Temporal variations in air pollution at two roundabouts in the city of Cotonou (Benin).

BACKGROUND: Air pollution has caused health and environmental problems around the world. In this study we analysed the temporal evolution of air pollution in Cotonou regarding the standards of Benin and of World Health Organization (WHO). DESIGN AND METHODS: Solar-powered electrochemical sensors (CO: carbon monoxide, SO2: sulphur dioxide, and O3/NO2: ozone/nitrogen dioxide) and photoionization detectors (for NMVOC: nonmethane volatile organic compounds) were permanently installed and monitored from June 2019 to March 2020 at Akpakpa PK3 (A) and Vèdokô Cica-Toyota (B) roundabouts. RESULTS: CO and SO2 concentrations at both roundabouts were significantly higher on weekends than on weekdays. The concentrations of NMVOC and O3 / NO2 on Sunday differed considerably from the other days of the week at A and B, respectively. There was a positive linear correlation between the concentrations of CO and SO2, O3 / NO2 and SO2, and CO O3 / NO2 to B, and only between CO and O3 / NO2, in A. At the two sites, the average of SO2 concentrations (in µg/m3) were higher than the WHO standard (500) for an exposure of 10 minutes (2258 A and 2143 B) and the Benin standard (1300) for 1 hour exposure (2181 in A and 2092 in B). CONCLUSION: Air pollution varies in hours and days in Cotonou. Standards are respected, except for SO2. Particular attention should be paid to the concentrations and the possible sources of gas. More sophisticated monitoring system should be put in place.

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.

"My right to walk, my right to live": pedestrian fatalities, roads and environmental features in Benin.

BACKGROUND: The implementation of road safety interventions in many developing countries usually focuses on the behavior of users. In order to draw more attention on the role of road infrastructure and physical environment in road safety interventions, this study aims to analyze the environmental and road factors associated with the pedestrians involved in traffic crashes in Benin. METHOD: The method used was an analysis of national road crash statistics for the period 2008 to 2015. The information available included the circumstances surrounding the collision, the road infrastructure, the vehicles and the individuals involved. A multiple logistic regression was used to identify predictors of pedestrian mortality in traffic crashes. RESULTS: During the period studied, 3760 crashes involved at least one pedestrian. The death rate among these pedestrians was 27.74% (CI 95%: 26.31-29.20). The mortality predictors were the area in which the crash occurred (OR = 4.94; CI 95%: 4.10-5.94), the day of the crash (OR = 2.17; CI 95%:1.34-3.52), light levels (OR = 1.30; CI 95%: 1.06-1.59), road classification (OR = 1.79; CI 95%: 1.46-2.20), the condition of the road surface (2.04, CI 95%: 1.41-2.95) and the position of the pedestrian during the crash (OR = 1.69; CI 95%: 1.19-2.38). CONCLUSIONS: These results support the need for a holistic approach to interventions aiming to tackle deaths on roads. Interventions should integrate environmental factors for greater pedestrian safety around roads with appropriate signs, roads in good condition and awareness campaigns for a proper use of road infrastructures.

Buruli ulcer treatment: Rate of surgical intervention differs highly between treatment centers in West Africa.

BACKGROUND: Antibiotic treatment proved itself as the mainstay of treatment for Buruli ulcer disease. This neglected tropical disease is caused by Mycobacterium ulcerans. Surgery persists as an adjunct therapy intended to reduce the mycobacterial load. In an earlier clinical trial, patients benefited from delaying the decision to operate. Nevertheless, the rate of surgical interventions differs highly per clinic. METHODS: A retrospective study was conducted in six different Buruli ulcer (BU) treatment centers in Benin and Ghana. BU patients clinically diagnosed between January 2012 and December 2016 were included and surgical interventions during the follow-up period, at least one year after diagnosis, were recorded. Logistic regression analysis was carried out to estimate the effect of the treatment center on the decision to perform surgery, while controlling for interaction and confounders. RESULTS: A total of 1193 patients, 612 from Benin and 581 from Ghana, were included. In Benin, lesions were most frequently (42%) categorized as the most severe lesions (WHO criteria, category III), whereas in Ghana lesions were most frequently (44%) categorized as small lesions (WHO criteria, category I). In total 344 (29%) patients received surgical intervention. The percentage of patients receiving surgical intervention varied between hospitals from 1.5% to 72%. Patients treated in one of the centers in Benin were much more likely to have surgery compared to the clinic in Ghana with the lowest rate of surgical intervention (RR = 46.7 CI 95% [17.5-124.8]). Even after adjusting for confounders (severity of disease, age, sex, limitation of movement at joint at time of diagnosis, ulcer and critical sites), rates of surgical interventions varied highly. CONCLUSION: The decision to perform surgery to reduce the mycobacterial load in BU varies highly per clinic. Evidence based guidelines are needed to guide the role of surgery in the treatment of BU.

