Continuous Circulation of Yellow Fever among Rural Populations in the Central African Republic

Viruses. 2022 Sep 12;14(9):2014. doi: 10.3390/v14092014.

Abstract

Yellow fever remains a public-health threat in remote regions of Africa. Here, we report the identification and genetic characterisation of one yellow-fever case observed during the investigation of a cluster of nine suspected haemorrhagic fever cases in a village in the Central African Republic. Samples were tested using real-time RT-PCR targeting the main African haemorrhagic fever viruses. Following negative results, we attempted virus isolation on VERO E6 cells and new-born mice and rescreened the samples using rRT-PCR. The whole viral genome was sequenced using an Illumina NovaSeq 6000 sequencer. Yellow-fever virus (YFV) was isolated from one woman who reported farming activities in a forest setting several days before disease onset. Phylogenetic analysis shows that this strain belongs to the East-Central African YFV genotype, with an estimated emergence some 63 years ago. Finally, five unique amino-acid changes are present in the capsid, envelop, NS1A, NS3, and NS4B proteins. More efforts are required to control yellow-fever re-emergence in resource-limited settings.

Keywords: Africa; haemorrhagic fever; next-generation sequencing; remote settings; yellow fever.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Central African Republic / epidemiology
  • Humans
  • Mice
  • Phylogeny
  • Rural Population
  • Yellow Fever* / epidemiology
  • Yellow fever virus / genetics

Grants and funding

This research was funded by the World Organisation for Animal Health (OIE) through the European Union (capacity building and surveillance for Ebola virus disease; EBO-SURSY, project reference: FOOD/2016/379-660), the Chinese Academy of Sciences, a Shanghai Municipal Science and Technology Major Project (grant No. 2019SHZDZX02), and by the Ministry of Science and Technology of China (grant No. 2022YFE0114700).