Emergence and spread of Mycobacterium ulcerans at different geographic scales

The classical lineage of Mycobacterium ulcerans is the most prevalent clonal group associated with Buruli ulcer in humans. Its reservoir is strongly associated with the environment. We analyzed together 1,045 isolates collected from 13 countries on two continents to define the evolutionary history and population dynamics of this lineage. We confirm that this lineage spread over 7,000 years from Australia to Africa with the emergence of outbreaks in distinct waves in the 18th and 19th centuries. In sharp contrast with its global spread over the last century, transmission chains are now mostly local, with little or no dissemination between endemic areas. This study provides new insights into the phylogeography and population dynamics of M. ulcerans, highlighting the importance of comparative genomic analyses to improve our understanding of pathogen transmission.

IMPORTANCE

Mycobacterium ulcerans is an environmental mycobacterial pathogen that can cause Buruli ulcer, a severe cutaneous infection, mostly spread in Africa and Australia. We conducted a large genomic study of M. ulcerans, combining genomic and evolutionary approaches to decipher its evolutionary history and pattern of spread at different geographic scales. At the scale of villages in an endemic area of Benin, the circulating genotypes have been introduced in recent decades and are not randomly distributed along the river. On a global scale, M. ulcerans has been spreading for much longer, resulting in distinct and compartmentalized endemic foci across Africa and Australia.

Mosquitoes provide a transmission route between possums and humans for Buruli ulcer in southeastern Australia

Buruli ulcer, a chronic subcutaneous infection caused by Mycobacterium ulcerans, is increasing in prevalence in southeastern Australia. Possums are a local wildlife reservoir for M. ulcerans and, although mosquitoes have been implicated in transmission, it remains unclear how humans acquire infection. We conducted extensive field survey analyses of M. ulcerans prevalence among mosquitoes in the Mornington Peninsula region of southeastern Australia. PCR screening of trapped mosquitoes revealed a significant association between M. ulcerans and Aedes notoscriptus. Spatial scanning statistics revealed overlap between clusters of M. ulcerans-positive Ae. notoscriptus, M. ulcerans-positive possum excreta and Buruli ulcer cases, and metabarcoding analyses showed individual mosquitoes had fed on humans and possums. Bacterial genomic analysis confirmed shared single-nucleotide-polymorphism profiles for M. ulcerans detected in mosquitoes, possum excreta and humans. These findings indicate Ae. notoscriptus probably transmit M. ulcerans in southeastern Australia and highlight mosquito control as a Buruli ulcer prevention measure.

Accelerating the healing of hard-to-heal wounds with food supplements: nutritional analysis in the Côte d'Ivoire

OBJECTIVE

Hard-to-heal wounds are an important, yet often neglected, public health issue in low- and middle-income countries (LMICs). Malnutrition has been identified as a risk factor for prolonged healing times. However, nutritional supplements are not routinely provided for patients with hard-to-heal wounds, and so this study aimed to investigate their benefits.

METHOD

This 9-month study was conducted in the Taabo Health and Demographic Surveillance System in the south-central part of Côte d'Ivoire. Patients with wounds (≥30mm2) were recruited. Treatment was standardised for inpatients (72%) and outpatients (28%). There were three intervention groups: supplemented with soy; orange flesh sweet potato (OFSP); or both. Another group was included without supplement, serving as control. General linear models were employed to assess the effects of log initial wound size, type of wound, food treatment group, haemoglobin, sex, age, place of treatment and body mass index on the rate of wound closure.

RESULTS

The cohort consisted of 56 patients, 41 of whom were placed in intervention groups, and the remainder as controls. Within the cohort, 37 (66%) patients suffered from Buruli ulcer, 15 (27%) from traumatic wounds and four (7%) from erysipelas. We found a significant effect (p=0.004) of diet supplemented with OFSP on the wound healing rate.

CONCLUSION

OFSP is a nutritional rehabilitation supplement, characterised by a high content of beta-carotene and carbohydrates. It is associated with shortened wound healing times, reduced discomfort and reduced cost of wound care. Further research should investigate the effect of a diet rich in beta-carotene, in combination with standard medical care, on hard-to-heal wound healing in LMICs.

Mycobacterium ulcerans not detected by PCR on human skin in Buruli ulcer endemic areas of south eastern Australia

INTRODUCTION

Mycobacterium ulcerans (MU) causes Buruli ulcer (Buruli), a geographically restricted infection that can result in skin loss, contracture and permanent scarring. Lesion-location maps compiled from more than 640 cases in south eastern Australia suggest biting insects are likely involved in transmission, but it is unclear whether MU is brought by insects to humans or if MU is already on the skin and inoculation is an opportunistic event that need not be insect dependent.

METHODS

We validated a PCR swab detection assay and defined its dynamic range using laboratory cultured M. ulcerans and fresh pigskin. We invited volunteers in Buruli-endemic and non-endemic areas to sample their skin surfaces with self-collected skin swabs tested by IS2404 quantitative PCR.

RESULTS

Pigskin validation experiments established a limit-of-detection of 0.06 CFU/cm2 at a qPCR cycle threshold (Ct) of 35. Fifty-seven volunteers returned their self-collected kits of 4 swabs (bilateral ankles, calves, wrists, forearms), 10 from control areas and 47 from endemic areas. Collection was timed to coincide with the known peak-transmission period of Buruli. All swabs from human volunteers tested negative (Ct ≥35).

CONCLUSIONS

M. ulcerans was not detected on the skin of humans from highly Buruli endemic areas.

Comprehensive Case-Control Study of Protective and Risk Factors for Buruli Ulcer, Southeastern Australia

To examine protective and risk factors for Buruli ulcer (BU), we conducted a case-control study of 245 adult BU cases and 481 postcode-matched controls across BU-endemic areas of Victoria, Australia. We calculated age- and sex-adjusted odds ratios for socio-environmental, host, and behavioral factors associated with BU by using conditional logistic regression. Odds of BU were >2-fold for persons with diabetes mellitus and persons working outdoors who had soil contact in BU-endemic areas (compared with indoor work) but were lower among persons who had bacillus Calmette-Guérin vaccinations. BU was associated with increasing numbers of possums and with ponds and bore water use at residences. Using insect repellent, covering arms and legs outdoors, and immediately washing wounds were protective; undertaking multiple protective behaviors was associated with the lowest odds of BU. Skin hygiene/protection behaviors and previous bacillus Calmette-Guérin vaccination might provide protection against BU in BU-endemic areas.

Statistical modeling based on structured surveys of Australian native possum excreta harboring Mycobacterium ulcerans predicts Buruli ulcer occurrence in humans

Background

Buruli ulcer (BU) is a neglected tropical disease caused by infection of subcutaneous tissue with Mycobacterium ulcerans. BU is commonly reported across rural regions of Central and West Africa but has been increasing dramatically in temperate southeast Australia around the major metropolitan city of Melbourne, with most disease transmission occurring in the summer months. Previous research has shown that Australian native possums are reservoirs of M. ulcerans and that they shed the bacteria in their fecal material (excreta). Field surveys show that locales where possums harbor M. ulcerans overlap with human cases of BU, raising the possibility of using possum excreta surveys to predict the risk of disease occurrence in humans.

Methods

We thus established a highly structured 12 month possum excreta surveillance program across an area of 350 km2 in the Mornington Peninsula area 70 km south of Melbourne, Australia. The primary objective of our study was to assess using statistical modeling if M. ulcerans surveillance of possum excreta provided useful information for predicting future human BU case locations.

Results

Over two sampling campaigns in summer and winter, we collected 2,282 possum excreta specimens of which 11% were PCR positive for M. ulcerans-specific DNA. Using the spatial scanning statistical tool SaTScan, we observed non-random, co-correlated clustering of both M. ulcerans positive possum excreta and human BU cases. We next trained a statistical model with the Mornington Peninsula excreta survey data to predict the future likelihood of human BU cases occurring in the region. By observing where human BU cases subsequently occurred, we show that the excreta model performance was superior to a null model trained using the previous year's human BU case incidence data (AUC 0.66 vs 0.55). We then used data unseen by the excreta-informed model from a new survey of 661 possum excreta specimens in Geelong, a geographically separate BU endemic area to the southwest of Melbourne, to prospectively predict the location of human BU cases in that region. As for the Mornington Peninsula, the excreta-based BU prediction model outperformed the null model (AUC 0.75 vs 0.50) and pinpointed specific locations in Geelong where interventions could be deployed to interrupt disease spread.

