Buruli ulcer

The mode of transmission


Over 50 years of experience have established the fact that Buruli ulcer is acquired through exposure to the environment, particularly through exposure to slow-moving or stagnant bodies of water. The importance of understanding the mechanism of transmission from the environment to human is obvious: if one can determine where the bacteria replicate, and how they are introduced into the patient, it may be possible to prevent exposure to infection.

Isolation of M. ulcerans by cultures from samples taken from the environment has not been rarely successful. However, knowledge about transmission has increased thanks to the use of new molecular techniques such as polymerase chain reaction (PCR).

The recent findings that M. ulcerans can be isolated from water bugs in endemic areas and can replicate in the salivary glands of these bugs heralds a major breakthrough in our understanding of the ecology of M. ulcerans. The bugs so far associated with M. ulcerans are large, easily identified and generally confined to specific aquatic niches.

This information, if confirmed by further studies, could have an enormous impact on the control of Buruli ulcer leading to the development of strategies to prevent human contact with infected insects in endemic areas.

The implementation of preventive strategies may be relatively simple and inexpensive. In addition, if people are informed of the risk of exposure to such insects, they may be more likely to pay attention to bites received while near the water and this could lead to earlier diagnosis of the disease.

Recommended studies:

  • To confirm the prevalence of M. ulcerans in water bugs (Naucoridae, Belostomatidae and Nepidae) in areas endemic for Buruli ulcer and the role these bugs may play in infection;
  • To identify other species which may play a role in maintaining M. ulcerans in the environment.