DENGUE FEVER AND ITS VECTORS IN BRAZIL

History of dengue in Brazil is covered from the first citations in the XIXth century to the great outbreaks for the last ten years. DEN-1 an d DEN-4 viruses have been isolated for the first time in 1982 during a n epidemic in Boa Vista, Roraima State. In 1986-1987, epidemics of den gue type 1 covered an extended area from Rio de Janeiro/Sao Paulo Stat es to the North East States of Brazil. During 1990-1991, dengue type 2 epidemics have been notified in the South East (Rio de Janeiro/Sao Pa ulo) and in some States of the interior of the country (Mato Grosso do Sul, Tocantins). DEN-1 virus was also circulating the same year in Sa o Paulo and Minas Gerais States. Recently (1994), an important outbrea k has been studied in Ceara State, where DEN-2 and DEN-1 virus have be en isolated. In Rio de Janeiro and Ceara (1990 and 1994, respectively) , it is probably the succession of infections by DEN-1 and DEN-2 virus es which has caused many DNF/DSS cases. The urban vector has always be en the mosquito Aedes aegypti, from which 4, 7 and 16 strains of DEN-4 , DEN-1 and DEN-2 have been isolated, respectively. In Brazil, transov arial transovarial transmission of dengue viruses by this species has not yet been shown to occur in nature.