Evaluation of clinical diagnosis scores for Boutonneuse fever.

Mediterranean spotted fever (MSF) is endemic in Tunisia. Diagnosis is confirmed retrospectively based on serology. Clinical features are suggestive of diagnosis if the triad (fever, rash, and eschar) is present. Otherwise clinical diagnosis could be difficult. A diagnosis score was already proposed by Raoult et al. The aim of this study was to evaluate this score, considering only clinical parameters, in order to help clinicians in diagnosing MSF before confirmation. We retrospectively analyzed 62 consecutive charts of patients with diagnosis of suspected MSF. Diagnosis confirmation was made by serology (IgG anti-R. conorii exceeding 128 or seroconversion). Epidemiological and clinical features and total score for each patient were reviewed. To validate the clinical score, we calculated sensitivity, specificity and the Youden index for each score in order to establish the ROC curve. SPSS was used for these statistical tests. Area under curve was 0.70 (P = 0.02). The cutoff score with the most predictive value of MSF diagnosis was 18, according to our study (sensitivity 60%, specificity 84,6% and Youden index 0.44). The MSF diagnosis score is a helpful tool to aid the clinician with presumptive management before confirmation. In our study we demonstrated that a score based only on epidemiological and clinical features could be sufficient, but we have to indicate that these results and cutoff score of 18 were from a retrospective study and should be confirmed by a well-designed prospective one.