title: Infectivity of symptomatic and asymptomatic Plasmodium vivax infections to a Southeast Asian vector, Anopheles dirus.
abstract: Plasmodium vivax is now the predominant species causing malarial infection and disease in most non-African areas, but little is known about its transmission efficiency from human to mosquitoes. Because the majority of Plasmodium infections in endemic areas are low density and asymptomatic, it is important to evaluate how well these infections transmit. Using membrane feeding apparatus, Anopheles dirus were fed with blood samples from 94 individuals who had natural P. vivax infections with parasitemias spanning four orders of magnitude. We found that the mosquito infection rate was positively correlated with blood parasitemia and that infection began to rise when parasitemia was >10parasites/μl. Below this threshold, mosquito infection is rare and associated with very few oocysts. These findings provide useful information for assessing the human reservoir of transmission and for establishing diagnostic sensitivity required to identify individuals who are most infective to mosquitoes.
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Kirakorn
authors.initials: K
authors.lastname: Kiattibutr
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Wanlapa
authors.initials: W
authors.lastname: Roobsoong
authors.affiliation: Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Patchara
authors.initials: P
authors.lastname: Sriwichai
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Teerawat
authors.initials: T
authors.lastname: Saeseu
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
authors.forename: Nattawan
authors.initials: N
authors.lastname: Rachaphaew
authors.affiliation: Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Chayanut
authors.initials: C
authors.lastname: Suansomjit
authors.affiliation: Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, Thailand.
authors.forename: Sureemas
authors.initials: S
authors.lastname: Buates
authors.affiliation: Malaria: Parasites & Hosts Unit, Department of Parasites & Insect Vectors, Institut Pasteur, Paris, France; Bioinformatics and Biostatistics Hub, Institut Pasteur, Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Obadia
authors.affiliation: Malaria: Parasites & Hosts Unit, Department of Parasites & Insect Vectors, Institut Pasteur, Paris, France; Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia.
authors.forename: Ivo
authors.initials: I
authors.lastname: Mueller
authors.affiliation: Department of Entomology, Pennsylvania State University, University Park, PA, USA.
authors.forename: Liwang
authors.initials: L
authors.lastname: Cui
authors.affiliation: Department of Molecular Tropical Medicine & Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Electronic address: wang.ngu@mahidol.edu.
authors.forename: Wang
authors.initials: W
authors.lastname: Nguitragool
authors.affiliation: Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. Electronic address: jetsumon.pra@mahidol.ac.th.
authors.forename: Jetsumon
authors.initials: J
authors.lastname: Sattabongkot
mesh_terms: D000293:Adolescent; D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D001210:Asia, Southeastern; D004197:Disease Reservoirs; D005260:Female; D006801:Humans; D016778:Malaria, Falciparum / Q000469:parasitology / Q000635:transmission; D016780:Malaria, Vivax / Q000469:parasitology / Q000635:transmission*; D000072138:Mosquito Vectors / Q000469:parasitology*; D010966:Plasmodium vivax / Q000502:physiology*
keywords: Anopheles dirus; Infectivity; Malaria; Membrane feeding assay; Plasmodium vivax; Transmission