RESUMO
Leishmania parasites were isolated from four of seven small rodent species captured in the State of Campeche, Mexico. Signs and/or symptoms of leishmanial infection were restricted to the tail of the mice. Peromyscus yucatanicus endemic to the peninsula of Yucatan and Oryzomys melanotis were added to the list of carriers of Leishmania. Leishmania (L.) mexicana, characterized by an indirect immunofluorescence antibody method using monoclonal antibodies, was identified in one Sigmodon hispidus and one Or. melanotis. The possible role of the different species as primary reservoirs of Leishmania in the peninsula of Yucatan is discussed.
Assuntos
Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/veterinária , Doenças dos Roedores/transmissão , Animais , Animais Selvagens , Anticorpos Monoclonais/imunologia , Antígenos de Protozoários/análise , Reservatórios de Doenças , Imunofluorescência/veterinária , Leishmania mexicana/imunologia , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , México/epidemiologia , Doenças dos Roedores/epidemiologia , Doenças dos Roedores/parasitologia , Roedores/parasitologia , Pele/parasitologia , Cauda/parasitologiaRESUMO
Seventy-five isolates from the State of Campeche, Mexico, an area endemic for localized cutaneous leishmaniasis (LCL), were characterized by isoenzyme markers (glucose phosphate isomerase, mannose phospate isomerase, nucleoside hydrolase, phosphoglucomutase, 6-phosphogluconate dehydrogenase, and glucose-6-phosphate dehydrogenase). Seventy (93.3%) were identified as Leishmania (Leishmania) mexicana and 5 (6.7%) as L. (Viannia) braziliensis. This is the first report of authochthonus human LCL caused by L. (V.) braziliensis in the State of Campeche, Yucatan Peninsula, Mexico.
Assuntos
Isoenzimas/análise , Leishmania braziliensis/enzimologia , Leishmania mexicana/enzimologia , Leishmaniose Cutânea/parasitologia , Adolescente , Adulto , Animais , Eletroforese em Acetato de Celulose , Feminino , Humanos , Leishmania braziliensis/classificação , Leishmania mexicana/classificação , Masculino , México , Pessoa de Meia-IdadeRESUMO
Cutaneous leishmaniasis, known as chiclero's ulcer in southeastern Mexico, is characterized by a predominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become chronic, causing destruction of the pinna and disfigurement. It is caused predominantly by Leishmania (L.) mexicana. Although pentavalent antimonials (Sb5+) are the mainstay of leishmanial therapy and have been used for more than 50 years, dosage regimens have been repeatedly modified and the best one has not been fully identified. The main purpose of the present study was to investigate the response of chiclero's ulcer to treatment with meglumine antimoniate. One hundred five patients were treated with meglumine antimoniate at a daily dose of 1 ampule per day (425 mg of Sb5+) until healing. The lesions healed after a mean of 25 days (range = 5-60 days).
Assuntos
Antiprotozoários/uso terapêutico , Leishmania mexicana , Leishmaniose Cutânea/tratamento farmacológico , Meglumina/uso terapêutico , Compostos Organometálicos/uso terapêutico , Adolescente , Adulto , Idoso , Animais , Criança , Pré-Escolar , Feminino , Humanos , Leishmania mexicana/isolamento & purificação , Masculino , Antimoniato de Meglumina , México , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Th1-type cellular immune responses (interferon-gamma) play a critical role in protection against Leishmania spp. infection, whereas Th2-type cytokines (interleukin (IL)-4, IL-10) have a counter-protective effect. IL-12, a potent inducer of Th1-type cellular immune responses, may play a pivotal role in the development of a protective response. We found that IL-10 and IL-12 mRNAs were expressed in most lesions of individuals with active cutaneous leishmaniasis. The quantity of IL-12 mRNA was highly variable but correlated strongly with the level of interferon-gamma expression. IL-12 expression also paralleled the expression of IL-10, a potent in vitro suppressor of IL-12 and interferon-gamma production. The more chronic, non-healing lesions generally had higher levels of IL-12 mRNA indicating that the expression of this cytokine alone was not sufficient to induce healing. Although the in situ production of IL-10 did not appear to block IL-12 expression, IL-10 may still promote disease by direct suppression of macrophage activation.
