Matthew R Mauldin, Andrea M McCollum, Yoshinori J Nakazawa, Anna Mandra, Erin R Whitehouse, Whitni Davidson, Hui Zhao, Jinxin Gao, Yu Li, Jeffrey Doty, Adesola Yinka-Ogunleye, Afolabi Akinpelu, Olusola Aruna, Dhamari Naidoo, Kuiama Lewandowski, Babak Afrough, Victoria Graham, Emma Aarons, Roger Hewson, Richard Vipond, Jake Dunning, Meera Chand, Colin Brown, Inbar Cohen-Gihon, Noam Erez, Ohad Shifman, Ofir Israeli, Melamed Sharon, Eli Schwartz, Adi Beth-Din, Anat Zvi, Tze Minn Mak, Yi Kai Ng, Lin Cui, Raymond T P Lin, Victoria A Olson, Tim Brooks, Nir Paran, Chikwe Ihekweazu, Mary G Reynolds, Exportation of Monkeypox Virus From the African Continent, The Journal of Infectious Diseases, Volume 225, Issue 8, 15 April 2022, Pages 1367–1376,


The largest West African monkeypox outbreak began September 2017, in Nigeria. Four individuals traveling from Nigeria to the United Kingdom (n = 2), Israel (n = 1), and Singapore (n = 1) became the first human monkeypox cases exported from Africa, and a related nosocomial transmission event in the United Kingdom became the first confirmed human-to-human monkeypox transmission event outside of Africa.

Epidemiological and molecular data for exported and Nigerian cases were analyzed jointly to better understand the exportations in the temporal and geographic context of the outbreak.

Isolates from all travelers and a Bayelsa case shared a most recent common ancestor and traveled to Bayelsa, Delta, or Rivers states. Genetic variation for this cluster was lower than would be expected from a random sampling of genomes from this outbreak, but data did not support direct links between travelers.

Monophyly of exportation cases and the Bayelsa sample, along with the intermediate levels of genetic variation, suggest a small pool of related isolates is the likely source for the exported infections. This may be the result of the level of genetic variation present in monkeypox isolates circulating within the contiguous region of Bayelsa, Delta, and Rivers states, or another more restricted, yet unidentified source pool.

monkeypox virus, viral genomes, exportation, travel epidemiology, border health, haplotype networks