Conclusions

This study highlights the One Health nature of BU by confirming a quantitative relationship between possum excreta shedding of M. ulcerans and humans developing BU. The excreta survey-informed modeling we have described will be a powerful tool for the efficient targeting of public health responses to stop BU.

Funding

This research was supported by the National Health and Medical Research Council of Australia and the Victorian Government Department of Health (GNT1152807 and GNT1196396).

Gold Panning-Related Chronic Cutaneous Ulcers in Guinea, West Africa

Chronic cutaneous ulcers caused potentially by several pathogens are of increasing concern in endemic tropical countries, including Guinea in West Africa, in rural populations exposed to aquatic environments during recreational, domestic, or agricultural activities. By plotting 1,011 cases of chronic cutaneous ulcers classified under the name Buruli ulcer in 24 of 33 Guinea health districts (72%) between 2018 and 2020 against the gold map and gold-panning map of Guinea, we revealed a significant spatial association between chronic cutaneous ulcer foci and gold-panning foci (P < 0.05), but not with nongold-panning foci (P = 0.12) in Guinea. Gold panning should be listed as an additional economic activity exposing populations to chronic cutaneous ulcers. Further research may aim to clarify whether any geological and biologic factors underlie such an association, besides the possibility that the unprotected skin of gold panners may be exposed to opportunistic, pathogen-contaminated environments in gold-panning areas.

Environmental risk factors associated with the presence of Mycobacterium ulcerans in Victoria, Australia

In recent years reported cases of Buruli ulcer, caused by Mycobacterium ulcerans, have increased substantially in Victoria, Australia, with the epidemic also expanding geographically. To develop an understanding of how M. ulcerans circulates in the environment and transmits to humans we analyzed environmental samples collected from 115 properties of recent Buruli ulcer cases and from 115 postcode-matched control properties, for the presence of M. ulcerans. Environmental factors associated with increased odds of M. ulcerans presence at a property included certain native plant species and native vegetation in general, more alkaline soil, lower altitude, the presence of common ringtail possums (Pseudocheirus peregrinus) and overhead powerlines. However, only overhead powerlines and the absence of the native plant Melaleuca lanceolata were associated with Buruli ulcer case properties. Samples positive for M. ulcerans were more likely to be found at case properties and were associated with detections of M. ulcerans in ringtail possum feces, supporting the hypothesis that M. ulcerans is zoonotic, with ringtail possums the strongest reservoir host candidate. However, the disparity in environmental risk factors associated with M. ulcerans positive properties versus case properties indicates the involvement of human behavior or the influence of other environmental factors in disease acquisition that requires further study.

Quantifying Population Burden and Effectiveness of Decentralized Surveillance Strategies for Skin-Presenting Neglected Tropical Diseases, Liberia

We evaluated programmatic approaches for skin neglected tropical disease (NTD) surveillance and completed a robust estimation of the burden of skin NTDs endemic to West Africa (Buruli ulcer, leprosy, lymphatic filariasis morbidity, and yaws). In Maryland, Liberia, exhaustive case finding by community health workers of 56,285 persons across 92 clusters identified 3,241 suspected cases. A total of 236 skin NTDs (34.0 [95% CI 29.1–38.9]/10,000 persons) were confirmed by midlevel healthcare workers trained using a tailored program. Cases showed a focal and spatially heterogeneous distribution. This community health worker‒led approach showed a higher skin NTD burden than prevailing surveillance mechanisms, but also showed high (95.1%) and equitable population coverage. Specialized training and task-shifting of diagnoses to midlevel health workers led to reliable identification of skin NTDs, but reliability of individual diagnoses varied. This multifaceted evaluation of skin NTD surveillance strategies quantifies benefits and limitations of key approaches promoted by the 2030 NTD roadmap of the World Health Organization.

Evaluation of the fluorescent-thin layer chromatography (f-TLC) for the diagnosis of Buruli ulcer disease in Ghana

Background

Buruli ulcer is a tissue necrosis infection caused by an environmental mycobacterium called Mycobacterium ulcerans (MU). The disease is most prevalent in rural areas with the highest rates in West and Central African countries. The bacterium produces a toxin called mycolactone which can lead to the destruction of the skin, resulting in incapacitating deformities with an enormous economic and social burden on patients and their caregivers. Even though there is an effective antibiotic treatment for BU, the control and management rely on early case detection and rapid diagnosis to avert morbidities. The diagnosis of Mycobacterium ulcerans relies on smear microscopy, culture histopathology, and PCR. Unfortunately, all the current laboratory diagnostics have various limitations and are not available in endemic communities. Consequently, there is a need for a rapid diagnostic tool for use at the community health centre level to enable diagnosis and confirmation of suspected cases for early treatment. The present study corroborated the diagnostic performance and utility of fluorescent-thin layer chromatography (f-TLC) for the diagnosis of Buruli ulcer.

Methodology/Principal findings

The f-TLC method was evaluated for the diagnosis of Buruli ulcer in larger clinical samples than previously reported in an earlier preliminary study Wadagni et al. (2015). A total of 449 patients suspected of BU were included in the final data analysis out of which 122 (27.2%) were positive by f-TLC and 128 (28.5%) by PCR. Using a composite reference method generated from the two diagnostic methods, 85 (18.9%) patients were found to be truly infected with M. ulcerans, 284 (63.3%) were uninfected, while 80 (17.8%) were misidentified as infected or noninfected by the two methods. The data obtained was used to determine the discriminatory accuracy of the f-TLC against the gold standard IS2404 PCR through the analysis of its sensitivity, specificity, positive (+LR), and negative (–LR) likelihood ratio. The positive (PPV) and negative (NPV) predictive values, area under the receiver operating characteristic curve Azevedo et al. (2014), and diagnostic odds ratio were used to assess the predictive accuracy of the f-TLC method. The sensitivity of f-TLC was 66.4% (85/128), specificity was 88.5% (284/321), while the diagnostic accuracy was 82.2% (369/449). The AUC stood at 0.774 while the PPV, NPV, +LR, and–LR were 69.7% (85/122), 86.9% (284/327), 5.76, and 0.38, respectively. The use of the rule-of-thumb interpretation of diagnostic tests suggests that the method is good for use as a diagnostic tool.

Conclusions/Significance

Larger clinical samples than previously reported had been used to evaluate the f-TLC method for the diagnosis of Buruli ulcer. A sensitivity of 66.4%, a specificity of 88.5%, and diagnostic accuracy of 82.2% were obtained. The method is good for diagnosis and will help in making early clinical decisions about the patients as well as patient management and facilitating treatment decisions. However, it requires a slight modification to address the challenge of background interference and lack of automatic readout to become an excellent diagnostic tool.

Methods and Approaches for Buruli Ulcer Surveillance in Africa: Lessons Learnt and Future Directions

Over 95% of the global burden of Buruli ulcer disease (BU) caused by Mycobacterium ulcerans occurs in equatorial Africa. National and sub-national programs have implemented various approaches to improve detection and reporting of incident cases over recent decades. Regional incidence rates are currently in decline; however, surveillance targets outlined in 2012 by WHO have been missed and detection bias may contribute to these trends. In light of the new 2030 NTD roadmap and disease-specific targets, BU programs are required to strengthen case detection and begin a transition towards integration with other skin-NTDs. This transition comes with new opportunities to enhance existing BU surveillance systems and develop novel approaches for implementation and evaluation.In this review, we present a breakdown and assessment of the methods and approaches that have been the pillars of BU surveillance systems in Africa: (1) Passive case detection, (2) Data systems, (3) Clinical training, (4) Active case finding, (5) Burden estimation, and (6) Laboratory confirmation pathways. We discuss successes, challenges, and relevant case studies before highlighting opportunities for future development and evaluation including novel data collection tools, risk-based surveillance, and integrated skin-NTD surveillance. We draw on both experience and available literature to critically evaluate methods of BU surveillance in Africa and highlight new approaches to help achieve 2030 roadmap targets.