Assuntos
Interleucina-10/biossíntese , Interleucina-12/biossíntese , Leishmaniose Cutânea/imunologia , Adolescente , Adulto , Southern Blotting , Criança , Feminino , Expressão Gênica , Humanos , Interferon gama/biossíntese , Interferon gama/genética , Interleucina-10/genética , Interleucina-12/genética , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
Sera from 223 human beings were assayed by enzyme-linked immunosorbent assay for immunoglobulin G antibodies to Leishmania mexicana mexicana promastigotes. 76% of 74 sera from patients with chiclero's ulcer gave positive reactions at a titre of 1:40; the positivity rate was lower in patients with long-standing infections. False positive reactions were obtained with only 7% of 56 sera from healthy individuals with positive Montenegro tests and with 6 of 7 sera from patients with Chagas disease. It is concluded that this method would be a useful contributory diagnostic method in cases of suspected chiclero's ulcer.
Assuntos
Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/imunologia , Leishmania mexicana/imunologia , Leishmaniose/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antiprotozoários/análise , Especificidade de Anticorpos , Doença de Chagas/imunologia , Criança , Reações Cruzadas , Humanos , México , Pessoa de Meia-Idade , Sensibilidade e EspecificidadeRESUMO
Cutaneous leishmaniasis in Mexico was first described in 1912. Since then, its existence has been repeatedly confirmed in the forest regions of the peninsula of Yucatan. In order to obtain reliable knowledge about the magnitude of this problem, we questioned and skin-tested a sample of 449 persons randomly selected from men aged 15-45 years. We found a positivity rate of 24 to 90% (mean 43%) in the seven rural health posts studied. Furthermore, 72 patients were examined between January and December 1987 by parasitological investigation (smear, isolation, culture and/or biopsy) and the Montenegro skin test; 56 had acquired the disease in 1987. Based on these data, we found an annual incidence rate of 508 per 100,000 inhabitants. Further long-term studies are indicated to determine the incidence and prevalence rates for this disease in other parts of the country.
Assuntos
Leishmaniose/epidemiologia , Adolescente , Adulto , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Testes Cutâneos , Inquéritos e QuestionáriosRESUMO
Immunity in leishmaniasis is mediated by T cells, but protective responses in humans have not been fully defined. In this study, the functional activity of CD4+ T cell clones derived from an immune individual was investigated to identify potentially protective responses. The T cells proliferated and produced interferon-gamma (IFN-gamma) in response to a soluble Leishmania donovani antigen extract and live amastigotes. There was considerable variation in the anti-leishmanial activity of the T cell clones when they were co-cultured with L. donovani infected monocytes isolated from an HLA-DR,DQ matched donor. All of the clones which demonstrated antigen specific reactivity by proliferation or cytokine production induced some degree of inhibition of intracellular parasite replication, but only a few of the clones induced pronounced leishmanicidal activity. There was strong correlation between the level of amastigote-induced IFN-gamma secretion and anti-leishmanial activity. This approach enables the identification of potentially protective immune responses in humans at the clonal level, and offers a means for the identification of the relevant antigen(s).
Assuntos
Antígenos de Protozoários/fisiologia , Linfócitos T CD4-Positivos/fisiologia , Leishmania donovani/imunologia , Leishmaniose/imunologia , Macrófagos/imunologia , Animais , Linfócitos T CD4-Positivos/classificação , Células Clonais , Cricetinae , Citotoxicidade Imunológica , Humanos , Interferon gama/biossíntese , Leucócitos Mononucleares/parasitologia , MesocricetusRESUMO
Human bait catches were carried out from 5 through 27 March 1994 in an endemic focus of cutaneous leishmaniasis in the state of Campeche, Mexico. Females of Lutzomyia cruciata (Coquillet) were dissected and 67% were parous. The number of total and parous females collected per day was analyzed by time series, but neither the gonotrophic cycle length nor survivorship could be estimated. However, a survival rate per oviposition cycle of 0.68 was estimated from the least square regression of parous on total females. Additional evidence for L. cruciata as a vector of human leishmaniasis is discussed.
