Survey of Wild Mammal Hosts of Cutaneous Leishmaniasis Parasites in Panama and Costa Rica

The eco-epidemiology of American cutaneous leishmaniasis (ACL) is driven by animal reservoir species that are a source of infection for sand flies that serve as vectors infecting humans with Leishmania spp parasites. The emergence and re-emergence of this disease across Latin America calls for further studies to identify reservoir species associated with enzootic transmission. Here, we present results from a survey of 52 individuals from 13 wild mammal species at endemic sites in Costa Rica and Panama where ACL mammal hosts have not been previously studied. For Leishmania spp. diagnostics we employed a novel PCR technique using blood samples collected on filter paper. We only found Leishmania spp parasites in one host, the two-toed sloth, Choloepus hoffmanni. Our findings add further support to the role of two-toed sloths as an important ACL reservoir in Central America

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

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

Clinical Cutaneous Leishmaniasis Rates Are Associated with Household Lutzomyia gomezi, Lu. Panamensis, and Lu. trapidoi Abundance in Trinidad de Las Minas, Western Panama

American cutaneous leishmaniasis (ACL) transmission patterns have been increasingly associated with domestic and peridomestic environments. Here, we present results from an epidemiological survey of 94 people from 24 households in Trinidad de Las Minas, western Panama. We studied the role of sand fly abundance, housing quality, peridomicile landscape matrix, and vegetation structure on shaping household clinical ACL rate patterns at Trinidad de Las Minas. We found that sand fly abundance was significantly associated with household clinical ACL rates, with a 6% rate increase for each additional Lutzomyia gomezi sand fly found inside a domicile

Climatic fuctuations and malaria transmission dynamics, prior to elimination, in Guna Yala, República de Panamá

Background: Malaria has historically been entrenched in indigenous populations of the República de Panamá. This scenario occurs despite the fact that successful methods for malaria elimination were developed during the creation of the Panamá Canal. Today, most malaria cases in the República de Panamá afect the Gunas, an indigenous group, which mainly live in autonomous regions of eastern Panamá. Over recent decades several malaria outbreaks have afected the Gunas, and one hypothesis is that such outbreaks could have been exacerbated by climate change, especially by anomalous weather patterns driven by the EL Niño Southern Oscillation (ENSO). Results: Monthly malaria cases in Guna Yala (1998–2016) were autocorrelated up to 2 months of lag, likely refecting parasite transmission cycles between humans and mosquitoes, and cyclically for periods of 4 months that might refect relapses of Plasmodium vivax, the dominant malaria parasite transmitted in Panamá. Moreover, malaria case number was positively associated (P < 0.05) with rainfall (7 months of lag), and negatively with the El Niño 4 index (15 months of lag) and the Normalized Diference Vegetation Index, NDVI (8 months of lag), the sign and magnitude of these associations likely related to the impacts of weather patterns and vegetation on the ecology of Anopheles albimanus, the main malaria vector in Guna Yala. Interannual cycles, of approximately 4-year periods, in monthly malaria case numbers were associated with the El Niño 4 index, a climatic index associated with weather and vegetation dynamics in Guna Yala at seasonal and interannual time scales. Conclusion: The results showed that ENSO, rainfall and NDVI were associated with the number of malaria cases in Guna Yala during the study period. These results highlight the vulnerability of Guna populations to malaria, an infection sensitive to climate change, and call for further studies about weather impacts on malaria vector ecology, as well as the association of malaria vectors with Gunas paying attention to their socio-economic conditions of poverty and cultural diferences as an ethnic minorityAntecedentes: La malaria ha estado históricamente arraigada en las poblaciones indígenas de la República de Panamá. Este escenario ocurre a pesar de que se desarrollaron métodos exitosos para la eliminación de la malaria durante la creación del Canal de Panamá. En la actualidad, la mayoría de los casos de malaria en la República de Panamá afectan a los gunas, un grupo indígena que viven principalmente en las regiones autónomas del este de Panamá. En las últimas décadas se han producido varios brotes de malaria Una de las hipótesis es que estos brotes podrían haberse visto exacerbados por el cambio climático, especialmente por los patrones meteorológicos anómalos provocados por la Oscilación del Sur del Niño (ENSO). Resultados: Los casos mensuales de malaria en Guna Yala (1998-2016) estuvieron autocorrelacionados hasta 2 meses de desfase, probablemente reflejando ciclos de transmisión del parásito entre humanos y mosquitos, y cíclicamente durante períodos de 4 meses que podrían reflejar recaídas de Plasmodium vivax, el parásito dominante de la malaria transmitido en Panamá. Además, el número de casos de malaria de casos de malaria se asoció positivamente (P < 0,05) con las precipitaciones (7 meses de retardo), y negativamente con el índice de El Niño 4 (15 meses de retraso) y el Índice de Vegetación de Diferencia Normalizada, NDVI (8 meses de retraso). de estas asociaciones probablemente estén relacionadas con el impacto de los patrones climáticos y la vegetación en la ecología del Anopheles albimanus, el principal vector de la malaria en Guna Yala. Los ciclos interanuales, de aproximadamente 4 años, en el número de casos de malaria El número de casos de malaria se asoció con el índice de El Niño 4, un índice climático asociado a la dinámica del tiempo y la vegetación en Guna Yala a escala temporal estacional e interanual. Conclusiones: Los resultados mostraron que el ENSO, las precipitaciones y el NDVI se asociaron con el número de casos de malaria en Guna Yala durante el periodo de estudio. Estos resultados ponen de manifiesto la vulnerabilidad de las poblaciones de Guna a la malaria, una infección sensible al cambio climático, y exigen que se realicen más estudios sobre los impactos meteorológicos en la ecología del vector de la malaria, así como la asociación de los vectores de la malaria con los Gunas prestando atención a sus condiciones socioeconómicas de pobreza y diferencias culturales como minoría étnicaUniversidad Nacional, Costa RicaEscuela de Medicina Veterinari

