Yellow Fever Virus in Mosquitoes from Rainforest Bordering Manaus, Brazil, 2022

Area of Science:

• Arbovirology
• Epidemiology
• Genomics

Background:

• Yellow fever virus (YFV) poses a significant public health threat, particularly in tropical regions.
• Mosquitoes of the genus Haemagogus are known vectors for YFV, especially in South America.
• Understanding YFV circulation in the Amazon Basin is crucial for predicting and preventing outbreaks.

Purpose of the Study:

• To detect the presence of yellow fever virus in mosquito populations in the Amazon rainforest.
• To genetically characterize the detected YFV to understand its evolutionary relationship and origin.
• To assess the potential for YFV re-emergence in the region.

Main Methods:

• Mosquitoes (Haemagogus spp.) were collected in the Amazon rainforest near Manaus, Brazil, in 2022.
• Viral RNA was extracted from collected mosquitoes.
• The complete viral genome was sequenced and phylogenetically analyzed.

Main Results:

• Yellow fever virus was detected in Haemagogus mosquitoes collected in 2022.
• The sequenced YFV genome belonged to the South American I genotype 1E lineage.
• Phylogenetic analysis indicated a basal position for the detected viral genome within this lineage.

Conclusions:

• The Amazon Basin continues to be a reservoir for yellow fever virus.
• The genetic data suggests ongoing viral evolution and circulation within the region.
• These findings underscore the importance of continued vector surveillance and public health interventions in the Amazon for YFV prevention.