Ericka Lima Almeida

Species diversity of Leishmania (Viannia) parasites circulating in an endemic area for cutaneous leishmaniasis located in the Atlantic rainforest region of northeastern Brazil.

Objectives  To identify the aetiological agents of cutaneous leishmaniasis and to investigate the genetic polymorphism of Leishmania (Viannia) parasites circulating in an area with endemic cutaneous leishmaniasis (CL) in the Atlantic rainforest region of northeastern Brazil.

Cutaneous and visceral leishmaniosis in dogs from a rural community in northeastern Brazil.

A community-based epidemiological study was carried out in a rural area in northeastern Brazil, where visceral leishmaniasis is endemic, but the primary vector Lutzomyia longipalpis has never been found. Forty-one dogs were screened by an indirect immunofluorescence antibody test (IFAT) for the presence of anti-Leishmania antibodies and 12 (29.3%) of them were positive. One of the IFAT-positive dogs was also positive for Leishmania amastigotes in bone marrow cytology and for Leishmania infantum by real-time polymerase chain reaction (PCR) on blood. One IFAT-negative dog was positive for L. infantum by PCR on bone marrow and other for Leishmania amastigotes in skin stained-smears. When tested for L. braziliensis by PCR, 20 dogs were positive. Considering all diagnostic tests, the estimated prevalence of Leishmania spp. infection in the studied rural dog population was 58.5%. There was no significant difference in IFAT-positivity in relation to age, gender, and clinical status of the dogs. When tested for L. infantum by real-time PCR, 20 ticks collected from IFAT-positive dogs were all negative. This study shows a high level of exposure to Leishmania spp. infection in dogs from a rural community in northeastern Brazil. In general, the results do not support the participation of ticks as vectors of L. infantum in this area, which is likely to be transmitted by Lutzomyia spp. other than L. longipalpis. Finally, this study highlights that the use of IFAT in areas where both L. infantum and L. braziliensis are present should be withdraw in order to avoid the unnecessary culling of dogs that are actually infected only by L. braziliensis.

Leishmaniose tegumentar americana causada por Leishmania (Viannia) braziliensis, em área de treinamento militar na Zona da Mata de Pernambuco

The aim of work was to study the epidemiology of American tegumentary leishmaniasis in a military training unit situated in Zona da Mata region of Pernambuco State. Between 2002 and 2003 twenty-three cases were notified by clinical exam, detection and/or isolation of parasite and Montenegro skin test. Seven stocks of Leishmania (Viannia) braziliensis were obtained from patients, identified by a panel of specific monoclonal antibodies and isoenzymatic electrophoresis profiles. An epidemiologic survey on prevalence of infection was carried out by Montenegro skin test in the population that underwent training activities during the same period, out of which 25.3% were identified as positive. These results in association with previous data from this area, shows the maintenance of a primary transmission cycle and the occurrence of periodical outbreaks after training activities in local areas of remnant Atlantic rain forest.

Clinical, epidemiological and laboratory aspects of patients with American cutaneous leishmaniasis in the State of Pernambuco

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% of the patients; indirect immunofluorescence, in 79%; direct investigation, in 58%; and polymerase chain reaction in 75%. 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.

Small mammals as hosts of Leishmania spp. in a highly endemic area for zoonotic leishmaniasis in North-Eastern Brazil

BACKGROUND Leishmania parasites cause leishmaniasis in humans and animals worldwide. These parasites are transmitted by phlebotomine sand flies, which become infected upon feeding on an infected mammalian host. We assessed the occurrence of Leishmania infection in small mammals in an area of cutaneous and visceral leishmaniasis endemicity. METHODS A total of 180 small mammals were trapped in 2003 and 2006 in a rural area in north-eastern Brazil. Spleen and skin samples from these animals were assessed by two PCR protocols, one targeting Leishmania (Viannia) spp. and other Leishmania (Leishmania) infantum. Additionally, serum samples were tested by an immunochromatographic test with rK39 as antigen. RESULTS Overall, 23.2% (38/164) of the animals were positive to L. (V.) spp. and 8.8% (14/160) to L. (L.) infantum). Five animals of four species (Didelphis albiventris, Nectomys squamipes, Rattus rattus and Holochilus sciureus) were positive by both PCR protocols, an overall co-infection rate of 2.5%. By serology, 5% (7/139) of the animals were positive, but all of them were PCR-negative. An isolate obtained from a water rat (N. squamipes) was characterized as L. (V.) braziliensis (zymodeme Z-74). CONCLUSIONS This study reinforces the involvement of different small mammals (e.g., N. squamipes, R. rattus and H. scieurus) in the transmission cycles of L. (V.) braziliensis and L. (L.) infantum in north-eastern Brazil. The finding of L. (V.) braziliensis infection in black rats suggests a rapid process of adaptation of a New World Leishmania species to an Old World rodent and raises interesting questions regarding the co-evolution of these parasites and their vertebrate hosts.

Clinical and hematological findings in Leishmania braziliensis-infected dogs from Pernambuco, Brazil

Canine cutaneous leishmaniasis by Leishmania braziliensis is a neglected, but widespread disease of dogs in South America. This paper describes clinical and hematological alterations in 17 L. braziliensis-infected dogs from Brazil. The most common hematological findings were thrombocytopenia (82.4%), anemia (70.6%), low packed cell volume (52.9%) and eosinophilia (41.2%). Twelve (70.6%) dogs displayed at least one evident physical alteration; 11 dogs (64.7%) presented skin lesions, four (23.5%) had weight loss and two (11.8%) onychogryphosis. L. braziliensis-infected dogs present clinical and hematological signs often observed in dogs infected by other pathogens. This indicates that veterinarians and public health workers should not consider the presence of non-specific clinical signs as diagnostic criteria for visceral leishmaniasis in dogs living endemic areas to avoid misdiagnosis and subsequent elimination of dogs infected by L. braziliensis.

Occupationally Acquired American Cutaneous Leishmaniasis

We report two occupationally acquired cases of American cutaneous leishmaniasis (ACL): one accidental laboratory autoinoculation by contaminated needlestick while handling an ACL lesion sample, and one acquired during field studies on bird biology. Polymerase chain reaction (PCR) assays of patient lesions were positive for Leishmania, subgenus Viannia. One isolate was obtained by culture (from patient 2 biopsy samples) and characterized as Leishmania (Viannia) naiffi through an indirect immunofluorescence assay (IFA) with species-specific monoclonal antibodies (mAbs) and by multilocus enzyme electrophoresis (MLEE). Patients were successfully treated with N-methyl-glucamine. These two cases highlight the potential risks of laboratory and field work and the need to comply with strict biosafety procedures in daily routines. The swab collection method, coupled with PCR detection, has greatly improved ACL laboratory diagnosis.

Leishmania (Viannia) braziliensis isolated from the saliva of patients in a cutaneous leishmaniasis-endemic area of northeastern Brazil

Several studies have described the use of non-invasive collection methods, mostly based on the detection of parasite DNA, for diagnosis. However, no Leishmania specimens have been isolated from saliva. Here, we report the first isolation of Leishmania braziliensis from the saliva of humans with cutaneous leishmaniasis but without lesions on their mucosa. The isolates were obtained from salivary fluid inoculated in hamsters and were tested by multilocus enzyme electrophoresis. Seven samples from 43 patients suspected of having the disease were identified for in vivo culture. These findings suggest that saliva is a clinical sample that allows the isolation of Leishmania sp.