Systematic review of M. Bovis BCG and other candidate vaccines for Buruli ulcer prophylaxis

Buruli ulcer, caused by Mycobacterium ulcerans, is a neglected tropical disease endemic to over 30 countries, with increasing incidence in temperate, coastal Victoria, Australia. Strategies to control transmission are urgently required. This study systematically reviews the literature to identify and describe candidate prophylactic Buruli ulcer vaccines. This review highlights that Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccine is the only vaccine studied in randomised controlled trials and confirms its importance as a benchmark for comparison against putative vaccines in pre-clinical studies. Nevertheless, BCG alone is unable to offer long-term protection in humans. A number of experimental vaccines that exceed the protection provided by BCG in mice have emerged, particularly those utilising recombinant BCG expressing immunogenic M. ulcerans proteins. Although progress is promising, there remain key questions about the optimal approach to characterising the immunological correlates of protection in humans and strategies to investigate the safety and efficacy of such vaccines in humans.

Correlation between Buruli Ulcer Incidence and Vectorborne Diseases, Southeastern Australia, 2000-2020

Researchers have hypothesized that mosquitoes are vectors involved in Mycobacterium ulcerans transmission. Previous findings of a correlation between incidence of M. ulcerans, which causes Buruli ulcer, and locally acquired vectorborne diseases in southeastern Australia further strengthened this argument. However, our updated data indicate that this correlation has not continued beyond 2008.

Caregiver burden in Buruli ulcer disease: Evidence from Ghana

BACKGROUND

Buruli ulcer disease (BUD) results in disabilities and deformities in the absence of early medical intervention. The extensive role of caregiving in BUD is widely acknowledged, however, associated caregiver burden is poorly understood. In this paper we assessed the burden which caregivers experience when supporting patients with BUD in Ghana.

METHOD/ PRINCIPAL FINDINGS

This qualitative study was conducted in 3 districts in Ghana between August and October 2019. 13 semi-structured interviews were conducted on caregivers of BUD patients in the local language of Twi. Data was translated into English, coded into broad themes, and direct content analysis approach was used to analyse results. The results show the caregivers face financial, psychological and health issues as a consequence of their caregiving role.

CONCLUSION/ SIGNIFICANCE

This study found significant caregiver burden on family members. It also highlighted the psychological burden caregivers experience and the limited knowledge of the disease within endemic communities. Further research is needed to quantify the caregiver burden of BUD at different economic levels in order to better understand the impact of possible caregiver interventions on patient outcomes.

Stable and Local Reservoirs of Mycobacterium ulcerans Inferred from the Nonrandom Distribution of Bacterial Genotypes, Benin

Mycobacterium ulcerans is the causative agent of Buruli ulcer, a neglected tropical disease found in rural areas of West and Central Africa. Despite the ongoing efforts to tackle Buruli ulcer epidemics, the environmental reservoir of its pathogen remains elusive, underscoring the need for new approaches to improving disease prevention and management. In our study, we implemented a local-scale spatial clustering model and deciphered the genetic diversity of the bacteria in a small area of Benin where Buruli ulcer is endemic. Using 179 strain samples from West Africa, we conducted a phylogeographic analysis combining whole-genome sequencing with spatial scan statistics. The 8 distinct genotypes we identified were by no means randomly spread over the studied area. Instead, they were divided into 3 different geographic clusters, associated with landscape characteristics. Our results highlight the ability of M. ulcerans to evolve independently and differentially depending on location in a specific ecologic reservoir.

Mapping suitability for Buruli ulcer at fine spatial scales across Africa: A modelling study

Buruli ulcer (BU) is a disabling and stigmatising neglected tropical disease (NTD). Its distribution and burden are unknown because of underdiagnosis and underreporting. It is caused by Mycobacterium ulcerans, an environmental pathogen whose environmental niche and transmission routes are not fully understood. The main control strategy is active surveillance to promote early treatment and thus limit morbidity, but these activities are mostly restricted to well-known endemic areas. A better understanding of environmental suitability for the bacterium and disease could inform targeted surveillance, and advance understanding of the ecology and burden of BU. We used previously compiled point-level datasets of BU and M. ulcerans occurrence, evidence for BU occurrence within national and sub-national areas, and a suite of relevant environmental covariates in a distribution modelling framework. We fitted relationships between BU and M. ulcerans occurrence and environmental predictors by applying regression and machine learning based algorithms, combined in an ensemble model to characterise the optimal ecological niche for the disease and bacterium across Africa at a resolution of 5km x 5km. Proximity to waterbodies was the strongest predictor of suitability for BU, followed potential evapotranspiration. The strongest predictors of suitability for M. ulcerans were deforestation and potential evapotranspiration. We identified patchy foci of suitability throughout West and Central Africa, including areas with no previous evidence of the disease. Predicted suitability for M. ulcerans was wider but overlapping with that of BU. The estimated population living in areas predicted suitable for the bacterium and disease was 46.1 million. These maps could be used to inform burden estimations and case searches which would generate a more complete understanding of the spatial distribution of BU in Africa, and may guide control programmes to identify cases beyond the well-known endemic areas.

Introduction of Mycobacterium ulcerans disease in the Bankim Health District of Cameroon follows damming of the Mapé River

Buruli ulcer (BU) is an emerging ulcerative skin disease caused by infection with Mycobacterium ulcerans. Efforts to control its spread have been hampered by our limited understanding of M. ulcerans reservoirs and transmission, and the factors leading to the emergence of BU disease in a particular region. In this report we investigate an anecdotal link between damming the Mapé River in Cameroon and the emergence of BU in the Health Districts bordering Lake Bankim, the impoundment created by the Mapé dam. We used bacterial population genomics and molecular dating to find compelling support for a 2000 M. ulcerans introduction event that followed about 10 years after the filling of the newly created impoundment in 1988. We compared the genomic reconstructions with high-resolution satellite imagery to investigate what major environmental alterations might have driven the emergence of the new focus.

Impact of common skin diseases on children in rural Côte d'Ivoire with leprosy and Buruli ulcer co-endemicity: A mixed methods study

BACKGROUND

Skin-related neglected tropical diseases (skin NTDs) occur against a background of a very high prevalence of common skin diseases in sub-Saharan Africa. In this study, we examined the knowledge, attitude and practices (KAP) and the impact of common skin diseases in children living in a leprosy and Buruli ulcer (BU) co-endemic district in a west African country of Côte d'Ivoire, in order to help inform disease control efforts for skin NTDs.

METHODS AND PRINCIPLE FINDINGS

Fourteen focus group discussions (FGDs) with schoolchildren, 5 FGDs with parents of a child affected with skin disease(s), and 27 in-depth semi-structured interviews with key personnel were conducted. The Children's Dermatology Quality of Life Index (CDLQI) questionnaire was applied to 184 schoolchildren with skin diseases. We found that there was ignorance or neglect towards skin diseases in general, due to their high prevalence and also the perceived minimal impact on children's daily lives. While the median score for the CDLQI questionnaire was 5 (IQR 2-9) out of 30, a range of scores was observed. Symptoms such as pruritus and experiencing bullying by classmates contributed to reduction in their quality of life. Poor hygiene was considered as a major cause of skin diseases.

CONCLUSIONS/SIGNIFICANCE

Despite their high impact on affected populations, we observed a high level of ignorance and neglect toward common skin diseases. There is a critical need to increase awareness of skin diseases, or skin health promotion, which supports changing of the health-seeking behaviour for skin conditions. This will aid in early detection and treatment of the skin NTDs, in addition to providing benefits for those affected by other skin diseases. Educational opportunities should be utilized to their utmost. One would be associated with water, sanitation, and hygiene (WASH) strategies, but careful messages need to be developed and delivered.

Integrated approach in the control and management of skin neglected tropical diseases in three health districts of Côte d'Ivoire

BACKGROUND

Neglected tropical diseases (NTDs) comprise 20 communicable diseases that are prevalent in rural poor and remote communities with less access to the health system. For effective and efficient control, the WHO recommends that affected countries implement integrated control interventions that take into account the different co-endemic NTDs in the same community. However, implementing these integrated interventions involving several diseases with different etiologies, requiring different control approaches and driven by different vertical programs, remains a challenge. We report here the results and lessons learned from a pilot test of this integrated approach based on integrated screening of skin diseases in three co-endemic health districts of Côte d'Ivoire, a West African country endemic for Buruli ulcer, leprosy and yaw.

METHOD

This cross-sectional study took place from April 2016 to March 2017 in 3 districts of Côte d'Ivoire co-endemic for BU, leprosy and yaws. The study was carried out in 6 stages: identification of potentially co-endemic communities; stakeholder training; social mobilization; mobile medical consultations; case detection and management; and a review meeting.

