title: Patterns in age-seroprevalence consistent with acquired immunity against Trypanosoma brucei in Serengeti lions.
abstract: Trypanosomes cause disease in humans and livestock throughout sub-Saharan Africa. Although various species show evidence of clinical tolerance to trypanosomes, until now there has been no evidence of acquired immunity to natural infections. We discovered a distinct peak and decrease in age prevalence of T. brucei s.l. infection in wild African lions that is consistent with being driven by an exposure-dependent increase in cross-immunity following infections with the more genetically diverse species, T. congolense sensu latu. The causative agent of human sleeping sickness, T. brucei rhodesiense, disappears by 6 years of age apparently in response to cross-immunity from other trypanosomes, including the non-pathogenic subspecies, T. brucei brucei. These findings may suggest novel pathways for vaccinations against trypanosomiasis despite the notoriously complex antigenic surface proteins in these parasites.
authors.affiliation: Centre for Infectious Disease, College of Medicine and Veterinary Medicine, The University of Edinburgh, Edinburgh, United Kingdom. sue.welburn@ed.ac.uk
authors.forename: Sue
authors.initials: S
authors.lastname: Welburn
authors.forename: Kim
authors.initials: K
authors.lastname: Picozzi
authors.forename: Paul G
authors.initials: PG
authors.lastname: Coleman
authors.forename: Craig
authors.initials: C
authors.lastname: Packer
mesh_terms: D056704:Adaptive Immunity; D017954:Africa South of the Sahara; D000375:Aging; D000818:Animals; D000835:Animals, Wild / Q000276:immunology; D004198:Disease Susceptibility / Q000276:immunology; D017753:Ecosystem; D006801:Humans; D008045:Lions / Q000097:blood / Q000276:immunology*; D008962:Models, Theoretical; D016016:Proportional Hazards Models; D016036:Seroepidemiologic Studies; D015996:Survival Rate; D017741:Survivors; D014197:Trees / Q000469:parasitology; D014346:Trypanosoma brucei brucei / Q000276:immunology*; D014353:Trypanosomiasis, African / Q000453:epidemiology / Q000276:immunology* / Q000401:mortality / Q000662:veterinary; D014370:Tsetse Flies / Q000469:parasitology