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British Medical Bulletin 2015Yaws, caused by Treponema pallidum ssp. pertenue, is endemic in parts of West Africa, Southeast Asia and the Pacific. The WHO has launched a campaign based on mass... (Review)
Review
INTRODUCTION
Yaws, caused by Treponema pallidum ssp. pertenue, is endemic in parts of West Africa, Southeast Asia and the Pacific. The WHO has launched a campaign based on mass treatment with azithromycin, to eradicate yaws by 2020.
SOURCES OF DATA
We reviewed published data, surveillance data and data presented at yaws eradication meetings.
AREAS OF AGREEMENT
Azithromycin is now the preferred agent for treating yaws. Point-of-care tests have demonstrated their value in yaws.
AREAS OF CONTROVERSY
There is limited data from 76 countries, which previously reported yaws. Different doses of azithromycin are used in community mass treatment for yaws and trachoma.
GROWING POINTS
Yaws eradication appears an achievable goal. The programme will require considerable support from partners across health and development sectors.
AREAS TIMELY FOR DEVELOPING RESEARCH
Studies to complete baseline mapping, integrate diagnostic tests into surveillance and assess the impact of community mass treatment with azithromycin are ongoing.
Topics: Anti-Bacterial Agents; Azithromycin; Cost-Benefit Analysis; Disease Eradication; Humans; Program Development; Sentinel Surveillance; Treponema pallidum; Yaws
PubMed: 25525120
DOI: 10.1093/bmb/ldu037 -
International Journal of STD & AIDS Sep 2015Yaws is a non-venereal endemic treponemal infection caused by Treponema pallidum sub-species pertenue, a spirochaete bacterium closely related to Treponema pallidum ssp.... (Review)
Review
Yaws is a non-venereal endemic treponemal infection caused by Treponema pallidum sub-species pertenue, a spirochaete bacterium closely related to Treponema pallidum ssp. pallidum, the agent of venereal syphilis. Yaws is a chronic, relapsing disease predominantly affecting children living in certain tropical regions. It spreads by skin-to-skin contact and, like syphilis, occurs in distinct clinical stages. It causes lesions of the skin, mucous membranes and bones which, without treatment, can become chronic and destructive. Treponema pallidum ssp. pertenue, like its sexually-transmitted counterpart, is exquisitely sensitive to penicillin. Infection with yaws or syphilis results in reactive treponemal serology and there is no widely available test to distinguish between these infections. Thus, migration of people from yaws-endemic areas to developed countries may present clinicians with diagnostic dilemmas. We review the epidemiology, clinical presentation and treatment of yaws.
Topics: Anti-Bacterial Agents; Female; Humans; Neglected Diseases; Penicillin G; Skin; Treatment Outcome; Treponema pallidum; Yaws
PubMed: 25193248
DOI: 10.1177/0956462414549036 -
Clinical Microbiology Reviews Jan 2014The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T.... (Review)
Review
The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents.
Topics: Animals; Disease Eradication; Disease Models, Animal; Endemic Diseases; Treponema; Treponemal Infections
PubMed: 24396138
DOI: 10.1128/CMR.00070-13 -
Tropical Medicine and Infectious Disease Aug 2018Yaws is one of the three endemic treponematoses and is recognised by the World Health Organization as a neglected tropical disease. Yaws is currently reported in 15... (Review)
Review
Yaws is one of the three endemic treponematoses and is recognised by the World Health Organization as a neglected tropical disease. Yaws is currently reported in 15 countries in the Pacific, South-East Asia, West and Central Africa, predominantly affects children, and results in destructive lesions of the skin and soft tissues. For most of the twentieth century penicillin-based treatment was the standard of care and resistance to penicillin has still not been described. Recently, oral azithromycin has been shown to be an effective treatment for yaws, facilitating renewed yaws eradication efforts. Resistance to azithromycin is an emerging threat and close surveillance will be required as yaws eradication efforts are scaled up globally.
