Spatio-temporal characterization of Trypanosoma cruzi infection and discrete typing units infecting hosts and vectors from non-domestic foci of Chile

Abstract

Background Trypanosoma cruzi is a protozoan parasite that is transmitted by triatomine vectors to mammals. It is classified in six discrete typing units (DTUs). In Chile, domestic vectorial transmission has been interrupted; however, the parasite is maintained in non-domestic foci. The aim of this study was to describe T . cruzi infection and DTU composition in mammals and triatomines from several non-domestic populations of North-Central Chile and to evaluate their spatio-temporal variations. Methodology/Principal findings A total of 710 small mammals and 1140 triatomines captured in six localities during two study periods (summer/winter) of the same year were analyzed by conventional PCR to detect kDNA of T . cruzi . Positive samples were DNA blotted and hybridized with specific probes for detection of DTUs TcI, TcII, TcV, and TcVI. Infection status was modeled, and cluster analysis was performed in each locality. We detected 30.1% of overall infection in small mammals and 34.1% in triatomines, with higher rates in synanthropic mammals and in M . spinolai . We identified infecting DTUs in 45 mammals and 110 triatomines, present more commonly as single infections; the most frequent DTU detected was TcI. Differences in infection rates among species, localities and study periods were detected in small mammals, and between triatomine species; temporally, infection presented opposite patterns between mammals and triatomines. Infection clustering was frequent in vectors, and one locality exhibited half of the 21 clusters found. Conclusions/Significance We determined T . cruzi infection in natural host and vector populations simultaneously in a spatially widespread manner during two study periods. All captured species presented T . cruzi infection, showing spatial and temporal variations. Trypanosoma cruzi distribution can be clustered in space and time. These clusters may represent different spatial and temporal risks of transmission.

Lizards and rabbits may increase Chagas infection risk in the Mediterranean-type ecosystem of South America

“…1A). This diurnal kissing bug species occurs from 26°S to 33°S 12 and shows a conspicuous spatial aggregation, often using rocky outcrops and bromeliads as refuge ( Fig. 1B), where it exhibits a sit-and-wait strategy to parasitize vertebrate hosts 7,[13][14][15][16] .…”

Trypanosomatid Infections among Vertebrates of Chile: A Systematic Review

“…The distribution of the endemic insectivorous species, Thylamys elegans , overlaps with the geographic distribution of M. spinolai and T. infestans [ 10 , 12 , 13 , 28 ]. Studies of T. cruzi infection in T. elegans have shown a high variability, from the complete absence of infection when assessed by optical microscopy, serology (indirect hemagglutination; IHA, hereafter), and/or xenodiagnosis (XD, hereafter) [ 29 , 30 ], to a range of 28.6–50.0% of infection by cPCR on blood [ 14 , 17 , 31 , 32 , 33 , 34 ]. See the detailed information in Table 2 and Supplementary Materials .…”

“…See the detailed information in Table 2 and Supplementary Materials . The T. cruzi discrete typing units (DTUs, hereafter) [ 35 ] reported circulating in T. elegans are TcI, TcII, TcV, and TcVI [ 14 , 31 ].…”

“…Among them, 13 species have been tested for T. cruzi infection, including three Abrothrix species, two Octodon species, Abrocoma bennetti , Chinchilla lanigera , Lagidium viscacia , O. longicaudatus , Phyllotis darwini , and Spalacopus cyanus , among others. From these, seven species have been reported as being infected by T. cruzi , with a high variation in the frequency of infection, mainly depending on the detection technique: A. bennetti (0–42.9%), Abrothrix longipilis (0–9.5%), Abrothrix olivaceus (0–71.0%), C. lanigera (20.0–40.0%), Octodon degus (8.3–70.4%), O. longicaudatus (0–50.0%), and P. darwini (0–100%) [ 14 , 15 , 17 , 29 , 30 , 31 , 32 , 33 , 34 , 40 , 41 , 42 , 43 , 44 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. See the detailed information in Table 2 and Table S1 in Supplementary Materials .…”

“…In Chile, the most studied trypanosomatid is Trypanosoma cruzi , transmitted by four triatomine vector species: the mainly domiciliated species Triatoma infestans , and the three wild endemic species Mepraia gajardoi , Mepraia parapatrica and Mepraia spinolai [ 9 , 10 , 11 , 12 , 13 , 14 ]. This flagellated protozoan has been reported infecting native as well as alien mammals [ 14 , 15 , 16 , 17 ]. However, the published reports on T. cruzi infection in mammals are scattered, without an exhaustive, organized and unbiased review of the available information for this as well as for other trypanosomatids potentially present in Chile.…”