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

Systematic review: Global host range, case fatality and detection rates of Mycobacterium ulcerans in humans and potential environmental sources

Fundamental aspects of the epidemiology and ecology of Mycobacterium ulcerans (MU) infections including disease burden, host range, reservoir, intermediate hosts, vector and mode of transmission are poorly understood. Understanding the global distribution and burden of MU infections is a paramount to fight against Buruli ulcer (BU). Four databases were queried from inception through December 2023. After critical review of published resources on BU, 155 articles (645 records) published between 1987 and 2023 from 16 countries were selected for this review. Investigating BU in from old endemic and new emerging foci has allowed detection of MU in humans, animals, plants and various environmental samples with prevalence from 0 % up to 100 % depending of the study design. A case fatality rate between 0.0 % and 50 % was described from BU patients and deaths occurred in Central African Republic, Gabon, Democratic Republic of the Congo, Burkina Faso and Australia. The prevalence of MU in humans was higher in Africa. Nucleic Acid Amplification Tests (NAAT) and non-NAAT were performed in > 38 animal species. MU has been recovered in culture from possum faeces, aquatic bugs and koala. More than 7 plant species and several environmental samples have been tested positive for MU. This review provided a comprehensive set of data on the updates of geographic distribution, the burden of MU infections in humans, and the host range of MU in non-human organisms. Although MU have been found in a wide range of environmental samples, only few of these have revealed the viability of the mycobacterium and the replicative non-human reservoirs of MU remain to be explored. These findings should serve as a foundation for further research on the reservoirs, intermediate hosts and transmission routes of MU.

Endemic infectious cutaneous ulcers syndrome in the Oti Region of Ghana: Study of cutaneous leishmaniasis, yaws and Haemophilus ducreyi cutaneous ulcers

BACKGROUND

A recent study detected cutaneous leishmaniasis (CL) in 31.9% of persons with skin ulcers in the Oti Region of Ghana, resulting in a need to investigate other potential causes of the unexplained skin ulcers.

METHODOLOGY/PRINCIPAL FINDINGS

A community based cross-sectional study was conducted in the Oti region to investigate skin ulcers of undetermined aetiologies. To confirm a diagnosis of cutaneous leishmaniasis, Buruli ulcer, Haemophilus ducreyi ulcers, or yaws, DNA obtained from each patient skin ulcer sample was systematically subjected to polymerase chain reaction (PCR) for Leishmania spp., Mycobacterium ulcerans, Haemophilus ducreyi, and Treponema pallidum sub species pertenue. A total of 101 skin ulcer samples were obtained from 101 persons. Co-infection of more than one organism was observed in 68.3% of the samples. Forty (39.6%) participants had a positive result for Leishmania spp., 68 (67.3%) for Treponema pallidum sub. Sp. pertenue, and 74 (73.3%) for H. ducreyi. Twenty (19.8%) of the patient ulcers were simultaneously infected with Leishmania spp., Treponema pallidum sub. Sp. pertenue, and H. ducreyi. None of the patients' lesions yielded a positive result for Mycobacterium ulcerans.

CONCLUSIONS/SIGNIFICANCE

This study detected single and mixed occurrence of the causative organisms of CL, yaws, and H. ducreyi cutaneous ulcers in CL endemic communities of the Oti Region in Ghana. These findings emphasize the importance of integrating multiple skin diseases on a common research platform and calls for the development of a comprehensive guideline for diagnosing and treating tropical ulcers in the study areas.

Utilising community volunteers can increase the detection and referral of Buruli ulcer cases in endemic communities in Southeast, Nigeria

BACKGROUND

Buruli ulcer (BU) is a debilitating neglected tropical disease which causes disability and mostly affects inhabitants in impoverished settings where access to medical care is challenging. This study aims to determine the effect of training community members as volunteers for or in the detection and referral of people who have Buruli ulcer to the hospital.

METHODS

The following study is a before and after study in the BU-endemic Local Government Areas (LGA) of Ebonyi State. A cluster random sampling technique was used to select 90 volunteers from three LGAs (30 from each LGA). In each LGA, the volunteers underwent a one-day training and six months field work to identify all those who have any form of ulcer on any part of their bodies. A short questionnaire was used to capture socio-demographic characteristics of the patient, site of the ulcer, duration of the ulcer, initial appearance of the ulcer, referral to hospital, result of laboratory investigation, and treatment received. The data was analysed using the Statistical Package for Social Sciences (SPSS) for Microsoft Windows version 20 software. The Z test statistic was used to compare the number of referred BU patients before and after the intervention by LGA. The Chi square test was used to examine the association between the dependent and independent variables.

