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Background and Aim: Canine vector-borne diseases represent an important issue for the welfare and health of animals, but also have great zoonotic potential. These diseases are caused by bacteria, nematodes such as filariae, and other parasites such as Leishmania spp. Given the difficulty in differentiating common microfilariae in dogs by microscopy and serological methods, molecular techniques such as polymerase chain reaction (PCR) and sequencing should be valuable for reaching a reliable diagnosis. This study aimed to use microscopy and PCR to identify the microfilarial species in dogs from Valle del Cauca, Colombia, and a possible association with Leishmania infantum parasites. Materials and Methods: This study was conducted on 270 dogs from Pradera and Florida municipalities. Microfilariae were detected in dogs by optical microscopy and amplification with 5.8S-ITS2-28S. Species identification was achieved through the amplification of the gene cytochrome oxidase I (COX1). Results: Microscopic detection of microfilariae was possible in 4.81% (13/270) of the dogs. In addition, by PCR of COX1 and Sanger sequencing of ITS2, Acanthocheilonema reconditum was identified as the circulating microfilarial species in 12 dogs, coinfecting with the species L. infantum (Leishmania donovani complex). Conclusion: To the best of our knowledge, this is the first report on A. reconditum and L. infantum mixed infection in dogs in Colombia, particularly in the Valle del Cauca. [ABSTRACT FROM AUTHOR]

The genus Lutzomyia has a variety of species, where some are vectors of the disease called leishmaniasis which has implications for public health developing different clinical manifestations that highly affect humans such as cutaneous, visceral and mucocutaneous leishmaniasis. The aim of the study was to update the registry of the Lutzomyia species that are present in six areas of the Atlántico department. Three traditional capture techniques were implemented, with CDC traps implemented from 18:00 to 6:00 o'clock, Shannon traps from 19:00 to 10:00 and active search with mouth aspirators on trunks, tree bases and other rest sites from 09:00 to 11:00 and 16:00 to 17:30, in six municipalities of the Atlántico department, Colombia. Ten phlebotomine species were captured during the present work, from which the finding of Lutzomyia longipalpis and Lutzomyia atroclavata are reported for the first time at the Atlántico department. From the ten species captured, Lutzomyia longipalpis has antecedents as a vector of Leishmania infantum in Colombia and other regions of Latin America. The most abundant species with the greatest spatial distribution was Lu. evansi, which is the main vector of visceral leishmaniasis in the Caribbean region. In conclusion, the richness of phlebotomineal fauna of the department of Atlántico is updated to twelve species, with the first record of Lu. longipalpis and Lu. atroclavata. Phlebotomy fauna is also reported for the first time in localities of the department of Atlántico such as Campeche, Puerto Colombia, Luruaco, Ponedera and Campo de la Cruz. [ABSTRACT FROM AUTHOR]

Introduction: this study aims to investigate the eco-epidemiological factors associated with Leishmania spp. infection in dogs from the Metropolitan Area of Bucaramanga (MAB)‚ Santander‚ eastern Colombia‚ which is a region at risk of VL. Methods: we conducted molecular and serological surveillance of Leishmania spp. in 207 dogs from MAB to determine the epidemiological factors associated with infection. Subsequently‚ we carried out a molecular and serological analysis of phlebotomine and humans in the area to describe the main features associated with the transmission cycle. Results: out of the 207 dogs tested‚ 37 (17.8 %‚ 95 % CI=12.6 - 23.1 %) were positive for Leishmania spp. by the IFAT test‚ and only 9 (4.3 %‚ 95 % CI=1.55 - 7.15 %) were positive for L. infantum in the molecular analysis. Multivariate analyses indicated that canine shelters had a higher prevalence of infection (p < 0.05). In the entomological survey‚ 69 blood-fed female phlebotomine of the genus Lutzomyia were captured in canine shelters‚ among them‚ 55 % were identified as Lutzomyia camposi‚ 29 % as Lu. ovallesi‚ 7 % as Lu. dubitans‚ 6 % as Lu. torvida‚ and 3 % as Lu. cayennensis. The identified meal sources of the phlebotomine included human‚ pig‚ avian‚ cattle‚ and porcupine (Coendou quichua) blood. However‚ no phlebotomine positive for Leishmania spp. were detected by molecular analyses. Finally‚ 14 humans who had frequent contact with L. infantum-positive dogs were analyzed through rK39 test‚ but none was positive for IgG/IgM antibodies. Conclusion: the molecular and serological analyses indicate a low prevalence of L. infantum in dogs from MAB‚ with canine shelters having the highest prevalence of infection. The entomological survey of canine shelters showed a significant diversity of phlebotomine without potential vectors of L. infantum‚ suggesting that the infection in dogs from these areas could take place in other locations or through other transmission routes. The circulation of L. infantum in multiple dogs from MAB suggests a latent risk of zoonotic transmission of VL in these cities. [ABSTRACT FROM AUTHOR]

