Evaluation of the biological efficacy and susceptibility in Aedes aegypti to the pyrethroid insecticides deltamethrin and cyfluthrin during the Zika virus outbreak in Kuna Yala, Panama / Evaluación de la eficacia biológica y de la sensibilidad de Aedes aegypti a los insecticidas piretroides deltametrina y ciflutrina durante el brote del virus Zika en Kuna Yala, Panamá.

Introduction. The development of resistance to insecticides in Aedes aegypti represents a major threat to public health. Surveillance and monitoring of the behavior of bioefficacy and susceptibility of insecticides is of fundamental importance to prolong the useful life of insecticide molecules. Objective. To evaluate the bioefficacy and susceptibility of the insecticides deltamethrin and cyfluthrin in Aedes aegypti during the zika epidemic outbreak in Kuna Yala, Panama. Methods and materials. The bioefficacy and susceptibility of deltamethrin and cyfluthrin in Aedes aegypti Ustupo using WHO standardized bioassays during the Zika epidemic outbreak in Kuna Yala, Panama. Results. In the bioassays with Aedes aegypti Ustupo, possible resistance to deltamethrin and cyfluthrin was observed, with a mortality rate of 95,3% and 94%, respectively. The bioefficacy results with Aedes aegypti Ustupo registered low bioefficacy of deltamethrin and cyfluthrin with average percentages of mortality in the intradomicile of 75% and 31,1%, respectively, while in the peridomicile it was 63,7% and 26,1%, respectively. Conclusion. The results of this study represent a challenge that the National Aedes Control Program must face in order to care for and maintain the toxic effect of insecticides applied against Aedes populations. It is necessary for the National Aedes Control Program to establish a resistance management program to evaluate resistance and its distribution in order to guarantee the sustainability of anti-vector interventions against Aedes populations.

Introducción. El desarrollo de la resistencia a insecticidas de Aedes aegypti representa una gran amenaza para la salud pública. La vigilancia y el monitoreo de la eficacia biológica a los insecticidas y la sensibilidad de las poblaciones de Aedes aegypti es de fundamental importancia para prolongar la vida útil de estas moléculas. Objetivo. Evaluar la eficacia biológica de los insecticidas deltametrina y ciflutrina y la sensibilidad de poblaciones de Aedes aegypti a estos insecticidas durante el brote epidémico de virus del Zika en Kuna Yala, Panamá. Métodos y materiales. Se evaluó la eficacia biológica de la deltametrina y la ciflutrina, y la sensibilidad a estos insecticidas de poblaciones de la cepa Aedes aegypti Ustupo, mediante bioensayos estandarizados por la Organización Mundial de la Salud durante el brote epidémico de virus del Zika en Kuna Yala, Panamá. Resultados. En los bioensayos con Aedes aegypti Ustupo se observó posible resistencia a deltametrina y a ciflutrina con un porcentaje de mortalidad del 95,3 y 94 %, respectivamente. Se registró baja eficacia biológica con la cepa Aedes aegypti Ustupo para la deltametrina y la ciflutrina, con medias de porcentajes de mortalidad de 75 y 31,1 %, en el intradomicilio, mientras que en el peridomicilio fue de 63,7 y 26,1 %, respectivamente. Conclusión. Los resultados de este estudio representan un desafío que debe enfrentar el Programa Nacional de Control de Aedes para lograr cuidar y mantener el efecto tóxico de los insecticidas aplicados contra las poblaciones de Aedes. Es necesario que el Programa Nacional de Control de Aedes establezca unos lineamientos de manejo de la resistencia para caracterizarla y evaluar la distribución geográfica de las poblaciones afectadas. Lo anterior con el propósito de garantizar la sostenibilidad de las intervenciones antivectoriales contra las poblaciones de Aedes.

