New Foci of Buruli Ulcer, Angola and Democratic Republic of Congo

We report 3 patients with laboratory-confirmed Buruli ulcer in Kafufu/Luremo, Angola, and Kasongo-Lunda, Democratic Republic of Congo. These villages are near the Kwango/Cuango River, which flows through both countries. Further investigation of artisanal alluvial mining as a risk factor for Buruli ulcer is recommended.


The Study
We studied 3 patients suspected of having BU who were admitted to the Dr Lelo Medical Center in Kinshasa (patient 1) and the Mother Teresa Buruli Ulcer Treatment Center in Kinshasa (patients 2 and 3). The study was reviewed and approved by the ethics committee of the Institute of Tropical Medicine, Antwerp, and the Public Health School of the Kinshasa University, Kinshasa, Ministère de l'Enseignement. The 3 patients provided verbal consent to participate in the study. Patients 1 and 2 were men 30 and 28 years of age, respectively, and patient 3 was a girl 13 years of age.
Characteristics of the patients are shown in the Table. Laboratory tests were performed on surgically excised tissues and exudates according to World Health Organization (WHO) recommendations (6). Patients were treated with rifampin and streptomycin for 12 weeks according to WHO recommendations (7). Four weeks after the beginning of treatment, surgical debridement was performed, followed by split-skin grafting. The patients were followed up at the 2 treatment centers and were considered cured when the lesions had completely healed.
All patients were residents of Kinshasa (DRC) and had no contacts with areas endemic for BU before traveling to areas along the Kwango/Cuango River where the BU skin lesions fi rst appeared. However, all patients had frequent contact through alluvial diamond mining (patients 1 and 2) or domestic activities (patient 3) along the Kwango/Cuan- On admission, all 3 patients had large ulcers (150-896 cm 2 ). Patient 1 had an ulcer on the right thigh, patient 2 on the right arm, and patient 3 on the left leg (Table). BU was confi rmed by Ziehl-Neelsen staining for acid-fast bacilli and a positive IS2404 PCR result (Table). Cultures remained negative after incubation for 12 months at 32°C. For patient 3, BU was also confi rmed by histopathologic analysis performed before treatment. A specimen showed a predominantly neutrophilic infl ammatory infi ltrate near extensive areas of necrosis associated with calcifi cation and clumps of extracellular acid-fast bacilli.
The 3 patients were considered cured after 3, 6, and 7 months, respectively, of hospitalization. No relapses were observed after follow-up periods of 42, 30, and 28 months, respectively.

Conclusions
BU patients in our study had advanced disease with ulcers >10 cm in diameter. They were cured by treatment with antimicrobial drugs and surgery in accordance with WHO recommendations for treatment of BU (6,7). The pa-tients were most likely infected during alluvial mining and use of water from the Kwango/Cuango River for domestic activities. Artisanal diamond mining in alluvial deposits along river banks consists of informal digging with basic equipment (often with unprotected hands and feet). Miners often work for long periods extracting diamonds from alluvial deposits along river banks. In Angola, mining areas are located in swamps that border the Kwango/Cuango River. Water sources used for domestic purposes along this slowfl owing river are unprotected, and proper hygienic procedures are lacking.
Epidemiologic studies have established a close association of BU and wetlands, especially those with slowfl owing or stagnant water (ponds, backwaters, and swamps) (8)(9)(10). In Uganda and in Benin, use of unprotected sources of water for domestic purposes increased the risk for contracting BU (10)(11)(12). Environmental factors, including poor hygienic conditions, along the Kwango/Cuango River make this region an area of high risk for contracting BU (10,13).
Studies have linked increased incidence of BU to human-made modifi cations such as expanded agricultural activities, deforestation, or construction of dams (14). Activities of both large mining enterprises and individual miners are responsible for environmental changes that may play a role in increased incidence of BU. Diamond-mining pits may become pools of stagnant waters that are a dangerous source of waterborne diseases.
In the 1950s in the Belgian Congo (now DRC), several cases of BU were reported in alluvial gold miners working in the mining camp of Kakerifu between the Nzoro and Kibali Rivers (1). Currently, in the gold-mining area of Amansie West District in Ghana, many BU infections occur among workers in contiguous alluvial mining operations (15). Diamond mines along the Cuango River in Angola may have infl uenced the emergence of BU cases along this river basin. However, whether the Cuango River fl oodplain is a region endemic for BU or if this region became endemic after diamond-mining activities is not known. The frequency of BU in Angola is not documented partly because of political changes after the country's independence in 1975. Surveys are urgently needed to determine the endemicity of BU in Angola. Our fi ndings emphasize the need for further investigation of diamond, gold, and any other gemstone mining as a risk factor for contracting BU, particularly in West and Central Africa, where mining is common. All areas along the Kwango/Cuango River in DRC and Angola should be investigated for foci of BU. The association of artisanal alluvial mining with BU draws attention to a disease that further diminishes the quality of life of persons who are already living under the precarious circumstances experienced by those who mine diamonds.