The epidemiology of EEE, WEE, SLE and Turlock viruses, with special reference to birds, in a tropical rain forest near Belém, Brazil (Publicado originalmente em 1966)

Abstract

Two thousand sixty-eight forest and open-field birds captured near Belém, Brazil, in 1963 and 1964 were tested for the presence of arboviruses, and 1,462 of the birds were tested for antibody using 25 viruses. Strains of Western Equine Encephalitis (WEE), St. Louis Encephalitis (SLE) and Turlock viruses were isolated from forest birds in 1964. There were forest birds with hemagglutination-inhibiting and neutralizing substance for Eastern Equine Encephalitis (EEE) virus in 1963 and for EEE, WEE, SLE and Turlock viruses in 1964. Antibody rates were much higher in forest birds than in open-field birds. In 1964 more than half the antibody detected for WEE, SLE and Turlock viruses was found in Coragyps atratus and birds of the family Formicariidae. There was little antibody for EEE, WEE, SLE or Turlock virus in forest rodents or marsupials. EEE virus was isolated from five pools of Culex (Melanoconion) taeniopus in 1963, 1964 and 1965. SLE virus was isolated from ground-foliage Culex (Culex) sp. (probably virgultus) in 1964. Possible cycles of EEE, WEE, SLE and Turlock viruses in the forest of the Instituto de Pesquisas e Experimentação Agropecuarias do Norte are discussed.