title: The "Buruli Score": Development of a Multivariable Prediction Model for Diagnosis of Mycobacterium ulcerans Infection in Individuals with Ulcerative Skin Lesions, Akonolinga, Cameroon.
abstract: BACKGROUND
  Access to laboratory diagnosis can be a challenge for individuals suspected of Buruli Ulcer (BU). Our objective was to develop a clinical score to assist clinicians working in resource-limited settings for BU diagnosis.
  Between 2011 and 2013, individuals presenting at Akonolinga District Hospital, Cameroon, were enrolled consecutively. Clinical data were collected prospectively. Based on a latent class model using laboratory test results (ZN, PCR, culture), patients were categorized into high, or low BU likelihood. Variables associated with a high BU likelihood in a multivariate logistic model were included in the Buruli score. Score cut-offs were chosen based on calculated predictive values. Of 325 patients with an ulcerative lesion, 51 (15.7%) had a high BU likelihood. The variables identified for the Buruli score were: characteristic smell (+3 points), yellow color (+2), female gender (+2), undermining (+1), green color (+1), lesion hyposensitivity (+1), pain at rest (-1), size >5cm (-1), locoregional adenopathy (-2), age above 20 up to 40 years (-3), or above 40 (-5). This score had AUC of 0.86 (95%CI 0.82-0.89), indicating good discrimination between infected and non-infected individuals. The cut-off to reasonably exclude BU was set at scores <0 (NPV 96.5%; 95%CI 93.0-98.6). The treatment threshold was set at a cut-off ≥4 (PPV 69.0%; 95%CI 49.2-84.7). Patients with intermediate BU probability needed to be tested by PCR.
  
  
  CONCLUSIONS
  We developed a decisional algorithm based on a clinical score assessing BU probability. The Buruli score still requires further validation before it can be recommended for wide use.
authors.affiliation: Epicentre, Paris, France.
authors.forename: Yolanda K
authors.initials: YK
authors.lastname: Mueller
authors.affiliation: Epicentre, Paris, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Bastard
authors.affiliation: Médecins Sans Frontières, Geneva, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Nkemenang
authors.affiliation: Médecins Sans Frontières, Geneva, Switzerland.
authors.forename: Eric
authors.initials: E
authors.lastname: Comte
authors.affiliation: Médecins Sans Frontières, Geneva, Switzerland.
authors.forename: Geneviève
authors.initials: G
authors.lastname: Ehounou
authors.affiliation: Centre Pasteur Cameroon, Yaounde, Cameroon.
authors.forename: Sara
authors.initials: S
authors.lastname: Eyangoh
authors.affiliation: Médecins Sans Frontières, Geneva, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Rusch
authors.affiliation: National Yaws, Leishmaniasis, Leprosy and Buruli Ulcer Control Programme, Ministry of Public Health, Yaounde, Cameroon.
authors.forename: Earnest Njih
authors.initials: EN
authors.lastname: Tabah
authors.affiliation: Geneva University Hospitals, Geneva, Switzerland.
authors.forename: Laurence Toutous
authors.initials: LT
authors.lastname: Trellu
authors.affiliation: Epicentre, Paris, France.|Institut de Recherche pour le Développement (IRD) UMI 233 - INSERM U 1175 - Montpellier University, Montpellier, France.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Etard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054312:Buruli Ulcer / Q000175:diagnosis*; D002163:Cameroon; D002648:Child; D002675:Child, Preschool; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012867:Skin / Q000473:pathology*; D055815:Young Adult