|
Contamination of broken skin
|
Unknown. Inoculation of M. ulcerans on to abraded skin does not cause infection in guinea pigs [11]. However, proper hygiene and wound care are associated with reduced odds of developing infection in Africa [12]. |
|
Breaking of contaminated skin
|
Possible. Needle puncture was sufficient to allow M. ulcerans to enter skin and cause infection in mice [9]. Infection has been reported following breaking of skin via human bite [13,14]. |
|
Via aquatic environments
|
Likely. Environmental M. ulcerans DNA identical to genetic profiles of local human Buruli ulcer cases [15]. Transmission mechanism unknown. |
Possible. Buruli ulcer case numbers increase in rainy seasons [16]. Transmission mechanism unknown. |
|
Human to human
|
Unlikely. Analysis of familial clusters suggests that infections were due to genetic predispositions, rather than human-to-human transmission [17]. |
Unlikely. Analysis of familial clusters found that family members were infected with different strains of M. ulcerans, suggesting that human-to-human transmission had not occurred [18]. |
|
Vertebrate to human
|
Unlikely. M. ulcerans has not been recovered from domestic animal samples [19]. M. ulcerans reported in wild grasscutters [20,21]. |
Unknown. Possums are hosts of M. ulcerans strains also isolated from human patients [8], part of same transmission chain. |
|
Aquatic insect vectors
|
Possible. M. ulcerans DNA has been recovered from African insects in endemic areas [22]. Insects have been shown to carry M. ulcerans and transmit to mice [23]. |
Unknown. Studies have not been conducted. |
|
Mosquito vectors
|
Unlikely. M. ulcerans has not been recovered from mosquito populations [24], and bacilli are not maintained through mosquito life cycle [25]. |
Likely. Very strong geographical correlation between M. ulcerans detection in mosquito populations and human Buruli ulcer cases [26]. Mosquito bites can facilitate M. ulcerans infection in mice [9]. |