Visceral leishmaniasis (VL) is a disease caused by species of the Leishmania donovani complex that is mainly transmitted through the urban cycle involving dogs as the primary reservoir. In Colombia, the incidence of VL is increasing, along with the spread of potential vectors. This study aims to investigate the eco-epidemiological factors associated with Leishmania spp. infection in dogs from the Metropolitan Area of Bucaramanga (MAB), Santander, eastern Colombia, which is a region at risk for VL. We conducted molecular and serological surveillance of Leishmania spp. in 207 dogs from MAB to determine the epidemiological factors associated with infection. Subsequently, we carried out a molecular and serological analysis of phlebotomine and humans, respectively, in areas with a higher prevalence of infection, aiming to describe the main features associated with the transmission cycle. Out of the 207 dogs tested, 37 (17.8%, 95% CI = 12.6–23.1%) were positive for the presence of Leishmania antibodies by the IFAT test, and only 9 (4.3%, 95% CI = 1.55–7.15%) were positive for L. infantum by PCR. Multivariate analyses indicated that canine shelters and dogs with clinical signs commonly associated with canine VL had a higher prevalence of infection (P < 0.05). In the entomological survey, 69 blood-fed female phlebotomine of the genus Lutzomyia were captured in canine shelters, among them, 55% were identified as Lutzomyia camposi , 29% as Lu. ovallesi , 7% as Lu. dubitans , 6% as Lu. torvida , and 3% as Lu. cayennensis. The identified meal sources of the phlebotomine included human, pig, avian, cattle, and porcupine (Coendou quichua) blood. However, no phlebotomine positive for Leishmania spp. were detected by molecular analyses. Finally, 14 humans who had frequent contact with L. infantum -positive dogs were analyzed through rK39 test, but none tested was positive for IgG/IgM antibodies. The molecular and serological analyses indicate the circulation of L. infantum in dogs from MAB, with canine shelters having the highest prevalence of infection. The entomological survey of canine shelters showed a significant diversity of phlebotomine without potential vectors of L. infantum , suggesting the presence of infection in dogs from these areas could take place in other locations or through other transmission routes. The circulation of L. infantum in multiple dogs from MAB suggests a latent risk of zoonotic transmission of VL in these cities. [Display omitted] • The epidemiological surveillance indicate a low prevalence of L. infantum in dogs from MAB, with canine shelters having the highest prevalence of infection. • The entomological survey of canine shelters showed a significant diversity of phlebotomine without potential vectors of L. infantum. • The circulation of L. infantum in multiple dogs from MAB suggests a latent risk of zoonotic transmission of VL. [ABSTRACT FROM AUTHOR]

Background: A comprehensive understanding of the biology of insects requires that they must be studied in an ecological context where microorganisms are considered an important component. Studies with phlebotomines from America have demonstrated the importance and potential role of intestinal microbiota in susceptibility and competence in developing Leishmania infection. Methods: The relative frequency and phylogeny of Wolbachia, Microsporidia, Arsenophonus, and Cardinium were determined in phlebotomine from Colombia. After, Illumina Miseq using the 16S rRNA gene was used. We studied the effect of the gut microbiota in female phlebotomines infected with Leishmania infantum. Finally, a metatranscriptomic analysis was performed to identify viral sequences in these vectors. Results: We provide information of natural infection of secondary endosymbionts in these sand flies. High percentages of relative abundance for Wolbachia (30%-83%) in Lu. gomezi, Ev. dubitans, Mi. micropyga and Br. hamata, were found. In bloodfed females of Lu. longipalpis and the group exposed to L. infantum (uninfected), Pseudomonas has a high relative abundance (75-85%), in contrast to guts positives to the infection for L. infantum (30-55). The virome shown two sequences related to the families of Mononegavirales and Hepelivirales, and the RNA-seq technique allowed the detection of natural infection by Leishmania (kDNA). Finally, the results also show an abundance of 57.36% in Pseudomonas at 25-27°C, 6.55% at 29-31°C and 13.20% at 31-33°C, while at the same ranges Bacillus presents an abundance of 1.21%, 61.54% and 37.64% respectively. Conclusion: Intestinal microbiota is determining in the establishment of Leishmania and endosymbionts such as Wolbachia can impair the composition of the microbiota. It contributes to the knowledge of viral sequences and the detection of natural infection by Leishmania. [ABSTRACT FROM AUTHOR]

