23 April 2010

Microbiologists work closely together with clinicians, immunologists with health politicians, anthropologists with ecologists – and all in pursuit of a single goal: generating and implementing knowledge to fight the terrible disease.

At this second meeting, the advantages of a consortium designed to cover a multitude of disciplines and the strong participation of the African partners were clearly demonstrated. Among the most important milestones is the refined phenotyping of mycobacterium ulcerans isolates. As a result, it is becoming possible to follow the spatial-temporal dissemination of certain genetic variants of the pathogen in an endemic area. This will produce additional findings on the transmission of the disease.
A successful technology transfer to Africa is another milestone. Professor Gerd Pluschke of the Swiss Tropical and Public Health Institute and scientific coordinator of the Stop Buruli consortium explains in concrete terms: "In Ghana in cooperation with the Australian research team it was possible to establish real-time PCR technology for the documentation of M. ulcerans DNA. This makes it possible to better analyze environmental samples with more accuracy, and at the same time local laboratory diagnosis capacities have become decisively stronger."

Overall there is progress to report for all four research axes that is well worth noting:

In the 'transmission' area, it was possible to create detailed maps on the dissemination of the Buruli ulcer in selected communities in Benin. Now the search is on for connections between the presence of the disease, environmental factors such as types of vegetation or the level of humidity and human activities. These microepidemological studies are being assessed statistically, and other possible factors are to be included – with the ambitious goal of revealing the secret surrounding the transmission of M. ulcerans.

With regard to diagnosis, two important advances have been achieved. The 'fine needle aspiration' (FNA) technique already successfully implemented in some regions for taking samples from patients has been validated and standardized. In contrast to other sampling methods, this technique allows the simple and relatively painless removal of samples from the tissue for diagnosis purposes. In order to put this method propagated by WHO to use as quickly as possible, training was conducted in Benin with international and resident experts and health personnel from Cameroon and Ghana. Additionally, in the coming weeks an e-learning animation will be provided to the countries impacted by the disease to explain the method step-by-step. In this way the Stop Buruli consortium is making a significant contribution to the introduction of the FNA diagnosis technique in the impacted countries.

The first results of a new diagnosis method based on an antigen-capture assay are very promising. In the event that further investigations are successful, a simpler and more cost effective test could be developed for quickly detecting Buruli. Further studies will show whether this hope is confirmed.

Within the therapy axis it has been possible to confirm with patient data the success of antibiotics therapy. "Paradox reactions" – wound expansions during antibiotics therapy – and their clinical management are to be investigated more thoroughly. The researchers would also like to collect data to arrive at recommendations for improved wound care and for treatment of very advanced ulcers.

Initial pilot studies have been successfully concluded in the sociocultural area. A joint research plan based on the initial results has been formulated and introduced. It aims to examine how the impacted population recognizes and treats Buruli, why health services are frequently sought out at a relatively late stage, and how well patients adhere to the prolonged treatment. Furthermore, proposals are to be drafted for improving access to diagnosis and therapy.

As Dr. Alphonse Um Boock, member of the consortium from Cameroon, stresses in his presentation: "Stop Buruli has improved how the disease is dealt with, and in the regions where research was conducted, new findings have already been included in the national Buruli ulcer control program of Cameroon. Now we must strive to keep these changes sustainable in order to guarantee the quality of the control of the disease in Cameroon and in other countries where Stop Buruli is active. The results of the social science studies could be crucial for this."

Against this backdrop we can look to the future with hope and assume that a much deeper knowledge about the puzzling Buruli disease will soon be available, with the priority goal of improving the detection, treatment and abatement of this neglected disease.

The main achievements at a glance

• Validation, standardization of the FNA diagnostic technique, with in-country training and development of an e-learning animation tool
• Establishment of real-time PCR technology in Ghana
• Use of new genome sequencing technologies for the characterization of the diversity and population structure of M. ulcerans
• Refinement of single nucleotide polymorphism (SNP) typing as a highly discriminatory and cost-effective genetic fingerprinting tool
• Development of a high-sensitivity antigen capture assay
• Social science pilot studies completed