Decrease in Mycobacterium ulcerans disease (Buruli ulcer) in the Lalo District of Bénin (West Africa).

BACKGROUND: Buruli ulcer (BU) is a chronic, necrotizing infectious skin disease caused by Mycobacterium ulcerans. In recent years, there has been a decrease in the number of new cases detected. This study aimed to show the evolution of its distribution in the Lalo District in Bénin from 2006 to 2017. METHODS: The database of the BU Detection and Treatment Center of Lalo allowed us to identify 1017 new cases in the Lalo District from 2006 to 2017. The annual prevalence was calculated with subdistricts and villages. The trends of the demographic variables and those related to the clinical and treatment features were analysed using Microsoft Excel® 2007 and Epi Info® 7. Arc View version® 3.4 was used for mapping. RESULTS: From 2006 to 2017, the case prevalence of BU in the Lalo District decreased by 95%. The spatial distribution of BU cases confirmed the foci of the distribution, as described in the literature. The most endemic subdistricts were Ahomadégbé, Adoukandji, Gnizounmè and Tchito, with a cumulative prevalence of 315, 225, 215 and 213 cases per 10,000 inhabitants, respectively. The least endemic subdistricts were Zalli, Banigbé, Lalo-Centre and Lokogba, with 16, 16, 10, and 5 cases per 10,000 inhabitants, respectively. A significant decrease in the number of patients with ulcerative lesions (p = 0.002), as well as those with category 3 lesions (p < 0.001) and those treated surgically (p < 0.001), was observed. The patients confirmed by PCR increased (from 40.42% in 2006 to 84.62% in 2017), and joint limitation decreased (from 13.41% in 2006 to 0.0% in 2017). CONCLUSION: This study confirmed the general decrease in BU prevalence rates in Lalo District at the subdistrict and village levels, as also observed at the country level. This decrease is a result of the success of the BU control strategies implemented in Bénin, especially in the Lalo District.

Diagnostic Accuracy of Clinical and Microbiological Signs in Patients With Skin Lesions Resembling Buruli Ulcer in an Endemic Region.

Background: The diagnosis of the neglected tropical skin and soft tissue disease Buruli ulcer (BU) is made on clinical and epidemiological grounds, after which treatment with BU-specific antibiotics is initiated empirically. Given the current decline in BU incidence, clinical expertise in the recognition of BU is likely to wane and laboratory confirmation of BU becomes increasingly important. We therefore aimed to determine the diagnostic accuracy of clinical signs and microbiological tests in patients presenting with lesions clinically compatible with BU. Methods: A total of 227 consecutive patients were recruited in southern Benin and evaluated by clinical diagnosis, direct smear examination (DSE), polymerase chain reaction (PCR), culture, and histopathology. In the absence of a gold standard, the final diagnosis in each patient was made using an expert panel approach. We estimated the accuracy of each test in comparison to the final diagnosis and evaluated the performance of 3 diagnostic algorithms. Results: Among the 205 patients with complete data, the attending clinicians recognized BU with a sensitivity of 92% (95% confidence interval [CI], 85%-96%), which was higher than the sensitivity of any of the laboratory tests. However, 14% (95% CI, 7%-24%) of patients not suspected to have BU at diagnosis were classified as BU by the expert panel. The specificities of all diagnostics were high (≥91%). All diagnostic algorithms had similar performances. Conclusions: A broader clinical suspicion should be recommended to reduce missed BU diagnoses. Taking into consideration diagnostic accuracy, time to results, cost-effectiveness, and clinical generalizability, a stepwise diagnostic approach reserving PCR to DSE-negative patients performed best.

Associated factors study into the belated screening for leprosy in Benin.

INTRODUCTION: In the absence of early treatment, leprosy, a neglected tropical disease, due to Mycobacterium leprae or Hansen Bacillus, causes irreversible grade 2 disability (G2D) numerous factors related to the individual, the community and the health care system are believed to be responsible for its late detection and management. This study aims to investigate the factors associated with belated screening for leprosy in Benin. METHODS: This was a cross-sectional, descriptive, and analytical study conducted from January 1 to June 31, 2019, involving all patients and staff in leprosy treatment centers and public peripheral level health structures in Benin. The dependent variable of the study was the presence or not of G2D, reflecting late or early screening. We used a logistic regression model, at the 5% threshold, to find the factors associated with late leprosy screening. The fit of the final model was assessed with the Hosmer-Lemeshow test. RESULTS: A number of 254 leprosy patients were included with a mean age of 48.24 ± 18.37 years. There was a male dominance with a sex ratio of 1.23 (140/114). The proportion of cases with G2D was 58.27%. Associated factors with its belated screening in Benin were (OR; 95%CI; p) the fear of stigma related to leprosy (8.11; 3.3-19.94; <0.001), multiple visits to traditional healers (5.20; 2.73-9.89; <0.001) and multiple visits to hospital practitioners (3.82; 2.01-7.27; <0.001). The unawareness of leprosy by 82.69% of the health workers so as the permanent decrease in material and financial resources allocated to leprosy control were identified as factors in link with the health system that helps explain this late detection. CONCLUSION: This study shows the need to implement strategies in the control programs to strengthen the diagnostic abilities of health workers, to improve the level of knowledge of the population on the early signs and symptoms of leprosy, to reduce stigmatization and to ban all forms of discrimination against leprosy patients.