The paediatric participation scale measuring participation restrictions among former Buruli Ulcer patients under the age of 15 in Ghana and Benin: Development and first validation results.

BACKGROUND: Buruli Ulcer (BU) is a neglected tropical disease caused by Mycobacterium ulcerans. Former BU patients may experience participation restrictions due to physical limitations, stigmatization and other social factors. A scale that measures participation restrictions among children, who represent almost half of the affected population, has not been developed yet. Here, we present the development of a scale that measures participation restrictions in former BU paediatric patients, the psychometric properties of this scale and the scales' results. METHODS: Items were selected and a scale was developed based on interviews with health care workers and former BU patients in and around the BU treatment centre in Lalo, Benin. Construct validity was tested using six a priori formulated hypotheses. Former BU patients under 15 years of age who received treatment in one of the BU treatment centres in Ghana and Benin between 2007-2012 were interviewed. RESULTS: A feasible 16-item scale that measures the concept of participation among children under 15 years of age was developed. In total, 109 (Ghana) and 90 (Benin) former BU patients were interviewed between 2012-2017. Five construct validity hypotheses were confirmed of which 2 hypotheses related to associations with existing questionnaires were statistically significant (p<0.05). In Ghana 77% of the former patients had a Paediatric Participation (PP) scale score of 0 compared to 22% in Benin. More severe lesions related to BU were seen in Benin. Most of the reported participation problems were related to sports, mainly in playing games with others, going to the playfield and doing sports at school. CONCLUSION: The preliminary results of the PP-scale validation are promising but further validation is needed. The developed PP-scale may be valid for use in patients with more severe BU lesions. This is the first research to confirm that former BU patients under 15-year face participation restrictions in important aspects of their lives.

Delayed versus standard assessment for excision surgery in patients with Buruli ulcer in Benin: a randomised controlled trial.

BACKGROUND: Surgical intervention was once the mainstay of treatment for Buruli ulcer disease, a neglected tropical disease caused by Mycobacterium ulcerans. Since the introduction of streptomycin and rifampicin for 8 weeks as standard care, surgery has persisted as an adjunct therapy, but its role is uncertain. We investigated the effect of delaying the decision to operate to 14 weeks on rates of healing without surgery. METHODS: In this randomised controlled trial, we enrolled patients aged 3 years or older with confirmed disease at one hospital in Lalo, Benin. Patients were randomly assigned (1:1) to groups assessing the need for excision surgery 8 weeks (standard care) or 14 weeks after initiation of antimicrobial treatment. The primary endpoint was the number of patients healed without the need for surgery (not including skin grafting), assessed in all patients in follow-up at 50 weeks (or last observation for those healed for >10 weeks). A doctor masked to treatment assignment checked the indications for surgery according to predefined criteria. This study is registered with ClinicalTrials.gov, number NCT01432925. FINDINGS: Between July 1, 2011, and Jan 15, 2015, 119 patients were enrolled, with two patients per group lost to follow-up. 55 (96%) of 57 participants in the delayed-decision group and 52 (90%) of 58 participants in the standard-care group had healed lesions 1 year after start of antimicrobial treatment (relative risk [RR] 1·08, 95% CI 0·97-1·19). 37 (67%) of 55 patients in the delayed-decision group had their lesions healed without surgical intervention, as did 25 (48%) of 52 in the standard-care group (RR 1·40, 95% CI 1·00-1·96). The time to heal and residual functional limitations did not differ between the two groups (median time to heal 21 weeks [IQR 10-27] in the delayed-decision group and 21 weeks [10-39] in the standard-care group; functional limitations in six [11%] of 57 and three [5%] of 58 patients; p=0·32). Postponing the decision to operate resulted in reduced median duration of hospitalisation (5 days [IQR 0-187] vs 131 days [0-224]; p=0·024) and wound care (153 days [IQR 56-224] vs 182 days [94-307]; p=0·036). INTERPRETATION: In our study, patients treated for Buruli ulcer benefited from delaying the decision to operate. Even large ulcers can heal with antibiotics alone, without delaying healing rate and without an increase in residual functional limitations. FUNDING: NWO-VENI grant 241500, BUG Foundation, and UBS OPTIMUS.