Evaluación de la eficacia biológica y de la sensibilidad de Aedes aegypti a los insecticidas piretroides deltametrina y ciflutrina durante el brote del virus Zika en Kuna Yala, Panamá / Evaluation of the biological efficacy and susceptibility in Aedes aegypti to the pyrethroid insecticides deltamethrin and cyfluthrin during the Zika virus outbreak in Kuna Yala, Panama

Introducción. El desarrollo de la resistencia a insecticidas de Aedes aegypti representa una gran amenaza para la salud pública. La vigilancia y el monitoreo de la eficacia biológica a los insecticidas y la sensibilidad de las poblaciones de Aedes aegypti es de fundamental importancia para prolongar la vida útil de estas moléculas. Objetivo. Evaluar la eficacia biológica de los insecticidas deltametrina y ciflutrina y la sensibilidad de poblaciones de Aedes aegypti a estos insecticidas durante el brote epidémico de virus del Zika en Kuna Yala, Panamá. Materiales y métodos. Se evaluó la eficacia biológica de la deltametrina y la ciflutrina, y la sensibilidad a estos insecticidas de poblaciones de la cepa Aedes aegypti Ustupo, mediante bioensayos estandarizados por la Organización Mundial de la Salud durante el brote epidémico de virus del Zika en Kuna Yala, Panamá. Resultados. En los bioensayos con Aedes aegypti Ustupo se observó posible resistencia a deltametrina y a ciflutrina con un porcentaje de mortalidad del 95,3 y 94 %, respectivamente. Se registró baja eficacia biológica con la cepa Aedes aegypti Ustupo para la deltametrina y la ciflutrina, con medias de porcentajes de mortalidad de 75 y 31,1 %, en el intradomicilio, mientras que en el peridomicilio fue de 63,7 y 26,1 %, respectivamente. Conclusión. Los resultados de este estudio representan un desafío que debe enfrentar el Programa Nacional de Control de Aedes para lograr cuidar y mantener el efecto tóxico de los insecticidas aplicados contra las poblaciones de Aedes. Es necesario que el Programa Nacional de Control de Aedes establezca unos lineamientos de manejo de la resistencia para caracterizarla y evaluar la distribución geográfica de las poblaciones afectadas. Lo anterior con el propósito de garantizar la sostenibilidad de las intervenciones antivectoriales contra las poblaciones de Aedes.

Introduction. The development of resistance to insecticides in Aedes aegypti represents a major threat to public health. Surveillance and monitoring of the biological efficacy and sensibility of Aedes aegypti populations to insecticides is fundamental to prolong the useful life of insecticide molecules. Objective. To evaluate the biological efficacy of deltamethrin and cyfluthrin and sensibility to insecticides in Aedes aegypti during the zika epidemic outbreak in Kuna Yala, Panama. Materials and methods. We assessed the biological efficacy of deltamethrin and cyfluthrin, and sensibility in the strain Aedes aegypti Ustupo using bioassays standardized by the World Health Organization during the Zika epidemic outbreak in Kuna Yala, Panama. Results. In the bioassays with Aedes aegypti Ustupo, we observed a possible resistance to deltamethrin and cyfluthrin with a mortality rate of 95,3 and 94%, respectively. The obtained results registered low biological efficacy of deltamethrin and cyfluthrin with average percentages of mortality of 75 and 31.1% in the intradomicile, and 63,7 and 26.1% in the peridomicile. Conclusion. The results of this study represent a challenge for the National Aedes Control Program to care for and maintain the toxic effect of insecticides applied against Aedes populations. There is a need for the National Aedes Control Program to establish some guidelines about resistance assessment and resistant populations' geographic distribution to guarantee the sustainability of anti-vector interventions against Aedes populations.

Long-term transmission patterns and public health policies leading to malaria elimination in Panamá.

BACKGROUND: The present study provides a countrywide perspective of the malaria situation in Panamá over a long-term framework, with the purpose of identifying historical malaria resurgence events and their potential causes. METHODS: A descriptive-ecological study was conducted by analysing demographic and epidemiological annual malaria time series data in Panamá (1884-2019) using several data sources. Malaria intensity indicators were calculated during the study period. The effects of El Niño Southern Oscillation on malaria transmission were also analysed using a retrospective analysis of malaria cases between 1957 and 2019. RESULTS: Several factors were identified responsible for malaria resurgence in Panamá, mostly related with Malaria Control Programme weakening. During the past 20 years (2000-2019) malaria has progressively increased in prevalence within indigenous settlements, with a predominance of male cases and a high proportion (15% of total cases) in children less than 5 years old. During this period, a significant and increasing proportion of the Plasmodium falciparum cases were imported. Retrospective analysis (1957-2019) evidenced that ENSO had a significant impact on malaria transmission dynamics in Panamá. CONCLUSIONS: Data analysis confirmed that although authorities have been successful in focalizing malaria transmission in the country, there are still neglected issues to be solved and important intercultural barriers that need to be addressed in order to achieve elimination of the disease by 2022. This information will be useful for targeting strategies by the National Malaria Elimination Programme.

