Evaluation of oligochromatography dipstick as a simplified molecular diagnostic tool for the diagnosis of cutaneous leishmaniasis

ABSTRACT

The demonstration of Leishmania parasite by microscopic examination of samples taken from skin lesions is of low sensitivity and requires expert parasitologists. On the other hand, molecular methods to detect Leishinania parasites are considered specific and sensitive. However, detection of amplicons by the classical methods is complex, expensive and needs equipments and highly trained personnel. This raises the demand for a simplified method of amplification and product detection. To evaluate the diagnostic accuracy of PCR Leishmania Oligo C-test for diagnosis of cutaneous leishmaniasis. The diagnostic accuracy of the Leishniania Oligo C-test was estimated in 30 skin scraping samples from patients presented at El Quorea specialized hospital, Taif, KSA. On the basis of parasitological detection of amastigotes by direct microscopic examination of Geimsa stained smears from skin lesions, patients were classified into confirmed cutaneous Ieishmaniasis [group A] and negative cases [group B]. Twenty patients were proved positive for Leishmania amastigotes by microscopic examination of stained smears. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic efficacy of the Leishmania Oligo C-test were 90%, 90%, 95%, 82%, 90%, respectively. These results indicate that this simple molecular technique may be employed for rapid diagnosis of cutaneous leishmaniasis. The Leishmania Oligo C-test showed high specificity and sensitivity when compared to results obtained by microscopic examination of skin scraping samples. The assay is a promising tool for simplified molecular detection of Leishmania parasites