Genomes reveal yellow fever’s deadly route through Brazil

New RNA sequences show the path that the virus travelled from the Amazon to the densely populated south. Nature highlights our recent paper at Science Advances.

An Aedes aegypti mosquito (artificially coloured). These insects are one of the key carriers of the virus that causes yellow fever. Credit: Dennis Kunkel Microscopy/SPL

The virus that causes yellow fever has a permanent foothold in the Brazilian Amazon, where the pathogen is widespread in wild animals living in the region’s forest. Now scientists have discovered that the virus has been travelling through a corridor that connects the Amazonian region to southeastern Brazil, where the disease has recently reemerged and caused waves of human outbreaks1.

Marta Giovanetti at the Oswaldo Cruz Foundation in Rio de Janeiro, Brazil, and her colleagues analysed almost 150 newly sequenced genomes of yellow fever virus samples collected in Brazil. This allowed them to identify a pattern of yellow fever spread connecting the Amazonian region, in northern Brazil, with states in midwestern and southeast Brazil.

The researchers also used epidemiological data to pinpoint disease hotspots, areas with a history of yellow fever and a high proportion of people who haven’t been vaccinated against the disease. The analysis showed that these hotspots were close to many of the largest cities in the area studied. One of yellow fever’s vectors, the Aedes aegypti mosquito, is usually abundant in such urban centres, which makes them especially susceptible to future outbreaks.



Giovanetti, M. et al. Sci. Adv. 9, eadg9204 (2023).

News date: 2023-09-01