RESULTS

We included in the study all patients with skin signs and symptoms at the screening stage who voluntarily accepted screening. In total, 2310 persons screened had skin lesions at the screening stage. Among them, 07 cases were diagnosed with Buruli ulcer. There were 30 leprosy cases and 15 yaws detected. Other types of ulcerations and skin conditions have been identified and represent the majority of cases detected. We learned from this pilot experience that integration can be successfully implemented in co-endemic communities in Côte d'Ivoire. Health workers are motivated and available to implement integrated interventions instead of interventions focused on a single disease. However, it is essential to provide capacity building, a minimum of drugs and consumables for the care of the patients identified, as well as follow-up of identified patients, including those with other skin conditions.

CONCLUSIONS

The results of this study show that the integration of activities can be successfully implemented in co-endemic communities under the condition of staff capacity building and minimal care of identified patients.

Global Epidemiology of Buruli Ulcer, 2010-2017, and Analysis of 2014 WHO Programmatic Targets

Buruli ulcer is a neglected tropical disease caused by Myocobacterium ulcerans; it manifests as a skin lesion, nodule, or ulcer that can be extensive and disabling. To assess the global burden and the progress on disease control, we analyzed epidemiologic data reported by countries to the World Health Organization during 2010–2017. During this period, 23,206 cases of Buruli ulcer were reported. Globally, cases declined to 2,217 in 2017, but local epidemics seem to arise, such as in Australia and Liberia. In 2013, the World Health Organization formulated 4 programmatic targets for Buruli ulcer that addressed PCR confirmation, occurrence of category III (extensive) lesions and ulcerative lesions, and movement limitation caused by the disease. In 2014, only the movement limitation goal was met, and in 2019, none are met, on a global average. Our findings support discussion on future Buruli ulcer policy and post-2020 programmatic targets.

Individual and clinical variables associated with the risk of Buruli ulcer acquisition: A systematic review and meta-analysis

BACKGROUND

Buruli ulcer (BU) is a necrotizing skin disease, caused by Mycobacterium ulcerans, with poorly understood acquisition risk factors. This review aims at evaluating the importance of individual-sex, age, family ties with history of BU, gene variants-and clinical-Bacillus Calmette-Guérin (BCG) immunization, Human Immunodeficiency Virus (HIV) infection-variables in this process.

METHODS

A systematic review was performed considering the following databases: ClinicalTrials.gov, Cochrane Controlled Register of Trials (CENTRAL), Current Contents Connect, Embase, MEDLINE, SciELO, Scopus and Web of Science. Eligible studies were critically appraised with The Joanna Briggs Institute checklists and heterogeneity was assessed with Cochran Q-test and I2 statistic. Published demographic data was descriptively analysed and clinical data pooled within random-effects modelling for meta-analysis.

RESULTS

A total of 29 studies were included in the systematic review. Two randomized controlled trials (RCTs) and 21 case-control studies were selected for meta-analysis. Studies show that BU mainly affects age extremes, more preponderately males among children. Data pooled from RCTs do not reveal BCG to be protective against BU (odds ratio (OR) = 0.63; 95% CI = 0.38-1.05; I2 = 56%), a finding case-control studies appear to corroborate. HIV infection (OR = 6.80; 95% CI = 2.33-19.85; I2 = 0%) and SLC11A1 rs17235409 A allele (OR = 1.86; 95% CI = 1.25-2.77; I2 = 0%) are associated with increased prevalence of the disease. No definite conclusions can be drawn regarding the influence of previous family history of BU.

DISCUSSION

While available evidence warrants further robustness, these results have direct implications on current interventions and future research programs, and foster the development of more cost-effective preventive and screening measures.

REGISTRATION

The study was registered at PROSPERO with number CRD42019123611.

Evaluation of the national tuberculosis surveillance and response systems, 2018 to 2019: National Tuberculosis, Leprosy and Buruli Ulcer Control Programme, Abuja, Nigeria

INTRODUCTION

Nigeria is among the countries with high Tuberculosis (TB) burden by global rating signifying the relevance of TB surveillance system evaluation in improving performance and capacity of the existing system. Hence, this evaluation was conducted in order to determine the gaps and proffer solution to enhance the TB surveillance system performance.

METHODS

questionnaires were administered to eight key informants using face-to-face interview method; data obtained was analyzed. Total number of TB cases and estimated number of cases for year 2018 was obtained. Percentage of positive cases using the GeneXpert test for 6 months (January to June 2019) was obtained. Available documents and publications on the National Tuberculosis, Leprosy and Buruli Ulcer Control Programme (NTBLCP) were also sought for information.

RESULTS

the NTBLCP has over 5,300 TB service points and 1,602 microscopy Centre's distributed across the country. Acceptance for the standard TB case definition was 100%, forms used are easy to fill and diagnosis is laboratory-based requiring specialized trainings for laboratory personnel. The system had 25% sensitivity, high data quality with 100% timeliness. The TB surveillance system is representative of all ages. The system was first designed as TB and Leprosy Control Programme but later Buruli ulcer was incorporated into the Programme. First quarter supervisory visits are skipped due to late funding and delayed budget approval. Major share of the funding comes from donor partners.

CONCLUSION

the system is useful, representative, acceptable, has good data quality, timely, and sensitive. The system is stable but needs to be funded more by the government. There is need for early funding and budget approval to avoid skipping of supervisory visits due to funding challenges. The system is not simple due the various test that need to be conducted before, during and after treatment to detect and verify that the patient is cured. We recommend continuous training of health workers, routine monitoring and evaluation, integration of TB care and prevention into other health services programmes like HIV/AIDS and active case search at all levels to increase the sensitivity of the system. Speed up the process of integration of NTBLCP surveillance system with IDSR for data harmonization in the country.

"Buruli ulcer and leprosy, they are intertwined": Patient experiences of integrated case management of skin neglected tropical diseases in Liberia

BACKGROUND

Skin neglected tropical diseases (NTDs) such as Buruli ulcer (BU) and leprosy produce significant stigma and disability. Shared clinical presentations and needs for care present opportunities for integrated case management in co-endemic areas. As global policies are translated into local integrated services, there remains a need to monitor what new configurations of care emerge and how individuals experience them.

METHODS

To explore patient experiences of integrated case management for skin NTDs, in 2018, we conducted a field-based qualitative case series in a leprosy rehabilitation centre in Ganta, Liberia where BU services were recently introduced. Twenty patients with BU (n = 10) and leprosy (n = 10) participated in in-depth interviews that incorporated photography methods. We contextualised our findings with field observations and unstructured interviews with health workers.

FINDINGS

The integration of care for BU and leprosy prompted new conceptualisations of these diseases and experiences of NTD stigma. Some patients felt anxiety about using services because they feared being infected with the other disease. Other patients viewed the two diseases as 'intertwined': related manifestations of the same condition. Configurations of inter-disease stigma due to fear of transmission were buffered by joint health education sessions which also appeared to facilitate social support between patients in the facility. For both diseases, medication and wound care were viewed as the cornerstones of care and appreciated as interventions that led to rehabilitation of the whole patient group through shared experiences of healing, avoidance of physical deformities and stigma reduction. Patient accounts of intense pain during wound care for BU and inability of staff to manage severe complications, however, exposed some shortcomings of medical care for the newly integrated service, as did patient fears of long-lasting disability due to lack of physiotherapy services.

SIGNIFICANCE

Under integrated care policies, the possibility of new discourses about skin NTD identities emerging along with new configurations of stigma may have unanticipated consequences for patients' experiences of case management. The social experience of integrated medication and wound dressing has the potential to link patients within a single, supportive patient community. Control programmes with resource constraints should anticipate potential challenges of integrating care, including the need to ameliorate lasting disability and provide adequate clinical management of severe BU cases.

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

Buruli ulcer is a necrotizing and disabling skin infection, caused by Mycobacterium ulcerans. The infection, a skin-related Neglected Tropical Diseases, affects mostly people living in limited resources settings. Since the introduction of rifampicin based combination antibiotic therapy as standard care, the role of surgery as adjunct therapy to kill M. ulcerans is less defined and understood. A randomized controlled trial showed benefit from delaying the decision to operate. Nevertheless, the rate of surgical interventions differs highly per clinic. We present the differences in rate of surgical interventions in six different Buruli ulcer treatment centers in Ghana and Benin. We demonstrate that these differences mainly depend on the opinion of the health care workers working in the treatment centers even after adjusting for disease severity.

