Overcoming the Negligence in Laboratory Diagnosis of Mucosal Leishmaniasis.

The northern region of Brazil, which has the largest number of cases of tegumentary leishmaniasis (TL) in the country, is also the region that has the highest diversity of species of vectors and Leishmania parasites. In this region, cases of mucosal leishmaniasis (ML), a clinical form of TL, exceed the national average of cases, reaching up to 12% of the total annual TL notifications. ML is associated with multiple factors, such as the parasite species and the viral endosymbiont Leishmania RNA virus 1 (LRV1). Being a chronic parasitological disease, laboratory diagnosis of ML poses a challenge for health services. Here, we evaluated more than 700 clinical samples from patients with clinical suspicion of TL, including patients with cutaneous leishmaniasis (CL) and mucosal leishmaniasis, comparing the results of parasitological tests-direct parasitological examination by microscopy (DP) and conventional PCR (cPCR) targeting of both kDNA and hsp70. The DP was performed by collecting material from lesions through biopsies (mucosal lesions) or scarification (cutaneous lesions); for PCR, a cervical brush was used for sample collection. Blood samples were tested employing standardized real-time PCR (qPCR) protocol targeting the HSP70 gene. PCR tests showed higher sensitivity than DP for both CL and ML samples. Considering ML samples only (N = 89), DP showed a sensitivity of 49.4% (N = 44) against 98.8% (N = 88) for kDNA PCR. The qPCR hsp70 for blood samples from patients with ML (N = 14) resulted in superior sensitivity (50%; N = 7) compared to DP (21.4%; N = 3) for samples from the same patients. Our results reinforced the need to implement a molecular test for the diagnosis of ML, in addition to proposing methods less invasive for collecting material from TL patients. Sample collection using a cervical brush in lesions observed in CL and ML patients is easy to perform and less invasive, compared to scarification and biopsies. Blood samples could be a good source for qPCR diagnosis for ML patients. Thus, we propose here a standardized method for collection and for performing of molecular diagnosis of clinical samples from suspicious ML patients that can be applied in reference services for improving ML diagnosis.

First report of Leishmania (Viannia) lindenbergi causing tegumentary leishmaniasis in the Brazilian western Amazon region.

Tegumentary Leishmaniasis (TL) in the Brazilian Amazon region is associated with several Leishmania species. In this report, we describe two cases of TL related to Leishmania lindenbergi occurring in different locations of Rondônia state. After clinical diagnosis, lesion samples were collected for parasitological diagnoses via direct microscopic visualization, parasite isolation, and PCR. PCR reactions were positive in both clinical samples. Parasite isolation was possible for both patients, and isolates were submitted to species identification by isoenzyme electrophoresis and DNA sequencing. This report is the first to describe human infections caused by L. lindenbergi since the initial description and record of human infection by this species in 2002.

First autochthonous case of canine visceral leishmaniasis in Rondônia, Brazil, a region with no history of visceral leishmaniasis.

This report describes the first autochthonous case of canine visceral leishmaniasis in Rondônia, northern Brazil. A canine resident of the municipality of Cacoal, with clinical signs and symptoms of visceral leishmaniasis, was treated by a veterinarian. Samples were analyzed by a reference laboratory. Dual-path platform (DPP) assay, indirect immunofluorescence technique (IIT), enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), isolation in a culture medium, and direct parasitological analysis were performed. DPP assay, IIT, and ELISA revealed positive results for Leishmania; PCR identified the species as Leishmania infantum. Based on the clinical presentation and test results, canine visceral leishmaniasis was diagnosed.

First autochthonous case of canine visceral leishmaniasis in Rondônia, Brazil, a region with no history of visceral leishmaniasis

Abstract This report describes the first autochthonous case of canine visceral leishmaniasis in Rondônia, northern Brazil. A canine resident of the municipality of Cacoal, with clinical signs and symptoms of visceral leishmaniasis, was treated by a veterinarian. Samples were analyzed by a reference laboratory. Dual-path platform (DPP) assay, indirect immunofluorescence technique (IIT), enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), isolation in a culture medium, and direct parasitological analysis were performed. DPP assay, IIT, and ELISA revealed positive results for Leishmania; PCR identified the species as Leishmania infantum. Based on the clinical presentation and test results, canine visceral leishmaniasis was diagnosed.