BACKGROUND & OBJECTIVE: Dengue viruses are spread and maintained in an Aedes aegypti-human- Ae. aegypti cycle in urban areas of the tropics. Dengue viruses are also maintained in nature by vertical transmission by Ae. aegypti. A study was undertaken in Chennai, a known endemic city in south India, to comprehend the natural vertical transmission dynamics in Ae. aegypti and to assess its epidemiological importance. METHODS: Ae. aegypti males collected in resting and landing collections were tested for dengue virus infection by antigen-capture enzyme-linked immunosorbent assay (ELISA) and further examined by insect bioassay, Toxorhynchites splendens inoculation-indirect immunofluorescence technique (Toxo-IFA) using serotype-specific monoclonal antibodies (Mabs), if found positive by ELISA. RESULTS: Of the 509 pools of Ae. aegypti males (n=5408) screened, 15 pools, collected in April, June- July, November-December in 2003 and March, May in 2004, were found positive for dengue virus infection and the minimum infection rate (MIR) among adult males was high in June 2003 (28.0/ 1000). Three positive pools could be serotyped as dengue-2 (2 pools) and dengue-3 (1 pool). INTERPRETATION & CONCLUSION: Dengue virus isolations from wild caught males of Ae. aegypti indicate the occurrence of transovarial transmission. Vertical transmission was mainly observed in summer months when dengue infections in humans were low suggesting that dengue viruses adopt a novel strategy of surviving adverse climatic conditions.
BACKGROUND & OBJECTIVE:Dengue viruses are spread and maintained in an Aedes aegypti-human- Ae. aegypti cycle in urban areas of the tropics. Dengue viruses are also maintained in nature by vertical transmission by Ae. aegypti. A study was undertaken in Chennai, a known endemic city in south India, to comprehend the natural vertical transmission dynamics in Ae. aegypti and to assess its epidemiological importance. METHODS:Ae. aegypti males collected in resting and landing collections were tested for dengue virus infection by antigen-capture enzyme-linked immunosorbent assay (ELISA) and further examined by insect bioassay, Toxorhynchites splendens inoculation-indirect immunofluorescence technique (Toxo-IFA) using serotype-specific monoclonal antibodies (Mabs), if found positive by ELISA. RESULTS: Of the 509 pools of Ae. aegypti males (n=5408) screened, 15 pools, collected in April, June- July, November-December in 2003 and March, May in 2004, were found positive for dengue virus infection and the minimum infection rate (MIR) among adult males was high in June 2003 (28.0/ 1000). Three positive pools could be serotyped as dengue-2 (2 pools) and dengue-3 (1 pool). INTERPRETATION & CONCLUSION:Dengue virus isolations from wild caught males of Ae. aegypti indicate the occurrence of transovarial transmission. Vertical transmission was mainly observed in summer months when dengue infections in humans were low suggesting that dengue viruses adopt a novel strategy of surviving adverse climatic conditions.
Authors: Luis Augusto Piedra; Liss Claudia Martinez; Armando Ruiz; Juan Ramon Vazquez; Maria Guadalupe Guzman; Jorge Rey; Juan Andres Bisset Journal: Am J Trop Med Hyg Date: 2021-11-08 Impact factor: 2.345
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Authors: G Le Goff; J Revollo; M Guerra; M Cruz; Z Barja Simon; Y Roca; J Vargas Florès; J P Hervé Journal: Parasite Date: 2011-08 Impact factor: 3.000
Authors: Selina Khatun; Apurba Chakraborty; Mahmudur Rahman; Nuzhat Nasreen Banu; Mohammad Mostafizur Rahman; S M Murshid Hasan; Stephen P Luby; Emily S Gurley Journal: PLoS Negl Trop Dis Date: 2015-07-10
Authors: Victor Emanuel Pessoa Martins; Carlos Henrique Alencar; Michel Toth Kamimura; Michel Tott Kamimura; Fernanda Montenegro de Carvalho Araújo; Salvatore Giovanni De Simone; Rosa Fireman Dutra; Maria Izabel Florindo Guedes Journal: PLoS One Date: 2012-07-25 Impact factor: 3.240
Authors: Benjamin M Althouse; Justin Lessler; Amadou A Sall; Mawlouth Diallo; Kathryn A Hanley; Douglas M Watts; Scott C Weaver; Derek A T Cummings Journal: PLoS Negl Trop Dis Date: 2012-11-29