Ecological interactions of sand flies, hosts, and Leishmania panamensis in an endemic area of cutaneous leishmaniasis in Colombia.

BACKGROUND: The transmission dynamics of leishmaniasis are complex. There is also a lack of information about the ecological relationships between the vector/host/parasite at a more local and specific level. The Andean region concentrates more than 50% of Colombia's cutaneous leishmaniasis (CL) cases. The study of the ecological interactions of sand flies through the identification of blood sources has provided information on the female's opportunistic behavior, feeding on various hosts. Therefore, this study aimed to determine sand flies' ecological interactions with Leishmania parasites and their blood sources in an endemic area of CL. RESULTS: A total of 4,621 sand flies were collected, comprising 20 species, in which the most abundant were Nyssomyia yuilli yuilli (55.4%), Psychodopygus ayrozai (14.5%) and Ps. panamensis (13.4%). Sequences of 12S gene fragment were analyzed using the BLASTn search tool. Blood-meal source identification was successfully performed for 47 sand flies, detecting seven vertebrate species, human and armadillo being the most frequent. Leishmania DNA was amplified in four female pools, constituted by Ny. yuilli yuilli and Ps. ayrozai, and the identification through RFLP detected Leishmania (Viannia) panamensis in the positive pools. CONCLUSIONS: The interactions between the sand fly species, local mammalian fauna and the Leishmania parasite in this active focus of CL, provide evidence of the potential role of two different species in the maintenance of the parasite transmission, important information for the understanding of the ecoepidemiology and transmission dynamics of the disease in Andean endemic areas. However its necessary further evaluations of the vector and host competence in the transmission and maintenance of Leishmania spp, in these complex and diverse areas.

Diversity and temporal distribution of sand flies in an endemic area of cutaneous leishmaniasis in Centre-West Colombia.

The community structure of sand flies indicates the level of adaptation of vector species in a region, and in the context of vector management and control, this information allows for identifying the potential risks of pathogen transmission. This study aimed to analyze sand fly diversity and spatial-temporal distribution in an endemic area of cutaneous leishmaniasis. The study was carried out in the Carrizales hamlet (Caldas), between September 2019 and October 2021. The monthly distribution of sand fly species was evaluated through collections with CDC traps. Shannon and evenness indices were calculated and used to compare species frequencies at each house. The association between climatic variables and the frequency of sand flies was evaluated using Spearman's correlation. A total of 6,265 females and 1,958 males belonging to 23 species were found. Low diversity and evenness were observed, with the dominance of Nyssomyia yuilli yuilli (Young & Porter). Ecological and diversity indices did not reveal differences between the houses. The sand fly community was composed of 3 dominant species, Ny. yuilli yuilli, Psychodopygus ayrozai (Barretto & Coutinho), and Ps. panamensis (Shannon), representing 75.8% of the total catches. No statistical association was found between the absolute frequency of sand flies, rainfall, and temperature. The results show one dominant species, this fact has epidemiological relevance since density influences parasite-vector contact. The high densities of sand flies recorded in peri- and intradomiciliary areas highlight the necessity of periodic monitoring of vector populations and control activities to reduce the risk of Leishmania transmission in this endemic area.

Updated geographical distribution and natural infection of Panstrongylus geniculatus (Latreille, 1811) in Antioquia department, Colombia.

The increase in outbreaks of Chagas disease in Colombia has required the strengthening of entomological surveillance with the active participation of the affected communities and the monitoring of the natural infection of the collected kissing bugs recollected inside households. The natural infection with Trypanosoma cruzi of triatomines collected by inhabitants of some municipalities of the department of Antioquia in 2019 was evaluated by molecular methods. This study described the intradomiciliary presence of Panstrongylus geniculatus (Latreille, 1811) in four cities of Antioquia: Barbosa, Liborina, Ituango, and Puerto Triunfo. This vector is reported for the first time in the municipalities Liborina, Barbosa, and Ituango. Furthermore, the natural infection with T. cruzi , DTUI, was reported in Barbosa and Liborina. The epidemiological implications of these findings are analyzed within the context of recent reports of outbreaks of Chagas disease in Antioquia.

Trypanosoma cruzi infection in domestic and synanthropic mammals such as potential risk of sylvatic transmission in a rural area from north of Antioquia, Colombia.