Effect of well drilling on Buruli ulcer incidence in Benin: a case-control, quantitative survey

BACKGROUND

Buruli ulcer is the third most common mycobacterial disease worldwide. The public health burden of this neglected tropical disease is large, particularly in poor areas of west and central Africa. The development of appropriate preventive strategies is hampered by an incomplete understanding of the epidemiology and transmission of the disease. We investigated the effect of the drilling of wells on Buruli ulcer incidence.

METHODS

In this case-control, quantitative survey, we obtained field data for Buruli ulcer incidence over a 10-year period from a specialised centre that collected data for the Ouémé and Plateau departments in Benin, and data for well drilling from the Ministry of Energy, Water and Mines in Benin. The coordinates of the wells drilled were obtained during site visits. A case-control study was then done to investigate the role of well water use in protecting against Buruli ulcer.

FINDINGS

We found a strong inverse correlation between the incidence of Buruli ulcer and the number of new wells drilled in the Bonou municipality (r²=0·8818). A case-control study (106 cases and 212 controls) showed that regular use of the water from the wells for washing, bathing, drinking, or cooking was protective against Buruli ulcer (adjusted odds ratio 0·1, 95% CI 0·04-0·44; p=0·0012).

INTERPRETATION

This study opens up new possibilities for developing an effective yet affordable policy to fight the disease on a substantial geographical scale. Our study shows that providing access to protected water is an efficient and feasable way to reduce the incidence of Buruli ulcer.

FUNDING

Fondation Francaise Raoul Follereau, French National Institute of Health and Medical Research, and Région Pays de Loire.

An integrated assessment of leprosy, Buruli ulcer, and yaws around the irrigated perimeters of Bagré and Kompienga in Burkina Faso

Burkina Faso shares its borders with six countries that regularly report cases of Buruli ulcer, yaws, and leprosy (Hansen disease), three neglected tropical diseases with dermatological manifestations. Treatment of leprosy has shown excellent results, and it appears to be essentially eliminated. The same cannot be said for Buruli ulcer or yaws, the epidemiology of which remains poorly elucidated. In this context, it was essential to review the situation of these three diseases through a joint survey in the health districts bordering the Côte d'Ivoire, Ghana and the irrigated areas around the dams of Kompienga and Bagré. Our team led a disease survey in these irrigated areas, and we report the results. To determine the current scale of the Buruli ulcer, leprosy, and yaws in the irrigated areas around these two dams and to formulate recommendations. This single-pass survey from April 10-18 was a transverse descriptive study, with sampling based on proximity to the dams. Overall, 1482 people were consulted. Among them, 413 (27.9%) presented dermatosis, distributed as follows: 28 suspected cases of yaws (6.8%), 7 suspected cases of Buruli ulcer (1.7%), 1 case of multibacillary leprosy (0.24%) in an 8-year-old girl, and 377 cases of other dermatoses, dominated by those of fungal origin. A large-scale investigation including all other irrigated areas might make it possible to understand the real situation.

Mapping the global distribution of Buruli ulcer: a systematic review with evidence consensus

BACKGROUND

Buruli ulcer can cause disfigurement and long-term loss of function. It is underdiagnosed and under-reported, and its current distribution is unclear. We aimed to synthesise and evaluate data on Buruli ulcer prevalence and distribution.

METHODS

We did a systematic review of Buruli ulcer prevalence and used an evidence consensus framework to describe and evaluate evidence for Buruli ulcer distribution worldwide. We searched PubMed and Web of Science databases from inception to Aug 6, 2018, for records of Buruli ulcer and Mycobacterium ulcerans detection, with no limits on study type, publication date, participant population, or location. English, French, and Spanish language publications were included. We included population-based surveys presenting Buruli ulcer prevalence estimates, or data that allowed prevalence to be estimated, in the systematic review. We extracted geographical data on the occurrence of Buruli ulcer cases and M ulcerans detection from studies of any type for the evidence consensus framework; articles that did not report original data were excluded. For the main analysis, we extracted prevalence estimates from included surveys and calculated 95% CIs using Byar's method. We included occurrence records, reports to WHO and the Global Infectious Diseases and Epidemiology Network, and surveillance data from Buruli ulcer control programmes in the evidence consensus framework to grade the strength of evidence for Buruli ulcer endemicity. This study is registered with PROSPERO, number CRD42018116260.

FINDINGS

2763 titles met the search criteria. We extracted prevalence estimates from ten studies and occurrence data from 208 studies and five unpublished surveillance datasets. Prevalence estimates within study areas ranged from 3·2 (95% CI 3·1-3·3) cases per 10 000 population in Côte d'Ivoire to 26·9 (23·5-30·7) cases per 10 000 population in Benin. There was evidence of Buruli ulcer in 32 countries and consensus on presence in 12.

INTERPRETATION

The global distribution of Buruli ulcer is uncertain and potentially wider than currently recognised. Our findings represent the strongest available evidence on Buruli ulcer distribution so far and have many potential applications, from directing surveillance activities to informing burden estimates.

FUNDING

AIM Initiative.

Assessment of community knowledge, attitude, and stigma of Buruli ulcer disease in Southern Nigeria

Background

Poor knowledge can influence timely care-seeking among persons with Buruli ulcer disease (BUD).

Objectives

To assess community knowledge, attitude and stigma towards persons with BUD in endemic settings of Southern Nigeria.

Methods

This was a cross-sectional survey conducted among adult community members in four States of Southern Nigeria. A semi-structured interviewer-administered questionnaire was administered to all participants.

Results

Of 491 adults who completed the survey, 315 (64.2%) belonged to the ≤40 years age group, 257 (52.3%) were males and 415 (84.5%) had some formal education. The overall mean (SD) knowledge score was 5.5±2.3 (maximum 10). Only 172 (35.0%) of the participants had a good knowledge of BUD. A total of 327 (66.6%) considered BUD as a very serious illness. Also, there was a high-level of stigma against BUD patients; 372 (75.8%) of the participants felt compassion for and desire to help them, 77 (15.7%) felt compassion but tended to stay away from them, and 53 (10.8%) feared them because they may infect them with the disease. Having a formal education and ethnicity were independent predictors of good knowledge of BUD.

Conclusion

There is poor community knowledge of BUD in endemic settings of Southern Nigeria which influenced the attitude and perceptions of community members towards persons with BUD

Epidemiology of Buruli Ulcer Infections, Victoria, Australia, 2011-2016

Buruli ulcer (BU) is a destructive soft-tissue infection caused by the environmental pathogen Mycobacterium ulcerans. In response to rising BU notifications in the state of Victoria, Australia, we reviewed all cases that occurred during 2011–2016 to precisely map the time and likely place of M. ulcerans acquisition. We found that 600 cases of BU had been notified; just over half were in residents and the remainder in visitors to defined BU-endemic areas. During the study period, notifications increased almost 3-fold, from 66 in 2013 to 182 in 2016. We identified 4 BU-endemic areas: Bellarine Peninsula, Mornington Peninsula, Frankston region, and the southeastern Bayside suburbs of Melbourne. We observed a decline in cases on the Bellarine Peninsula but a progressive increase elsewhere. Acquisitions peaked in late summer. The appearance of new BU-endemic areas and the decline in established areas probably correlate with changes in the level of local environmental contamination with M. ulcerans.

Confirmed Case of Buruli Ulcer, Senegal, 2018

Buruli ulcer is a necrotizing skin disease caused by Mycobacterium ulcerans and is usually associated with tropical climates and exposure to slow-moving or stagnant water. We report a case of Buruli ulcer that may have originated in an urban semiarid area of Senegal.

A survey on Mycobacterium ulcerans in Mosquitoes and March flies captured from endemic areas of Northern Queensland, Australia

Mycobacterium ulcerans is the causative agent of Buruli ulcer (BU). This nontuberculous mycobacterial infection has been reported in 34 countries worldwide. In Australia, the majority of cases of BU have been recorded in coastal Victoria and the Mossman-Daintree areas of north Queensland. Mosquitoes have been postulated as a vector of M. ulcerans in Victoria, however the specific mode of transmission of this disease is still far from being well understood. In the current study, we trapped and analysed 16,900 (allocated to 845 pools) mosquitoes and 296 March flies from the endemic areas of north Queensland to examine for the presence of M. ulcerans DNA by polymerase chain reaction. Seven of 845 pools of mosquitoes were positive on screening using the IS2404 PCR target (maximum likelihood estimate 0.4/1,000). M. ulcerans DNA was detected from one pool of mosquitoes from which all three PCR targets: IS2404, IS2606 and the ketoreductase B domain of mycolactone polyketide synthase gene were detected. None of the March fly samples were positive for the presence of M. ulcerans DNA.

