Filter paper performance in PCR for cutaneous leishmaniasis diagnosis

Abstract INTRODUCTION: The objective of this study was to evaluate the performance of filter paper (FP) for lesion scraping collection in a polymerase chain reaction (PCR) for cutaneous leishmaniasis (CL) diagnosis. METHODS: Lesion scrapings from 48 patients were collected and analyzed for PCR. RESULTS: PCR with FP detected up to three Leishmania braziliensis promastigotes. Considering the direct search by microscopy or PCR of samples collected in STE buffer as standards, the sensitivity of PCR with FP was 100%. CONCLUSIONS: FP can be useful for CL diagnosis in remote regions, allowing high sensitivity in the detection of the parasite by PCR.

Epidemiological and clinical characteristics of cutaneous leishmaniasis and their relationship with the laboratory data, south of Brazil

OBJECTIVE: To evaluate clinical, epidemiological and laboratorial aspects for the understanding of the disease characteristics and its relationship with diagnostic tests. METHODS: A retrospective, descriptive and analytical study involving 2,660 American cutaneous leishmaniasis (ACL) suspected patients from southern Brazil was undertaken between April 1986 and December 2005. Data on population characteristics and laboratory tests were obtained. Diagnostic laboratory tests used were direct search for Leishmania spp. (DS), Montenegro skin test (MST) and indirect immunofluorescent assay (IFA). RESULTS: 62.3 percent of patients were positive for at least one laboratory test. DS test was positive in 65.1 percent; MST in 92.3 percent and IFA in 70.0 percent. Although Cohen's Kappa test did not reveal any agreement with laboratory diagnosis for ACL, the association between MST and IFA tests increased positiveness to 98.9 percent; MST and DS to 97.2 percent; and IFA and DS to 85 percent. IFA and MST positiveness were higher among patients with < 2-month lesion-evolution time. Most ACL patients were male (72.6 percent) in the age range of 15-49 years, featuring lesions during two months or less (53.9 percent) and a cutaneous form of the disease (88.0 percent). CONCLUSION: Findings suggest that for the adequate identification of ACL cases a combination of laboratory tests that involves the association of MST with at least another test should be used.

Polymerase chain reaction with lesion scrapping for the diagnosis of human American tegumentary leishmaniasis

The objective of this work was to compare the polymerase chain reaction (PCR) using lesion scrapping with other conventional techniques for the diagnosis of the American tegumentary leishmaniasis (ATL). For this, patients with cutaneous lesions suspected to be ATL were studied. The DNA was amplified with the MP1L/MP3H primers. From the 156 studied patients, 79 (50.6 percent) presented positive parasite direct search (PD), 81 (51.9 percent) had positive Montenegro skin test (MST), and 90 (57.7 percent) presented PD and/or MST positive. The PCR was positive in all of the positive-PD patients (100 percent sensitivity), in 91.1 percent of the positive PD and/or MST patients, and in 27.3 percent of the patients that presented negative PD and positive MST. The PCR positivity was similar to the PD (P = 0.2482) and inferior to the MST (P = 0.0455), and to the PD/MST association (P = 0.0133). The high PCR sensitivity, and positivity in those cases where the PD was negative, highlights the importance of this technique as an auxiliary tool for the diagnosis of ATL.

Leishmaniose tegumentar americana canina em municípios do norte do Estado do Paraná, Brasil / Canine American cutaneous leishmaniasis in municipalities of northern Paraná State, Brazil

A leishmaniose tegumentar americana (LTA) é endêmica no norte do Estado do Paraná, Brasil, afetando tanto o homem como os cães. O objetivo deste trabalho foi estudar a ocorrência da doença na população canina em áreas endêmicas de LTA. No período de setembro de 1999 a julho de 2002, foram investigados cães em sete localidades rurais de cinco municípios onde ocorreram casos humanos autóctones da doença, utilizando métodos parasitológicos e sorológicos. Dos 67 cães estudados, 14 (20,9 por cento) tinham lesões sugestivas de LTA, dos quais 3 (21,4 por cento) estavam infectados por Leishmania sp. Trinta e sete (55,2 por cento) cães apresentaram imunofluorescência indireta positiva para Leishmania (Viannia) braziliensis. Os resultados mostram a ocorrência simultânea de leishmaniose humana e canina e indicam a necessidade de estudos adicionais para esclarecer o papel do cão no ciclo de transmissão do parasito nessas áreas.