Presence of the point mutations Val1016Gly in the voltage-gated sodium channel detected in a single mosquito from Panama.

BACKGROUND: In Panama, arboviroses such as dengue fever, and more recently chikungunya fever and Zika disease, are transmitted by Aedes aegypti and Aedes albopictus. Their control is based on the elimination of breeding sites and fogging with pyrethroid insecticides. However, one of the significant issues derived from the prolonged use of pyrethroid insecticide is the development of resistance mechanisms, such as knockdown resistance or kdr. The objective of this study was to evaluate the presence of kdr mutations in a partial region of the VGSC gene in samples of wild-caught Aedes mosquitoes from different locations of the Metropolitan Region of Panama. RESULTS: Based on the analysis of 194 sequences of the VGSC gene, two kdr mutations (Ile1011Met and Val1016Gly) were detected in a specimen of Ae. aegypti. The frequency of kdr mutations in the evaluated samples of Ae. aegypti was 0.01. CONCLUSIONS: This study provides evidence for a low frequency of kdr mutations in Ae. aegypti populations in Panama. It is possible that these changes have no impact on vector control interventions. To our knowledge, we report, for the first time in America the Val1016Gly mutation documented in Asia. In general terms, this result is highly relevant to the Aedes Control Programme in Panama since it constitutes a feasible approach for the timely detection of resistance as well as for the development of strategies.

Enzootic mosquito vector species at equine encephalitis transmission foci in the República de Panamá.

The identification of mosquito vector species present at arboviral enzootic transmission foci is important to understand transmission eco-epidemiology and to propose and implement prevention and control strategies that reduce vector-borne equine encephalitis transmission. The goal of this study was to identify mosquito species potentially involved in the transmission of enzootic equine encephalitis, in relation to their abundance and diversity at three endemic regions in the República de Panamá. We sampled adult mosquitoes during the dry and rainy season of Panamá. We employed CDC light traps with octanol, EV traps with CO2 and Trinidad 17 traps baited with live hamsters. Traps were deployed in the peridomicile and extradomicile of houses from 18:00 to 6:00 h. We estimated the abundance and diversity of sampled species. We collected a total of 4868 mosquitoes, belonging to 45 species and 11 genera, over 216 sampling nights. Culex (Melanoconion) pedroi, a major Venezuelan equine encephalitis vector was relatively rare (< 2.0% of all sampled mosquitoes). We also found Cx. (Mel) adamesi, Cx. (Mel) crybda, Cx. (Mel) ocossa, Cx. (Mel) spissipes, Cx. (Mel) taeniopus, Cx. (Mel) vomerifer, Aedes scapularis, Ae. angustivittatus, Coquillettidia venezuelensis, Cx. nigripalpus, Cx. declarator, Mansonia titillans, M. pseudotitillans and Psorophora ferox all species known to be vectorially competent for the transmission of arboviruses. Abundance and diversity of mosquitoes in the sampled locations was high, when compared with similar surveys in temperate areas. Information from previous reports about vectorial competence / capacity of the sampled mosquito species suggest that sampled locations have all the elements to support enzootic outbreaks of Venezuelan and Eastern equine encephalitides.

Social representations of malaria in the Guna indigenous population of Comarca Guna de Madungandi, Panama.

BACKGROUND: The purpose of the study was to recognize the social representation of the Guna indigenous population by identifying cultural elements related to malaria, in order to create an intercultural approach to any health intervention to control and prevent the disease. METHODS: This qualitative study has an anthropological focus that used participant observation, informal conversations, focus groups, interviews, in-depth interviews with key actors. Analyses included review, classification and categorization of interviews. RESULTS: Malaria within the Guna culture is in harmony with several cultural factors, such as magic, religion, beliefs, myths, and nature. The health system must include these factors in its intercultural approach to ensure the sustainability of anti-malarial intervention measures. Until this is not properly addressed, the Guna population of Madungandi will remain a permanent source of risk for malaria transmission in this region and for the rest of the country. CONCLUSION: The findings of this study contribute new variables that can facilitate an intercultural approach to improve the perception of malaria in the indigenous population of Comarca Guna de Madungandi, Panama.

Dermatitis Due to Paederus Colombinus: Report of an Epidemic Outbreak of 68 Cases in the Province of Darien, Panama.

