Corte De Pedra Research Articles

Factores de riesgo para la transmisión de leishmaniasis cutánea en niños de 0 a 5 años en un área endémica de Leishmania (Viannia) braziliensis

With the purpose of identifying risk factors for cutaneous leishmaniasis transmission in children from 0 to 5 years, a matched case-control study was carried out in Corte de Pedra, Bahia, Brazil, an endemic area of Leishmania (Viannia) braziliensis. Children with a positive leishmanin skin test and one or more active lesions or scars consistent with cutaneous leishmaniasis were defined as cases. Forty cases and 71 controls were selected and matched by age and place of residence. The presence of a family member with a history of cutaneous leishmaniasis in the year prior to the appearance of the disease in the child was found to be an important risk factor (MORMH = 17.75; 95%CI: 4.08-77.25). No evidence of association between the disease and other risk factors was found, such as child's habits inside or outside the house, domiciliary or peridomiciliary characteristics, or presence of vectors or probable reservoir animals. These findings support the hypothesis that humans serve as both the reservoir and source of infection for this age group.

Genetic variability in geographical populations of Lutzomyia whitmani elucidated by RAPD-PCR.

Unequivocal identification of phlebotomine sand flies is of crucial importance in epidemiological studies of leishmaniasis, because certain species may act as vectors, depending on behavior and physiology. For Lutzomyia whitmani, a major vector of American human cutaneous leishmaniasis in Brazil, an increasing number of studies have suggested the existence of a species complex. In the present work, we evaluated the genetic variability of L. whitmani populations from four Brazilian foci of that disease: Corte de Pedra, Ilhéus, Martinho Campos, and Serra de Baturité. Computational analysis of 85 characters, generated by RAPD-polymerase chain reaction, demonstrated high intrapopulational variability. Those characters led to sex discrimination in three of the populations, with the exception of Martinho Campos individuals, in which sex distinction was not complete. One and two interpopulational phenograms were obtained for females and males, respectively. A higher similarity was observed among the specimens from Ilhéus, Corte de Pedra, and Serra de Baturité, whereas the Martinho Campos population remained external to that cluster. These results, which are in partial accordance with a previous morphometric survey of L. whitmani from the same regions, provide additional evidence to support the existence of at least two spatial clusters of biogeographical populations of L. whitmani in Brazil.

Phenetic studies on randomly amplified polymorphic DNA-polymerase chain reaction-variability of four geographical populations of Lutzomyia whitmani (Diptera: Psychodidae) in Brazil.

Previous evaluation of the genetic variability of four biogeographical populations of Lutzomyia whitmani from known foci of cutaneous leishmaniasis in Brazil demonstrated two main spatial clusters: Corte de Pedra-BA, Ilhéus-BA and Serra de Baturité-CE in the first cluster, and Martinho Campos-MG in the second. Further analysis showed a high degree of homogeneity in Corte de Pedra population but not in the others, which presented a significant percentage of specimens displaced from their phenon of origin (discrepant individuals). In the present work we analyzed the frequencies of association coefficients in the matrixes of similarity per population of Lutzomyia whitmani from both sexes and the general phenograms obtained, in a more detailed study of those discrepant specimens. Populational stability was observed for Corte de Pedra population, whereas the three remaining populations showed varying degrees of heterogeneity and different displacements according to sex. Our results strongly suggested the existence of a genetic flow between the lineages North-South/North-East and Ilhéus/Serra do Baturité of Lutzomyia whitmani.

Multiclonal Leishmania braziliensis population structure and its clinical implication in a region of endemicity for American tegumentary leishmaniasis.

In Corte de Pedra (CP), northeastern Brazil, Leishmania braziliensis causes three distinct forms of American tegumentary leishmaniasis (ATL). To test the hypothesis that strain polymorphism may be involved in this disease spectrum and accurately characterize the parasite population structure in CP, we compared one L. major, two non-CP L. braziliensis, one CP L. amazonensis, and 45 CP L. braziliensis isolates, obtained over a 10-year period from localized cutaneous, mucosal, and disseminated leishmaniasis patients, with randomly amplified polymorphic DNA (RAPD). Electrophoretic profiles were mostly unique across species. All typing protocols revealed polymorphism among the 45 CP L. braziliensis isolates, which displayed eight different RAPD patterns and greater than 80% overall fingerprint identity, attesting to the adequacy of the tools to assess strain variability in CP's geographically limited population of parasites. The dendrogram based on the sum of RAPD profiles of each isolate unveiled nine discrete typing units clustered into five clades. Global positioning showed extensive overlap of these clades in CP, precluding geographic sequestration as the mechanism of the observed structuralization. Finally, all forms of ATL presented a statistically significant difference in their frequencies among the clades, suggesting that L. braziliensis genotypes may be accompanied by specific disease manifestation after infection.

