Eco-Epidemiology of Chagas Disease in an Endemic Area of Colombia: Risk Factor Estimation, Trypanosoma cruzi Characterization and Identification of Blood-Meal Sources in Bugs

Abstract

Abstract. The Sierra Nevada de Santa Marta (SNSM) is a mountainous area in Colombia that is highly endemic to Chagas disease. We explored some eco-epidemiological attributes involved in the Chagas disease transmission scenario in three Indigenous communities. An epidemiological survey was done, where parasite infection in reservoirs and insects, Trypanosoma cruzi genotyping, identification of blood-meal sources in intradomiciliary insects using the high-resolution melting technique, and some risk factors were evaluated. The results suggest that several dwelling conditions such as thatched palm roofs and mud walls carried the highest risk of finding intradomiciliary Rhodnius prolixus, which 56.41% were infected with T. cruzi and fed with human blood. Moreover, T. cruzi Ia was the most frequent haplotype found in insects. These results indicate the existence of a domestic T. cruzi transmission cycle that does not overlap with the sylvatic cycle, and highlight the need for efficient entomological control focused to this area.

Identification of blood-feeding sources in Panstrongylus, Psammolestes, Rhodnius and Triatoma using amplicon-based next-generation sequencing

“…2 ), and around 80% of the samples evaluated were infected with T. cruzi , which is a similar result to that reported in previous studies on Triatoma and Rhodnius [ 42 – 45 ]. Human blood was the main feeding source of R. prolixus and P. geniculatus (Additional file 3 : Figure S1), as has been previously reported for these and other triatomine species [ 8 , 9 , 31 ]. Moreover, reads belonging to H. sapiens were abundant regardless of the geographical location or the triatomine species, possibly due to the already reported preference of triatomines for the blood of H. sapiens [ 46 ].…”

“…In the case of R. prolixus and P. geniculatus , human blood was the main feeding source (Additional file 3 : Figure S1), as has been previously reported [ 9 , 22 , 31 ]. The ecology of these species is complex as they have been found in armadillo nests as well as within human dwellings [ 48 , 65 ].…”

“…According to this study, the infection rate varied among triatomines feeding upon different vertebrates in a way suggesting that diet specialization plays a pivotal role in defining the transmission dynamics of Chagas disease. Although the described range of triatomine feeding sources is wide [ 7 , 8 , 10 , 22 , 31 ] and is known to affect crucial aspects of their life-cycles and interactions, this aspect has not been vastly evaluated in order to completely understand the dynamics involved. Furthermore, only a few studies have been conducted using next-generation sequencing (NGS), particularly amplicon-based sequencing [ 9 , 32 , 33 ], despite its capacity to reveal multiple host species simultaneously and characterize many more samples than traditional techniques [ 32 ].…”

Eco-epidemiological study of an endemic Chagas disease region in northern Colombia reveals the importance of Triatoma maculata (Hemiptera: Reduviidae), dogs and Didelphis marsupialis in Trypanosoma cruzi maintenance

“…We carried out a cytochrome b gene high-resolution melting (HRM) analysis from insect faeces following standard procedures reported elsewhere [18, 29]. Briefly, the cyt b gene was amplified using the primers forward (5′-CCCCTCAGAATGATATTTGTCCTCA- 3′) and reverse (5′-CCATCCAACATCTCAGCATGATGAAA-3′) [30].…”

Rhodnius prolixus Colonization and Trypanosoma cruzi Transmission in Oil Palm (Elaeis guineensis) Plantations in the Orinoco Basin, Colombia

“…Other studies in the northeast of Colombia have indicated that sylvatic and domestic cycles do not overlap. 49 Our study suggests a T. cruzi transmission scenario with a high T. cruzi natural infection prevalence in triatomines that could be maintained by both sylvatic and domestic mammals, but the precise contribution of each remains to be ascertained. A similar scenario of transmission was reported in Sierra Nevada de Santa Marta indigenous communities where authors reported overlapping domestic and sylvatic cycles of T. cruzi.…”