INTRODUCTION: Contact dermatitis due to Paederus is a particular form of accident by animal contact. It is characterized by the sudden onset of erythematous and vesicular lesions with burning sensation on exposed areas of the body. The aim of this study was to describe the epidemiological and clinical findings of an outbreak of Paederus dermatitis in Panama. METHODS: Clinical and epidemiological findings of an outbreak of contact dermatitis caused by Paederus sp. in the province of Darien in eastern Panama is reported. After reviewing the clinical records, a clinical-epidemiological questionnaire was developed and used in 20 communities where reported cases were found. We captured and collected the specimens for species characterization for three consecutive days using three different methods of capture. RESULTS: During May-July, 2014, 68 cases of Paederus irritant contact dermatitis occurred in 20 communities of the Darien. Fifty-three percent were females. The age group of zero to five years had the highest number of cases, 15 (22%). The most common clinical presentation was the classical linear dermatitis (58%); 42% of the subjects had mirror image lesions, multiple vesicular-pustular lesions, and crust lesions. Symptoms were most commonly reported as a burning sensation (65%), followed by pruritus in 60%, pain (25%), and fever (nine percent). A total of 81 specimens of Paederus were collected, 68% in peridomiciliary areas. CONCLUSIONS: This Paederus sp. dermatitis report represents one of the largest outbreak described in Latin America and the diagnosis could be confused with others skin diseases like pyodermitis or other contact dermatitis.

Use of DNA barcoding to distinguish the malaria vector Anopheles neivai in Colombia.

A reference 535 bp barcode sequence from a fragment of the mitochondrial gene cytochrome oxidase I (COI), acquired from specimens of An. neivai Howard, Dyar & Knab, 1913 from its type locality in Panama, was used as a tool for distinguishing this species from others in the subgenus Kerteszia. Comparisons with corresponding regions of COI between An. neivai and other species in the subgenus (An. bellator Dyar & Knab 1906, An. homunculus Komp 1937, An cruzii Dyar & Knab, 1908 and An. laneanus Corrêa & Cerqueira, 1944) produced K2P genetic distances of 8.3-12.6%, values well above those associated with intraspecific variation. In contrast, genetic distances among 55 specimens from five municipalities in the Colombian Pacific coastal state of Chocó were all within the range of 0-2.5%, with an optimized barcode threshold of 1.3%, the limit for unambiguous differentiation of An. neivai. Among specimens from the Chocó region, 18 haplotypes were detected, two of which were widely distributed over the municipalities sampled. The barcode sequence permits discrimination of An. neivai from sympatric species and indicates genetic variability within the species; aspects key to malaria surveillance and control as well as defining geographic distribution and dispersion patterns.

Short-term suppression of Aedes aegypti using genetic control does not facilitate Aedes albopictus.

BACKGROUND: Under permit from the National Biosafety Commission for the use of genetically modified organisms, releases of a genetically engineered self-limiting strain of Aedes aegypti (OX513A) were used to suppress urban pest Ae. aegypti in West Panama. Experimental goals were to assess the effects on a coexisting population of Ae. albopictus and examine operational parameters with relevance to environmental impact. RESULTS: Ae. albopictus populations were shown to be increasing year upon year at each of three study sites, potentially reflecting a broader-scale incursion into the area. Ae. albopictus abundance was unaffected by a sustained reduction in Ae. aegypti by up to 93% through repeated releases of OX513A. Males accounted for 99.99% of released OX513A, resulting in a sustained mating fraction of 75%. Mean mating competitiveness of OX513A was 0.14. The proportion of OX513A in the local environment decreased by 95% within 25 days of the final release. CONCLUSIONS: There was no evidence for species replacement of Ae. aegypti by Ae. albopictus over the course of this study. No unintentional environmental impacts or elevated operational risks were observed. The potential for this emerging technology to mitigate against disease outbreaks before they become established is discussed.