PubMed: 30274488
DOI: 10.3390/tropicalmed3030092 -
Emerging Infectious Diseases Apr 2021We confirmed endemicity and autochthonous transmission of yaws in Liberia after a population-based, community-led burden estimation (56,825 participants). Serologically...
We confirmed endemicity and autochthonous transmission of yaws in Liberia after a population-based, community-led burden estimation (56,825 participants). Serologically confirmed yaws was rare and focal at population level (24 cases; 2.6 [95% CI 1.4-3.9] cases/10,000 population) with similar clinical epidemiology to other endemic countries in West Africa. Unsupervised classification of spatially referenced case finding data indicated that yaws was more likely to occur in hard-to-reach communities; healthcare-seeking was low among communities, and clinical awareness of yaws was low among healthcare workers. We recovered whole bacterial genomes from 12 cases and describe a monophyletic clade of Treponema pallidum subspecies pertenue, phylogenetically distinct from known TPE lineages, including those affecting neighboring nonhuman primate populations (Taï Forest, Côte d'Ivoire). Yaws is endemic in Liberia but exhibits low focal population prevalence with evidence of a historical genetic bottleneck and subsequent local expansion. Reporting gaps appear attributable to challenging epidemiology and low disease awareness.
Topics: Animals; Cote d'Ivoire; Genomics; Humans; Liberia; Treponema pallidum; Yaws
PubMed: 33754988
DOI: 10.3201/eid2704.204442 -
PLoS Neglected Tropical Diseases Dec 2015
Review
Topics: Anti-Bacterial Agents; Azithromycin; Global Health; Humans; Trachoma; Yaws
PubMed: 26633176
DOI: 10.1371/journal.pntd.0004071 -
Sexually Transmitted Infections Dec 2022Current rapid tests for syphilis and yaws can detect treponemal and non-treponemal antibodies. We aimed to critically appraise the literature for rapid diagnostic tests... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Current rapid tests for syphilis and yaws can detect treponemal and non-treponemal antibodies. We aimed to critically appraise the literature for rapid diagnostic tests (RDTs) which can better distinguish an active infection of syphilis or yaws.
METHODS
We conducted a systematic review and meta-analysis, searching five databases between January 2010 and October 2021 (with an update in July 2022). A generalised linear mixed model was used to conduct a bivariate meta-analysis for the pooled sensitivity and specificity. Heterogeneity was assessed using the I statistic. We used the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) to assess the risk of bias and Grading of Recommendations, Assessment, Development and Evaluations (GRADE) to evaluate the certainty of evidence.
RESULTS
We included 17 studies for meta-analyses. For syphilis, the pooled sensitivity and specificity of the treponemal component were 0.93 (95% CI: 0.86 to 0.97) and 0.98 (95% CI: 0.96 to 0.99), respectively. For the non-treponemal component, the pooled sensitivity and specificity were 0.90 (95% CI: 0.82 to 0.95) and 0.97 (95% CI: 0.92 to 0.99), respectively. For yaws, the pooled sensitivity and specificity of the treponemal component were 0.86 (95% CI: 0.66 to 0.95) and 0.97 (95% CI: 0.94 to 0.99), respectively. For the non-treponemal component, the pooled sensitivity and specificity were 0.80 (95% CI: 0.55 to 0.93) and 0.96 (95% CI: 0.92 to 0.98), respectively.
CONCLUSIONS
RDTs that can differentiate between active and previously treated infections could optimise management by providing same-day treatment and reducing unnecessary treatment.
PROSPERO REGISTRATION NUMBER
CRD42021279587.