Genetic variants in human BCL2L11 (BIM) are associated with ulcerative forms of Buruli ulcer.

Buruli ulcer (BU) is a devastating skin mycobacterial infection characterized by extensive cell death, which was previously suggested to be mediated by Bcl2-like protein 11 (BIM, encoded by the BCL2L11 gene). We here report the association of genetic variants in BCL2L11 with ulcerative forms of the disease in a cohort of 618 Beninese individuals. Our results show that regulation of apoptosis in humans contributes to BU lesions associated with worse prognosis, prompting for further investigation on the implementation of novel methods for earlier identification of at-risk patients.

Report of a series of 82 cases of Buruli ulcer from Nigeria treated in Benin, from 2006 to 2016.

BACKGROUND: Nigeria is one of the countries endemic for Buruli ulcer (BU) in West Africa but did not have a control programme until recently. As a result, BU patients often access treatment services in neighbouring Benin where dedicated health facilities have been established to provide treatment free of charge for BU patients. This study aimed to describe the epidemiological, clinical, biological and therapeutic characteristics of cases from Nigeria treated in three of the four treatment centers in Benin. METHODOLOGY/PRINCIPAL FINDINGS: A series of 82 BU cases from Nigeria were treated in three centres in Benin during 2006-2016 and are retrospectively described. The majority of these patients came from Ogun and Lagos States which border Benin. Most of the cases were diagnosed with ulcerative lesions (80.5%) and WHO category III lesions (82.9%); 97.5% were healed after a median hospital stay of 46 days (interquartile range [IQR]: 32-176 days). CONCLUSIONS/SIGNIFICANCE: This report adds to the epidemiological understanding of BU in Nigeria in the hope that the programme will intensify efforts aimed at early case detection and treatment.

Improving clinical and epidemiological predictors of Buruli ulcer.

BACKGROUND: Buruli ulcer (BU) is a chronic necrotizing infectious skin disease caused by Mycobacterium ulcerans. The treatment with BU-specific antibiotics is initiated after clinical suspicion based on the WHO clinical and epidemiological criteria. This study aimed to estimate the predictive values of these criteria and how they could be improved. METHODOLOGY/PRINCIPAL FINDINGS: A total of 224 consecutive patients presenting with skin and soft tissue lesions that could be compatible with BU, including those recognized as unlikely BU by experienced clinicians, were recruited in two BU treatment centers in southern Benin between March 2012 and March 2015. For each participant, the WHO and four additional epidemiological and clinical diagnostic criteria were recorded. For microbiological confirmation, direct smear examination and IS2404 PCR were performed. We fitted a logistic regression model with PCR positivity for BU confirmation as outcome variable. On univariate analysis, most of the clinical and epidemiological WHO criteria were associated with a positive PCR result. However, lesions on the lower limbs and WHO category 3 lesions were rather associated with a negative PCR result (respectively OR: 0.4, 95%CI: 0.3-0.8; OR: 0.5, 95%IC: 0.3-0.9). Among the additional characteristics studied, the characteristic smell of BU was strongest associated with a positive PCR result (OR = 16.4; 95%CI = 7.5-35.6). CONCLUSION/SIGNIFICANCE: The WHO diagnostic criteria could be improved upon by differentiating between lesions on the upper and lower limbs and by including lesion size and the characteristic smell recognized by experienced clinicians.

Global epidemiology of yaws: a systematic review.

BACKGROUND: To achieve yaws eradication, the use of the new WHO strategy of initial mass treatment with azithromycin and surveillance twice a year needs to be extended everywhere the disease occurs. However, the geographic scope of the disease is unknown. We aimed to synthesise published and unpublished work to update the reported number of people with yaws at national and subnational levels and to estimate at-risk populations. METHODS: We searched PubMed and WHO databases to identify published data for prevalence of active and latent yaws from Jan 1, 1990, to Dec 31, 2014. We also searched for ongoing or recently completed unpublished studies from the WHO yaws surveillance network. We estimated yaws prevalence (and 95% CIs). We collected yaws incidence data from official national surveillance programmes at the first administrative level from Jan 1, 2010, to Dec 31, 2013, and we used total population data at the second administrative level to estimate the size of at-risk populations. FINDINGS: We identified 103 records, of which 23 published articles describing 27 studies and four unpublished studies met the inclusion criteria. Prevalence of active disease ranged from 0·31% to 14·54% in yaws-endemic areas, and prevalence of latent yaws ranged from 2·45% to 31·05%. During 2010-13, 256 343 yaws cases were reported to WHO from 13 endemic countries, all of which are low-income and middle-income countries. 215 308 (84%) of 256 343 cases reported to WHO were from three countries-Papua New Guinea, Solomon Islands, and Ghana. We estimated that, in 2012, over 89 million people were living in yaws-endemic districts. INTERPRETATION: Papua New Guinea, Solomon Islands, and Ghana should be the focus of initial efforts at implementing the WHO yaws eradication strategy. Community-based mapping and active surveillance must accompany the implementation of yaws eradication activities. FUNDING: None.