Subcutaneous Granulomatous Inflammation due to Basidiobolomycosis: Case Reports of 3 Patients in Buruli Ulcer Endemic Areas in Benin.

BACKGROUND: Basidiobolomycosis is a rare subcutaneous mycosis, which can be mistaken for several other diseases, such as soft tissue tumors, lymphoma, or Buruli ulcer in the preulcerative stage. Microbiological confirmation by PCR for Basidiobolus ranarum and culture yield the most specific diagnosis, yet they are not widely available in endemic areas and with varying sensitivity. A combination of histopathological findings, namely, granulomatous inflammation with giant cells, septate hyphal fragments, and the Splendore-Hoeppli phenomenon, can confirm basidiobolomycosis in patients presenting with painless, hard induration of soft tissue. CASE PRESENTATIONS: We report on three patients misdiagnosed as suffering from Buruli ulcer, who did not respond to Buruli treatment. Histopathological review of the tissue sections from these patients suggests basidiobolomycosis. All patients had been lost to follow-up, and none received antifungal therapy. On visiting the patients at their homes, two were reported to have died of unknown causes. The third patient was found alive and well and had experienced local spontaneous healing. CONCLUSION: Basidiobolomycosis is a rare subcutaneous fungal disease mimicking preulcerative Buruli ulcer. We stress the importance of the early recognition by clinicians and pathologists of this treatable disease, so patients can timely receive antifungal therapy.

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.

Spatial Analysis of Anthropogenic Landscape Disturbance and Buruli Ulcer Disease in Benin.

BACKGROUND: Land use and land cover (LULC) change is one anthropogenic disturbance linked to infectious disease emergence. Current research has focused largely on wildlife and vector-borne zoonotic diseases, neglecting to investigate landscape disturbance and environmental bacterial infections. One example is Buruli ulcer (BU) disease, a necrotizing skin disease caused by the environmental pathogen Mycobacterium ulcerans (MU). Empirical and anecdotal observations have linked BU incidence to landscape disturbance, but potential relationships have not been quantified as they relate to land cover configurations. METHODOLOGY/PRINCIPAL FINDINGS: A landscape ecological approach utilizing Bayesian hierarchical models with spatial random effects was used to test study hypotheses that land cover configurations indicative of anthropogenic disturbance were related to Buruli ulcer (BU) disease in southern Benin, and that a spatial structure existed for drivers of BU case distribution in the region. A final objective was to generate a continuous, risk map across the study region. Results suggested that villages surrounded by naturally shaped, or undisturbed rather than disturbed, wetland patches at a distance within 1200 m were at a higher risk for BU, and study outcomes supported the hypothesis that a spatial structure exists for the drivers behind BU risk in the region. The risk surface corresponded to known BU endemicity in Benin and identified moderate risk areas within the boundary of Togo. CONCLUSIONS/SIGNIFICANCE: This study was a first attempt to link land cover configurations representative of anthropogenic disturbances to BU prevalence. Study results identified several significant variables, including the presence of natural wetland areas, warranting future investigations into these factors at additional spatial and temporal scales. A major contribution of this study included the incorporation of a spatial modeling component that predicted BU rates to new locations without strong knowledge of environmental factors contributing to disease distribution.

Clinical Epidemiology of Buruli Ulcer from Benin (2005-2013): Effect of Time-Delay to Diagnosis on Clinical Forms and Severe Phenotypes.

Buruli Ulcer (BU) is a neglected infectious disease caused by Mycobacterium ulcerans that is responsible for severe necrotizing cutaneous lesions that may be associated with bone involvement. Clinical presentations of BU lesions are classically classified as papules, nodules, plaques and edematous infiltration, ulcer or osteomyelitis. Within these different clinical forms, lesions can be further classified as severe forms based on focality (multiple lesions), lesions' size (>15 cm diameter) or WHO Category (WHO Category 3 lesions). There are studies reporting an association between delay in seeking medical care and the development of ulcerative forms of BU or osteomyelitis, but the effect of time-delay on the emergence of lesions classified as severe has not been addressed. To address both issues, and in a cohort of laboratory-confirmed BU cases, 476 patients from a medical center in Allada, Benin, were studied. In this laboratory-confirmed cohort, we validated previous observations, demonstrating that time-delay is statistically related to the clinical form of BU. Indeed, for non-ulcerated forms (nodule, edema, and plaque) the median time-delay was 32.5 days (IQR 30.0-67.5), while for ulcerated forms it was 60 days (IQR 20.0-120.0) (p = 0.009), and for bone lesions, 365 days (IQR 228.0-548.0). On the other hand, we show here that time-delay is not associated with the more severe phenotypes of BU, such as multi-focal lesions (median 90 days; IQR 56-217.5; p = 0.09), larger lesions (diameter >15 cm) (median 60 days; IQR 30-120; p = 0.92) or category 3 WHO classification (median 60 days; IQR 30-150; p = 0.20), when compared with unifocal (median 60 days; IQR 30-90), small lesions (diameter ≤15 cm) (median 60 days; IQR 30-90), or WHO category 1+2 lesions (median 60 days; IQR 30-90), respectively. Our results demonstrate that after an initial period of progression towards ulceration or bone involvement, BU lesions become stable regarding size and focal/multi-focal progression. Therefore, in future studies on BU epidemiology, severe clinical forms should be systematically considered as distinct phenotypes of the same disease and thus subjected to specific risk factor investigation.