In Colombia, dogs and opossum are the most important mammals in domestic and sylvatic T. cruzi transmission. However, the role of both species has not been evaluated in areas where both species converge in the peridomestic area. To evaluate the infection status of domestic and wild mammals in peridomestic habitats of Puerto Valdivia, Antioquia Department. The infection of domestic dogs and small wild mammals was performed by hemoculture, molecular and serological methods. Additionally, the infection in children under 15 years old and triatomine searches was carried out. We found that 16.07% and 34% dogs, and 59.1% and 61.1% Didelphis marsupialis were found positive by molecular and serological methods respectively. Moreover, in 25% and 75% of the infected dogs were detected TcIDom and TcI sylvatic, respectively, while all the D. marsupialis were infected with TcI. Six Rattus rattus and three Proechimys semispinosus were captured but without T. cruzi infection. Finally, none of the 82 children were positive and no triatomine bugs were captured. D. marsupialis and domestics dogs have an important role in the transmission of T. cruzi suggesting a potential risk in T. cruzi transitions areas.

Presence of Aedes (Stegomyia) aegypti (Linnaeus, 1762) and its natural infection with dengue virus at unrecorded heights in Colombia.

INTRODUCTION: Aedes aegypti is the main vector of urban yellow fever, dengue, chikungunya and Zika viruses. The biogeographical distribution of this species has expanded due to global warming, and socioeconomic and cultural factors. The changes in the altitudinal distribution patterns of this vector and its natural infection are priority fields of research to develop entomological, virological and public health surveillance strategies.  OBJECTIVE: To evaluate the presence of A. aegypti and its natural infection with dengue virus in altitudes above 1.800 meters above sea level in two peripheral municipalities of the Valle de Aburrá, Antioquia, Colombia.  MATERIALS AND METHODS: Twenty-one ovitraps were set in the municipalities of Bello and San Pedro de los Milagros, at altitudes ranging from 1.882 to 2.659 masl. Emerged adults caught in the ovitraps were tested by RT-PCR for dengue virus detection.  RESULTS: We collected 367 A. aegypti adults, seven of which were found as high as 2.302 masl in Tierradentro, Bello. We detected serotype 2 dengue infection in 12 A. aegypti specimens collected in the neighbourhood of París, in Bello, at 1.984 masl.  CONCLUSION: We recorded A. aegypti at 2.302 masl, so far the highest altitudinal record in Colombia for this vector. Furthermore, mosquitoes collected at 1.984 masl were positive for dengue virus. These findings are significant as they identify regions in Colombia at risk of potential autochthonous transmission of dengue and other arboviruses by A. aegypti.

Presencia de Aedes ( Stegomyia ) aegypti (Linnaeus, 1762) y su infección natural con el virus del dengue en alturas no registradas para Colombia / Presence of Aedes ( Stegomyia ) aegypti (Linnaeus, 1762) and its natural infection with dengue virus at unrecorded heights in Colombia

Introducción. Aedes aegypti es el principal vector de fiebre amarilla urbana, dengue, chikungunya y zika. Se ha demostrado que la distribución biogeográfica de esta especie se ha expandido debido al calentamiento global y a factores socioeconómicos y culturales. Los cambios en los patrones de la distribución altitudinal de este vector y su infección con el virus son prioridades de la investigación encaminada a desarrollar estrategias de vigilancia entomológica y virológica en salud pública. Objetivo. Evaluar la presencia de A. aegypti y su infección natural por el virus del dengue en alturas superiores a los 1.800 msnm en dos municipios periféricos del Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. Se instalaron 21 ovitrampas en los municipios de Bello y San Pedro de los Milagros, en un rango altitudinal de 1.882 a 2.659 msnm. Los adultos que emergieron de las ovitrampas se evaluaron con reacción en cadena de la polimerasa en tiempo real (RT-PCR) para la detección del virus del dengue. Resultados. Se recolectaron 367 adultos de A. aegypti , siete de los cuales se encontraron a una altitud de 2.302 msnm en Tierradentro, Bello. Se detectaron 12 especímenes de A. aegypti positivos para dengue serotipo 2 en el barrio París de Bello, a 1.984 msnm. Conclusión. Por primera vez se registró A. aegypti a 2.302 msnm, la mayor altitud registrada para este vector en Colombia. De igual forma, se encontró infección con el virus del dengue a 1.984 msnm. Estos hallazgos son significativos, ya que determinan regiones de Colombia con riesgo potencial de transmisión autóctona de dengue y otros arbovirus por A. aegypti .

