Factores de riesgo asociados con la leishmaniasis cutánea en dos comunidades rurales de Panamá Oeste

Introducción: La leishmaniasis cutánea (LC) es una enfermedad zoonótica endémica en Panamá. Su agente causal son protozoarios del género Leishmania y la transmiten insectos flebotominos. Objetivo: Evaluar los factores de riesgos asociados con la LC y la diversidad de flebotominos en dos comunidades rurales de Panamá Oeste. Metodología: Se seleccionaron dos comunidades endémicas para LC: Trinidad de las Minas (TM), de alta incidencia y Las Pavas (LP), de baja incidencia. Los factores de riesgo asociados con la LC fueron evaluados mediante una encuesta aplicada a100 personas (TM: n=50; LP: n=50). Se colectaron flebotominos con trampas CDC durante tres noches consecutivas en temporada lluviosa y seca. Resultados: La mayoría de las personas confirmó conocer sobre la LC (TM: 96% y LP: 68%). No se encontraron diferencias significativas entre las características sociodemográficas, estructura de las viviendas, composición del peridomicilio y abundancia/diversidad de animales domésticos en ambas comunidades. El reporte de perezosos cercanos al peridomicilio fue mayor en TM (70%) vs LP (32%). La especie de flebotomino antropofílica más abundante durante la temporada seca fue Lutzomyia gomezi (TM: 40.1% y LP: 10.4%). Durante la temporada lluviosa fue Nyssomyia trapidoi (43.4%) en TM y Psychodopygus panamensis (75.7%) en LP. Las especies zoofílicas más comunes en ambas comunidades fueron Trichopygomyia triramula y Pressatia dysponeta. Conclusión: La mayor incidencia de LC en TM podría estar condicionada a su ecología montañosa, con una cobertura boscosa cercana más extensa y una mayor frecuencia de mamíferos reservorios silvestres. Se confirmó la presencia de vectores de LC en el peridomicilio de ambas comunidades. (provisto por Infomedic International)

Introduction: Cutaneous leishmaniasis (CL) is a zoonotic disease endemic in Panama. Its causal agent are protozoa of the genus Leishmania and is transmitted by phlebotomine sandflies. Objective: To evaluate the risk factors associated with CL and the diversity of phlebotomine sandflies in two rural communities in western Panama. Methodology: Two CL endemic communities were selected: Trinidad de las Minas (TM), with high incidence and Las Pavas (LP), with low incidence. The risk factors associated with CL were assessed by means of a survey applied to 100 people (TM: n=50; LP: n=50). Phlebotomine sandflies were collected with CDC traps during three consecutive nights in rainy and dry season. Results: The majority of people confirmed knowledge about CL (TM: 96% and LP: 68%). No significant differences were found between sociodemographic characteristics, housing structure, peridomicile composition and abundance/diversity of domestic animals in both communities. The report of sloths near the peridomicile was higher in TM (70%) vs LP (32%). The most abundant anthropophilic phlebotomine species during the dry season was Lutzomyia gomezi (TM: 40.1% and LP: 10.4%). During the rainy season it was Nyssomyia trapidoi (43.4%) in TM and Psychodopygus panamensis (75.7%) in LP. The most common zoophilic species in both communities were Trichopygomyia triramula and Pressatia dysponeta. Conclusion: The higher incidence of CL in TM could be conditioned to its mountainous ecology, with a more extensive nearby forest cover and a higher frequency of wild mammal reservoirs. The presence of CL vectors in the peridomicile of both communities was confirmed. (provided by Infomedic International)

Evaluation of cytochrome b sequence to identify Leishmania species and variants: the case of Panama

