Environmental risk factors of leishmaniasis in Bahia State, Brazil using NASA Earth observation satellites / Fatores de risco ambientais para leishmanioses no estado da Bahia, Brasil, utilizando satélites da NASA de observação da Terra

NASA’s Earth Observing Satellites (EOS) were used to calculate three vegetation indices, extract precipitation and elevation data, and then evaluate their applicability for assessing risk of visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) in Bahia State, Brazil. Regression models showed that either form of leishmaniasis can be predicted by NDVI, NDMI, NDWI data products and TRMM) precipitation data (R2 = 0.370; p<0.001). Elevation was not significantly associated with the distribution of either VL or CL. In areas of high annual precipitation, CL was 3.6 times more likely to occur than VL. For vegetative moisture (NDMI), CL was 2.11 times more likely to occur than VL. Odds of CL occurrence increased to 5.5 times when vegetation (NDVI) and 13.5 times when liquid water content of vegetation canopies (NDWI) was considered. Areas at risk of CL and VL were mapped based on the selected explanatory variables. Accuracy of models were assessed using area under the receiver operating characteristic curve (AUC=0.72). We propose that statewide scale risk models based on use of EOS products will be a useful tool at 1 km2 spatial resolution to enable health workers to identify and target high risk areas to prevent transmission of leishmaniasis.

Os satélites de observação da Terra (SOT) da NASA foram usados para calcular três índices de vegetação, extrair dados de precipitação e elevação e avaliar sua aplicabilidade para identificar o risco para leishmaniose visceral (LV) e leishmaniose tegumentar (LT) no Estado da Bahia, Brasil. Modelos de regressão mostraram que ambas as formas de leishmaniose podem ser preditas pelos NDVI, NDMI, NDWI e precipitação TRMM (R2 = 0,370; p<0,001). A elevação não foi significativamente associada à distribuição de LV ou LT. Em áreas de alta precipitação anual, a LT foi 3,6 vezes mais provável de ocorrer do que a LV. Para a umidade vegetativa (NDMI), a LT apresentou 2,11 maior probabilidade de ocorrer do que a LV. As chances de ocorrência de LT aumentaram para 5,5 vezes em relação com a vegetação (NDVI) e 13,5 vezes quando o conteúdo de água líquida dos dosséis da vegetação (NDWI) foi considerado. Áreas em risco de LT e LV foram mapeadas com base nas variáveis explicativas selecionadas. A precisão dos modelos foi avaliada usando a área sob curva característica de operação do receptor (Curva COR=0,72). Propusemos que os modelos de risco em escala estadual baseados no uso de produtos SOT são uma ferramenta útil na resolução espacial de 1 km2 por permitir que profissionais de saúde identifiquem e direcionem áreas de alto risco para evitar a transmissão da leishmaniose.

Are Aedes aegypti mosquitoes potential vectors for leishmaniasis? ­ Case report / Mosquitos Aedes aegypti são vetores potenciais de leishmaniose? ­ Relato de caso

In Brazil dipters of the Lutzomyia genus are the main vectors of leishmaniasis for humans and animals. However, other hematophagous insects such as ticks, fleas, and horse flies may also be considered potential vectors of this protozoon. This paper, regarding an endemic area for visceral leishmaniasis, is the the first description of the Leishmania spp. presence in Aedes aegypti mosquitoes. Two A. aegypti mosquitoes were captured: one of them was feeding on a polysymptomatic dog with leishmaniasis, confirmed by parasitic demonstration and positive PCR for Leishmania spp., and the other was collected in the environment where the dog was isolated. The mosquito engorged with dog's blood was crushed between two microscopic slides and the other one was processed by the polymerase chain reaction assay (PCR) searching for the presence of Leishmania spp. DNA. Amastigote forms of Leishmania sp, were observed in the smear prepared from one mosquito by microscopic examination, as well as other protozoa's flagellated forms. In the other insect it was observed Leishmania DNA amplification. This observation reinforces the role of dogs as sources of infection of Leishmania spp. even to other potential vector species.(AU)