Conocimientos, actitudes y prácticas sobre la malaria en la población indígena guna de la comarca de Madungandí, Panamá, 2012 / Knowledge, attitudes and practices regarding malaria in the indigenous Guna population of the Madungandí region, Panamá, 2012

Introducción. Las encuestas sobre comportamientos, actitudes y prácticas permiten determinar el grado de conocimiento de la población sobre la malaria o paludismo, así como las actitudes y prácticas que contribuyen a su transmisión. Objetivo. Identificar los conocimientos, actitudes y prácticas que favorecen la transmisión de la malaria en la población indígena guna de Madungandí. Materiales y métodos. Se hizo un estudio transversal mediante una encuesta a los jefes de familia de una muestra de 40 % de las viviendas en tres comunidades con alta incidencia de malaria. La encuesta se hizo con encuestadores gunas e integrantes del equipo de investigación, y con la ayuda de un traductor. El análisis se hizo en Epi-Info 6.04. Resultados. El rango de edad de los encuestados fluctuaba entre los 20 y los 70 años. Todos los encuestados indicaron pertenecer a la etnia guna y hablar su lengua; 64 % eran del sexo masculino y 30 % eran analfabetas. La mitad de los encuestados (51 %) manifestó haber enfermado de malaria, por lo menos, una vez en los últimos ocho años y 89 % reconoció la enfermedad como un problema de salud. El 63 % manifestó que el médico tradicional "inadule" curaba la malaria, y 78 % practicaba la "fuma de la pipa" y la "quema del cacao" para prevenirla. Conclusión. Dado el limitado conocimiento sobre la malaria y su vector, así como la actitud de colaboración de la población guna, es necesario iniciar programas educativos y de participación comunitaria para mejorar las prácticas de prevención y control en las comunidades, y disminuir así la incidencia de la enfermedad en la comarca de Madungandí.

Introduction: Knowledge, attitudes and practices surveys allow to determine the degree of knowledge on the management of malaria in a given population, as well as the attitudes and practices that contribute or not to its transmission. Objective: To identify the knowledge, attitudes and practices that favor or not the transmission of malaria in the indigenous Guna population of Madungandí. Materials and methods: A cross-sectional study was conducted by applying a survey to the heads of the families in a sample of 40% of households in three communities with high malaria incidence. Local Guna residents and translators were part of the research team that applied the questionnaires. The statistical analysis was performed in Epi-Info 6.04. Results: The age range of those surveyed was between 20 and 70 years. All responders indicated that they belonged to and spoke the language of the Guna ethnic group, 64% were male and 30% were illiterate. Half (51%) of the responders declared they had suffered malaria at least once in the last eight years, and 89% accepted that malaria was a health problem. Sixty-three per cent responded that their traditional doctors, “inadule”, cured malaria and 7.0 % practiced the “pipe smoking” and “cocoa burn” rituals to prevent the disease. Conclusion: Considering the limited knowledge about malaria and its vector, as well as the willingness to collaborate shown by the Guna population, it is essential to initiate educational and participative programs to improve control and prevention activities in the communities aimed at achieving a reduction in malaria incidence in the Madungandí indigenous region.

Characterization of a recent malaria outbreak in the autonomous indigenous region of Guna Yala, Panama.

BACKGROUND: This study aims to describe the epidemiological and entomological factors associated with a recent malaria outbreak that occurred in 2012 in a socially marginalized population from Guna Yala Comarca in Panama. METHODS: A descriptive and observational study was conducted by analysing demographic and epidemiological data from all malaria cases registered during 2012 in the Comarca Guna Yala, Panama. Malaria intensity indicators were calculated during the study period. Entomological evaluations were performed monthly, from October to December 2012, in the three communities that presented the most intense malaria transmission during the first semester of 2012. Anopheles breeding habitats were also characterized. RESULTS: During the studied period, 6754 blood smears were examined (17.8 % of the total population), and 143 were confirmed as positive for Plasmodium vivax. A significant increase of malaria transmission risk indicators (API: 3.8/1000, SPR: 2.1 %) was observed in Guna Yula, when compared with previous years, and also in comparison with estimates from the whole country. Anopheles albimanus was the most abundant and widespread (877; 72.0 %) vector species found in the three localities, followed by Anopheles punctimacula (231; 19.0 %) and Anopheles aquasalis (110; 9.0 %). Three An. albimanus pools were positive for P. vivax, showing an overall pooled prevalence estimate of 0.014. CONCLUSIONS: Data analysis confirmed that during 2012 a malaria epidemic occurred in Guna Yala. Panama. This study provides baseline data on the local epidemiology of malaria in this vulnerable region of Panamá. This information will be useful for targeting control strategies by the National Malaria Control Programme.

[Knowledge, attitudes and practices regarding malaria in the indigenous Guna population of the Madungandí region, Panamá, 2012]. / Conocimientos, actitudes y prácticas sobre la malaria en la población indígena guna de la comarca de Madungandí, Panamá, 2012.