The causative agent of Buruli ulcer is Mycobacterium ulcerans. This destructive skin disease is characterized by extensive and painless necrosis of skin and underlying tissues usually on extremities of body due to production of toxin named mycolactone. The disease is prevalent in Africa and coastal Australia. The exact mode of transmission and potential environmental reservoir for the pathogen still remain obscure. Aquatic and biting insects have been identified as potential niche in transmission and maintenance of pathogen in the environment. In this study we screened mosquitoes and march flies captured from endemic areas of northern Queensland for the presence of M. ulcerans DNA. We found seven pools of mosquito out of 845 pools positive for IS2404. In only one of the seven samples were the additional targets IS2606 and KR detected. None of the March fly samples were positive. The results could indicate a low burden of the bacteria in the environment coinciding with a comparatively low number of human cases of M. ulcerans infection seen during the trapping period of the study.

Spontaneous healing of Mycobacterium ulcerans disease in Australian patients

Background

Mycobacterium ulcerans causes necrotising infections of skin and soft tissue mediated by the polyketide exotoxin mycolactone that causes cell apoptosis and immune suppression. It has been postulated that infection can be eradicated before the development of clinical lesions but spontaneous resolution of clinical lesions has been rarely described.

Methodology/Principal findings

We report a case series of five Australian patients who achieved healing of small M. ulcerans lesions without antibiotics or surgery. The median age of patients was 47 years (IQR 30–68 years) and all patients had small ulcerative lesions (median size 144mm², IQR 121-324mm²). The median duration of symptoms prior to diagnosis was 90 days (IQR 90–100 days) and the median time to heal from diagnosis without treatment was 68 days (IQR 63–105 days). No patients recurred after a median follow-up of 16.6 months (IQR 16.6–17.9 months) from the development of symptoms and no patients suffered long-term disability from the disease.

Conclusions

We have shown that healing without specific treatment can occur for small ulcerated M. ulcerans lesions suggesting that in selected cases a robust immune response alone can cure lesions. Further research is required to determine what lesion and host factors are associated with spontaneous healing, and whether observation alone is an effective and safe form of management for selected small M. ulcerans lesions.

Mycobacterium ulcerans causes a destructive infection of skin and soft tissue known as Buruli ulcer that when severe can lead to serious long-term deformity and disability. It is currently not well documented whether people with Mycobacterium ulcerans disease can cure themselves without treatment. In our study we describe five people with small ulcers who cured their disease without specific medical or surgical treatment. This suggests that a proportion of people can develop an immune response sufficient enough to eradicate the disease without the help of medical intervention. This is an important step, as recognition of this possibility provides important further insights into the human immune response against the disease. It also opens the possibility to further studies that may determine characteristics of the organism and hosts that favour spontaneous healing of lesions. This knowledge may in turn improve efforts to prevent and control the disease which are currently lacking.

Knowledge and practices of health practitioners on treatment of Buruli ulcer in the Mbonge, Ekondo Titi and Muyuka Health Districts, South West Region, Cameroon

INTRODUCTION

After tuberculosis and leprosy, Buruli ulcer (BU) is the third most common mycobacterial infection. Buruli ulcer begins as a localized skin lesion that progresses to extensive ulceration thus leading to functional disability, loss of economic productivity and social stigma. This study is aimed at assessing the knowledge and practices among health practitioners on the treatment of BU in the Mbonge, Ekondo Titi and Muyuka Health Districts of the South West Region of Cameroon.

METHODS

This is a cross-sectional study that investigates participants' knowledge and practices on the treatment of BU. The study uses a qualitative method of structured questionnaires in the process of data collection.

RESULTS

Seventy percent (70%) of the participants acknowledged they encounter cases of BU in their respective Hospitals or Health centers. Among these, 48% agreed they managed BU in their facilities and up to 91.7% noted that their community members are aware that BU is managed in their facility while seventy percent of the medical practitioners indicated they cannot identify the various stages of BU. Eighty-one percent of the practitioners from Muyuka HD indicated they could not identify the various stages of BU. More than 63% of the practitioners regarded BU patients as normal people in their communities however, practitioners that practiced for less than 5 years were likely not to admit BU patients in the same room with other patients. Beliefs such as being cursed (47.06%) and being possessed (29.41%) were reported by practitioners that acknowledged the existence of traditional beliefs in the community.

CONCLUSION

Despite the fact that a majority of the health practitioners knew what BU is, most of them demonstrated lack of knowledge on the identification of the various stages and management of the illness. Practitioners demonstrated positive attitude towards patients although they would not admit them in the same room with other patients. Considering the poor knowledge on identification and management demonstrated by most of the practitioners, management of the disease would be inadequate and may even aggravate the patient's situation. Training and onsite mentorship on screening, identification and management of BU is therefore highly recommended amongst health personnel practicing in endemic areas.

The association of rainfall and Buruli ulcer in southeastern Australia

Background

Buruli ulcer has been increasing in incidence in southeastern Australia with unclear transmission mechanisms. We aimed to investigate the link between rainfall and case numbers in two endemic areas of the state of Victoria; the Bellarine and Mornington Peninsulas.

Methodology

We created yearly and monthly graphs comparing rainfall with local Buruli ulcer incidence for the period 2004–2016 by endemic region and then considered a range of time lag intervals of 0–24 months to investigate patterns of correlation.

Conclusions

Optimal positive correlation for the Bellarine Peninsula occurred with a 12-month prior rainfall lag, however, no significant correlation was observed on the Mornington Peninsula for any time lag. These results provide an update in evidence to further explore transmission mechanisms which may differ between these geographically proximate endemic regions.

Buruli ulcer, a mycobacterial infection resulting in destructive soft tissue lesions, has been increasing in incidence in southeastern Australia over recent years. Exact transmission mechanisms and therefore preventative measures remain unclear. We aimed to investigate a possible link between Buruli ulcer and rainfall for two major endemic areas of the state of Victoria; the Bellarine and Mornington Peninsulas. Our results demonstrate a positive correlation with rainfall on the Bellarine Peninsula with a prior rainfall lag of 12 months but no correlation on the Mornington Peninsula. Established time-frames such as the incubation period and average delay to diagnosis (due to slow and often asymptomatic progression of the disease) make up a total of at least 5–6 months. On the Bellarine Peninsula, there appears to be another 5–6 months of unaccounted time from rainfall to transmission of the pathogen. This provides a basis to explore previously proposed transmission mechanisms which, based on the discrepancy noted with rainfall correlation, may differ between endemic regions.

Implementing active community-based surveillance-response system for Buruli ulcer early case detection and management in Ghana

Background

Buruli Ulcer (BU) is one of the most neglected debilitating tropical diseases caused by Mycobacterium ulcerans, which causes considerable morbidity and disability. Building on earlier findings that community-based interventions could enhance case detection and reduce treatment dropout and defaulter rates, we established an active surveillance-response system in an endemic sub-district in the Ga West municipality of Ghana to enhance early case detection, diagnosis and treatment to reduce or eliminate severe ulcers and its related disabilities.

Methods

We established surveillance response system, implemented in collaboration with the sub-district disease control officers, selected clinical staff and trained community-based volunteers. The active community-based surveillance- response system was implemented for 12 months. Also, pre and post intervention surveys were conducted to document any change in perceptions on BU in the study population over the period. The baseline and endline surveys were conducted in August 2016 and August 2017 respectively.

Results

On average, each person was seen 11 times in 12 months. In all 75 skin lesions were detected during surveillance rounds, out of which 17 were suspected to be BU and 12 out of the 17 were confirmed as BU using Polymerase chain reaction (PCR). Out of the 12, five, three and four were categories I, II and III lesions respectively. Physical examination was done on 94% of the people seen during the surveillance rounds. Knowledge on BU has also increased in the communities at the end of the study.

Conclusion

The findings from this study have demonstrated that it is possible to establish surveillance-response system for BU and by extension, other neglected tropical diseases to enhance control and elimination efforts through the use of community-based volunteers.

The study revealed that it is feasible to train periphery health workers and community-based volunteers to implement a community-based active surveillance–response system for early buruli ulcer (BU) case detection, diagnosis and treatment at outpatient clinics. At the end of 12 months follow-up, there were 36084 surveillance person contacts made with physical bodily examination done on 93.77% of them. The average surveillance contact per person was 11.3 (91.7%). We believe that this was achieved largely because of the use of community-based volunteers for the surveillance visits. Given the high number of non-BU skin lesions detected during the surveillance period, it is recommended that any BU surveillance-response system must be an integrated one to aid the detection, diagnosis and treatment of other skin conditions to make it more cost effective, this has become even more imperative because the number of BU cases have been declining in most endemic communities in Ghana, since the introduction of antibiotics treatment.