RESULTS

The mean age of volunteers was 39 ± 9.5 while mean age of the patients was 42.3 ± 17.1. Most of the ulcers were on the legs (79.4%) and lasted 1-5 years (65.6%). There was a significant increase in the proportion of BU suspects identified by the community volunteers in all 3 LGAs (Afikpo north (p =  < 0.001), Abakaliki (p = 0.02), Ikwo (p = 0.001). The duration of the ulcer was associated with the detection and referral of the patients with higher levels of detection and referral among those whose ulcer had lasted 1-5 years in two of the LGAs (P < 0.001).

CONCLUSION

We recommend that program managers and stakeholders integrate and scale up the services of trained community health volunteers for the rapid detection of Buruli ulcer cases in rural endemic communities. Awareness and sensitization campaigns on BU preventive measures should be intensified.

Variable Number Tandem Repeat Profiling of Mycobacterium ulcerans Reveals New Genotypes in Buruli Ulcer Endemic Communities in Ghana and Côte d’Ivoire

Buruli ulcer (BU), a necrotic skin disease caused by Mycobacterium ulcerans, is mainly prevalent in West Africa, but cases have also been reported in other tropical parts of the world. It is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d’Ivoire. Heterogeneity among M. ulcerans from different geographical locations has not been clearly elucidated, and some studies seem to suggest genetic differences between M. ulcerans in humans and in the environment. This study aimed at identifying genetic differences among M. ulcerans strains between two BU endemic countries: Ghana and Côte d’Ivoire. Clinical samples consisting of swabs, fine needle aspirates, and tissue biopsies of suspected BU lesions and environmental samples (e.g., water, biofilms from plants, soil, and detrital material) were analyzed. BU cases were confirmed via acid fast staining and PCR targeting the 16S rRNA, IS2404, IS2606, and ER domain genes present on M. ulcerans. Heterogeneity among M. ulcerans was determined through VNTR profiling targeting 10 loci. Eleven M. ulcerans genotypes were identified within the clinical samples in both Ghana and Côte d’Ivoire, whiles six M. ulcerans genotypes were found among the environmental samples. Clinical M. ulcerans genotypes C, D, F, and G were common in both countries. Genotype E was unique among the Ghanaian samples, whiles genotypes A, Z, J, and K were unique to the Ivorian samples. Environmental isolates were found to be more conserved compared with the clinical isolates. Genotype W was observed only among the Ghanaian environmental samples. Genotype D was found to be prominent in both clinical and environmental samples, suggesting evidence of possible transmission of M. ulcerans from the environment, particularly water bodies and biofilms from aquatic plants, to humans through open lesions on the skin.

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.

Detection of cutaneous leishmaniasis in three communities of Oti Region, Ghana

Background

Cutaneous leishmaniasis (CL) is the most common type of leishmaniasis, a neglected tropical disease caused by parasites of the genus Leishmania. In Ghana, some studies in the Volta region have detected Leishmania parasites among persons with skin ulcers.

Methodology/Principal findings

Using a cross-sectional study design, the prevalence of CL in three communities of the Oti Region of Ghana was investigated. Demographic and epidemiological data were obtained by a structured interviewer administered questionnaire. A total of 426 (12.4%) out of 3,440 participants screened had at least one skin ulcer. Of 595 skin ulcers sampled and tested by PCR for Leishmania infection, 150 (25.2%) ulcers from 136 individuals tested positive, accounting for an overall CL prevalence of 31.9% among persons with skin ulcers. Individual community CL prevalence of 23.2%, 29.8%, and 36.8% was observed in Ashiabre, Keri, and Sibi Hilltop respectively among persons with skin ulcers.

Conclusions/Significance

Confirmation of CL in the study area suggests an active cycle of transmission of Leishmania infection. The observation of skin ulcers which tested negative to Leishmania infection suggests a need to test for additional causes of skin ulcers such as Treponema pallidum pertenue and Mycobacterium ulcerans in the study area.