BACKGROUND The genetic heterogeneity of Leishmania parasites is a major factor responsible for the wide variety of Leishmania-associated manifestations. Consequently, understanding the genetic make-up of Leishmania species using suitable molecular markers is an important component of realising local and regional scale disease risk. The cytochrome b (cytb) is frequently used to type New World Leishmania species. However, its potential to discriminate Leishmania species and variants requires further evaluation. OBJECTIVES To explore the capacity of cytb gene to identify New World Leishmania species and variants and to develop an approach able to type local Leishmania species and variants. METHODS We retrieved 360 partial and complete Leishmania cytb gene sequences publicly available in GenBank database to study all single nucleotide polymorphisms (SNPs) across the cytb gene that differentiate New World Leishmania species. This information was used to develop an approach based upon the polymorphisms found in a DNA segment of 948bp. We also compared the typing results found with this technique with the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) profiling obtained using HSP70 gene as target. One hundred Panamanian isolates were used to both typed Leishmania species and assess local genetic variability. FINDINGS We found complete agreement between our cytb approach and the PCR-RFLP profiling method based on HSP70 for Leishmania species identification. Ninety-two isolates were identified as L. panamensis, although other Viannia species were found circulating at a lower frequency. Three L. panamensis haplotypes were identified in Panamanian provinces. We also provide an initial report of L. guyanensis haplotypes circulating in Panama. MAIN CONCLUSIONS Cytb gene sequence encompasses key main SNPs that aid to identify Leishmania species. The cytb approach developed with this information was able to identify and assess genetic variability of local Leishmania species found in this study.

Risk factors associated with Trypanosoma cruziexposure in domestic dogs from a rural community in Panama

Chagas disease, caused by Trypanosoma cruziinfection, is a zoonosis of humans, wild and domestic mammals, including dogs. In Panama, the main T. cruzivector is Rhodnius pallescens, a triatomine bug whose main natural habitat is the royal palm, Attalea butyracea. In this paper, we present results from three T. cruziserological tests (immunochromatographic dipstick, indirect immunofluorescence and ELISA) performed in 51 dogs from 24 houses in Trinidad de Las Minas, western Panama. We found that nine dogs were seropositive (17.6% prevalence). Dogs were 1.6 times more likely to become T. cruziseropositive with each year of age and 11.6 times if royal palms where present in the peridomiciliary area of the dog’s household or its two nearest neighbours. Mouse-baited-adhesive traps were employed to evaluate 12 peridomestic royal palms. All palms were found infested with R. pallescenswith an average of 25.50 triatomines captured per palm. Of 35 adult bugs analysed, 88.6% showed protozoa flagellates in their intestinal contents. In addition, dogs were five times more likely to be infected by the presence of an additional domestic animal species in the dog’s peridomiciliary environment. Our results suggest that interventions focused on royal palms might reduce the exposure to T. cruzi infection.

Conocimientos y factores de riesgo relacionados con la enfermedad de Chagas en dos comunidades panameñas donde Rhodnius pallescens es el vector principal / Knowledge and risk factors related to Chagas´ disease in two Panamanian communities where Rhodnius pallescens is the main vector

Introducción. La implementación de los programas de vigilancia, prevención y control de la enfermedad de Chagas requiere una aproximación integral. La sostenibilidad de los programas depende de la participación comunitaria amparada en un conocimiento básico del problema. Objetivo. Evaluar los conocimientos de los entrevistados que facilitan o limitan la vigilancia, prevención y control de la enfermedad de Chagas en dos comunidades endémicas de Panamá donde Rhodnius pallescens es el vector principal. Materiales y métodos. Mediante un cuestionario se evaluaron los conocimientos y los factores de riesgo relacionados con la enfermedad de Chagas en 201 personas mayores de 10 años de las comunidades endémicas de Las Pavas y Lagartera Grande, ubicadas en la ribera oeste del Canal de Panamá. Con ayuda de los moradores también se evaluó la presencia de chinches triatominos en 93 viviendas a lo largo de un año. Resultados. De las personas entrevistadas, 69,2 % (139/201) tenía pocos o muy pocos conocimientos sobre la enfermedad de Chagas y 93 % (187/201) estaba expuesto a factores de riesgo moderados o altos. Se capturaron chinches triatominos en 20,4 % (19/93) de las viviendas evaluadas, de los cuales, el 86,8 % (66/76) era R. pallescens. Se encontró asociación significativa entre la presencia de chinches dentro de las viviendas y las viviendas catalogadas como precarias (p<0,01). Conclusión. A pesar de que en estas dos comunidades se han desarrollado programas de educación sanitaria, es necesario reforzar los conocimientos básicos sobre la enfermedad de Chagas antes de establecer medidas de prevención y vigilancia que involucren la participación activa de sus habitantes.

