ABSTRACT
ABSTRACT This study was conducted to characterize the transmission cycle of the tegumentary leishmaniasis (TL) in an old colonization area at Pernambuco State, Brazil. The aims were to identify autochthonous cases, sandflies fauna, domestic animals as possible reservoir hosts and the Leishmania species involved in this endemic area. A total of 168 suspected human cases of TL and 272 domestic animals (canine, feline, equine, goat, and sheep) were included. The sandflies were captured and identified by species. Patients were predominantly male and the average age was 37+18.1 years old. Of 85 patients who had skin lesions, 25.6% of them had direct positive smears for TL and 34 isolates were identified as Leishmania (Viannia) braziliensis. The confirmation for TL diagnosed by molecular detection (PCR) was almost three times more sensitive than the direct test [p < 0.001; PR = 2.72] associated with clinical examination. The Kappa test on PCR between two different specimens, biopsy, and skin lesion swab was 60.8% (p < 0.001). More than 200 specimens of sandflies (80 males and 159 females) were captured and identified as Lutzomyia whitmani (99.6%) and Lu. evandroi (0.4%). The detection of L. (V.) braziliensis by Real-Time PCR in the blood of a captured fed female was positive in 59.3% of Lu. whitmani. Of the 272 domestic animals included, 61.76% were male (n = 168). Thirty-six animals (13.2%) had lesions compatible with TL (34 dogs, 1 cat and 1 sheep) and 3 of them, all dogs, had lesions on the snout, showing destruction of cartilage and mucosa. The study suggests the participation of domestic animals as possible reservoirs. However, further studies are necessary to better understand the transmission cycle and take recommended measures in order to control the disease.
ABSTRACT
The diagnosis for American cutaneous leishmaniasis is based on an association of clinical, epidemiological and laboratory characteristics. The present study identified the circulating species of Leishmania in the State of Pernambuco, described its clinical-epidemiological characteristics and diagnosed the disease. Nineteen patients presenting active lesions who had been diagnosed through clinical evaluation and laboratory tests were selected. The tests included direct investigation, in vitro culturing, Montenegro skin test, indirect immunofluorescence and polymerase chain reaction. The Montenegro Skin Test showed positive results in 89 percent of the patients; indirect immunofluorescence, in 79 percent; direct investigation, in 58 percent; and polymerase chain reaction in 75 percent. Seven Leishmania (Viannia) braziliensis samples were isolated from these patients and were characterized by means of specific monoclonal antibodies. These data confirm that a combination of different diagnosis techniques is needed in order to obtain efficient results and that, so far, Leishmania (Viannia) braziliensis is the only species responsible for American cutaneous leishmaniasis infection in Pernambuco. Thus, it is essential to identify the parasite species involved in cases of human disease in an endemic area in order to determine the clinical and epidemiological characteristics, especially with regard to diagnosis, therapy development and disease prognosis.
O diagnóstico da leishmaniose cutânea americana é baseado na associação dos aspectos clínicos, epidemiológicos e laboratoriais. O presente estudo identificou a espécie de Leishmania circulante no Estado de Pernambuco, descreveu os aspectos clínico-epidemiológicos e diagnosticou a doença. Foram selecionados 19 pacientes apresentando lesão ativa e diagnosticados através de avaliação clínica e pelos exames laboratoriais que incluíram a pesquisa direta, cultivo in vitro, intradermorreação de Montenegro, imunofluorescência indireta e reação em cadeia de polymerase. A intradermorreação de Montenegro apresentou resultado positivo em 89 por cento dos pacientes. A imunofluorescência indireta apresentou 79 por cento de positividade, a pesquisa direta apresentou 58 por cento e a reação em cadeia de polymerase 75 por cento de positividade. Sete amostras de Leishmania (Viannia) braziliensis foram isoladas desses pacientes e caracterizadas através de anticorpos monoclonais específicos. Esses dados confirmam que é necessário a combinação de diferentes técnicas diagnósticas para se obter resultados eficientes e que, até o momento, a Leishmania (Viannia) braziliensis é a única espécie responsável pela infecção da leishmaniose cutânea americana em Pernambuco. Portanto, a identificação da espécie do parasito envolvido nos casos da doença no homem em uma área endêmica é essencial para o conhecimento dos aspectos clínicos e epidemiológicos, sobretudo para o diagnóstico e para o desenvolvimento da terapia e prognóstico da doença.