Table 1.

A summary of KoRV transmission modes

Subtype	Endogenous or exogenous	Transmission mode	Study area
KoRV-A	Endogenous	Vertical	Wild and captive Australian koala populations [4, 9, 13, 17, 54], koalas in a Japanese zoo [24]
KoRV-B	Exogenous, highly prevalent and associated with diseases	Both horizontal and vertical	Wild koala populations in Australia [9, 17], koalas in a US zoo [7], koalas in a Japanese zoo [14, 24]
KoRV-C	Exogenous with low prevalence	Horizontal and vertical	US zoo [57], Japanese zoo [16]
KoRV-D	Exogenous	Horizontal	Wild koala populations in Australia [15, 17]
KoRV-E	Exogenous with low prevalence	Horizontal	Wild koala in Australia [15], koalas in a US zoo [73]
KoRV-F	Exogenous	Horizontal	Wild koala populations in Australia [17, 18]
KoRV-G	Ongoing exogenous with low prevalence	Horizontal	Wild koala populations in Australia [18]
KoRV-H	Ongoing exogenous with low prevalence	Horizontal	Wild koala populations in Australia [18]
KoRV-I	Ongoing exogenous and low prevalent	Horizontal	Wild koala populations in Australia [18]