Topics: Humans; Yaws; Syphilis; Diagnostic Tests, Routine; Sensitivity and Specificity
PubMed: 36180209
DOI: 10.1136/sextrans-2022-055546 -
Clinical Epidemiology 2014Yaws, a neglected tropical disease, is targeted for eradication by 2020 through large-scale mass-treatment programs of endemic communities. A key determinant for the... (Review)
Review
Yaws, a neglected tropical disease, is targeted for eradication by 2020 through large-scale mass-treatment programs of endemic communities. A key determinant for the success of the eradication campaign is good understanding of the disease epidemiology. We did a review of historical trends and new information from endemic countries, with the aim of assessing the state of knowledge on yaws disease burden. Transmission of yaws is now present in Africa, Asia, and the South Pacific. At least 12 countries are known to harbor yaws cases and 21 to 42 million people live in endemic areas. Between 2008 and 2012 more than 300,000 new cases were reported to the World Health Organization. Yaws presented high geographical variation within a country or region, high seasonality for incidence of active disease, and evidence that low standards of hygiene predispose to suffering of the disease. Key data issues include low levels of reporting, potential misdiagnosis, and scarce documentation on prevalence of asymptomatic infections. Currently available data most likely underestimates the magnitude of the disease burden. More effort is needed in order to refine accuracy of data currently being reported. A better characterization of the epidemiology of yaws globally is likely to positively impact on planning and implementation of yaws eradication.
PubMed: 24729728
DOI: 10.2147/CLEP.S44553 -
PLoS Neglected Tropical Diseases Jul 2017Yaws is endemic in Ghana. The World Health Organization (WHO) has launched a new global eradication campaign based on total community mass treatment with azithromycin....
INTRODUCTION
Yaws is endemic in Ghana. The World Health Organization (WHO) has launched a new global eradication campaign based on total community mass treatment with azithromycin. Achieving high coverage of mass treatment will be fundamental to the success of this new strategy; coverage is dependent, in part, on appropriate community mobilisation. An understanding of community knowledge, attitudes and practices related to yaws in Ghana and other endemic countries will be vital in designing effective community engagement strategies.
METHODS
A verbally administered questionnaire was administered to residents in 3 districts in the Eastern region of Ghana where a randomised trial on the treatment of yaws was being conducted. The questionnaire combined both quantitative and qualitative questions covering perceptions of the cause and mechanisms of transmission of yaws-like lesions, the providers from which individuals would seek healthcare for yaws-like lesions, and what factors were important in reaching decisions on where to seek care. Chi-square tests and logistic regression were used to assess relationships between reported knowledge, attitudes and practices, and demographic variables. Thematic analysis of qualitative data was used to identify common themes.
RESULTS
A total of 1,162 individuals participated. The majority of individuals (n = 895, 77%) reported that "germs" were the cause of yaws lesions. Overall 13% (n = 161) of respondents believed that the disease was caused by supernatural forces. Participants frequently mentioned lack of personal hygiene, irregular and inefficient bathing, and washing with dirty water as fundamental to both the cause and the prevention of yaws. A majority of individuals reported that they would want to take an antibiotic to prevent the development of yaws if they were asymptomatic (n = 689, 61.2%), but a substantial minority reported they would not want to do so. A majority of individuals (n = 839, 72.7%) reported that if they had a yaws-like skin lesion they would seek care from a doctor or nurse. Both direct and indirect costs of treatment were reported as key factors affecting where participants reported they would seek care.
DISCUSSION
This is the first study that has explored community knowledge, attitudes and practices in relation to yaws in any endemic population. The belief that 'germs' are in some way related to disease through a variety of transmission routes including both contact and dirty water are similar to those reported for other skin diseases in Ghana. The prominent role of private healthcare providers is an important finding of this study and suggests engagement with this sector will be important in yaws eradication efforts. Strategies to address the substantial minority of individuals who reported they would not take treatment for yaws if they were currently asymptomatic will be needed to ensure the success of yaws eradication efforts. The data collected will be of value to the Ghana Health Service and also to WHO and other partners, who are currently developing community mobilisation tools to support yaws eradication efforts worldwide.
Topics: Adult; Anti-Bacterial Agents; Female; Ghana; Health Knowledge, Attitudes, Practice; Humans; Logistic Models; Male; Middle Aged; Patient Acceptance of Health Care; Surveys and Questionnaires; Treponema pallidum; Yaws
PubMed: 28759580
DOI: 10.1371/journal.pntd.0005820