Lineage-specific serology confirms Brazilian Atlantic forest lion tamarins, Leontopithecus chrysomelas and Leontopithecus rosalia, as reservoir hosts of Trypanosoma cruzi II (TcII)

Abstract

Background Trypanosoma cruzi, the agent of Chagas disease in humans, has a vast reservoir of mammalian hosts in the Americas, and is classified into six genetic lineages, TcI-TcVI, with a possible seventh, TcBat. Elucidating enzootic cycles of the different lineages is important for understanding the ecology of this parasite, the emergence of new outbreaks of Chagas disease and for guiding control strategies. Direct lineage identification by genotyping is hampered by limitations of parasite isolation and culture. An indirect method is to identify lineage-specific serological reactions in infected individuals; here we describe its application with sylvatic Brazilian primates.MethodsSynthetic peptides representing lineage-specific epitopes of the T. cruzi surface protein TSSA were used in ELISA with sera from Atlantic Forest Leontopithecus chrysomelas (golden-headed lion tamarin), L. rosalia (golden lion tamarin), Amazonian Sapajus libidinosus (black-striped capuchin) and Alouatta belzebul (red-handed howler monkey).ResultsThe epitope common to lineages TcII, TcV and TcVI was recognised by sera from 15 of 26 L. chrysomelas and 8 of 13 L. rosalia. For 12 of these serologically identified TcII infections, the identity of the lineage infection was confirmed by genotyping T. cruzi isolates. Of the TcII/TcV/TcVI positive sera 12 of the 15 L. chrysomelas and 2 of the 8 L. rosalia also reacted with the specific epitope restricted to TcV and TcVI. Sera from one of six S. libidinous recognised the TcIV/TcIII epitopes.ConclusionsThis lineage-specific serological surveillance has verified that Atlantic Forest primates are reservoir hosts of at least TcII, and probably TcV and TcVI, commonly associated with severe Chagas disease in the southern cone region of South America. With appropriate reagents, this novel methodology is readily applicable to a wide range of mammal species and reservoir host discovery.

A lineage-specific rapid diagnostic test (Chagas Sero K-SeT) identifies Brazilian Trypanosoma cruzi II/V/VI reservoir hosts among diverse mammalian orders

“…The Chagas Sero K-SeT with Leontopithecus spp. sera demonstrated the capacity of this RDT for lineage-specific serology of primates, previously achieved only with ELISA using conjugated anti-human IgG [18]. Previous reports [29,30] hypothesised that primates could be reservoir hosts of TcII; however, searches for TcII infections in Brazilian Amazonian primates only yielded TcI and TcIV.…”

“…Regarding the latter point, the application of serology based on lineage-specific antigens has great potential for resolving the cryptic ecological cycles and the discovery of novel reservoir hosts of this parasite. Applications of T. cruzi lineage-specific serology to naturally-infected animals are with dogs [17,26], primates [18] and sympatric dogs, cats, and armadillo [20]. We have applied Chagas Sero K-SeT to exploit the capacity of Protein G to recognise TSSApep-II/V/VI specific IgG from a range of mammalian Orders.…”

“…Among the primates, the Chagas Sero K-SeT showed that 19 of 68 (29%) L. rosalia in Rio de Janeiro State and 27 of 35 (77%) of L. chrysomelas in the northern Brazilian State of Bahia were seropositive, indicating a high prevalence of TcII/V/VI infections, for which the natural hosts were previously poorly known. For L. rosalia and L. chrysomelas, 8 and 23 of the same samples, respectively, were previously tested by TSSApep ELISA [18]. In all but one case the Chagas Sero K-SeT RDT result accorded with the ELISAs; the non-matching case was positive by the RDT but negative by ELISA; Kappa test = 0.84 (95% confidence intervals: 0.64-1.00) (S1 Appendix).…”

Wild Mammal Translocations: A Public Health Concern

“…Correspondingly, several other studies where carried out on the same place involving Trypanosoma cruzi infection on the populations of lion tamarins that are considered as one of the species that are reservoir hosts of this protozoan, the etiological agent of Chagas' disease. [38] Lisboa et al [39] analyzed the Trypanosoma cruzi infection in Leontopithecus rosalia.…”

“…Finally, Kerr et al [38] through lineage-specific serology, verified that Atlantic forest lion tamarins, Leontopithecus chrysomelas and Leontopithecus rosalia, were reservoir hosts of Trypanosoma cruzi II (TcII), a lineage that has been commonly associated with severe Chagas disease in South America.…”