Introduction: The implementation of surveillance, control and prevention measures for Chagas´ disease requires an integrated approach. The sustainability of programs depends on community participation supported on a basic understanding of the problem. Objective: To evaluate the knowledge of people interviewed which facilitates or limits the surveillance, prevention and control of Chagas´ disease in two endemic Panamanian communities where Rhodnius pallescens is the main vector. Materials and methods: A questionnaire assessed the knowledge and risk factors related to Chagas´ disease in 201 people over 10 years of age from the endemic communities of Las Pavas and Lagartera Grande located on the western shore of Panama Canal. Additionally, with the help of the residents, the presence of triatomine bugs in 93 dwellings was evaluated during a year. Results: Of those interviewed, 69.2% (139/201) had poor or very poor knowledge about Chagas´ disease. Nearly 93% (187/201) was exposed to moderate or high risk factors. Triatomine bugs were collected in 20.4% (19/93) of the evaluated homes; 80% (66/76) of them were R. pallescens . Significant association was found between the presence of triatomines inside the houses and precarious housing (p<0.01). Conclusion: Despite having been exposed to health education-related programs, it is necessary to strengthen the basic knowledge about Chagas´ disease in the two communities before establishing prevention and surveillance measures which involve active participation of its inhabitants.

Prevalencia de autoanticuerpos contra receptores autonómicos en pacientes panameños con cardiopatía chagásica crónica y con otras formas de cardiopatía / Prevalence of autoantibodies against autonomic receptors in patients with chronic cardiopathies

Introducción. La enfermedad de Chagas es la principal causa de cardiomiopatía crónica en Centroamérica. Existe controversia sobre los mecanismos causantes de la patología cardiaca observada durante la fase crónica de esta parasitosis. Varios estudios han detectado la presencia de autoanticuerpos circulantes dirigidos contra receptores beta-adrenérgicos y colinérgicos muscarínicos del miocardio en pacientes chagásicos, que pueden desencadenar señales intracelulares y alterar la función cardiaca durante el curso de la enfermedad. Objetivo. Nuestro objetivo principal fue comparar la frecuencia sérica de estos autoanticuerpos en pacientes chagásicos crónicos con la observada en pacientes con otras formas de cardiopatía y en controles sanos. Materiales y métodos. Se determinó la prevalencia de autoanticuerpos contra receptores beta-adrenérgicos y colinérgicos muscarínicos en cuatro grupos de pacientes panamelos: 53 pacientes chagásicos, 25 pacientes seronegativos con insuficiencia cardiaca, 25 pacientes con diferentes tipos de arritmia cardiaca y 25 controles sanos. Resultados. Los autoanticuerpos contra receptores autonómicos fueron más frecuentes en el grupo de pacientes con cardiopatía chagásica crónica (24,5%) comparados con el grupo de insuficiencia cardiaca (20,0%) y con el grupo con arritmias cardiacas (16,0%). Al comparar la proporción de autoanticuerpos entre el grupo de pacientes con cardiopatía chagásica crónica y los controles sanos, se detectaron diferencias muy significativas (24,5% versus 0%; p=0,0015). De los 53 pacientes con infección crónica, 48 (90,6%) presentaron algún grado de alteración cardiaca. Conclusiones. En comparación con el grupo de controles sanos, la frecuencia de los autoanticuerpos contra receptores autonómicos se encuentra significativamente aumentada en pacientes con enfermedad de Chagas crónica y con otras formas de cardiopatía.