INTRODUCTION: Knowledge, attitudes and practices surveys allow to determine the degree of knowledge on the management of malaria in a given population, as well as the attitudes and practices that contribute or not to its transmission. OBJECTIVE: To identify the knowledge, attitudes and practices that favor or not the transmission of malaria in the indigenous Guna population of Madungandí. MATERIALS AND METHODS: A cross-sectional study was conducted by applying a survey to the heads of the families in a sample of 40% of households in three communities with high malaria incidence. Local Guna residents and translators were part of the research team that applied the questionnaires. The statistical analysis was performed in Epi-Info 6.04. RESULTS: The age range of those surveyed was between 20 and 70 years. All responders indicated that they belonged to and spoke the language of the Guna ethnic group, 64% were male and 30% were illiterate. Half (51%) of the responders declared they had suffered malaria at least once in the last eight years, and 89% accepted that malaria was a health problem. Sixty-three per cent responded that their traditional doctors, “inadule”, cured malaria and 7.0 % practiced the “pipe smoking” and “cocoa burn” rituals to prevent the disease. CONCLUSION: Considering the limited knowledge about malaria and its vector, as well as the willingness to collaborate shown by the Guna population, it is essential to initiate educational and participative programs to improve control and prevention activities in the communities aimed at achieving a reduction in malaria incidence in the Madungandí indigenous region.

Estimation of Aedes aegypti (Diptera: Culicidae) population size and adult male survival in an urban area in Panama.

Traditional mosquito control strategies rely heavily on the use of chemical insecticides. However, concerns about the efficiency of traditional control methods, environmental impact and emerging pesticide resistance have highlighted the necessity for developing innovative tools for mosquito control. Some novel strategies, including release of insects carrying a dominant lethal gene (RIDL®), rely on the sustained release of modified male mosquitoes and therefore benefit from a thorough understanding of the biology of the male of the species. In this report we present the results of a mark-release-recapture study aimed at: (i) establishing the survival in the field of laboratory-reared, wild-type male Aedes aegypti and (b) estimating the size of the local adult Ae. aegypti population. The study took place in Panama, a country where recent increases in the incidence and severity of dengue cases have prompted health authorities to evaluate alternative strategies for vector control. Results suggest a life expectancy of 2.3 days for released male mosquitoes (confidence interval: 1.78-2.86). Overall, the male mosquito population was estimated at 58 males/ha (range 12-81 males/ha), which can be extrapolated to an average of 0.64 pupae/person for the study area. The practical implications of these results are discussed.

Estimation of Aedes aegypti (Diptera: Culicidae) population size and adult male survival in an urban area in Panama

Traditional mosquito control strategies rely heavily on the use of chemical insecticides. However, concerns about the efficiency of traditional control methods, environmental impact and emerging pesticide resistance have highlighted the necessity for developing innovative tools for mosquito control. Some novel strategies, including release of insects carrying a dominant lethal gene (RIDL®), rely on the sustained release of modified male mosquitoes and therefore benefit from a thorough understanding of the biology of the male of the species. In this report we present the results of a mark-release-recapture study aimed at: (i) establishing the survival in the field of laboratory-reared, wild-type male Aedes aegypti and (b) estimating the size of the local adult Ae. aegypti population. The study took place in Panama, a country where recent increases in the incidence and severity of dengue cases have prompted health authorities to evaluate alternative strategies for vector control. Results suggest a life expectancy of 2.3 days for released male mosquitoes (confidence interval: 1.78-2.86). Overall, the male mosquito population was estimated at 58 males/ha (range 12-81 males/ha), which can be extrapolated to an average of 0.64 pupae/person for the study area. The practical implications of these results are discussed.

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

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.

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.

When climate change couples social neglect: malaria dynamics in Panamá.

A major challenge of infectious disease elimination is the need to interrupt pathogen transmission across all vulnerable populations. Ethnic minorities are among the key vulnerable groups deserving special attention in disease elimination initiatives, especially because their lifestyle might be intrinsically linked to locations with high transmission risk. There has been a renewed interest in malaria elimination, which has ignited a quest to understand factors necessary for sustainable malaria elimination, highlighting the need for diverse approaches to address epidemiological heterogeneity across malaria transmission settings. An analysis of malaria incidence among the Guna Amerindians of Panamá over the last 34 years showed that this ethnic minority was highly vulnerable to changes that were assumed to not impact malaria transmission. Epidemic outbreaks were linked with El Niño Southern Oscillations and were sensitive to political instability and policy changes that did not ensure adequate attention to the malaria control needs of the Gunas. Our results illustrate how the neglect of minorities poses a threat to the sustainable control and eventual elimination of malaria in Central America and other areas where ethnic minorities do not share the benefits of malaria control strategies intended for dominant ethnic groups.