Assuntos
Psychodidae/fisiologia , Animais , Feminino , Humanos , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/transmissão , México/epidemiologiaRESUMO
Sandflies attracted by human bait were caught in an endemic focus of localized cutaneous leishmaniasis in the state of Campeche, Mexico. Catches were carried out monthly from February 1994 to January 1995 between 18:00 and 22:00 h. Lutzomyia cruciata was the only species caught. The highest population peak of Lu. cruciata was found in March with lesser peaks in February, December 1994, and January 1995. Maximum biting rate of Lu. cruciata was found between 18:00 and 19:00 h. The host-seeking females of Lu. cruciata were directly related to levels of humidity between 88 and 100%. Low and high temperature had a negative effect upon Lu. cruciata activity. The possible role of Lu. cruciata as vector of leishmaniasis in the state of Campeche, Mexico is discussed.
Assuntos
Insetos Vetores/fisiologia , Leishmaniose Cutânea/transmissão , Psychodidae/fisiologia , Análise de Variância , Animais , Feminino , Humanos , Umidade , Mordeduras e Picadas de Insetos/epidemiologia , Leishmaniose Cutânea/epidemiologia , Modelos Lineares , México/epidemiologia , Dinâmica Populacional , Estações do Ano , TemperaturaRESUMO
In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.
Assuntos
Reservatórios de Doenças/parasitologia , Leishmania mexicana/isolamento & purificação , Marsupiais/parasitologia , Roedores/parasitologia , Animais , Reservatórios de Doenças/veterinária , Doenças Endêmicas , Leishmaniose Cutânea/epidemiologia , Leishmaniose Cutânea/transmissão , Leishmaniose Cutânea/veterinária , Marsupiais/classificação , México/epidemiologia , Prevalência , Roedores/classificação , Estações do AnoRESUMO
Leishmania mexicana is the parasite causing most cases of human cutaneous leishmaniasis in southern Mexico, where Lutzomyia olmeca olmeca and Lu. cruciata are the most probable vectors. In the present study, sandflies were collected during one transmission season (November 2001-March 2002) in the village of La Guadalupe and the nearby village of Dos Naciones, in the southern Mexican county of Calakmul. Using Shannon traps, Disney traps and CDC light traps, 5983 sandflies (Brumptomyia and Lutzomyia) were caught. In Dos Naciones the numbers of Lu. panamensis caught in Shannon or CDC traps outnumbered those of the other sandfly species. In La Guadalupe, in contrast, the most abundant species in the collections made with Shannon or CDC traps was Lu. cruciata , followed by Lu. olmeca olmeca and Lu. deleoni. In both locations, the numbers of sandflies attracted to Shannon traps peaked between 18.00 and 22.00 hours. Given the abundance of Lu. olmeca olmeca in the collections made with Shannon and Disney traps (it was the only species caught in the latter), this species is probably the primary vector of Le. mexicana in Calakmul county.
Assuntos
Insetos Vetores/classificação , Leishmaniose Cutânea/transmissão , Psychodidae/classificação , Animais , Feminino , Humanos , Leishmaniose Cutânea/epidemiologia , Masculino , México/epidemiologia , Densidade Demográfica , Saúde da População Rural , Estações do Ano , Fatores de TempoRESUMO
Vectors of cutaneous leishmaniasis in the State of Campeche were studied in relation to the transmission cycle of Leishmania (Le.) mexicana. To determine how transmission of leishmaniasis occurs, we collected phlebotomine sand flies for two years. In the first year (October 1990 to November 1991) the collections were made with CDC light traps, Shannon traps and direct captures at natural shelters around the village (< 200 m) of La Libertad. In the second year (February 1993 to January 1994) the catches were performed at 8 km southeast of La Libertad in the forest. Female sand flies were examined for Leishmania. During the first year, 347 sand flies of nine species were collected, most of which were Lutzomyia deleoni (61.3%). When all nine species were considered, more females than males were captured. Low densities of anthropophillic species of sand flies around the village indicated that sylvatic transmission was taking place. For the second year. 1484 sand flies of 16 species were caught. The most common were L. olmeca olmeca (21.7%), L. cruciata (19.2%) and L. ovallesi (14.1%). Similarly, more females were caught than males. Thirty-five females of five species were found infected with flagellates believed to be Leishmania sp. The highest infection rate was found in L. olmeca olmeca (7.1%) followed by L. cruciata (4.5%) and L. ovallesi (1.1%). These data plus other evidence on the epidemiology of human cases and results from reservoir studies are discussed in relation to the sylvatic transmission cycle.
