Skin Scraping is the Most Accessible Technique for the Parasitological Diagnosis of American Tegumentary Leishmaniasis

We read with interest the article in the November 2014 issue of the Journal by Sousa and others entitled: “Press Imprint Smear: A Rapid, Simple, and Cheap Method for the Diagnosis of Cutaneous Leishmaniasis Caused by Leishmania (Viannia) braziliensis.” We agree with those authors that direct diagnosis by microscopic visualization of amastigotes is the first choice for the diagnosis of leishmaniasis. Advantages include speed, simple execution, and low operational cost, allowing use in poor endemic areas. The results obtained using a press imprint smear were very satisfactory, reaching a sensitivity of approximately 85%, while other direct diagnostic tests, such as traditional imprint, skin scraping, and slit skin smear, for leishmaniasis have had sensitivity values around 60–70%. The authors state that their method is cheaper than skin scraping. However, they did not consider the necessity of using anesthetic drugs, suturing material, a minimally structured outpatient setting, and sterile equipment in biopsy procedures. In addition, the described procedure must be performed by medical professionals, and this is the biggest drawback to the method in endemic settings. All of these aspects increase the cost of the imprint smear method, making it undoubtedly more expensive than skin scraping. In addition, skin scraping may be performed by a well-trained technician, facilitating the use of this procedure in areas with poor infrastructure. In relation to slide interpretation, the authors state that “A technician can learn to identify amastigotes with a short training course.” In fact, the finding of amastigotes of Leishmania sp. is not always an easy task. The possibility of the presence of other microorganisms in the lesion, such as Sporothrix schenckii and Histoplasma capsulatum, besides artifacts, highlights the need for skilled professionals for this procedure. We have conducted training courses in some Brazilian regions for professionals who conduct direct examination for leishmaniasis, and so appreciate the challenges in this activity. In addition to training, it is important to produce and disseminate informational materials, such as photomicrographs with amastigotes and other microorganisms, to enforce training, as exists for other health problems, such as malaria. We are pleased to note that other groups share our enthusiasm, and have worked to improve direct examination, which is the tool of choice, to safely diagnose leishmaniasis in endemic areas.