Cutaneous leishmaniotic ulcers with Corynebacterium diphtheriae

In a prospective study to evaluate the influence of secondary bacterial infection on the evaluation of cutaneous leishmaniasis, in Corte de Pedra (Bahia), we isolated Corynebacterium diphtheriae in 7 (8.3%) out of 84 patients with ulcers studied. Due to the small number of patients with the presence of the bacteria in the ulcer, we could not conclude whether Corynebacterium diphtheriae behaves only as a colonizer nor its influence on the healing of the leishmaniotic ulcer.

Immunoglobulin E antileishmanial antibody response in cutaneous leishmaniasis.

High levels of antileishmanial immunoglobulin E (IgE) antibodies are associated with disease activity in visceral leishmaniasis. Herein, we report our observations about the relationship between antileishmanial IgE antibodies and clinical aspects of cutaneous leishmaniasis. This study was carried out with 45 patients (29 male and 16 female), with ages ranging from 11 to 48 years. All subjects were from an area to which leishmaniasis is endemic, Corte de Pedra (Bahia, Brazil), and the duration of the illness was </=30 days. The patients were classified as positive or negative for IgE serology in enzyme-linked immunosorbent assay with leishmanial antigens. IgE antibodies were detected in 18 patients (optical density, 0.421 +/- 0.30; 95% confidence interval, 0.27 to 0.57), and only 3 (17%) had more than one ulcer. In this group the diameter of Montenegro's reaction was 18 +/- 12.2 mm. In the group with negative IgE serology, 11 of 27 patients (48%) presented two or more cutaneous ulcers, and the mean of the skin test result was 9 +/- 6.9 mm. There was a positive correlation between IgE antibody levels and Montenegro's reaction size and an inverse correlation between IgE antileishmanial antibodies and the number of skin ulcers. The presence of antileishmanial IgE antibodies in cutaneous leishmaniasis may be a result of immunoregulatory events with clinical implications.

Socioeconomic factors and attitudes towards household prevention of American cutaneous leishmaniasis in an endemic area in Southern Bahia, Brazil

A survey was conducted to identify socioeconomic conditions and attitudes towards household prevention of American cutaneous leishmaniasis in Corte de Pedra, located in the county of Tancredo Neves, an endemic region in southern Bahia, Brazil. A questionnaire was applied in July 1997, focusing on social and economic variables, habits, and attitudes towards prevention of arthropod bites. All families (100%) living in the study area were surveyed, comprising 168 households with 851 individuals. Approximately 66.7% of the families earned up to one minimum wage, supporting an average of 5.1 residents per household. Most (57.2%) of the families did not use any type of protection against bites. Fumigation by burning various types of materials was the most customary form of prevention. Individual protection measures were rarely used. Since there was evidence of household and peridomiciliary transmission in the study area, use of impregnated bed nets is an alternative for intradomiciliary protection.

Morphometric and phenetic studies of five geographical populations of Lutzomyia whitmani (Diptera: Psychodidae) in Brazil.

A morphometric survey examined adult specimens of Lutzomyia whitmani (Antunes & Coutinho) captured at 5 municipalities in southeastern and northeastern Brazil to compare the populations. The localities were Ilhéus (Bahia), Martinho Campos (Minas Gerais), Corte de Pedra (Bahia), Baturité (Ceará), and Amaraji (Pernambuco): all are known foci of American cutaneous leishmaniasis. Fifteen males and 15 females from each population were analyzed morphometrically for 42 and 37 characters, respectively. Statistical data alone were insufficient to discriminate among the 5 populations. Further analysis generated phenograms that indicated there were 2 spatial clusters: the 1st was composed of specimens from Ilhéus (Bahia) and Baturité (Ceará) and the 2nd of specimens from Martinho Campos (Minas Gerais), Corte de Pedra (Bahia), and Amaraji (Pernambuco). Although insufficient to define the taxonomic status of the populations studied, the results delineated the existence of biogeographical structuring within L. whitmani. Complementary studies on the susceptibility to Leishmania braziliensis infection in the 5 populations are in progress to clarify the relationship between the 2 biogeographical clusters and American cutaneous leishmaniasis transmission in those Brazilian regions.