Assuntos
Insetos Vetores , Leishmania mexicana , Leishmaniose Cutânea/transmissão , Psychodidae , Animais , Feminino , Humanos , Masculino , MéxicoRESUMO
The state of Tabasco is localized in the endemic area of cutaneous leishmaniasis where both diffuse cutaneous leishmaniasis and mucocutaneous leishmaniasis have recently been reported. The objective of the present study was to obtain reliable information of the situation of this disease--which has a great relevance as a worldwide public health problem--through determination of the allergic index in a randomized sample from Ranchería Miguel Hidalgo, Comalcalco Municipality, Tabasco, Mexico. We found an allergic index of 56 per cent. Farmers and housewives had the highest positive responses to the Montenegro skin test. We found no statistical differences between males and females. Moreover, 3 patients with active lesions and people with scars suggestive of prior leishmaniasis were detected during the study. This village should be considered a high endemic focus.
Assuntos
Reservatórios de Doenças , Leishmaniose Cutânea/epidemiologia , Adolescente , Adulto , Fatores Etários , Animais , Anticorpos Antiprotozoários/sangue , Criança , Pré-Escolar , Reservatórios de Doenças/estatística & dados numéricos , Feminino , Humanos , Lactente , Leishmania mexicana/imunologia , Leishmaniose Cutânea/imunologia , Masculino , México/epidemiologia , Pessoa de Meia-Idade , População Rural/estatística & dados numéricos , Estudos Soroepidemiológicos , Fatores SexuaisRESUMO
Localized cutaneous leishmaniasis (LCL), known as "chiclero's ulcer" in southeast Mexico, was described by Seidelin in 1912. Since then, the sylvatic region of the Yucatan peninsula has been identified as an endemic focus of LCL. The purpose of the present work was to describe the clinical picture of LCL caused by Leishmania (Leishmania) mexicana in the Yucatan peninsula. A total of 136 cases of LCL, based on isolation and characterization of L. (L.) mexicana by isoenzymes and/or monoclonal antibodies, were selected. Some variability of clinical features regarding number, type, size, form, location and time of evolution of the lesions was observed. The most frequently observed presentation was a single, ulcerated, rounded small lesion, located on the ear, with an evolution time of less than three months, with neither cutaneous metastases nor lymphatic nor mucosal involvement. This picture corresponds to previous studies carried out in the same endemic area where an organism of the L. mexicana complex has been incriminated as a major aetiological agent of classical "chiclero's ulcer", confirming that in the Yucatan peninsula LCL due to L. (L.) mexicana when located on the pinna of the ear is a remarkable characteristic.
Assuntos
Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/patologia , Adolescente , Adulto , Animais , Criança , Feminino , Humanos , Leishmaniose Cutânea/parasitologia , Masculino , MéxicoRESUMO
In the State of Campeche, Mexico, zoonotic cutaneous leishmaniasis is mainly due to Leishmania (L.) mexicana. The parasite population is maintained in a mammalian species, a reservoir in which the ideal course of infection should be long and relatively nonpathogenic. The objective of the present study was to document the retention of L. (L.) mexicana in 29 naturally infected rodents. These cricetids lived in captivity for up to two years and were tested monthly for the presence of the parasite, by cultures of needle aspirates from the base of the tail. Peromyscus yucatanicus and Ototylomys phyllotis were incriminated as the primary reservoir hosts. The finding that the multiplication of parasites in P. yucatanicus might be triggered by temperature, suggests that this animal would be a good choice for further research on L. (L.) mexicana.
