title: Enhanced malaria parasite transmission from helminth co-infected mice.
abstract: Helminth infections are prevalent in malaria-endemic areas, yet the potential for helminths to alter malaria transmission has not been closely examined. We used the Echinostoma caproni-Plasmodium yoelii murine model of co-infection to assess the impact of helminth co-infection on malaria transmission. In four replicate experiments, Anopheles stephensi mosquitoes exposed to co-infected mice five days post-malaria infection had a higher rate of infectivity (80.1%, n = 241) than those exposed to malaria only-infected mice (72.0%, n = 232, P = 0.039). Intensity of malaria parasite transmission was also greater, with approximately two-fold more oocysts (geometric mean = 19.2 versus 10.5, P = 0.004) and an increase in sporozoite burden observed in mosquitoes exposed to co-infected mice. Malaria parasite prevalence and anemia were similar between co-infected and malaria only-infected mice, which suggested that enhanced malaria parasite transmission was due to helminth-induced modulation of host responses.
authors.affiliation: Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA. nkumar@jhsph.edu
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Noland
authors.forename: Thaddeus K
authors.initials: TK
authors.lastname: Graczyk
authors.forename: Bernard
authors.initials: B
authors.lastname: Fried
authors.forename: Nirbhay
authors.initials: N
authors.lastname: Kumar
mesh_terms: D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D004449:Echinostoma / Q000254:growth & development*; D004451:Echinostomiasis / Q000469:parasitology*; D005260:Female; D007303:Insect Vectors / Q000469:parasitology*; D008288:Malaria / Q000150:complications / Q000469:parasitology* / Q000635:transmission*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D033661:Oocysts / Q000469:parasitology; D010967:Plasmodium yoelii / Q000254:growth & development*; D013997:Time Factors