Introduction. ChagasL disease is the main cause of chronic myocardiopathy in Central America. The mechanisms proposed for this cardiac pathology during the chronic phase remain controversial. Several studies have detected the presence of circulating autoantibodies against ƒÀ-adrenergic and cholinergic muscarinic receptors of the myocardium in patients with Chagas disease. These autoantibodies can trigger intracellular signals and modify the cardiac function during the progression of the disease. Objectives. The serological frequency of these autoantibodies was compared among patients with chronic Chagas disease, patients with other cardiopathies and healthy controls. Materials and methods. The prevalence of autoantibodies against ƒÀ-adrenergic and cholinergic muscarinic receptors was determined in four groups of Panamenian patients: 53 chagasic patients, 25 serologically negative patients with cardiac insufficiency, 25 patients with cardiac arrhythmia and 25 healthy individuals. Results. The antibodies against autonomic receptors were more frequently observed in patients with chronic chagasic cardiomyopathy (24.5%) compared to the cardiac insufficiency group (20.0%) and the cardiac arrhythmia group (16.0%). The proportion of autoantibodies was significantly different between the groups with chronic chagasic cardiomyopathy and healthy controls (24.5% versus 0%; p=0.015). Of the 53 chronically infected chagasic patients, 48 (90%) showed some degree of cardiac dysfunction. Conclusions. The frequency of autoantibodies against autonomic receptors is significantly increased in patients with chronic Chagas disease and in patients with other cardiopathies.

Molecular characterization of human Trypanosoma cruzi isolates from endemic areas in Panama

The present work provides information on Trypanosoma cruzi genotype circulating in endemic areas of Chagas disease in Panama. A total of 26 crude stocks of T. cruzi, isolated from the blood of persons with different clinical profiles of Chagas disease were collected and crio-conserved until used. Most of the stocks had been characterized by means of isoenzyme electrophoresis on cellulose acetate membranes. The clinical profiles of infected persons included 9 (34.6 percent) asymptomatic and 17 acute (65.4 percent) including 5 (19.2 percent) fatal cases, 2 under 5 years old and 3 adults. A multiplex-PCR assay based on the amplification of the non-transcribed spacer of the mini-exon gene was performed. All stocks of T. cruzi included in the study were found to correspond to Tc I group. This result supports the predominance of T. cruzi-I in the transmission cycles affecting the human population in the Republic of Panama.

Predominance of Trypanosoma rangeli infection in children from a Chagas disease endemic area in the west-shore of the Panama canal

A total of 206 serum samples from children (3-14 years old) living in the Amador County (La Chorrera District, Province of Panama) were screened by indirect immunofluorescence antibody test (IFAT) for the presence of antibodies against Trypanosoma cruzi. Positive sera were confirmed by recombinant enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. The presence of blood trypanosomes was investigated by hemoculture and subsequently identify by a duplex polymerase chain reaction (PCR) followed by dot blot hybridization. The results indicated a prevalence of 9.7 percent for trypanosome infections, a seroprevalence of 2.9 percent against T. cruzi and a predominance of T. rangeli infection (6.8 percent). The immunological and clinical implications of these findings are discussed.

Eco-epidemiological aspects of Trypanosoma cruzi, Trypanosoma rangeli and their vector (Rhodnius pallescens) in Panama

A epidemiologia da infecção do T. cruzi foi investigada na margem oriental do canal do Panamá, na região central da Republica do Panamá. A informação obtida durante o estudo avaliou fatores de risco da doença de Chagas nesta área. Entre 1999 e 2000, 1110 triatomíneos foram coletados: 1050 triatomíneos (94,6) em palmeiras, 27 (2,4) em habitats periurbanos e 33 (3,0) no interior de casas. Todos os espécimens foram identificados como R. pallescens. Não havia nenhuma evidência de domiciliação do vetor. O exame de glândulas salivares de 380 R. pallescens revelaram taxa de infecção natural por Trypanosoma de 7,6, mas o conteúdo da ampola rectal de 373 triatomíneos mostrou 45 de positividade. Os perfis de isoenzimas em Trypanosomas isolados demonstraram que 85,4 (n = 88) eram T. cruzi e 14,6 (n = 15) eram T. rangeli. A análise da refeição de sangue de 829 R. pallescens demonstrou comportamento zoofílico do vetor, sendo os gambás a fonte preferencial de sangue. Soroprevalência nos seres humanos de ambos locais de estudo foi menos que 2. Nossos resultados demonstram que T. cruzi sobrevive na área em associação equilibrada com R. pallescens e com diversas espécies diferentes de mamíferos em seus nichos naturais. Entretanto, a área é um risco eminente de infecção para sua população, pelo que é importante executar um programa educacional na comunidade a respeito das medidas, do conhecimento e do controle da doença.