Persisting social participation restrictions among former Buruli ulcer patients in Ghana and Benin.

BACKGROUND: Buruli ulcer may induce severe disabilities impacting on a person's well-being and quality of life. Information about long-term disabilities and participation restrictions is scanty. The objective of this study was to gain insight into participation restrictions among former Buruli ulcer patients in Ghana and Benin. METHODS: In this cross-sectional study, former Buruli ulcer patients were interviewed using the Participation Scale, the Buruli Ulcer Functional Limitation Score to measure functional limitations, and the Explanatory Model Interview Catalogue to measure perceived stigma. Healthy community controls were also interviewed using the Participation Scale. Trained native interviewers conducted the interviews. Former Buruli ulcer patients were eligible for inclusion if they had been treated between 2005 and 2011, had ended treatment at least 3 months before the interview, and were at least 15 years of age. RESULTS: In total, 143 former Buruli ulcer patients and 106 community controls from Ghana and Benin were included in the study. Participation restrictions were experienced by 67 former patients (median score, 30, IQR; 23;43) while 76 participated in social life without problems (median score 5, IQR; 2;9). Most restrictions encountered related to employment. Linear regression showed being female, perceived stigma, functional limitations, and larger lesions (category II) as predictors of more participation restrictions. CONCLUSION: Persisting participation restrictions were experienced by former BU patients in Ghana and Benin. Most important predictors of participation restrictions were being female, perceived stigma, functional limitations and larger lesions.

Psychometric properties of the participation scale among former buruli ulcer patients in Ghana and Benin.

BACKGROUND: Buruli ulcer is a stigmatising disease treated with antibiotics and wound care, and sometimes surgical intervention is necessary. Permanent limitations in daily activities are a common long term consequence. It is unknown to what extent patients perceive problems in participation in social activities. The psychometric properties of the Participation Scale used in other disabling diseases, such as leprosy, was assessed for use in former Buruli ulcer patients. METHODS: Former Buruli ulcer patients in Ghana and Benin, their relatives, and healthy community controls were interviewed using the Participation Scale, Buruli Ulcer Functional Limitation Score, and the Explanatory Model Interview Catalogue to measure stigma. The Participation Scale was tested for the following psychometric properties: discrimination, floor and ceiling effects, internal consistency, inter-item correlation, item-total correlation and construct validity. RESULTS: In total 386 participants (143 former Buruli ulcer patients with their relatives (137) and 106 community controls) were included in the study. The Participation Scale displayed good discrimination between former Buruli ulcer patients and healthy community controls. No floor and ceiling effects were found. Internal consistency (Cronbach's alpha) was 0.88. In Ghana, mean inter-item correlation of 0.29 and item-total correlations ranging from 0.10 to 0.69 were found while in Benin, a mean inter-item correlation of 0.28 was reported with item-total correlations ranging from -0.08 to 0.79. With respect to construct validity, 4 out of 6 hypotheses were not rejected, though correlations between various constructs differed between countries. CONCLUSION: The results indicate the Participation Scale has acceptable psychometric properties and can be used for Buruli ulcer patients in Ghana and Benin. Future studies can use this Participation Scale to evaluate the long term restrictions in participation in daily social activities of former BU patients.

Clinical considerations on Buruli ulcer employing two molecular tests for the detection of Mycobacterium ulcerans in 100 skin biopsies.