Determinación de la sensibilidad a insecticidas organofosforados, carbamato y piretroides en poblaciones de Aedes aegypti Linneaus, 1762 ( Díptera: Culicidae ) de Panamá / Determining the status of susceptibility to organophosphate, carbamate and pyrethroids insecticides in populations of Aedes aegypti Linneaus, 1762 ( Diptera: Culicidae ) in Panamá

Introducción. Se llevó a cabo un estudio para determinar la sensibilidad de Aedes aegypti provenientes de regiones de alto riesgo de transmisión de dengue en Panamá, a insecticidas organofosforados, carbamatos y piretroides. Objetivo. Evaluar la sensibilidad a insecticidas piretroides, organofosforados y carbamatos en poblaciones de Ae. aegypti provenientes de ocho sitios pertenecientes a siete municipios de Panamá. Materiales y métodos. Se recolectaron poblaciones de Ae. aegypti en diferentes tipos de criaderos localizados en áreas urbanas y se criaron en condiciones controladas de laboratorio. Con la generación F 1 de cada una de las cepas se hicieron bioensayos de sensibilidad siguiendo la metodología estandarizada por la Organización Mundial de la Salud para larvas y adultos. Resultados. Las ocho cepas de Ae. aegypti resultaron sensibles a los insecticidas piretroides deltametrina, lambdacihalotrina y ciflutrina, el organofosforado fenitrotión y los carbamato propoxur y bendiocarb. Solo la cepa CHITRE resultó con resistencia moderada al insecticida deltametrina en larvas (FR 50 =5x). Sin embargo, en adultos resultó sensible. Conclusiones. Es necesaria la vigilancia periódica de la sensibilidad de las poblaciones de Ae. aegypti de los municipios evaluados, con el propósito de conservar en las poblaciones el carácter sensible a estos insecticidas. Los insecticidas aplicados para el control de Ae. aegypti pueden seguir siendo utilizados en los municipios evaluados, pero depende de la sensibilidad de los mosquitos en el área específica.

Introduction: We studied the susceptibility to organophosphate, carbamate and pyrethroid insecticides of Aedes aegypti from different regions of high transmission risk for dengue in Panama. Objective: To evaluate the susceptibility to organophosphate, carbamate and pyrethroid insecticides in Ae. aegypti from eight sites belonging to seven municipalities in Panamá. Materials and methods: We collected Ae. aegypti larval populations in different types of breeding sites located in urban areas. Insects were reared in laboratory control conditions. With the F 1 generation of each strain we performed susceptibility bioassays using WHO standardized methodology for larvae and adults. Results: The eight Ae. Aegypti strains were susceptible to the pyrethroid insecticides: deltamethrin, lambdacyhalothrin and cifluthrin, to the organophosphate fenitrothrion, and to the carbamates propoxur and bendiocarb. Only the CHITRE strain exhibited a moderate resistance to the insecticide deltamethrin in larvae (FR 50 =5x). However, adults were susceptible. Conclusions: It is necessary to perform periodic surveillance to evaluate the susceptibility of Ae. aegypti populations in the studied municipalities with the purpose of preserving their susceptible. The insecticides applied for Ae. aegypti control can still be used in the evaluated municipalities; however it will depend on the susceptibility of the mosquitoes in the specific area.

[Determining the status of susceptibility to organophosphate, carbamate and pyrethroids insecticides in populations of Aedes aegypti Linneaus, 1762 (Diptera: Culicidae) in Panamá]. / Determinación de la sensibilidad a insecticidas organofosforados, carbamato y piretroides en poblaciones de Aedes aegypti Linneaus, 1762 (Díptera: Culicidae) de Panamá

