Case Report: Successful Sporozoite Challenge Model in Human Volunteers with Plasmodium vivax Strain Derived from Human Donors

• Autor(a) principal: Herrera, Socrates
• Data de Publicação: 2009
• Outros Autores: Fernandez, Olga, Manzano, Maria R., Murrain, Bermans, Vergara, Juana, Blanco, Pedro, Palacios, Ricardo [UNIFESP], Velez, Juan Diego, Epstein, Judith E., Chen-Mok, Mario, Reed, Zarifah Hussain, Arevalo-Herrera, Myriam
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.4269/ajtmh.2009.09-0194; http://repositorio.unifesp.br/handle/11600/31909

Successful establishment of a Plasmodium vivax sporozoite challenge model in humans is described. Eighteen healthy adult, malaria-naive volunteers were randomly allocated to Groups A-C and exposed to 3 +/- 1, 6 +/- 1, and 9 +/- 1 bites of Anopheles albimanus mosquitoes infected with P vivax, respectively. Seventeen volunteers developed signs and symptoms consistent with malaria, and geometric mean prepatent periods of 11.1 days (9.3-11) for Group A; 10.8 days (9.8-11.9) for Group B; and 10.6 days (8.7-12.4) for Group C, with no statistically significant difference among groups (Kruskal-Wallis, P = 0.70). One volunteer exposed to eight mosquito bites did not develop a parasitemia. No differences in parasite density were observed and all individuals successfully recovered after anti-malarial treatment. None of the volunteers developed parasite relapses within an 18-month follow-up. in conclusion, malaria-naive volunteers can be safely and reproducibly infected with bites of 2-10 An. albimanus mosquitoes carrying P vivax. sporozoites. This challenge method is suitable for vaccine and anti-malarial drug testing.