OBJECTIVES: Buruli ulcer (BU) is an infected cutaneous lesion, the etiological agent of which is Mycobacterium ulcerans. Diagnosis is confirmed by the identification of acid-fast bacilli and culture. In clinically suspicious forms with negative bacteriological or Ziehl-Neelsen (ZN) findings, molecular tests are used. This study compared the concordance of nested polymerase chain reaction (PCR) (targeting IS2404) and PCR (targeting IS2606) in different clinical situations. METHODS: A total of 57 samples were sourced from 39 BU patients. Control samples (n = 43) were obtained from non-BU ulcers in 38 patients. Samples were divided into two pieces and submitted to, respectively, histological examination and ZN staining, and PCR. Subsamples submitted to PCR were divided and submitted to nested PCR IS2404 and PCR IS2606, respectively. RESULTS: Of the 57 BU biopsies, positive results were obtained by nested PCR in 18 (31.6%) and by IS2606 PCR in 37 (64.9%) cases. Sequencing of the positive samples confirmed the specificity of amplicons in all nested PCR samples and in 26 of 37 (70.2%) samples positive to IS2606. Hence, nested PCR was more specific (100% vs. 93%) and less sensitive (32% vs. 46%) than IS2606 PCR. In the BU samples, nested PCR was negative in 15 instances, and IS2606 PCR was negative in 11 instances in which ZN histology had been positive (false negatives). Both PCRs were positive in six ZN-negative smears. CONCLUSIONS: We considered 57 samples from 39 BU patients in various clinical stages and at different times after the beginning of therapy. These provided positive results in 18 cases with IS2404 nested PCR and in 37 cases with PCR IS2606; only 26 of the latter remained positive subsequent to sequencing. Hence, even if IS2404 PCR is considered more specific, in subjects who appear to fail to respond to therapy, it is advisable to also carry out IS2606 PCR. A possible interpretation of the discordance between the two techniques due to unavoidable technical errors as well as to different sensitivity of the two tests at M. ulcerans DNA low concentration (i.e. in recent infection and in well-treated cases) is discussed.

Towards rational use of antibiotics for suspected secondary infections in Buruli ulcer patients.

BACKGROUND: The emerging disease Buruli ulcer is treated with streptomycin and rifampicin and surgery if necessary. Frequently other antibiotics are used during treatment. METHODS/PRINCIPAL FINDINGS: Information on prescribing behavior of antibiotics for suspected secondary infections and for prophylactic use was collected retrospectively. Of 185 patients that started treatment for Buruli ulcer in different centers in Ghana and Bénin 51 were admitted. Forty of these 51 admitted patients (78%) received at least one course of antibiotics other than streptomycin and rifampicin during their hospital stay. The median number (IQR) of antibiotic courses for admitted patients was 2 (1, 5). Only twelve patients received antibiotics for a suspected secondary infection, all other courses were prescribed as prophylaxis of secondary infections extended till 10 days on average after excision, debridement or skin grafting. Antibiotic regimens varied considerably per indication. In another group of BU patients in two centers in Bénin, superficial wound cultures were performed. These cultures from superficial swabs represented bacteria to be expected from a chronic wound, but 13 of the 34 (38%) S. aureus were MRSA. CONCLUSIONS/SIGNIFICANCE: A guide for rational antibiotic treatment for suspected secondary infections or prophylaxis is needed. Adherence to the guideline proposed in this article may reduce and tailor antibiotic use other than streptomycin and rifampicin in Buruli ulcer patients. It may save costs, reduce toxicity and limit development of further antimicrobial resistance. This topic should be included in general protocols on the management of Buruli ulcer.

Perceptions on the effectiveness of treatment and the timeline of Buruli ulcer influence pre-hospital delay reported by healthy individuals.

BACKGROUND: Delay in seeking treatment at the hospital is a major challenge in current Buruli ulcer control; it is associated with severe sequelae and functional limitations. Choosing alternative treatment and psychological, social and practical factors appear to influence delay. Objectives were to determine potential predictors for pre-hospital delay with Leventhal's commonsense model of illness representations, and to explore whether the type of available dominant treatment modality influenced individuals' perceptions about BU, and therefore, influenced pre-hospital delay. METHODOLOGY: 130 healthy individuals aged >18 years, living in BU-endemic areas in Benin without any history of BU were included in this cross-sectional study. Sixty four participants from areas where surgery was the dominant treatment and sixty six participants from areas where antibiotic treatment was the dominant treatment modality were recruited. Using a semi-structured interview we measured illness perceptions (IPQ-R), knowledge about BU, background variables and estimated pre-hospital delay. PRINCIPAL FINDINGS: The individual characteristics 'effectiveness of treatment' and 'timeline acute-chronic' showed the strongest association with pre-hospital delay. No differences were found between regions where surgery was the dominant treatment and regions where antibiotics were the dominant treatment modality. CONCLUSIONS: Individual characteristics, not anticipated treatment modality appeared predictors of pre-hospital delay.