Circulation of antibodies against yellow fever virus in a simian population in the area of Porto Primavera Hydroelectric Plant, São Paulo, Brazil

Abstract

SUMMARYYellow fever (YF) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. In the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. Surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. An ELISA (enzyme-linked immunosorbent assay) was standardized for estimation of the prevalence of IgG antibodies against yellow fever virus in monkey sera (Alouatta caraya) from the reservoir area of Porto Primavera Hydroelectric Plant, in the state of São Paulo, Brazil. A total of 570 monkey sera samples were tested and none was reactive to antibodies against yellow fever virus. The results corroborate the epidemiology of yellow fever in the area. Even though it is considered a transition area, there were no reports to date of epizootics or yellow fever outbreaks in humans. Also, entomological investigations did not detect the presence of vectors of this arbovirus infection. ELISA proved to be fast, sensitive, an adequate assay, and an instrument for active search in the epidemiological surveillance of yellow fever allowing the implementation of prevention actions, even before the occurrence of epizootics.

First report of yellow fever virus in non-human primates in the State of Parana, Brazil

“…These animals can be infected by small doses of YFV, whereas animals in the genus Cebus are highly resistant to YFV. In contrast, Old World primates are highly resistant to YFV and rarely demonstrate yellow fever 3,4 . The susceptibility of non-human primates and the identifi cation of cases in these animals is the main indicator of the circulation of YFV in forest areas in the Americas 3,4 .…”

“…In contrast, Old World primates are highly resistant to YFV and rarely demonstrate yellow fever 3,4 . The susceptibility of non-human primates and the identifi cation of cases in these animals is the main indicator of the circulation of YFV in forest areas in the Americas 3,4 . Recently, human cases of sylvatic yellow fever in Brazil have been preceded by reports of the disease in animals 5 .…”

Distribución geográfica del mono aullador rojo (Alouatta seniculus) y la fiebre amarilla en Colombia

“…Entre tales especies se destacan las del género Alouatta spp., que resulta involucrado en la mayoría de los casos de muerte reportados en primates no humanos en zonas con circulación comprobada del virus de la fiebre amarilla. Los dos aspectos clave para resaltar en este género son su amplia distribución (3,4,13,14).…”

“…La fiebre amarilla es una enfermedad viral aguda, producida por un arbovirus del género Flavivirus, familia Flaviviridae, que además es zoonótica, endémica y con el riesgo de reemerger en seres humanos, pese a que existe vacuna, por lo cual se la considera de interés en salud pública (2,4,5).…”

“…), la deforestación, el crecimiento demográfico, la cobertura de la vacunación, los perfiles ocupacionales y la variabilidad climática, los cuales afectan la distribución del agente, del huésped y del vector (figura 2). A estos factores se suman, en Colombia, el desplazamiento forzado, la explotación de zonas selváticas vírgenes, la violencia y el narcotráfico, factores que complican la situación (4,6,7). La fiebre amarilla se combate con la vacunación y con adecuadas medidas de vigilancia (8).…”