No abstract

Buruli ulcer (BU), a neglected tropical disease of the skin, caused by Mycobacterium ulcerans, occurs most frequently in children in West Africa. Risk factors for BU include proximity to slow flowing water, poor wound care and not wearing protective clothing. Man-made alterations of the environment have been suggested to lead to increased BU incidence. M. ulcerans DNA has been detected in the environment, water bugs and recently also in mosquitoes. Despite these findings, the mode of transmission of BU remains poorly understood and both transmission by insects or direct inoculation from contaminated environment have been suggested. Here, we investigated the BU epidemiology in the Mapé basin of Cameroon where the damming of the Mapé River since 1988 is believed to have increased the incidence of BU. Through a house-by-house survey in spring 2010, which also examined the local population for leprosy and yaws, and continued surveillance thereafter, we identified, till June 2012, altogether 88 RT-PCR positive cases of BU. We found that the age adjusted cumulative incidence of BU was highest in young teenagers and in individuals above the age of 50 and that very young children (<5) were underrepresented among cases. BU lesions clustered around the ankles and at the back of the elbows. This pattern neither matches any of the published mosquito biting site patterns, nor the published distribution of small skin injuries in children, where lesions on the knees are much more frequent. The option of multiple modes of transmission should thus be considered. Analyzing the geographic distribution of cases in the Mapé Dam area revealed a closer association with the Mbam River than with the artificial lake.

BackgroundSkin disorders are generally considered to be more prevalent in the rural areas of Cameroon. This study was carried out to verify this assumption by describing the spectrum of skin disorders in a rural setting of Cameroon.MethodsWe carried out a community-based clinical skin examination of 400 consenting subjects from 4 villages of Cameroon: Nyamanga (27%), Yebekolo (24%), Mbangassina (23%) and Bilomo (26%).ResultsThe overall prevalence of skin diseases in our sample was 62% {95% CI: 57.2%, 66.8%} (248/400). The commonest skin disorders were: fungal infections (25.4%), parasitic infestations (21.4%), atrophic skin disorders (11.7%), hypertrophic skin disorders (9.7%), disorders of skin appendages {acne} (8.9%), benign neoplasm (6.5%), bacterial skin infections (5.2%), pigmentation disorders (4.8%), and dermatitis/eczema (4.0%). Skin infections and infestations constituted 52.82% of all skin disorders. The overall prevalence of infectious and parasitic infestation was 32.75% {95%CI: 28.17%, 37.59%} (131/400) as against 29.25% {95%CI: 24.83%, 33.98%} (117/400) for non-infectious disorders.Among people with skin infections/parasitic infestations, those with fungal infections and onchocercal skin lesions were the most prevalent, accounting for 48.1% (63/131) and 35.1% (46/131); and an overall prevalence of 15.75% {95%CI: 12.3%, 19.7%} (63/400) and 11.5% {95%CI: 8.5%, 15.0%} (46/400) respectively.There was secondary bacterial infection in 12.1% {95%CI: 8.31%, 16.82%} (30/248) of subjects with skin diseases. Hypertrophic and atrophic disorders of the skin were mainly keloids (9.68%), scarification marks (6.05%) and burn scars (5.65%). Skin diseases like dermatitis and eczema (4.03%), malignant tumours and pigmentation disorders were rare in our sample.The proportion of subjects diagnosed with skin disorders after examination (62.8%) was significantly higher than the proportion of 40.8% that declared having skin diseases (p < 0.0001).ConclusionThe prevalence of skin diseases in the rural Mbam valley is alarming, dominated by easily treatable or preventable skin infections and their magnitude is highly neglected by the community, contrasting with findings in the urban setting. Similar studies are needed in other ecological/demographic settings of the country in order to construct a better understanding of the epidemiology of skin disorders. This would lead to the development of national policies to improve skin care.