No Brasil, os dípteros do gênero Lutzomyia são os principais vetores da leishmaniose para humanos e animais. No entanto, tem sido constatado que outras espécies de invertebrados hematófagos, como carrapatos, pulgas e mutucas, também podem ser vetores desse protozoário. Este trabalho, realizado em uma área endêmica de leishmaniose visceral, é a primeira descrição da presença de Leishmania spp. em mosquitos da espécie A. aegypti. Dois mosquitos A. aegypti foram capturados no local onde estava isolado um cão polissintomático acometido por leishmaniose visceral, confirmada pela demonstração do parasita em biópsias de órgãos e por resultado positivo na prova de PCR para Leishmania spp. Um dos mosquitos estava sugando o sangue do cão e o outro estava livre no ambiente. O mosquito ingurgitado com o sangue do animal foi esmagado entre duas lâminas de microscopia e o outro foi processado por meio da reação em cadeia pela polimerase (PCR) aplicada à pesquisa do ADN de Leishmania spp. Ao exame microscópico do esfregaço preparado com o mosquito que estava parasitando o cão foram observadas formas amastigotas de Leishmania spp., bem como formas flageladas de outra espécie de protozoário. No outro inseto foi detectada amplificação de ADN do gênero Leishmania. Esta constatação reforça o papel dos cães como fontes de infecção de Leishmania spp. até mesmo para outras espécies de vetores potenciais.(AU)

Risk factors for the transmission of kala-azar in Fangak, South Sudan

"This article reports a case controlled study of kala-azar done in Fangak County in 2007. Fifty-six percent of the cases were under 5 years old. Most patients came for treatment two months or more after the onset of symptoms. Outdoor night-time activities and the use of ""smoking"" (non-insecticide treated) bed nets were associated with kala-azar infection whereas the use of bed nets during the rainy season decreased the risk of infection. It is recommended that there should be a greater distribution of treated bed nets and more kala-azar treatment centres in the county. Note: This article reports the results of a study into some risk factors for the transmission of kala-azar in Fangak in 2007. There was another recent outbreak in this area on 2010 (1; 2). Recommendations were again made to distribute more treated bed nets and to open more kala-azar treatment centres. The official Ministry of Health guideline for the treatment of kala-azar is at the end of this article."

Leishmaniasis / Leishmaniasis

La leishmaniasis se considera una enferemedad zoonótica que puede afectar al hombre al entrar en contacto con el ciclo de transmisión del parásito, convirtiéndose en una antropozoonosis. En la actualidad, es una de las seis endemias consideradas prioridad en el mundo. Las zonas de mayor prevalencia de leishmaniasis en paraguay, corresponden a los nuevos asentamientos poblacionales, especialmente de los departamentos de canindeyú y San Pedro, en ñareas rurales boscosas de tierra poco explotadas producto del avance de la frontera agrícola. El objetivo de este trabajo es brindar información actualizada y completa de la epidemiología, etiología, ciclo biológico, reservorios, histopatología, diagnostico, clínica y tratamiento. Con el propósito de que sirva al profesional de la salud como material de lectura acerca estas zoonosis tan freceuntes en nuestro país, de manera que se logre diagnosticar precozmente al paciente, y así sentar base al tratamiento adecuado.

Fagócitos mononucleares inflamatórios potencialmente envolvidos no transporte de leishmania em hospedeiros vertebrados / Fagócitos mononuclear potentially inflammatory involved in the transport of leishmaniasis in vertebrate hosts