Introducción. La enfermedad de Chagas y la leishmaniasis tradicionalmente se han considerado zoonosis endémicas de áreas rurales del país. Sin embargo, la aparición de casos de estas enfermedades en áreas urbanas sugiere nuevos ciclos de circulación de estos parásitos. Por esta razón, se ha propuesto a los perros como centinelas de estos agentes zoonóticos, dado su rol como huéspedes accidentales o reservorios. Objetivo. Evaluar la circulación silenciosa de Leishmania spp. y Trypanosoma cruzi en perros de zonas urbanas de la ciudad de Sincelejo, Sucre. Materiales y métodos. Se analizaron 100 muestras de sangre de perros para amplificar la región ITS1 de Leishmania spp. Las muestras positivas se utilizaron para amplificar la región conservada del minicírculo del ADN del cinetoplasto de Leishmania infantum y para el análisis de polimorfismos de longitud de fragmentos de restricción con la endonucleasa HaeIII. Por otra parte, se amplificó un fragmento del ADN satelital de T. cruzi. Además, se evaluó la presencia de infecciones por Ehrlichia canis y Anaplasma platys, como potencialmente modificadoras de las manifestaciones clínicas. Resultados. De los 100 perros estudiados, se detectó: Leishmania spp. en 32, T. cruzi en 12, ambos parásitos en 7 y L. infantum en 18. Se encontraron infecciones por anaplasmatáceos en 18, y coinfecciones por bacterias y parásitos en 8 de los perros. En general, 47 de los animales estaban infectados por, al menos, un agente etiológico. Conclusión. Se demuestra la circulación de L. infantum y T. cruzi en zonas urbanas de Sincelejo, así como coinfecciones de estos parásitos junto con parásitos de la familia Anaplasmataceae. El presente estudio demuestra la conveniencia del uso de perros en la vigilancia epidemiológica de estos agentes zoonóticos.

Highlights: [•] Lutzomyia evansi has climatic restrictions to its geographic distribution. [•] Lutzomyia evansi is predicted to mantain the same altitudinal distribution in the, future. [•] Lutzomyia longipalpis is expected to shift towards higher lands. [•] Both species will reduce their distribution under climate change. [ABSTRACT FROM AUTHOR]

Insecticides are an important tool for controlling insect vectors of microorganism pathogens. The aim of this study was to determine the diagnostic dosages of deltamethrin and lambdacyhalothrin for the sand fly Lutzomyia evansi (Núñez-Tovar), a vector of Leishmania infantum in Colombia. Sand flies were collected in the Estación Experimental de Fauna Silvestre of Colosó, Sucre, a natural reserve that had not been previously treated with insecticides. Glass bottles were used for bioassays, following the simplified method (CDC) for detecting insecticide resistance. Wild females of L. evansi were exposed to different concentrations of insecticides during a test period of 80 minutes. The diagnostic dosages of deltamethrin and lambdacyhalothrin were established in 0,0007%, and 0,00035%, respectively, and the resistance threshold was calculated to be ten minutes for both insecticides, exposure period during which the mortality reached 100%. The time-mortality data suggest that lambdacyhalothrin have a lethal effect on L. evansi at a lower concentration than deltamethrin. The last insecticide was less toxic than lambdacyhalothrin. [ABSTRACT FROM AUTHOR]

Abstract: Leishmania infantum and Trypanosoma cruzi are zoonotic parasites that are endemic throughout many parts of Latin America. Infected dogs play an important role in transmission of both parasites to humans. A serological survey of Leishmania and Trypanosoma infection was conducted on 365 dogs from São Paulo, Brazil and Bogatá, Colombia, South America. Serum samples were examined by the indirect immunofluorescent antibody test (IFAT). Anti-Leishmania IgG antibodies were detected in 5 of 107 from Brazil (4.7%) and in 4 of 258 dogs (1.6%) from Colombia. Titers ranged from 1:25 to 1:100. Anti-T. cruzi antibodies were not detected in any of the dogs from either Brazil or Colombia. The results show a low prevalence of anti-Leishmania antibodies and no antibodies against T. cruzi in these canine populations. Our study suggests that dogs play a limited role in the spread of L. infantum and T. cruzi in these urban areas of Brazil and Colombia. [Copyright &y& Elsevier]

