A Clinical Prediction Rule for American Cutaneous Leishmaniasis in Colombia

Abstract

Neither parasitological nor molecular diagnosis of leishmaniasis is widely available in clinical settings where American cutaneous leishmaniasis (ACL) is endemic. Therefore four clinical prediction rules for ACL were developed which incorporated physical examination findings (clinical rule), physical examination and leishmanin skin test (LST) (clinical-LST rule), physical examination and historical information (clinical-historical rule), or physical examination, historical information and LST (clinical-historical-LST rule). One hundred parasitologically diagnosed ACL cases and 38 cases of chronic skin lesions of other aetiologies comprised the derivation set. The validation set consisted of 124 ACL cases and 35 patients with lesions of other aetiologies. Components of each rule were selected by bivariate analysis, then step-wise logistic regression. Sensitivity, specificity and efficiency were calculated for each score threshold; the threshold achieving greatest efficiency was selected for each rule. When these rules were applied to the validity set the sensitivity, specificity and efficiency were respectively: clinical 93%, 31%, 79%; clinical-LST 90%, 73%, 85.9%; clinical-historical 97%, 51%, 87%; clinical-historical-LST 92%, 70%, 87%. Inclusion of LST skin test consistently improved the specificity of the rules. Should a given clinical setting warrant optimizing either sensitivity or specificity alone, the rule thresholds can be adjusted. These and other prediction rules, once evaluated in other settings, should be incorporated into leishmaniasis control programmes.

Proposal of a histopathological predictive rule for the differential diagnosis between American tegumentary leishmaniasis and sporotrichosis skin lesions

“…A clinical predictive rule for the diagnosis of ATL has already been suggested 37 and validated 38 . Anatomopathological scoring systems for the classification and prognosis of neoplasms are well known and have been used for several decades 39,40 .…”

PCR-Based Diagnosis of Acute and Chronic Cutaneous Leishmaniasis Caused by Leishmania ( Viannia )

“…27:1186-1193, 1998). The reference standard for cases of leishmaniasis consisted of combined laboratory criteria (conventional laboratory methods or supplemental laboratory methods) and previously evaluated clinical criteria (40). A case of CL was required to meet either the laboratory or the clinical criteria.…”

“…In order to apply the reference standard and thereby identify additional cases of CL, supplemental laboratory procedures were performed and clinical prediction rule criteria established in a prior study (40) were utilized when all conventional methods were negative for the initial clinical sample. The additional specimens were obtained and evaluated by the three assays described above and by inoculation of macerated biopsies into hamsters.…”

The epidemiology and control of leishmaniasis in Andean countries

“…Differential diagnosis is important because diseases of other etiologies (e.g. leprosy, skin cancers, tuberculosis) with a similar clinical spectrum to leishmaniasis are often present in leishmaniasis-endemic areas (Weigle et al, 1993a). Although many researchers have suggested that taxonomic discrimination of Leishmania infecting LCL patients (at least distinguishing L. (Viannia) and L. (Leishmania) subgenera) is important for therapeutic decisions (Rodriguez et al, 1994;Mimori et al, 1998), this is not practiced in any country, not least because there is currently insufficient evidence to tailor treatment protocols according to parasite type.…”