A Case of Yellow Fever in a Brown Howler (Alouatta Fusca) in Southern Brazil

Abstract

Abstract. Many brown howlers (Alouatta fusca) have died in a 3-month period in a subtropical forest in Southern Brazil. One was examined after a systemic illness. According to clinical signs, and necropsy and histopathology findings, yellow fever virus (YFV) infection was suspected. Tissue sections from liver, kidney, and lymphoid organs were screened by immunohistochemistry for YFV antigens. Cells within those tissues stained positively with a polyclonal antibody against YFV antigens (1:1,600 dilution), and yellow fever was diagnosed for the first time in the brown howler in the area.Yellow fever virus (YFV) infection is an acute arthropod-borne Flavivirus (family Togaviridae) infection that causes fever, jaundice, albuminuria, and hemorrhage. It occurs in 2 forms: urban and sylvan. There are 2 types of endemic areas: humid forests and emerging zones where urban and sylvan forms intermingle. 3 The vectors are Aedes aegypti in urban areas, 9 A. albopictus in suburban areas, 10 and tree-hole-breeding mosquitoes (Haemagogus spp.) in the forests. 9 The virus circulates in the forests in mosquito vectors causing scattered epizootics in nonimmune monkeys. Alternatively, transmission may be vertical from the female mosquito to her offspring, allowing virus survival from one rainy season to the next in A. aegypti eggs. 3 Yellow fever remains endemic in many regions of Africa and South America, despite the existence of an effective vaccine. 2,9 Currently, YFV infection may be confused with other similar hemorrhagic conditions. 2,4,9 In humans, severe necrotic lesions are seen at autopsy 2 in many organs, particularly the liver. Microscopically, YFV infection is characterized by midzonal necrosis of the liver with microvesicular fatty change

Frequency of histopathological changes in Howler monkeys ( Alouatta sp.) naturally infected with yellow fever virus in Brazil

“…These changes have previously been described in natural or experimental YF primate infection (2) (9) . In the fi nal stages of YFV infection, hypotension is considered responsible for oliguria and acute tubular necrosis development (1) .…”

“…These changes may refl ect the splenic response to viral infection, however necrosis of the lymphoid follicles that usually occurs in YF was not observed (1) (2) . Spleen, heart, and lung changes had a lower frequency than those registered in the liver and kidneys, and did not allow determination of the real importance of these organs in the diagnosis of YF in Brazilian Howler monkeys.…”

Biotin-avidin sandwich elisa with specific human isotypes IgG1 and IgG4 for Culicidae mosquito blood meal identification from an epizootic yellow fever area in Brazil

“…Haemagogus leucocelaenus emphasize the risk of yellow fever transmission and highlight the need for careful monitoring in the area (1,22).…”

Avaliação do impacto da epizootia de Febre Amarela sobre as populações de primatas não humanos nas unidades de conservação do Rio Grande do Sul, Brasil

“…Há relatos de mortalidades em primatas devido à febre amarela, incluindo aquelas que afetaram bugios, mas muitas vezes o número de animais afetados é incerto (COLLIAS; SOUTHWICK, 1952;ELTON, 1952;VARGAS-MENDEZ;ELTON, 1953;ANDERSON;DOWNS, 1965;BEJARANO, 1979;SOPER, 1979;MENDES, 1989;DÉGALLIER et al, 1992a;1992b;VASCONCELOS et al, 2001;COLOMBIA, 2002;BRYANT et al, 2003;SALLIS et al, 2003a;RIFAKIS et al, 2006;AGOSTINI et al, 2008;HOLZMANN et al, 2010). No mais recente surto, a partir dos primeiros registros em Misiones, Argentina (HOLZMANN et al, 2010) a propagação do VFA no Rio Grande do Sul tomou sentido oeste-leste, com a detecção de FA em primatas avançando pelo Estado ao ritmo de 100km/ mês (ALMEIDA et al, 2012).…”