Low incidence of recurrent Buruli ulcers in treated Australian patients living in an endemic region

We examined recurrent Buruli ulcer cases following treatment and assumed cure in a large cohort of Australian patients living in an endemic area. We report that while the recurrence rate was low (2.81 cases/year/1000 population), it remained similar to the estimated risk of primary infection within the general population of the endemic area (0.85–4.04 cases/year/1,000 population). The majority of recurrent lesions occurred in different regions of the body and were separated by a median time interval of 44 months. Clinical, treatment and epidemiological factors combined with whole genome sequencing of primary and recurrent isolates suggests that in most recurrent cases a re-infection was more likely as opposed to a relapse of the initial infection. Additionally, all cases occurring more than 12 months after commencement of treatment were likely re-infections. Our study provides important prognostic information for patients and their health care providers concerning the nature and risks associated with recurrent cases of Buruli ulcer in Australia.

Mycobacterium ulcerans (M. ulcerans) causes a necrotising infection of skin and soft-tissue known as Buruli ulcer. Since the regular use of antibiotics for Buruli ulcer treatment in Australian populations was introduced at the turn of the century, treatment success rates have been very high. However there is no information from the Australian setting on the risk of recurrent disease following treatment and assumed cure, despite this being important prognostic information for patients, their families and health-care providers. Furthermore, it is also not known if recurrent disease represents late relapse of the initial treated infection or a subsequent new infection. In our study we have shown for the first time in Australian patients living in an endemic area that the incidence of recurrent Buruli ulcer following treatment and healing is low, and that this risk is similar to the estimated risk of primary infection within the general population of the endemic area. Furthermore, we have used clinical, treatment and epidemiological data supported by genomic information of M. ulcerans organisms to determine that the majority of recurrent lesions appear to result from re-infection. This suggests that for a proportion of treated patients’ acquired protective immunity against the development of recurrent M. ulcerans disease does not develop from their initial infection.

Mycobacterium ulcerans DNA in Bandicoot Excreta in Buruli Ulcer-Endemic Area, Northern Queensland, Australia

To identify potential reservoirs/vectors of Mycobacterium ulcerans in northern Queensland, Australia, we analyzed environmental samples collected from the Daintree River catchment area, to which Buruli ulcer is endemic, and adjacent coastal lowlands by species-specific PCR. We detected M. ulcerans DNA in soil, mosquitoes, and excreta of bandicoots, which are small terrestrial marsupials.

Laboratory confirmation of Buruli ulcer cases in Ghana, 2008-2016

Background

Buruli ulcer (BU), a necrotizing skin infection caused by Mycobacterium ulcerans is the third most important mycobacterial disease globally after tuberculosis and leprosy in immune competent individuals. This study reports on the retrospective analyses of microbiologically confirmed Buruli ulcer (BU) cases in seventy-five health facilities in Ghana.

Method/Principal findings

Pathological samples were collected from BU lesions and transported either through courier services or by car directly to the laboratory. Samples were processed and analysed by IS2404 PCR, culture and Ziehl-Neelsen staining for detection of acid-fast bacilli. From 2008 to 2016, we analysed by PCR, 2,287 samples of 2,203 cases from seventy-five health facilities in seven regions of Ghana (Ashanti, Brong Ahafo, Central, Eastern, Greater Accra, Northern and Volta). The mean annual positivity rate was 46.2% and ranged between 14.6% and 76.2%. The yearly positivity rates from 2008 to 2016 were 52.3%, 76.2%, 56.7%, 53.8%, 41.2%, 41.5%, 22.9%, 28.5% and 14.6% respectively. Of the 1,020 confirmed cases, the ratio of female to male was 518 and 502 respectively. Patients who were 15 years of age and below accounted for 39.8% of all cases. The median age was 20 years (IQR = 10–43). Ulcerative lesions were 69.2%, nodule (9.6%), plaque (2.9%), oedema (2.5%), osteomyelitis (1.1%), ulcer/oedema (9.5%) and ulcer/plaque (5.2%). Lesions frequently occurred on the lower limbs (57%) followed by the upper limbs (38%), the neck and head (3%) and the least found on the abdomen (2%).

Conclusions/Significance

Our findings show a decline in microbiological confirmed rates over the years and therefore call for intensive education on case recognition to prevent over-diagnosis as BU cases decline.

Buruli ulcer (BU), a necrotizing skin disease caused by Mycobacterium ulcerans, is currently reported in 33 countries, with the greatest disease burden mostly in West African countries along the gulf of Guinea. The lack of pain associated with BU disease enhances delay in seeking medical treatment that could result to complications. The current existing control strategy is early case detection. Previously BU diagnosis was based solely on clinical evidence by a healthcare worker, however, since other skin conditions present similar clinical signs as BU there is the need for further laboratory diagnosis. We microbiological confirmed all clinically diagnosed cases by IS2404 PCR, and Ziehl-Neelsen. We found that over 50% of the clinically diagnosed cases were not BU, thereby averting any unnecessary antimycobacterial treatment with the associated side effects.

Molecular detection of Mycobacterium ulcerans in the environment and its relationship with Buruli ulcer occurrence in Zio and Yoto districts of maritime region in Togo

BACKGROUND

Buruli Ulcer (BU) is a neglected tropical skin infection caused by Mycobacterium ulcerans. Residence near aquatic areas has been identified as an important source of transmission of M. ulcerans with increased risk of contracting Buruli ulcer. However, the reservoir and the mode of transmission are not yet well known. The aim of this study was to identify the presence of M. ulcerans in the environment and its relationship with Buruli ulcer occurrence in Zio and Yoto districts of the maritime region in south Togo.

METHODS

A total of 219 environmental samples including soil (n = 119), water (n = 65), biofilms/plants (n = 29) and animals' feces (n = 6) were collected in 17 villages of Zio and Yoto districts of the maritime region in Togo. DNA of M. ulcerans including IS2404 and IS2606 insertions sequences and mycolactone ketoreductase-B gene (KR-B) was detected using real time PCR amplification (qPCR) technique. In parallel, clinical samples of patients were tested to establish a comparison of the genetic profile of M. ulcerans between the two types of samples. A calibration curve was generated for IS2404 from a synthetic gene of M. ulcerans Transposase pMUM001, the plasmid of virulence.

RESULTS

In the absence of inhibition of the qPCR, 6/219 (2.7%) samples were tested positive for M. ulcerans DNA containing three sequences (IS2404/IS2606/KR-B). Positive samples of M. ulcerans were consisting of biofilms/plants (3/29; 10.3%), water (1/65; 1.7%) and soil (2/119; 1.5%). Comparative analysis between DNA detected in environmental and clinical samples from BU patients showed the same genetic profile of M. ulcerans in the same environment. All these samples were collected in the environment of Haho and Zio rivers in the maritime region.

CONCLUSION

This study confirms the presence of M. ulcerans in the environment of the Zio and Yoto districts of the maritime region of Togo. This may explain partially, the high rates of Buruli ulcer patients in this region. Also, water, plants and soil along the rivers could be possible reservoirs of the bacterium. Therefore, Haho and Zio rivers could be potential sources of infection with M. ulcerans in humans in these districts.

Developing a Buruli ulcer community of practice in Bankim, Cameroon: A model for Buruli ulcer outreach in Africa

Background

In the Cameroon, previous efforts to identify Buruli ulcer (BU) through the mobilization of community health workers (CHWs) yielded poor results. In this paper, we describe the successful creation of a BU community of practice (BUCOP) in Bankim, Cameroon composed of hospital staff, former patients, CHWs, and traditional healers.

Methods and principle findings

All seven stages of a well-defined formative research process were conducted during three phases of research carried out by a team of social scientists working closely with Bankim hospital staff. Phase one ethnographic research generated interventions tested in a phase two proof of concept study followed by a three- year pilot project. In phase three the pilot project was evaluated. An outcome evaluation documented a significant rise in BU detection, especially category I cases, and a shift in case referral. Trained CHW and traditional healers initially referred most suspected cases of BU to Bankim hospital. Over time, household members exposed to an innovative and culturally sensitive outreach education program referred the greatest number of suspected cases. Laboratory confirmation of suspected BU cases referred by community stakeholders was above 30%. An impact and process evaluation found that sustained collaboration between health staff, CHWs, and traditional healers had been achieved. CHWs came to play a more active role in organizing BU outreach activities, which increased their social status. Traditional healers found they gained more from collaboration than they lost from referral.

