemiology ,Female ,MILIEU RURAL ,Adult ,EPIDEMIOLOGIE ,medicine.medical_specialty ,Adolescent ,TRANSMISSION ,Plasmodium falciparum ,INDICE DE TRANSMISSION ,malaria ,MESH: Insect Vectors ,MESH: Disease Vectors ,Malaria transmission ,parasitic diseases ,ETUDE COMPARATIVE ,medicine ,Animals ,Humans ,PARASITE ,MESH: Prevalence ,IMMUNITE ,Aged ,Estimation ,MESH: Adolescent ,MESH: Humans ,MESH: Child, Preschool ,Public Health, Environmental and Occupational Health ,Immunity ,Infant, Newborn ,Infant ,MESH: Adult ,PALUDISME ,MESH: Rural Health ,MESH: Cameroon ,medicine.disease ,biology.organism_classification ,Virology ,MESH: Male ,Insect Vectors ,Culicidae ,Parasitology ,Rural area ,MESH: Culicidae ,MESH: Female ,Malaria - Abstract
International audience; Malaria transmission from humans to mosquitoes was assessed in two neighbouring villages in a rural area near Yaoundé, Cameroon during high and low transmission seasons during 1998-2000, using several indices previously evaluated in different areas endemic for malaria but never directly compared. These indices were estimated from human parasitological data and mosquito infection rates and, for each individual, thick blood films were prepared at the same time as experimental infection of laboratory-bred mosquitoes. Among the 685 volunteers examined, the prevalence of Plasmodium falciparum gametocyte carriers was 16%, and 8% of individuals were able to infect mosquitoes. The percentage of mosquitoes that became infected by feeding on the infectious individuals was 21%. Children aged < 10 years contributed to about 75% of the infectious reservoir, although they constituted only 35% of the total population. Differences were found between the transmission seasons and the villages, and varied according to the index examined. Although there were more infectious individuals in one of the two villages, they were less infectious than those in the other village during the high transmission season. Comparative analysis of the transmission indices suggests the existence of functioning transmission-blocking immunity in one of the villages, which until now has been only hypothetically considered to play a role in malaria transmission in a natural setting. The epidemiological value of all the indices used and their accuracy in estimating the human infectious reservoir and its natural or induced variations are discussed.
- Published
- 2003