Detection of DNA from Leishmania (Viannia): Accuracy of Polymerase Chain Reaction for the Diagnosis of Cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL) can occur in skin and mucosa, causing disfiguring lesions. The laboratory diagnosis of CL involves immunological methods and optical detection of the parasite, al of which have limitations. There is a need for more effective diagnostic methods for CL which wil allow treatment to be initiated more promptly in order to help prevent the development of severe forms of mucosal disease, and to estimate the prognosis of the infection. The polymerase chain reaction (PCR) has been widely used to diagnose CL, because of its higher sensitivity. This study estimated the accuracy and compared PCRs of samples from lesion scarification (PCR-L) and blood sample-enriched leukocytes (PCR-B) with three conventional diagnostic techniques: parasite direct search (DS), Montenegro skin test (MST), and indirect immunofluorescence reaction (IIF). The study included 276 patients under suspicion of CL. We conducted a cross-sectional study, in which patients were selected by convenience sampling. We used MP3H/MP1L primers to generate a Leishmania (Viannia) (minicircle kDNA) fragment of 70-bp. Of 106 patients with CL, 83.87%, 51.67%, 64.52%, 85.71%, or 96.10% tested positive by PCR-L, PCR-B, DS, IIF, or MST, respectively. Five patients tested positive only by PCR-L, and two other patients only by PCR-B. PCR-L is indicated for use in patients with chronic lesions or Leishmania reinfection, which may progress to mucosal lesion. PCR-B is indicated for use in patients with negative results in conventional tests or for patients with no apparent lesion. PCR is not only useful in diagnosing CL but also helps to identify the infecting species.     

Preliminary study on feeding preference of Nyssomyia neivai (Pinto) and Nyssomyia whitmani (Antunes & Coutinho) (Diptera: Psychodidae) in a rural area of the State of Paraná, South Brazil

Due to the importance of sandflies in the American cutaneous leishmaniasis epidemiology, we investigated the feeding preference of sandflies related to domestic animals common in domiciliary environments in endemic rural areas, where this disease occurs. The sandflies were collected with Falc?o light traps, installed in cages, each one containing one domestic animal kind (pig, dog, rabbit or chicken), in Recanto Marista, in Doutor Camargo municipality. Forty five collections were made, totaling 135h of collections per trap. A total of 2,854 sandflies of the following species were collected: Brumptomyia brumpti (Larousse), Evandromyia correalimai (Martins, Coutinho & Luz), Evandromyia cortelezzii (Brèthes), Expapillata firmatoi (Barreto, Martins & Pellegrino), Micropygomyia ferreirana (Barreto, Martins & Pellegrino), Migonemyia migonei (Fran?a), Nyssomyia neivai (Pinto), Nyssomyia whitmani (Antunes & Coutinho), Pintomyia fischeri (Pinto), Pintomyia monticola (Costa Lima), Pintomyia pessoai (Coutinho & Barreto), Psathyromyia lanei (Barreto & Coutinho) and Psathyromyia shannoni (Dyar). The dominant species was N. neivai. N. neivai and N. whitmani did not show any feeding preference towards the animals used as bait. It was concluded that N. neivai and N. whitmani are opportunist and, probably, the females adjust their feeding habits to the availability of hosts, suggesting their feeding eclecticism in the anthropic environments.     

Larval habitats of sand flies in rural areas of southern Brazil

We report the results of an investigation of natural larval sand fly habitats in the Recanto Marista, Doutor Camargo municipality, Paraná state, Brazil, from May, 2010 to August, 2012. We used Alencar emergence traps (AT), experimental traps (ET), and soil samples incubated in a biochemical oxygen demand incubator. Eight sand flies were collected with ATs. One specimen was collected with an ET and 21 were collected in soil samples. The collected species were Brumptomyia brumpti, Micropygomyia ferreirana, Migonemyia bursiformis, Migonemyia migonei, Nyssomyia neivai, Nyssomyia whitmani, and Pintomyia pessoai. The laval habitats of sand flies were located in the Recanto Marista, especially between tree roots, but the number of adults that emerged in the traps and soil samples was small despite the high density of sand flies that has been recorded in the Recanto Marista.