Table 2.

Timing of Introduction Events of Four Selected Epidemic Lineage Mu_A1 Clones in Their Respective Hydrological Basin

Hydrological basin	Endemic hotspot	Approx. start of colonial rule	Mean t(MRCA)	95% HPD t(MRCA)	First reported cases
Congo	Songololo Territory	1885a	1905	1855–1941	1961d (Andersen 1965)
Nyong	Between Ayos and Akonolinga	1884c	1901	1848–1937	1969 (Ravisse 1977; Ravisse et al. 1975)
Oueme	Southeastern Benin	1892b	1890	1835–1932	1988 (Muelder and Nourou 1990)
Kouffo	Southeastern Benin	1892b	1977	1959–1988	1977 (Aguiar 1997)

^aFounding of the Belgian Congo Free State.

^bKingdom of Dahomey annexed into the French colonial empire.

^cGerman Empire claimed the colony of Kamerun and began a steady push inland.

^dBased on interviews and observations of healed lesions in the villages of the Songololo territory it was believed that M. ulcerans infections already existed in the area in 1935 (Meyers et al. 1974a). HDP, highest probability density interval; t(MRCA), time to most recent common ancestor.