Absence of yellow fever virus circulation in wildlife rodents from Brazil

Abstract

Yellow fever (YF), caused by the yellow fever virus (YFV), is an emerging viral zoonosis that affects humans and non-human primates (NHP). In South America, YF is naturally maintained through enzootic/sylvatic cycles involving NHPs and mosquitoes (Haemagogus and Sabethes). In this study, we retrospectively analyzed wildlife rodents to better understand their role in a potential alternative YF sylvatic cycle. The plaque reduction neutralization test was performed to detect anti-YFV antibodies, while qPCR targeting the NS5 region of flaviviruses and standard PCR targeting the CprM region were applied to detect YFV RNA in tissue and blood samples. YFV was not evidenced in any of the tested samples. These findings provide additional information regarding sylvatic YFV and emphasize the importance of YFV surveillance in wild animals as potential reservoirs/hosts given the well-established enzootic cycle in the studied areas, mainly in the Atlantic Forest.

Keywords: Capybaras; Ecology; Flavivirus; Rodents; Small mammals; Yellow fever.

Fig. 1

Spatial distribution of the studied wildlife mammals. The map of Brazil shows each location where wildlife mammals where captured, including Serro, Sabará, Ouro Preto, Serra do Caraça, and Contagem in the Metropolitan Region of Belo Horizonte (State of Minas Gerais, Southeastern region) and Caldas Novas city (State of Goiás, Central-Western region)

Fig. 2

Landscape overview of the studied areas. 1 Sabará, located in the Metropolitan Region of Belo Horizonte (Capital of Minas Gerais State), represents a transition environment between the Atlantic Forest and the Savannah biomes, having also great anthropogenic influence; 2 Caldas Novas (Goiás State) has a predominant Savannah biome. The sampling site is located in an urban area, surrounded by fragments of forest; 3 Serro, located in the Jequitinhonha Valley, central region of Minas Gerais State, in a transition area between the Atlantic Forest and the Savannah biomes; 4 Contagem, also part of the Metropolitan Region of Belo Horizonte, in a transition environment between the Atlantic Forest and the Savannah biomes similar to Sabará, suffering from anthropogenic influence; 5 Ouro Preto, a historic city of Minas Gerais State, located in Serra do Espinhaço, Atlantic forest biome. It is located in the metallurgical zone of the State, where the economy is based mainly on mining activities; 6 Serra do Caraça, a tourist site classified as a private reserve of natural heritage, also located in Serra do Espinhaço. The Serra do Caraça has predominant vegetation from Atlantic Forest, with areas of Savannah and elevation fields

Fig. 3

A work flow chart highlighting the steps and methods employed in this study