Assuntos
Reservatórios de Doenças , Leishmania mexicana/crescimento & desenvolvimento , Roedores/parasitologia , Animais , Feminino , Leishmania mexicana/isolamento & purificação , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/transmissão , Masculino , MéxicoRESUMO
The nature of the host cellular immune response largely determines the expression of disease following infection with the intracellular protozoans Leishmania spp. In experimental animals control and resolution of infection are mediated by gamma interferon and tumor necrosis factor alpha (TNF-alpha), whereas disease progression is associated with the production of interleukin 4 (IL-4), IL-5, IL-10, and transforming growth factor beta (TGF-beta). We have analyzed the profile of cytokine gene expression directly in the lesions of 13 patients with localized cutaneous leishmaniasis due to Leishmania mexicana. All but one patient had a single lesion, and the time of evolution ranged from 8 days to 18 months. Cytokine gene expression was quantitated by reverse transcriptase PCR and interpolation from a standard curve. Gamma interferon, TNF-alpha, IL-1 alpha, IL-6, IL-10, and TGF-beta gene expression was present in all samples. IL-3 and IL-4 gene expression was barely detectable in 1 and 3 of 13 samples, respectively. IL-2 and IL-5 mRNAs were not found. A significant increase in the expression of IL-1 alpha, TNF-alpha, IL-10, and TGF-beta was observed in late lesions (> or = 4 months) compared with that in early lesions (< or = 2 months). Because of their inhibitory effects on macrophage function, the expression of IL-10 and TGF-beta may play a role in the immunopathogenesis of chronic cutaneous leishmaniasis.
Assuntos
Citocinas/biossíntese , Leishmaniose Cutânea/metabolismo , Sequência de Bases , Doença Crônica , Citocinas/genética , Humanos , Interleucina-10/biossíntese , Leishmaniose Cutânea/patologia , Dados de Sequência Molecular , RNA Mensageiro/análise , Fator de Crescimento Transformador beta/biossínteseRESUMO
The genus Leishmania includes 30 described species which infect a wide variety of mammalian hosts. The precise identification of leishmanial parasites at the species level is very important in order to determine whether an organism, causing the disease in a given area, is of the same biotype as that found in suspected mammalian reservoirs. The objectives of the present study were (1) to identify leishmanial parasites isolated from humans and wild rodents from the State of Campeche, an endemic focus of localized cutaneous leishmaniasis (LCL) in southern Mexico, using an indirect immunofluorescent assay (IFA) with monoclonal antibodies (Mabs); and (2) to determine if the parasites of the two types of hosts were of the same biotype. All the wild rodents (six Ototylomys phyllotis, eight Oryzomys melanotis, five Peromyscus yucatanicus and two Sigmodon hispidus) and 96% (24/25) of the human isolates were identified as Leishmania (L.) mexicana confirming that this specific LCL focus is a wild zoonosis. The presence of one human isolate of L. (Viannia) braziliensis in the State of Campeche, confirmed the importance of an accurate taxonomic identification at species level.
Assuntos
Anticorpos Monoclonais , Leishmania/isolamento & purificação , Animais , Reservatórios de Doenças , Interações Hospedeiro-Parasita , Humanos , Leishmania/classificação , Leishmania/imunologia , México , Roedores/parasitologiaRESUMO
In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.
En la Península de Yucatán, México, la Leishmaniosis Cutánea es causada por Leishmania (L.) mexicana en 95% de los casos humanos, con una incidencia de 5.08% por cada 100,000 habitantes. El ciclo de transmisión se limita a la estación de invierno (noviembre- marzo). Un estudio de mamíferos silvestres incrimina a Ototylomys phyllotis y Peromyscus yucatanicus como reservorios primarios de L. (L.) mexicana en el foco de infección de La Libertad, Campeche. En el presente estudio, se documenta la prevalencia de infección/enfermedad causada por L. (L.) mexicana en pequeños mamíferos, durante cinco estaciones de transmisión (1994-2004) en cinco focos de CL del estado de Campeche. Los focos separados por solamente 100 km. de distancia, aún cuando tienen abundancias relativas de pequeños roedores similares, fueron significativamente diferentes en relación a la prevalencia de síntomas así como de infección. Las tasas de transmisión y las especies de reservorios parecen estar cambiando tanto en el tiempo como en el espacio, lo cual impide el establecimiento de adecuadas medidas de control de la enfermedad aún en un área endémica tan pequeña como lo es el sur de la Península de Yucatán.