INTRODUCTION: We studied the susceptibility to organophosphate, carbamate and pyrethroid insecticides of Aedes aegypti from different regions of high transmission risk for dengue in Panama. OBJECTIVE: To evaluate the susceptibility to organophosphate, carbamate and pyrethroid insecticides in Ae. aegypti from eight sites belonging to seven municipalities in Panamá. MATERIALS AND METHODS: We collected Ae. aegypti larval populations in different types of breeding sites located in urban areas. Insects were reared in laboratory control conditions. With the F 1 generation of each strain we performed susceptibility bioassays using WHO standardized methodology for larvae and adults. RESULTS: The eight Ae. Aegypti strains were susceptible to the pyrethroid insecticides: deltamethrin, lambdacyhalothrin and cifluthrin, to the organophosphate fenitrothrion, and to the carbamates propoxur and bendiocarb. Only the CHITRE strain exhibited a moderate resistance to the insecticide deltamethrin in larvae (FR 50 =5x). However, adults were susceptible. CONCLUSIONS: It is necessary to perform periodic surveillance to evaluate the susceptibility of Ae. aegypti populations in the studied municipalities with the purpose of preserving their susceptible. The insecticides applied for Ae. aegypti control can still be used in the evaluated municipalities; however it will depend on the susceptibility of the mosquitoes in the specific area.

Caracterización de la transmisión de la malaria por Plasmodium vivax en la región fronteriza de Panamá con Costa Rica en el municipio de Barú, Panamá / Characterization of Plasmodium vivax malaria transmission at the border of Panamá and Costa Rica

Introducción. Pocos estudios describen los factores asociados con la dinámica de transmisión de la malaria, o paludismo, por Plasmodium vivax en las regiones endémicas de Panamá. Objetivo. Caracterizar la dinámica de transmisión de la malaria producida por P. vivax en la región fronteriza de Panamá con Costa Rica. Materiales y métodos. Se llevó a cabo un estudio observacional, descriptivo y transversal. Se evaluaron la incidencia parasitaria anual, el índice de láminas positivas y el índice anual de exámenes de sangre. Se identificaron los anofelinos vectores, y se caracterizaron sus criaderos preferenciales, densidad larvaria e índice de picada/hombre/noche. Se hizo búsqueda pasiva y activa de casos sospechosos mediante examen de gota gruesa. Resultados. De 10.401 muestras de gota gruesa, 83 resultaron positivas para P. vivax. El 84 % de los casos provenía de zonas rurales, el 79 % constituía una población económicamente activa, la mediana de edad fue de 36 años y, la media, de 30 años. El 58,5 % de los casos fueron de sexo masculino. La incidencia parasitaria anual fue de 4,1 por 1.000 habitantes; el índice de láminas positivas fue de 0,8 % y el índice anual de exámenes de sangre fue de 51,9 %. El 65,0 % de los casos diagnosticados registró entre 100 y 2.000 parásitos/μl de sangre. Se identificaron los mosquitos vectores Anopheles albimanus y An. punctimacula. Conclusión. Es necesario el seguimiento de estudios entomológicos, el fortalecimiento de la vigilancia epidemiológica, la consideración de los factores de riesgo y la realización de un trabajo en coordinación con las autoridades de salud de Costa Rica, para controlar la malaria en esta región.

Introduction. Few studies have described the factors associated with Plasmodium vivax transmission dynamics in endemic regions from Panamá. Objective. Malaria transmission dynamics produced by P. vivax were characterized at the border between Panamá and Costa Rica. Materials and methods. In the municipality of Barú, an observational, descriptive and cross-sectional study was undertaken to measure the annual parasite index (API), slide positivity index (SPR), and the annual blood examination rate (ABER). The most frequent symptoms and signs in malaria patients were recorded. The anopheline species were identified in the area and the preferred larval habitats, the density of larval populations in the larval habitats and the bites/human/night were characterized. Results. Of a total of 10,401 thick smear blood samples, 83 were positive for P. vivax. Of these, 84% came from rural areas and 79% were from economically active individuals. The median and average ages were 36 and 30 years, respectively, and 58.5% of the malaria cases were male. API was 4.1/1,000 inhabitants; SPR was 0.8% and ABER was 51.9%. Of the diagnosed cases, 54% showed blood parasitemias ranging between 100-2,000 parasites/μl. The majority of the cases were observed in May and June. Two mosquito vector species were identified-- Anopheles albimanus and An. punctimacula. Conclusion. These observations indicate the advisibility of continued entomological studies, strengthening of epidemiological surveillance, consideration of additional risk factors and evaluation of work performance in the border region. This will require coordination with health authorities of both countries to control malaria in this region.