Introduction: Aedes aegypti is the main vector of urban yellow fever, dengue, chikungunya and Zika viruses. The biogeographical distribution of this species has expanded due to global warming, and socioeconomic and cultural factors. The changes in the altitudinal distribution patterns of this vector and its natural infection are priority fields of research to develop entomological, virological and public health surveillance strategies. Objective: To evaluate the presence of A. aegypti and its natural infection with dengue virus in altitudes above 1.800 meters above sea level in two peripheral municipalities of the Valle de Aburrá, Antioquia, Colombia. Materials and methods: Twenty-one ovitraps were set in the municipalities of Bello and San Pedro de los Milagros, at altitudes ranging from 1.882 to 2.659 masl. Emerged adults caught in the ovitraps were tested by RT-PCR for dengue virus detection. Results: We collected 367 A. aegypti adults, seven of which were found as high as 2.302 masl in Tierradentro, Bello. We detected serotype 2 dengue infection in 12 A. aegypti specimens collected in the neighbourhood of París, in Bello, at 1.984 masl. Conclusion: We recorded A. aegypti at 2.302 masl, so far the highest altitudinal record in Colombia for this vector. Furthermore, mosquitoes collected at 1.984 masl were positive for dengue virus. These findings are significant as they identify regions in Colombia at risk of potential autochthonous transmission of dengue and other arboviruses by A. aegypti .

Ampliación de la distribución de Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) en el departamento de Caldas: potencial aumento del riesgo de leishmaniasis visceral / Expansion of the distribution of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) in the department of Caldas: Increased risk of visceral leishmaniasis

Introducción. Diversos estudios a nivel taxonómico y molecular sugieren que Lutzomyia longipalpis, principal vector de la leishmaniasis visceral en Latinoamérica, es un complejo de especies con amplia distribución a lo largo del continente y con adaptaciones a diferentes hábitats. Objetivo. Realizar vigilancia entomológica en el área de influencia de la hidroeléctrica Miel I. Materiales y métodos. Se utilizaron trampas adhesivas en una intersección de 400 km, aproximadamente, para la captura de insectos, los cuales fueron identificados con la clave taxonómica de Young y Duncan. Resultados. En este estudio se reporta la presencia de Lu. longipalpis en los municipios de Norcasia a una altitud de 392 msnm y en Marquetalia a 1.387 msnm; es el primer reporte a esta altura para esta especie en Colombia. Conclusiones. Se sugiere que la ampliación de la distribución geográfica y altitudinal de Lu. longipalpisen el país podría estar relacionada con la existencia del complejo de especies Lu. longipalpis, o a factores ambientales como el aumento de temperatura debido al cambio climático global que viene sucediendo en las últimas décadas. Esta última hipótesis sugeriría que se están creando nuevos hábitats propicios para el establecimiento de Lu. longipalpis, lo cual genera un nuevo riesgo epidemiológico de posibles nuevos focos de leishmaniasis visceral en el país.

Introduction: Diverse taxonomical and molecular studies suggest that Lutzomyia longipalpis, main vector of visceral leishmaniasis in Latin America, is a complex of species widely distributed throughout the continent and adapted to different habitats. Objective: To carry out entomological surveillance in the area of influence of the Miel I Hydroelectric Plant. Materials and methods: Adhesive traps were used in a transect covering an area of approximately 400 km for the capture of insects, which were then identified using the Young and Duncan taxonomical key. Results: This study reports the presence of Lutzomyia longipalpis in the municipalities of Norcasia at an altitude of 392 masl, and in Marquetalia at 1,387 masl. Conclusions: We suggest that the increase in the geographical and altitudinal distribution could be related to the existence of the Lu. longipalpis species complex, or to environmental factors, such as the rise in temperature due to global climate changes, which create the establishment of Lu. longipalpis, generating a new epidemiological risk for new visceral leishmaniasis foci in the country.

[Expansion of the distribution of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) in the department of Caldas: Increased risk of visceral leishmaniasis]. / Ampliación de la distribución de Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) en el departamento de Caldas: potencial aumento del riesgo de leishmaniasis visceral.

INTRODUCTION: Diverse taxonomical and molecular studies suggest that Lutzomyia longipalpis , main vector of visceral leishmaniasis in Latin America, is a complex of species widely distributed throughout the continent and adapted to different habitats. OBJECTIVE: To carry out entomological surveillance in the area of influence of the Miel I Hydroelectric Plant. MATERIALS AND METHODS: Adhesive traps were used in a transect covering an area of approximately 400 km for the capture of insects, which were then identified using the Young and Duncan taxonomical key. RESULTS: This study reports the presence of Lutzomyia longipalpis in the municipalities of Norcasia at an altitude of 392 masl, and in Marquetalia at 1,387 masl. CONCLUSIONS: We suggest that the increase in the geographical and altitudinal distribution could be related to the existence of the Lu. longipalpis species complex, or to environmental factors, such as the rise in temperature due to global climate changes, which create the establishment of Lu. longipalpis , generating a new epidemiological risk for new visceral leishmaniasis foci in the country.