Leishmania spp. infection rate and feeding patterns of sand flies (Diptera: Psychodidae) from a hyperendemic cutaneous leishmaniasis community in Panamá

Abstract. American cutaneous leishmaniasis (ACL) is a common and important vector-borne parasitic zoonosis in Panam ´a. Here, we study Leishmania spp. infection rates and blood-feeding patterns among common sand flies in Trinidad de Las Minas, a rural community with hyperendemic ACL transmission, and where a deltamethrin fogging trial was performed. Sand flies were collected from April 2010 to June 2011 with light traps installed inside and in the peridomicile of 24 houses. We restricted our analysis to the most abundant species at the study site: Lutzomyia trapidoi, Lutzomyia gomezi, Lutzomyia panamensis, Lutzomyia triramula, and Lutzomyia dysponeta. We detected Leishmania spp. infection in sand flies by polymerase chain reaction (PCR) amplification of the internal transcribed spacer region 1 (ITS-1) in pooled females (1–10 females per pool). Host species of engorged sand flies were identified using a cytochrome b PCR. From 455 sand fly pools analyzed, 255 pools were positive for Leishmania spp., with an estimated infection rate (confidence interval) of 0.096 [0.080–0.115] before the deltamethrin fogging which slightly, but not significantly (P > 0.05), increased to 0.116 [0.098–0.136] after the deltamethrin fogging. Blood meal analysis suggested that pigs, goats, and birds were the most common sand fly blood sources, followed by humans and domestic dogs. DNA sequencing from a subsample of ITS-1 positive pools suggests that Leishmania panamensis, Leishmania naiffi, and other Leishmania spp. were the parasite species infecting the most common vectors at the study site. Our data confirm an association between sand fly species, humans, domestic dogs, and pigs and Leishmania spp. parasites in rural Panamá.Resumen. La leishmaniasis cutánea americana (LCA) es una zoonosis parasitaria común e importante transmitida por vectores en Panamá. Aquí estudiamos las tasas de infección por Leishmania spp. y los patrones de alimentación sanguínea entre las moscas de la arena comunes en Trinidad de Las Minas, una comunidad rural con transmisión hiperendémica de LCA, y donde se realizó un ensayo de nebulización con deltametrina. Las moscas de la arena fueron recolectadas desde abril de 2010 hasta junio de 2011 con trampas de luz instaladas dentro y en el peridomicilio de 24 casas. Restringimos nuestro análisis a las especies más abundantes en el lugar de estudio: Lutzomyia trapidoi, Lutzomyia gomezi, Lutzomyia panamensis, Lutzomyia triramula y Lutzomyia dysponeta. Se detectó la infección por Leishmania spp. en los flebótomos mediante la amplificación por reacción en cadena de la polimerasa (PCR) de la región espaciadora transcrita interna 1 (ITS-1) en hembras agrupadas (1-10 hembras por grupo). Las especies hospedadoras de las moscas de la arena engordadas se identificaron mediante una PCR del citocromo b. De los 455 grupos de moscas de la arena analizados, 255 grupos resultaron positivos a Leishmania spp., con una tasa de infección estimada (intervalo de confianza) de 0,096 [0,080-0,115] antes de la nebulización con deltametrina, que aumentó ligeramente, pero no significativamente (P > 0,05), a 0,116 [0,098-0,136] después de la nebulización con deltametrina. El análisis de la harina de sangre sugirió que los cerdos, las cabras y los pájaros eran las fuentes de sangre más comunes de la mosca de la arena, seguidos por los humanos y los perros domésticos. La secuenciación del ADN de una submuestra de grupos positivos al ITS-1 sugiere que Leishmania panamensis, Leishmania naiffi y otras Leishmania spp. fueron las especies de parásitos que infectaron a los vectores más comunes en el lugar del estudio. Nuestros datos confirman una asociación entre las especies de moscas de la arena, los seres humanos, los perros domésticos y los cerdos y los parásitos de Leishmania spp. en las zonas rurales de Panamá.Instituto Conmemorativo Gorgas de Estudios de la Salud (ICGES), PanamáUniversidad de Panamá, PanamáInstituto Costarricense de Investigación y enseñanza en Nutrición y Salud (INCIENSA), Costa RicaUniversidad Nacional, Costa RicaEscuela de Medicina Veterinari

