Leishmaniose tegumentar americana: análise epidemiológica de pacientes de diferentes regiões de Minas Gerais e caracterização molecular do gênero Leishmania

Abstract

The american tegumentary leishmaniasis, (ATL), one of clinic forms of leishmaniasis, is in expansion in Brazil and represent important cause of morbidity for populations who live in endemic areas. Profile epidemiological studies, health services and treatment are needs to establish strategies of disease control, as well as to employ new tools laboratorials, like PCR ones. This research evaluated the epidemiological aspects, diagnoses and treatment from patients with ATL from different regions Minas Gerais, beyond to use varied extraction techniques DNA and different primers in PCR to make possible the identification and differentiation of the etiological agents. Additionally, it compared the positivity of the primers addressed to the conserved (150/152) and variable (13Y/13Z) region of the Leishmania kDNA minicircle in biological samples of patients suggestive to ATL. It was to carried out epidemiological studies, diagnoses and treatment of 824 patients with ATL, being 261 from Southern and Southwestern regions of Minas Gerais state (SSMG) and 563 from river Doce valley (VRD). The data were obtained from notification files Regional Health Authorities – RHA of SSMG and from Leishmaniasis ambulatory “Dr. Paulo Araújo Magalhães” at Caratinga city (VRD) between 2002 and 2006. Thirty nine patients from these regions and with suggestive ATL lesions were submitted to laboratorial exams, beyond of the PCR. The DNA samples extracted by heating, phenol/ chloroform technique, proteinase K and by Wizard kit, and later used in the PCR and PCR-RFLP. In the period analyzed, it was observed decrease of 59.7% of ATL cases in SSMG and of up to 25.7% in VRD. The cutaneous clinic form was predominant with 91.9 and 93.6% in SSMG and VRD respectively. The greatest part of the patients from SSMG has urban residence (51.7%) while in VRD the rural was predominant (95.7%). In the SSMG there was positivity in 55.6, 10.7 and 19.5% of ATL cases in the Montenegro test (MT), parasitological and histopatological exams, respectively. In the VRD the positivity was 84.0 in the MT and 73.0% in the parasitological exam. Discharge from the treatment due to cure varied of 71.8 to 92.0% in the SSMG and reached 78.0% in VRD. From the 39 suggestive patients, 32 were confirmed to ATL. The DNA extractions allowed observing that even starting from total degraded DNA was possible to detect kDNA of Leishmania. In the suggestive samples, the positivity of DNA with 13Y/13Z and 150/152 was about 56.4 and 76.9% respectively. In the confirmed patients to ATL, the positivity to 13Y/13Z was about 68.7% and to 150/152 was of 93.7%. The employment of the primers 150/152 was viable, what doesn't discard the use of 13Y/13Z, given the expressive positivity reached in samples that request simplified extraction of DNA and with low cost. PCR-RFLP made possible the identification of L. (V.) braziliensis in the patients' biological samples with LTA. The data of the present work they also reinforce the need of actions that establish a reference center in the diagnosis and treatment of LTA in SSMG.