Conclusion/ Significance

Setting up lines of communication, and promoting collaboration and trust between community stakeholders and health staff is essential to the control of neglected tropical diseases. It is also essential to health system strengthening and emerging disease preparedness. The BUCOP model described in this paper holds great promise for bringing communities together to solve pressing health problems in a culturally sensitive manner.

Buruli ulcer (BU) is a neglected tropical disease primarily found in West Africa largely effecting the rural poor. BU has a known cause and cure, but an unknown route of transmission and a poorly understood incubation period. If not treated early and in a timely manner, BU often progresses to an advanced state requiring surgery and prolonged wound care. In the Cameroon, previous efforts to mobilize community health workers and educate community members to identify cases of BU yielded poor results. In this paper, we describe steps undertaken to create a successful BU community of practice (BUCOP) composed of community stakeholders working in concert with clinic staff. The success of the BUCOP was measured in terms of numbers of suspected BU cases referred and confirmed, a decline in treatment drop out, and sustained collaboration among stakeholders both during and following the pilot project. Pilot project success is attributed to an innovative and culturally sensitive approach to BU outreach education, increased levels of patient assistance, and mutual respect among BUCOP members for what each stakeholder contributed to BU detection, treatment, psychosocial support, and spiritual protection.

The incubation period of Buruli ulcer (Mycobacterium ulcerans infection) in Victoria, Australia - Remains similar despite changing geographic distribution of disease

BACKGROUND

Buruli ulcer (BU) is a geographically-restricted infection caused by Mycobacterium ulcerans; contact with an endemic region is the primary risk factor for disease acquisition. Globally, efforts to estimate the incubation period of BU are often hindered as most patients reside permanently in endemic areas. However, in the south-eastern Australian state of Victoria, a significant proportion of people who acquire BU are visitors to endemic regions. During a sustained outbreak of BU on the Bellarine peninsula we estimated a mean incubation period of 4.5 months. Since then cases on the Bellarine peninsula have declined but a new endemic area has developed centred on the Mornington peninsula.

METHOD

Retrospective review of 443 cases of BU notified in Victoria between 2013 and 2016. Telephone interviews were performed to identify all cases with a single visit to an endemic region, or multiple visits within a one month period. The incubation period was defined as the time between exposure to an endemic region and symptom onset. Data were subsequently combined with those from our earlier study incorporating cases from 2002 to 2012.

RESULTS

Among the 20 new cases identified in short-term visitors, the mean incubation period was 143 days (4.8 months), very similar to the previous estimate of 135 days (4.5 months). This was despite the predominant exposure location shifting from the Bellarine peninsula to the Mornington peninsula. We found no association between incubation period and age, sex, location of exposure, duration of exposure to an endemic region or location of BU lesion.

CONCLUSIONS

Our study confirms the mean incubation period of BU in Victoria to be between 4 and 5 months. This knowledge can guide clinicians and suggests that the mode of transmission of BU is similar in different geographic regions in Victoria.

Risk factors for Mycobacterium ulcerans infection (Buruli Ulcer) in Togo ─ a case-control study in Zio and Yoto districts of the maritime region

BACKGROUND

Buruli ulcer (BU) is a neglected mycobacterial skin infection caused by Mycobacterium ulcerans. This disease mostly affects poor rural populations, especially in areas with low hygiene standards and sanitation coverage. The objective of this study was to identify these risk factors in the districts of Zio and Yoto of the Maritime Region in Togo.

METHODS

We conducted a case-control study in Zio and Yoto, two districts proved BU endemic from November 2014 to May 2015. BU cases were diagnosed according to the WHO clinical case definition at the Centre Hospitalier Régional de Tsévié (CHR Tsévié) and confirmed by Ziehl-Neelsen (ZN) microscopy and IS2404 polymerase chain reaction (PCR). For each case, up to two controls matched by sex and place of residence were recruited. Socio-demographic, environmental or behavioral data were collected and conditional logistic regression analysis was used to identify and compare risk factors between BU cases and controls.

RESULTS

A total of 83 cases and 128 controls were enrolled. The median age was 15 years (range 3-65 years). Multivariate conditional logistic regression analysis after adjustment for potential confounders identified age (< 10 years (OR =11.48, 95% CI = 3.72-35.43) and 10-14 years (OR = 3.63, 95% CI = 1.22-10.83)), receiving insect bites near a river (OR = 7.8, 95% CI = 1.48-41.21) and bathing with water from open borehole (OR = 5.77, (1.11-29.27)) as independent predictors of acquiring BU infection.

CONCLUSIONS

This study identified age, bathing with water from open borehole and receiving insect bites near a river as potential risk of acquiring BU infection in Zio and Yoto districts of the Maritime Region in south Togo.

Increased Severity and Spread of Mycobacterium ulcerans, Southeastern Australia

Reported cases of Mycobacterium ulcerans disease (Buruli ulcer) have been increasing in southeastern Australia and spreading into new geographic areas. We analyzed 426 cases of M. ulcerans disease during January 1998–May 2017 in the established disease-endemic region of the Bellarine Peninsula and the emerging endemic region of the Mornington Peninsula. A total of 20.4% of cases patients had severe disease. Over time, there has been an increase in the number of cases managed per year and the proportion associated with severe disease. Risk factors associated with severe disease included age, time period (range of years of diagnosis), and location of lesions over a joint. We highlight the changing epidemiology and pathogenicity of M. ulcerans disease in Australia. Further research, including genomic studies of emergent strains with increased pathogenicity, is urgently needed to improve the understanding of this disease to facilitate implementation of effective public health measures to halt its spread.

Exposure Risk for Infection and Lack of Human-to-Human Transmission of Mycobacterium ulcerans Disease, Australia

We conducted epidemiologic and genetic analyses of family clusters of Mycobacterium ulcerans (Buruli ulcer) disease in southeastern Australia. We found that the incidence of M. ulcerans disease in family members was increased. However, the risk for exposure appeared short-term and not related to human-human transmission.

Mycobacterium ulcerans infection (Buruli ulcer) in French Guiana, South America, 1969-2013: an epidemiological study

BACKGROUND

Mycobacterium ulcerans infection is the third most common mycobacterial disease in the world after tuberculosis and leprosy. To date, transmission pathways from its environmental reservoir to humans are still unknown. In South America, French Guiana has the highest reported number of M ulcerans infections across the continent. This empirical study aimed to characterise the epidemiology of M ulcerans infection in French Guiana between 1969 and 2013.

METHODS

Data were collected prospectively mainly by two dermatologists at Cayenne Hospital's dermatology department between Jan 1, 1969, and Dec 31, 2013, for age, date of diagnosis, sex, residence, location of the lesion, type of lesion, associated symptoms, and diagnostic method (smear, culture, PCR, or histology) for all confirmed and suspected cases of M ulcerans. We obtained population data from censuses. We calculated mean M ulcerans infection incidences, presented as the number of cases per 100 000 person-years.

FINDINGS

245 patients with M ulcerans infections were reported at Cayenne Hospital's dermatology department during the study period. M ulcerans infection incidence decreased over time, from 6·07 infections per 100 000 person-years (95% CI 4·46-7·67) in 1969-83 to 4·77 infections per 100 000 person-years (3·75-5·79) in 1984-98 and to 3·49 infections per 100 000 person-years (2·83-4·16) in 1999-2013. The proportion of children with infections also declined with time, from 42 (76%) of 55 patients in 1969-83 to 26 (31%) of 84 in 1984-98 and to 22 (21%) of 106 in 1999-2013. Most cases occurred in coastal areas surrounded by marshy savannah (incidence of 21·08 per 100 000 person-years in Sinnamary and 21·18 per 100 000 person-years in Mana). Lesions mainly affected limbs (lower limbs 161 [66%] patients; upper limbs 60 [24%] patients). We diagnosed no bone infections.

INTERPRETATION

The decrease of M ulcerans infection incidence and the proportion of children with infections over a 45 year period in this ultra-peripheral French territory might have been mostly driven by improving living conditions, prophylactic recommendations, and access to health care.

FUNDING

Agence Nationale de la Recherche.