Eco-epidemiological Insights into Psammolestes arthuri

Chagas disease, caused by Trypanosoma cruzi, affects millions of people and is primarily transmitted by triatomine bugs. Psammolestes arthuri, although not traditionally considered an epidemiologically significant vector due to its primary ornithophilic feeding habits, has been found naturally infected with T. cruzi. This study aimed to assess the infection rate, parasite load, and feeding patterns of Ps. arthuri in two municipalities of Casanare, eastern Colombia. A total of sixty-one (61) Ps. arthuri specimens were collected from San Luis de Palenque (n=43) and Tauramena (n=18) between April and October 2023. To assess T. cruzi infection, qPCR was performed, and feeding preferences were identified through 12S rRNA gene sequencing. The results revealed a 68.8% infection rate with T. cruzi and a mean parasite load of 70.40 parasites/mL. No significant differences in parasite load were found across developmental stages, although adult males exhibited higher loads. Regarding feeding preferences, Anhinga rufa was the predominant source (64.9%), followed by Phalacrocorax brasilianus (6.8%), Homo sapiens, and other species. This study showed that P. arthuri is infected with T. cruzi in Casanare. Despite its primary ornitophilic diet, human blood in nymphs indicates an adaptation to feeding on humans, especially in proximity to human dwellings. These findings underline the importance of considering birds in Chagas disease surveillance and raise the possibility of synanthropic transmission cycles.