# Molecular diagnosis of trypanosomatids in Didelphis marsupialis reveals risk areas for Trypanosoma cruzi transmission and sympatric circulation with T. rangeli in the metropolitan area of Bucaramanga, Santander, Colombia

## TL;DR

Wild opossums in Colombia's Bucaramanga area show T. cruzi and T. rangeli infections, highlighting risks for Chagas disease transmission.

## Contribution

Identifies sympatric circulation of T. cruzi and T. rangeli in opossums and confirms an enzootic transmission cycle in urban areas.

## Key findings

- 14.3% of opossums tested positive for trypanosomatids, including T. cruzi DTU TcI and T. rangeli.
- T. cruzi infections were concentrated in peripheral neighborhoods adjacent to forested areas.
- Co-infection with T. cruzi and T. rangeli was observed in one opossum.

## Abstract

The adaptation of wild animals to urban environments can lead to increased contact with humans and a higher risk of exposure to zoonotic agents. Didelphis marsupialis (common opossum) is an important reservoir of Trypanosoma cruzi and Leishmania spp., which commonly affect human populations in Latin America. Therefore, this study aimed to assess the frequency of trypanosomatid infections and characterize T. cruzi DTUs in common opossums from the Metropolitan Area of Bucaramanga (MAB), Santander, Colombia. A total of 70 individuals from four municipalities (Bucaramanga, Floridablanca, Girón, and Piedecuesta) were analyzed by PCR using blood samples, of which 14.3 % (95 % CI: 7.95–24.3 %) tested positive for trypanosomatids. Next-generation sequencing of 18S and Hsp70 genes in positive samples identified T. cruzi DTU TcI and T. rangeli in nine (12.9 %, 95 % CI: 6.91–22.66 %) and two (2.86 %, 95 % CI: 0.79–9.83 %) samples, respectively, including one case of co-infection (1.43 %, 95 % CI: 0.04–7.7 %). A heatmap revealed a high concentration of T. cruzi-positive cases in peripheral neighborhoods of Bucaramanga adjacent to forested areas. This study confirms the presence of an enzootic transmission cycle of T. cruzi in the MAB, highlighting the role of D. marsupialis as an important reservoir, particularly in peripheral neighborhoods of Bucaramanga. The sympatric circulation of T. cruzi and T. rangeli in opossums from the MAB introduces new epidemiological challenges for Chagas disease control in these areas, emphasizing the need for improved diagnostic strategies to differentiate both parasites in patients and epidemiological studies including vectors and reservoirs.

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•Molecular analyses in opossums from MAB reveal a lower T. cruzi infection rate.•The study confirms an enzootic T. cruzi cycle in MAB, especially in peripheral neighborhoods.•Analyses reveal the sympatric circulation of T. cruzi and T. rangeli in opossums from MAB.

Molecular analyses in opossums from MAB reveal a lower T. cruzi infection rate.

The study confirms an enzootic T. cruzi cycle in MAB, especially in peripheral neighborhoods.

Analyses reveal the sympatric circulation of T. cruzi and T. rangeli in opossums from MAB.