Comparison of various cytodiagnostic tests in the rapid diagnosis of cutaneous leishmaniasis

Background In poor endemic areas of cutaneous leishmaniasis (CL), lacking sufficient laboratory infrastructure, cheap and rapid diagnostic methods are critical in management. Objective To compare the diagnostic accuracy of newer smear techniques with slit skin smear technique in the rapid diagnosis of CL. Patients and methods: This interventional and comparative study was carried out at Combined Military Hospital Muzaffarabad, Azad Kashmir, from January 2008 to June 2008. Patients with suspected CL lesions, fulfilling the inclusion criteria were enrolled in the study. In every patient, dental broach smear (DBS), dental broach saline smear (DBSS), slit-skin smear (SSS) and fine needle aspiration biopsy smear (FNABS) were made from the active edge of the lesions and then stained with Leishman’s stain, except FNABS (stained with H E stain). At least 100 fields were examined under oil immersion lens to identify Leishman-Donovan (LD) bodies based on their morphology before declaring the specimen as negative. Newer techniques i.e. DBS, DBSS, and FNABS were compared with SSS. Sensitivity, specificity, positive and negative predictive values, accuracy, and likelihood ratio were calculated using statistical program SPSS version 12.0. Results Sixty patients were enrolled which included 31 (51.7%) males and 29 (48.3%) females, ranging in age from 3 to 68 years (mean 25.4+21.9 years). FNABS showed highest positive rate (55%) followed by DBS (46.6%), SSS (36.6%) and DBSS (25%). DBS showed highest sensitivity and specificity, followed by FNABS. Conclusion DBS and FNABS showed a better yield than the traditional SSS method of direct microscopy in CL.