This study reports a broadening of the altitudinal range and a new host for Plasmodium (Haemamoeba) lutzi in Colombia. The study was conducted in the city of Bogotá, located in the Eastern Cordillera of Colombia at 2,560 m asl (meters above sea level) with an average annual temperature of 15 C. In total, 156 specimens of birds belonging to 25 species and 14 families were captured using mist nets. The blood samples were collected through venipuncture and analyzed by light microscopy. Plasmodium (H.) lutzi was only found in 2 individuals of Turdus fuscater (Great Thrush). This parasite has previously been reported in Aramides cajaneus (before: Aramides cajanea) (Grey-Necked Wood Rail), a bird found in the lowlands of Brazil, Venezuela, and Colombia. This finding provides evidence for a broad host range for P. lutzi that include 2 different orders, Gruiformes and Passeriformes, and also altitudinal expansion of its distribution. The blood stages were compared with the parasite's original descriptions, and the sequence of the parasite's mitochondrial genome (mtDNA) confirms that P. lutzi is a sister taxa of Plasmodium relictum, as previously proposed.

Despite intensive research during the last few decades, understanding of ecological and physiological factors related to haemosporidian infections in birds is still fragmentary. Since more model organisms are needed in order to understand these infections in the wild, we analysed avian haemosporidian infections in the rufous-collared sparrow (Zonotrichia capensis, Emberizidae) in a dry forest of the Ecuadorian Andes. Parasite diversity was screened using molecular and morphological approaches. By molecular diagnosis, we identified three linages that were phylogenetically placed in the context of molecular haemosporidian diversity and associated with a morphospecies. By microscopy, we identified five described morphospecies and one additional undescribed morphospecies. We found that avian haemosporidian prevalence on the study site was 76.3%. Additionally, we used a series of generalized linear models to explore the potential relationship of parasite prevalence and parasitaemia with a set of variables related to physiological and environmental conditions. Although our results revealed associations of haemosporidian infections with precipitation, age and sampling site, the models only explained a small fraction of the variation.

Background: Viruses such as the dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) pose major threats to human health, causing endemic, emerging, and reemerging diseases. These arboviruses have complex life cycles involving Aedes mosquitoes, driven by environmental, ecological, socioeconomic, and cultural factors. In Colombia, Aedes aegypti is the primary vector, but Aedes albopictus is expanding across the country. Understanding the unique characteristics of each species is crucial for managing arbovirus spread, particularly in areas where they coexist. Methodology/Principal findings: We conducted an entomological survey of Ae. aegypti and Ae. albopictus (larvae, pupae, and adults) in urban and rural areas of four municipalities across different elevations (200–2200 meters above sea level (masl)) in Colombia. Household conditions and knowledge of DENV were assessed through interviews. Female Ae. albopictus were tested individually for arbovirus RNA, while Ae. aegypti were tested in pools (as the accepted primary arbovirus vector in the country). Both species were found up to 2100 masl. Ae. aegypti comprised 78% of the immature forms collected, while Ae. albopictus made up 22%. Larvae from both species coexisted in common artificial breeding sites in urban and rural areas, with no evidence of competition. Ae. albopictus preferred rural areas, lower elevations (270 mm), and lowest household conditions, while Ae. aegypti was more abundant in urban areas, intradomicile environments, and areas with moderate precipitation (100–400 mm). Potential female-human contact was higher for Ae. aegypti (0.02–0.22 females per person), particularly in urban areas, while Ae. albopictus exhibited lower female per person: 0.001–0.08, with the highest values in rural Patía. Natural infections of DENV (12.4%) and CHIKV (12.4%) were found in Ae. aegypti, while Ae. albopictus showed CHIKV (41.2%) and DENV (23%) infections, with virus dissemination to the legs and salivary glands. Conclusions/significance: Integrating household conditions and community knowledge with environmental data can enhance predictive models for the eco-epidemiological characterization of Aedes-borne viruses, especially in areas where two vector species with distinct ecological characteristics coexist. Our findings highlight the need to consider Ae. albopictus as a potentially significant arbovirus vector in Colombia, especially given the presence of arboviruses in its salivary glands, its use of artificial breeding sites, its biting risk inside homes, and its differing ecological preferences and seasonal associations compared to Ae. aegypti.