Cutaneous leishmaniasis (CL) is a neglected tropical disease caused by parasites of the genus Leishmania and is transmitted by various species of female sandflies. CL usually begins as painless nodules and is usually characterized by skin ulcers which may be single or multiple. Although ulcers due to CL are often self-healing, they may become painful and result in scarring after healing. Typically, CL occurs on exposed parts of the body such as the neck, limbs, and face, which may be easily accessible to sandflies. Although cases of CL had previously been reported in some parts of the Volta region of Ghana, no previous case of CL had been reported in the Oti region. This study was initiated following reports of skin ulcers which were suggestive of CL in some communities of the Oti region. This study confirmed Leishmania infection in 150(25.5%) out of 595 skin ulcer samples obtained from 426 study participants. Given that 445(74,8%) of the skin ulcers tested negative for Leishmania parasite suggests a need for investigation of additional causes of skin ulcers such as yaws and Buruli ulcer in the study area.

Rifampicin and clarithromycin (extended release) versus rifampicin and streptomycin for limited Buruli ulcer lesions: a randomised, open-label, non-inferiority phase 3 trial

BACKGROUND

Buruli ulcer is a neglected tropical disease caused by Mycobacterium ulcerans infection that damages the skin and subcutis. It is most prevalent in western and central Africa and Australia. Standard antimicrobial treatment with oral rifampicin 10 mg/kg plus intramuscular streptomycin 15 mg/kg once daily for 8 weeks (RS8) is highly effective, but streptomycin injections are painful and potentially harmful. We aimed to compare the efficacy and tolerability of fully oral rifampicin 10 mg/kg plus clarithromycin 15 mg/kg extended release once daily for 8 weeks (RC8) with that of RS8 for treatment of early Buruli ulcer lesions.

METHODS

We did an open-label, non-inferiority, randomised (1:1 with blocks of six), multicentre, phase 3 clinical trial comparing fully oral RC8 with RS8 in patients with early, limited Buruli ulcer lesions. There were four trial sites in hospitals in Ghana (Agogo, Tepa, Nkawie, Dunkwa) and one in Benin (Pobè). Participants were included if they were aged 5 years or older and had typical Buruli ulcer with no more than one lesion (caterories I and II) no larger than 10 cm in diameter. The trial was open label, and neither the investigators who took measurements of the lesions nor the attending doctors were masked to treatment assignment. The primary clinical endpoint was lesion healing (ie, full epithelialisation or stable scar) without recurrence at 52 weeks after start of antimicrobial therapy. The primary endpoint and safety were assessed in the intention-to-treat population. A sample size of 332 participants was calculated to detect inferiority of RC8 by a margin of 12%. This study was registered with ClinicalTrials.gov, NCT01659437.

FINDINGS

Between Jan 1, 2013, and Dec 31, 2017, participants were recruited to the trial. We stopped recruitment after 310 participants. Median age of participants was 14 years (IQR 10-29) and 153 (52%) were female. 297 patients had PCR-confirmed Buruli ulcer; 151 (51%) were assigned to RS8 treatment, and 146 (49%) received oral RC8 treatment. In the RS8 group, lesions healed in 144 (95%, 95% CI 91 to 98) of 151 patients, whereas lesions healed in 140 (96%, 91 to 99) of 146 patients in the RC8 group. The difference in proportion, -0·5% (-5·2 to 4·2), was not significantly greater than zero (p=0·59), showing that RC8 treatment is non-inferior to RS8 treatment for lesion healing at 52 weeks. Treatment-related adverse events were recorded in 20 (13%) patients receiving RS8 and in nine (7%) patients receiving RC8. Most adverse events were grade 1-2, but one (1%) patient receiving RS8 developed serious ototoxicity and ended treatment after 6 weeks. No patients needed surgical resection. Four patients (two in each study group) had skin grafts.

INTERPRETATION

Fully oral RC8 regimen was non-inferior to RS8 for treatment of early, limited Buruli ulcer and was associated with fewer adverse events. Therefore, we propose that fully oral RC8 should be the preferred therapy for early, limited lesions of Buruli ulcer.

FUNDING

WHO with additional support from MAP International, American Leprosy Missions, Fondation Raoul Follereau France, Buruli ulcer Groningen Foundation, Sanofi-Pasteur, and BuruliVac.

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.

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.