Table 2.

Distribution of clades of monkeypox virus along with major epidemiological features. ⁴ , ⁴⁹ , ⁵⁰ , ⁵¹ , ⁵² , ⁵³ , ⁵⁴ , ⁵⁵ , ⁵⁶

Clade nomenclature based on origin	Revised clade	Lineages (N)	Reported year	Regions	Known transmission mode	Epidemiologic features	Number of cases
Central Africa	I	0	Early years of report (1970s) to 2020	Congo, CAR, DRC (majority of cases), Gabon, South Sudan, Cameroon	Mainly animal to human, unknown, and human to human	Sporadic cases, outbreaks, and endemic cases Case fatality rate 9.8%	1090 About 30,000a
West Africa	IIa	0	Early years of report (1970s) to 2022	Nigeria, Liberia, Sierra Leone, Ivory Coast, Cameroon	Animal to human, human to human, and unknown	Sporadic cases, outbreaks, endemic, and travelers’ cases Case fatality rate 3.5%	252
New West African	IIb	27	2017 to present	Americas, Europe, Africa, Asia, and Oceania	Human to human	Pandemic Case fatality rate 0.1%	85,800

^a Suspected cases.