title: Natural transovarial transmission of dengue virus 4 in Aedes aegypti from Cuiabá, State of Mato Grosso, Brazil.
abstract: BACKGROUND
  Dengue is the most prevalent arboviral disease in tropical areas. In Mato Grosso, outbreaks are reported every year, but studies on dengue in this state are scarce.
  
  
  METHODS
  Natural transovarial infection of Aedes aegypti by a flavivirus was investigated in the Jardim Industriário neighborhood of Cuiabá, Mato Grosso. Eggs were collected with ovitraps during the dry, intermediate, and rainy seasons of 2012. After the eggs hatched and the larvae developed to adulthood, mosquitoes (n = 758) were identified and allocated to pools of 1-10 specimens according to the collection location, sex, and climatic period. After RNA extraction, multiplex semi-nested RT-PCR was performed to detect the four dengue virus (DENV) serotypes, yellow fever virus, West Nile virus and Saint Louis encephalitis virus.
  
  
  RESULTS
  DENV-4 was the only flavivirus detected, and it was found in 8/50 pools (16.0%). Three of the positive pools contained females, and five contained males. Their nucleotide sequences presented 96-100% similarity with DENV-4 genotype II strains from Manaus, Amazonas. The minimum infection rate was 10.5 per 1000 specimens, and the maximum likelihood estimator of the infection rate was 11.6 (95% confidence interval: 4.8; 23.3).
  
  
  CONCLUSIONS
  This study provides the first evidence of natural transovarial infection by DENV-4 in Ae. Aegypti in Mato Grosso, suggesting that this type of infection might serve as a mechanism of virus maintenance during interepidemic periods in Cuiabá, a city where dengue epidemics are reported every year. These results emphasize the need for efficient vector population control measures to prevent arbovirus outbreaks in the state.
authors: Instituto de Saúde Coletiva, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors: Lucinéia Claudia de Toni Aquino da
authors: LC
authors: Cruz
authors: Departamento de Ciências Básicas da Saúde, Faculdade de Medicina, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors: Otacília Pereira
authors: OP
authors: Serra
authors: Departamento GPA da Saúde, Centro Universitário de Várzea Grande, Várzea Grande, MT, Brazil.
authors: Fábio Alexandre
authors: FA
authors: Leal-Santos
authors: Departamento de Ciências Básicas da Saúde, Faculdade de Medicina, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors: Ana Lucia Maria
authors: AL
authors: Ribeiro
authors: Departamento de Ciências Básicas da Saúde, Faculdade de Medicina, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors: Renata Dezengrini
authors: RD
authors: Slhessarenko
authors: Instituto de Saúde Coletiva, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
authors: Marina Atanaka dos
authors: MA
authors: Santos
mesh_terms: D000330:Aedes / Q000821:virology*; D000818:Animals; D001938:Brazil; D003716:Dengue Virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D005838:Genotype; D007303:Insect Vectors / Q000821:virology*; D008297:Male; D010063:Ovum / Q000821:virology*; D012621:Seasons