Diagnosis of Cutaneous and Mucocutaneous Leishmaniasis in Colombia: A Comparison of Seven Methods

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  • * Department of Epidemiology, School of Hygiene and Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, Maryland 21205
  • Tulane University International Collaboration in Infectious Diseases Research Program, Centro Internacional de Investigaciones Médicas, Tulane University-COLCIENCIAS, Apartado Aéreo 5390, Cali, Colombia
  • Hospital Regional “San Andrés,” Servicio de Salud de Occidente, Tumaco, Nariño, Colombia
  • § Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, New Orleans, Louisiana 70112

Seven methods of diagnosing leishmaniasis were compared in 177 patients presenting with lesions of the skin (165) or mucosa (12) in Tumaco and Cali, Colombia. The three methods of visualizing amastigotes in tissue samples (histological staining of tissue sections, impression smears of punch biopsies, and smears of dermal scraping from slits in the lesion margins) were less sensitive than the four Leishmania isolation methods (aspiration of lesion border cultured in biphasic media, aspirate inoculated into hamster nasal tissue, culture of punch biopsy macerate, and hamster inoculation of macerate). The aspirate-culture and biopsy-hamster methods employed in this study proved most sensitive of the four methods for the recovery of parasites. The combined overall sensitivity of the 7 methods was 67% for all enrolled patients and 75% for Montenegro skin test-positive patients. The individual sensitivities for the methods for all patients and Montenegropositive patients, respectively, were: histopathology 14% and 16%, impression smear 19% and 21%, dermal scraping 22% and 26%, aspirate-culture 58% and 64%, aspirate-hamster 38% and 41%, biopsy-culture 50% and 55%, and biopsy-hamster 52% and 57%. All methods were less sensitive in lesions of greater than 6 months duration than in lesions of more recent onset. Mucosal lesions were best diagnosed by the culture or hamster inoculation of a macerated mucosal biopsy. The diagnosis by inoculation of hamsters was achieved within 2 to 12 weeks, a mean of 34.5 days. Promastigotes were seen on Senekjie's medium within 3–8 days. Based on these results we recommend dermal scraping smears for immediate diagnosis and culture of aspirates for a definitive parasitological diagnosis of cutaneous lesions. Culture and hamster inoculation of macerated biopsies are recommended for the diagnosis of mucosal lesions.