A infecção por protozoários do gênero Leishmania modula a função de integrinas em fagócitos inflamatórios. Essa alteração pode interferir na migração celular e apresentação de antígenos ao sistema imune. O objetivo deste estudo é identificar populações de fagócitos mononuc1eares inflamatórios potencialmente envolvidos no transporte de Leishmania em hospedeiros vertebrados. Inicialmente, definimos um modelo que permite o estudo do processo de migração em um grande número de fagócitos mononucleares inflamatórios. Para isso, foi induzida peritonite em camundongos da linhagem BALB / c com a injeção de Tioglicolato e foram examinadas a cinética de migração celular para o linfonodo regional e as populações de fagócitos mononuc1eares que compõem o exsudato e sua susceptibilidade à infecção com Leishmania. O influxo celular para o peritônio foi crescente, atingindo o pico de peritonite por volta do quarto dia. A partir de então, o número de células diminuiu, atingindo um platô por volta dos quarenta dias, permanecendo estável até o centésimo dia. Inicialmente, entre 4 horas e o primeiro dia, houve aumento de polimorfonuc1eares (9+ - 4 por cento, - 12+ - 8 por cento das células), seguindo um predomínio de fagócitos mononuc1eares (primeiro ao quarto dia) e posterior aparecimento de linfócitos (quadragésimo ao centésimo dia). A migração de fagócitos mononuc1eares para os linfonodos regionais foi observada 8 horas após o estímulo inflamatório, tornando-se máxima a partir do quarto dia. A migração das células foi confirmada em ensaios de injeção e rastreamento de células marcadas, observando-se a substancial migração dessas células para o linfonodo em um período de doze-vinte e quatro horas...

Histopathological study of three leishmania major strains

Amastigotes count in inoculated foot pad and histopathological study of infected mice were performed to study three Leishmania major strains: the Senegalese strain MHOM/SN/00/DKI[SN], the Sudanese strain MHOM/SD/89/UG8[SD], and the Saudi strain MHOM/SA/84/JISH[SA]. Eight-week-old male BALB/c mice were divided into three groups. Each group was infected with one of the studied strains. Amastigotes in the inoculated foot of infected. mice in the three groups were counted at 30 and 45 days using modified fluorescence diacetate/ethidium bromide viability test. The number of amastigotes in the SA group was found to be significantly lower than that of the other two groups at both durations. There was no significant difference between the number of amastigotes in the SN and SD strains at 30 days. but it was significantly higher in the SN group than that of the SD group at 45 days post-inoculation. In the animals studied, tissue samples were obtained from the skin, liver, spleen, and testes for gross pathological changes and histopathological evaluation. The SD strain started earlier and led a more aggressive course. The SN and SA strains were less aggressive. The SA strain showed changes at an earlier time and resulted in a more aggressive course of the disease. The SN and SA strains were less aggressive. The SA strain showed the most chronic course of the three

Zymodene and serodeme characterization of Leishmania isolates obtained from Costa Rican patients

Third-four Leishmania isolates obtained from Costa Rican patients, from different geographical areas, were characterized by isoenzyne electrophoresis and indirect immunofluorescense with monoclonal antibodies. Thirty-two were characterized as L. panamensis strains and two were L. braziliensis variants. We confirm the evident predominance of L. panamensis as the main etiological agent of leishmaniasis in Costa Rica and the existence of L. braziliensis in the country.

New horizons in leishmania cultivation

Three newly developed and cost effective semi defined liquid culture media for the maintenance and bulk cultivation of the promastigote forms of the protozoan parasite Leishmania are studied. Leishmania major [MHOM/PK/88/DESTO] amastigote forms were aspirated from the wet type open ulcerative lesions of the infected patients and introduced in traditional blood agar based biphasic medium NNN for transformation into promastigote form. Promastigotes were then subcultured in most widely used commercially available liquid medium 199 supplemented with 10% heat inactivated foetal calf serum [HIFCS] + 2% sterile human urine as well as in three newly developed liquid media for comparison of growth. All three media studied were found capable of supporting excellent growth in the absence of HIFCS, an essential and extremely costly ingredient of virtually all liquid culture media