Pintomyia evansi is recognized by its vectorial competence in the transmission of parasites that cause fatal visceral leishmaniasis in rural and urban environments of the Caribbean coast of Colombia. The effect on and the variation of the gut microbiota in female P. evansi infected with Leishmania infantum were evaluated under experimental conditions using 16S rRNA Illumina MiSeq sequencing. In the coinfection assay with L. infantum, 96.8% of the midgut microbial population was composed mainly of Proteobacteria (71.0%), followed by Cyanobacteria (20.4%), Actinobacteria (2.7%), and Firmicutes (2.7%). In insect controls (uninfected with L. infantum) that were treated or not with antibiotics, Ralstonia was reported to have high relative abundance (55.1–64.8%), in contrast to guts with a high load of infection from L. infantum (23.4–35.9%). ASVs that moderately increased in guts infected with Leishmania were Bacillus and Aeromonas. Kruskal–Wallis nonparametric variance statistical inference showed statistically significant intergroup differences in the guts of P. evansi infected and uninfected with L. infantum (p < 0.05), suggesting that some individuals of the microbiota could induce or restrict Leishmania infection. This assay also showed a negative effect of the antibiotic treatment and L. infantum infection on the gut microbiota diversity. Endosymbionts, such as Microsporidia infections (<2%), were more often associated with guts without Leishmania infection, whereas Arsenophonus was only found in guts with a high load of Leishmania infection and treated with antibiotics. Finally, this is the first report that showed the potential role of intestinal microbiota in natural populations of P. evansi in susceptibility to L. infantum infection. [ABSTRACT FROM AUTHOR]

Introduction: Since entomological surveillance is the main control strategy for visceral leishmaniasis, updated information on the distribution and ecology of involved vector species is necessary for planning preventive measures., Objective: To present the updated and geo-referenced distribution of L. longipalpis and L. evansi, vectors of visceral leishmaniasis in Colombia, considering their relationship with their habitat., Materials and Methods: Distribution was estimated from records of the sand fly specimens collected since 1967. The information was organized in a database from which the localities were selected and geographically analyzed with Arc view in order to develop the distribution maps., Results: 40 localities were established for L. longipalpis along the upper (24), middle (11) and lower (5) Magdalena river valley. L. evansi was recorded in 19 localities of the middle (5) and lower (14) Magdalena valley., Conclusions: Both species showed consistent association with dry tropical forest (sensu Holdridge 1967), confirming the epidemiological risk for visceral leishmaniasis in these areas.

Lutzomyia evansi is the vector of Leishmania chagasi in northern Colombia. Differences in feeding success were revealed, when this phlebotomine sand fly was fed on five species of small mammal hosts from an endemic focus of visceral leishmaniasis. In each trial, 50 female sand flies were provided access to similar-sized depilated areas of the hind foot of each of 44 individual mammals and allowed to feed for 30 minutes. The number of engorged sand flies was counted at the end of each trial and compared among host species by analysis of variance and Tukey's multiple comparisons test. Sand flies fed least successfully on Sciurus granatensis, a common squirrel in the endemic area. It has not been found infected with L. chagasi. Intermediate numbers of sand flies engorged on Heteromys anomalus and Zygodontomys brevicauda, but these two mammals have not been found infected with L. chagasi and are not expected to be important in transmission. Sand flies fed most successfully on Didelphis marsupialis and Proechimys canicollis. These are the two most abundant mammals in the endemic area and frequently are infected. Results provided further evidence that these two species are the wild mammals with the greatest impact on transmission of L. chagasi in northern Colombia.

The feeding behavior, seasonality, and natural infection rate of Lutzomyia evansi (Nuñez-Tovar) with Leishmania chagasi (Cuna & Chagas) was studied during a 12-mo period at 2 hamlets, El Contento and Vidales. Sand fly abundance in extra-, peri-, and intradomestic habitats was evaluated with sticky traps and CDC light traps, whereas human bait and Shannon trap collections were made only in peridomestic habitats. All trapping methods showed a clear predominance of L. evansi throughout the year. Sand flies were present during most of the year, with the exception of the driest months (February and March). Although the total number of sand flies was higher in El Contento than in Vidales, a larger proportion of L. evansi was found in intradomestic habitat than in the peri- and extradomestic habitats at Vidales. Also, sand flies from Vidales had a higher infection rate with L. chagasi than did those from El Contento. Although 2 of 9 promastigote infections detected in L. evansi were identified as L. chagasi, the difficulty of isolating and propagating leishmania strains from this visceral leishmaniasis focus precluded characterization of most parasite samples. Parous and infected sand flies were most abundant toward the end of the rainy season (October-December). For this reason, control strategies based on reducing sand fly populations or avoiding human-vector contact should be concentrated during the October-December period.