Temporal Variation of Trypanosoma cruzi Infection in Native Mammals in Chile

Abstract

In the present study, we compared Trypanosoma cruzi infection in four native mammals from a hyperendemic area of Chagas disease in Chile for two different periods to assess the occurrence of interannual variation (1999– 2000 vs. 2005–2006). Parasite detection in mammals is performed by polymerase chain reaction assays and confirmed by Southern blot analysis and hybridization test with a universal probe. Results showed significant differences in the levels of T. cruzi infection between the compared periods. We suggest that the major El Nin˜ o event occurred in 1997–1998, a large-scale global climatic fluctuation, could be indirectly explaining the extremely high T. cruzi infection in 1999–2000 by means of a time-lag response of the wild transmission cycle of Chagas disease in semiarid Chile after the irruption of small rodent populations.