Leishmaniasis in the Eastern Mediterranean Region

Leishmaniasis is recognized as an important public health problem in some Member States of the Eastern Mediterranean Region owing to its considerable impact on morbidity and its potential to spread in epidemics, which impose a heavy burden on national health services. The increased incidence of leishmaniasis in countries of the Region is due to several reasons including influx of nonimmune population into natural foci of transmission, changes in ecology of vectors and reservoir host, reduction in the use of residual insecticides for the control of malaria and improvements in diagnosis and reporting of positive cases

Cultivation of leishmaniasis sp in nutrient broth

Bone-marrow aspiration and biopsy material samples obtained from two patients, one diagnosed as visceral and the other as cutaneous leishmaniasis, were inoculated in Novy, McNeal, Nicolle [NNN] medium and nutrient broth [NB], containing fetal calf serum [FCS], penicillin and streptomycin. Both media were incubated at 27C for 10 days and observed daily for L. infantum and L. major promastigotes. Promastigotes were observed in nutrient broth after the first day, while in NNN media after the second or third day of incubation, indicating the effectiveness of nutrient broth in early diagnosis of both forms of leishmaniasis

Ocular leishmaniasis: a cause of blindness

Leishmaniasis involving the eye and causing blindness is rare. Three cases of blindness caused by leishmaniasis are described in this report; two were caused by the direct extension of conjunctival leishmaniasis and one was caused by the systemic dissemination of kala-azar. Histologic sections of the enucleated eye balls showed multiple non-caseating granulomas in the bulbar conjunctiva, iris, ciliary body and retina. At higher magnification these granulomas revealed leishman bodies. This blindness can be prevented by early diagnosis and prompt vigorous treatment with glucantime

susceptibility of the Egyptian phlebotomus papatasi to five insecticides

The present study was undertaken to establish a baseline susceptibility levels of the Egyptian P. papatasi to five insecticides [BHC and DDT [chlorinated hydrocarbon], permethrin [synthetic pyrethroides], malathion [organophosphorus] and propoxur [carbamate]]. The results obtained revealed that the laboratory bred P. papatasi were more susceptible to the five insecticides than the wild caught ones. The insecticidal efficiency of the five insecticides based on LC50 was in the following descending order: Propoxur, permethrin, BHC, DDT and malathion for laboratory bred flies and propoxur, permethrin, BHC, malathion then DDT for wild caught flies. The least LC50 was when using propoxur for both the wild caught flies [0.0014%] and laboratory bred ones [0.00043%]. The least LT50 was when using propoxur for both the wild caught flies [4.8 seconds] and the laboratory bred flies [2.2 seconds]

Antigenic differences among Leishmania amazonensis isolates and their relationship with distinct clinical forms of the disease

Immunoblot analysis was used to investigate antigenic differences among clinical isolates of Leishmania amazonensis and their role in the etiology of the diseases. Western blots of promastigote homogenates were analyzed with either monoclonal antibodies (MAbs) specific for the L. mexicana complex (M-4, M-6, M-9 and M-11) or polyclonal sera from L. amazonensis infected patients with the various forms of clinical disease. In the case of the MAbs, no significant variation was observed among the strains of L. amazonensis, isolated from cases of cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), diffuse cutaneous leishmaniasis (DCL), visceral leishmaniasis (VL) or post kala-azar dermal leishmaniasis (PKDL), in either the relative morbility (Mr) or the quantitative amount (intensity) of the antigenic determinats. In the case of the sera of the infected patients, the patterns of antigenic reactivity of these strains revealed that, despite showing the presence of shared antigens, differences were observed between some of the antigenic components of the various isolates of L. amazonensis that were recognized by a single serum. Differences were also demonstrated between the antigenic determinants of a single isolate of L. amazonensis that were recognized by the different patient's sera. No apparent association was consistently found, however, between the Mr components identified in these isolates and clinical form of the disease or the geographical area of isolation. In addition, the spectrum of antigens recognized by the sera from patients with the same clinical form were not identical; although in some instances, similar Mr antigens were shared. These results indicate that isolates of L. amazonensis are not antigenically identical (homogeneous) and that the immune responses (antibodies) observed among infected patients are heterogeneous