Natural vertical transmission of dengue viruses by Aedes aegypti in Bolivia
Autor(es): Le Goff, G.; Revollo, J.; Guerra, M.; Cruz, M.; Barja, S. Z.; Roca, Y.; Vargas, F. J.; Herve, J. P.
Resumo: The natural transmission of dengue virus from an infected female mosquito to its progeny, namely the vertical transmission, was researched in wild caught Aedes aegypti during an important outbreak in the town of Santa Cruz de la Sierra, Bolivia. Mosquitoes were collected at the preimaginal stages (eggs, larvae and pupae) then reared up to adult stage for viral detection using molecular methods. Dengue virus serotypes 1 and 3 were found to be co-circulating with significant higher prevalence in male than in female mosquitoes. Of the 97 pools of Ae. aegypti (n = 635 male and 748 female specimens) screened, 14 pools, collected in February-May in 2007, were found positive for dengue virus infection: five DEN-1 and nine DEN-3. The average true infection rate (TIR) and minimum infection rate (MIR) were respectively 1.08 % and 1.01 %. These observations suggest that vertical transmission of dengue virus may be detected in vectors at the peak of an outbreak as well as several months before an epidemic occurs in human population.Original Abstract: La transmission naturelle du virus de la dengue d'un moustique femelle infecte a sa descendance, a savoir la transmission verticale, a ete recherchee chez des Aedes aegypti sauvages captures lors d'une importante epidemie dans la ville de Santa Cruz de la Sierra (Bolivie). Les moustiques collectes aux stades preimaginaux (oeufs, larves et nymphes) ont ete mis en elevage jusqu'au stade adulte pour la detection de particules virales de la dengue en utilisant une methode de biologie moleculaire. La detection moleculaire a revele la co-circulation de deux serotypes de la dengue, DEN-1 et DEN-3, avec une prevalence significativement plus elevee chez les moustiques males que chez les moustiques femelles. Parmi les 97 pools d'Ae. aegypti testes (n = 635 males et 748 femelles), 14 pools, recoltes entre fevrier et mai 2007, ont ete trouves positifs pour un serotype de la dengue: cinq en DEN-1 et neufen DEN-3. Le taux d'infection moyen (TIR) et le taux minimum d'infection (MIR) etaient respectivement de 1,08 % et 1,01 %. Ces observations suggerent que la transmission verticale des virus de la dengue peut etre detectee chez les vecteurs aussi bien au pic de I'epidemie dans la population humaine que plusieurs mois avant le debut de l'epidemie.
Palavras-Chave: Parasites; Human diseases; Viral diseases; Viruses; Disease detection; Hosts; Disease transmission; Public health; Epidemics; Serotypes; Dengue; Vectors; Progeny; Sex differences; Infection; Dengue virus; Aedes aegypti
Imprenta: Parasite, v. 18, n. 3, p. 277-280, 2011.
Descritores: Aedes aegypti - Viral infections ; Aedes aegypti - Molecular methods ; Aedes aegypti - Virus ; Aedes aegypti - Transmission ; Aedes aegypti - Dengue ; Aedes aegypti - Epidemic ; Aedes aegypti - Public health
Data de publicação: 2011
