Improving clinical and epidemiological predictors of Buruli ulcer.

Gilbert Adjimon Ayelo,René Fiodessihoue,Akpeedje Anita Carolle Wadagni,Didier Codjo Agossadou,Françoise Portaels,Miriam Eddyani,Dissou Affolabi,Ghislain Emmanuel Sopoh,Jean-Gabin Houezo,Epco Hasker,Bouke C De Jong,Ange Dodji Dossou,Yves Thierry Barogui

doi:10.1371/journal.pntd.0006713

Abstract

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

Highlights

Buruli ulcer (BU) is a chronic necrotizing infectious disease of the skin caused by Mycobacterium ulcerans
This is an analytical prospective study of 224 consecutive patients presenting with skin and soft tissue lesions that could be compatible with BU, living in a BU endemic region, who were recruited in the “Centre de Depistage et de Traitement de l’Ulcère de Buruli” (CDTUB) of Allada and Lalo in southern Benin between March 2012 and March 2015
PCR was positive for 98 (43.7%) participants among whom 9 participants had been clinically diagnosed as non-BU (10.0% of patients diagnosed as clinically non-BU)

Summary

Introduction

Buruli ulcer (BU) is a chronic necrotizing infectious disease of the skin caused by Mycobacterium ulcerans. The diagnosis of BU is based on epidemiological and clinical criteria defined by the World Health Organization (WHO) [2,4]. The clinical WHO criteria are (i) lesions on the upper or lower limbs since these represent about 85% of BU cases [4,8,9,10,11]; (ii) painless nodules, plaques or edema of the skin that, without treatment, evolve to a necrotic ulceration with [4,8] (iii) undermined and often hyperpigmented edges; (iv) lesions that are generally not accompanied by adenopathy, nor fever, and (v) that may become painful in case of superinfection [2,4]. Buruli ulcer (BU) is a chronic necrotizing infectious skin disease caused by Mycobacterium ulcerans. This study aimed to estimate the predictive values of these criteria and how they could be improved

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Conclusion