Buruli ulcer (BU: Mycobacterium ulcerans infection) is the third most frequent mycobacterial disease in humans, next to tuberculosis and leprosy, often causing serious skin ulcerations, deformities, and disability. It has dramatically emerged since the 1980's in tropical and subtropical regions of the world, especially West Africa. Rapid diagnostic tests are lacking, surveillance and reporting are inadequate, and antibiotic treatment is ineffective. The epidemiology is poorly understood; however, there is increased incidence in populations near wetlands or swamps, often created as a result of human environmental disturbance. Recent findings suggest a role of aquatic insects (e.g., Hemiptera) in the transmission of M. ulcerans. DNA of M. ulcerans has been identified by PCR from wetland water, plant biofilms and detritus, and recently cultured from aquatic bugs (Hemiptera). These insects commonly bite humans and have been shown to transmit M. ulcerans to mice via their bite. There is a poor understanding of the associations between BU outbreaks, the limnological and biological characteristics of nearby water-bodies, and the habitat and biology of populations of biting water bugs and other aquatic invertebrates that may play a role in the ecological distribution and potential transmission of M. ulcerans. The proposed study takes a systematic, spatially-explicit hierarchical approach to determine these associations in regions of Ghana, Africa. A foodweb-based hypothesis is proposed to determine the extent of M. uclerans within the aquatic invertebrate trophic community of standing waterbodies in BU endemic and non-endemic areas. The study will identify the trophic relationships and links of potential aquatic invertebrate M. ulcerans reservoirs to macrophyte biofilms using PCR. Data from identified invertebrate reservoirs will be analyzed with landscape features (e.g., deforestation, agriculture), BU incidence, and limnological and biological characteristics of waterbodies to better understand the epidemiology of this important emerging disease.