Estudo comparativo entre antimoniato de meglumina, isotianato de pentamidina e sulfato de aminosidine, no tratamento de lesões cutâneas primárias por Leishmania (Viannia) braziliensis (L(V)b)

With the aim of comparing the therapeutic efficacy, tolerability and toxicity of meglumine antimoniate, aminosidine sulphate and pentamidine isethionate, a field study was conducted on randomized treatment of patients with primary cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis (L(V)b), in Corte de Pedra, BA, from October 1992 up to January 1993. Forty six patients were treated and distributed into three groups, two with 15 and one with 16 subjects. All patients were submitted to clinical examination, histopathological and immunological investigations, as diagnostic criterium. All patients were treated by intramuscular route. Group 1 received pentamidine 4 mg/kg/every 2 days, for 8 applications; Group 2 received aminosidine 20 mg/kg/day, for 20 days, and Group 3 received meglumine 10 mg Sbv/kg/day, for 20 days. Failure of therapy was defined as ulceration of the skin lesion four months after treatment. Such failure occurred in five cases as follows: two cases in patients of group 1 one case in patients of group 2, and two cases in group 3, after the first year of follow up. In the evaluation after three years we reviewed fifteen patients, five in each group; except for one in Group 3, all of them were cured. Statistical significance of the results between the three schedules used was not verified.

An outbreak of human Leishmania (Viannia) braziliensis infection

The occurrence of acute cutaneous leishmaniasis among inhabitants of 10 farms within 10 Km of the hamlet of Corte de Pedra, Bahia, Brazil was studied prospectively from 1984-1989. A mean population of 1,056 inhabitants living in 146 houses were visited every 6 months and the number of skin ulcers recorded. A leishmanin skin test survey was done people with suggestive skin scars or active disease in 1984. The incidence of skin ulcers due to Leishmania (Viannia) braziliensis (Lvb) reached 83/1,000 inhabitants but declined sharply in the subsequent 2 years. Retrospective data shows that leishmaniasis is a sporadic endemic disease. Although the reasons for this epidemic are unclear some possible aetiological factors are discussed.

Origin of patients carrying American tegumentary leishmaniasis in the endemic areas of Tres Braços and Corte de Piedra--State of Bahia-Brazil

De acordo com o cadastro de 1416 pacientes portadores de leishmaniose tegumentar americana (L. T.A) referentes ao período de janeiro de 1976 a maio de 1987, os autores realizaram um levantamento da procedência dos casos dessa parasitose atendidos nas áreas endêmicas de Três Braços e Corte de Pedra no estado da Bahia. Os pacientes procediam de 24 dos 89 municípios que compõem a região cacaueira da Bahia, destacando-se os municípios de Valença, Wenceslau Guimarães e Teolândia como os de maior prevalência, somando juntos 923 casos (65,1%), com 520 destes residindo em umas poucas localidades contínuas entre si, formando uma área endêmica, com transmissão ocorrendo provavelmente no peri, intradomicílio e nas lavouras de cacau e cravo localizadas nas encostas da floresta atlântica. Nota-se que a partir de 1983, houve um aumento do número de casos em toda a região, havendo evidências da leishmaniose tegumentar americana comportasse como uma doença ocupacional em toda a região estudada.

Predominance of Leishmania braziliensis braziliensis in the regions of Três Braços and Corte de Pedra, Bahia, Brazil

Cette etude confirme que dans ces 2 regions du Bresil le principal parasite est L.b. braziliensis qui infecte les hommes, les chiens et les mulets. L'espece L. mexicana ne joue qu'un tres petit role dans la transmission

Research on antibodies to arbovirus in the serum of residents of the village of Corte de Pedra, Valencia, Bahia

A serological survey for research on antibodies to arbovirus was carried out on 288 residents of the rural zone of the village of Corte de Pedra, Valença, Bahia. It was observed that 3.8% of the sample population presented HI and N antibodies against Flaviviruses (Ilhéus 6, St. Louis 2, Yellow fever 3 and Rocio 1). One person, who had previously lived in the Amazon region, had antibodies to Mayaro. The authors were unable to detect either N antibodies for Piry virus in a random sample of 75 persons or CF antibodies against viruses of the Changuinola and Phlebotomus groups and ungrouped BE AR 408005 and BE AR 421710 in another random sample of 28 individuals. Complementary studies should be conducted in order to define the transmission of the different viruses in the area.

Natural infection of Equus asinus by Leishmania braziliensis braziliensis-Bahia, Brazil

In Corte de Pedra, Valença, state of Bahia, a donkey, Equus asinus, was found naturally infected with Leishmania braziliensis braziliensis. The parasite was isolated from a lesion located on a castration scar, and identified by means of monoclonal antibodies.