Population Dynamics of <i>Anopheles albimanus</i> (Diptera: Culicidae) at Ipetí-Guna, a Village in a Region Targeted for Malaria Elimination in Panamá

Anopheles albimanus Wiedemann is a major malaria vector in Mesoamerica and the Caribbean whose population dynamics, in response to changing environments, has been relatively poorly studied. Here, we present monthly adult and larvae data collected from May 2016 to December 2017 in Ipet&#237;-Guna, a village within an area targeted for malaria elimination in the Rep&#250;blica de Panam&#225;. During the study period we collected a total of 1678 Anopheles spp. mosquitoes (1602 adults and 76 larvae). Over 95% of the collected Anopheles spp. mosquitoes were An. albimanus. Using time series analysis techniques, we found that population dynamics of larvae and adults were not significantly correlated with each other at any time lag, though correlations were highest at one month lag between larvae and adults and four months lag between adults and larvae. Larvae population dynamics had cycles of three months and were sensitive to changes in temperature with 5 months lag, while adult abundance was correlated with itself (1 month lag) and with the normalized difference vegetation index (NDVI) with three months lag. A key observation from our study is the absence of both larvae and adults of An. albimanus between January and April from environments associated with Guna population&#8217;s daily activities, which suggests this time window could be the best time to implement elimination campaigns aimed at clearing Plasmodium spp. parasites from Guna populations using, for example, mass drug administration

Diversity, Co-Occurrence, and Nestedness Patterns of Sand Fly Species (Diptera: Psychodidae) in Two Rural Areas of Western Panamá

Cutaneous Leishmaniasis transmission in the New World is observed in areas with rich sand fly species’ faunas. The diversity and composition of sand fly species can change in response to seasonal weather and land use changes. Here, we present results from a two-year-long study where we collected, using Centers for Disease Control (CDC) light traps, sand flies from two rural areas, Las Pavas (LP) and Trinidad de las Minas (T) in western Panamá. Over 710 trap-nights, we collected 16,156 sand flies from 15 genera and 35 species. We identified 34 species in T, and the most abundant species collected was Nyssomyia trapidoi (Fairchild and Hertig, 1952) (n = 2278, 37%), followed by Psychodopygus panamensis (Shannon, 1926) (n = 1112, 18%), and Trichopygomyia triramula (Fairchild and Hertig, 1952) (n = 1063, 17%). In LP, we identified 26 species, and the most abundant species collected were Ty. triramula (n = 4729, 48%), and Ps. panamensis (n = 3444, 35%). We estimated a higher species’ richness in T (Chao2 ± S.E.: 36.58 ± 3.84) than in LP (27.49 ± 2.28). In T, species’ richness was significantly higher in the rainy season, but no seasonal differences were observed in LP. Species’ assemblages were nested in the two areas. Phlebotomine sand fly species’ abundance increased at the two sites during the rainy season. Our data suggest that seasonality is more important than land use as a factor driving sand fly species’ diversity at the studied sites

Diversity, Co-Occurrence, and Nestedness Patterns of Sand Fly Species (Diptera: Psychodidae) in Two Rural Areas of Western Panamá

Cutaneous Leishmaniasis transmission in the New World is observed in areas with rich sand fly species’ faunas. The diversity and composition of sand fly species can change in response to seasonal weather and land use changes. Here, we present results from a two-year-long study where we collected, using Centers for Disease Control (CDC) light traps, sand flies from two rural areas, Las Pavas (LP) and Trinidad de las Minas (T) in western Panamá. Over 710 trap-nights, we collected 16,156 sand flies from 15 genera and 35 species. We identified 34 species in T, and the most abundant species collected was Nyssomyia trapidoi (Fairchild and Hertig, 1952) (n = 2278, 37%), followed by Psychodopygus panamensis (Shannon, 1926) (n = 1112, 18%), and Trichopygomyia triramula (Fairchild and Hertig, 1952) (n = 1063, 17%). In LP, we identified 26 species, and the most abundant species collected were Ty. triramula (n = 4729, 48%), and Ps. panamensis (n = 3444, 35%). We estimated a higher species’ richness in T (Chao2 ± S.E.: 36.58 ± 3.84) than in LP (27.49 ± 2.28). In T, species’ richness was significantly higher in the rainy season, but no seasonal differences were observed in LP. Species’ assemblages were nested in the two areas. Phlebotomine sand fly species’ abundance increased at the two sites during the rainy season. Our data suggest that seasonality is more important than land use as a factor driving sand fly species’ diversity at the studied sites