Date of Award


Degree Name



Public Health


Gabriel Ibarra-Mejia


Background Leishmaniasis and Chagas's Disease are two of the seventeen diseases considered as Neglected Tropical Diseases (NTF) by the CDC. Ten million people worldwide are at risk of being infected by Leishmaniasis and Chagas' disease affects six million people in the world; however, these are mostly cases in Latin America. The vector for Chagas' disease, triatomine, has been identified near El Paso, Texas region to be positive for Trypanosoma cruzi. Recent studies have also shown positive results for Chagas' disease and Leishmaniasis in sylvatic animals in El Paso.

Objective To determine the prevalence of Trypanosoma cruzi and/or Leishmania spp. infection in collected tissue samples from sylvatic animals, a study was conducted in the El Paso County Region to 1) identify DNA of Leishmania spp. and T. cruzi in tissue samples from sylvatic animals such as foxes, coyotes, skunks and raccoons, and 2) identify and locate positive cases on a El Paso county map to determine the geographical areas where the animals were captured as a mean to identify potential locations for the presence of the vector insect.

Methods This study is a cross sectional study analyzing extracted DNA collected from tissue samples from spleen, heart and skin of wild animals captured in El Paso County, Texas region during an 18-month time period. Polymerase Chain Reaction (PCR) was used as the method of identification using TCZ primers for T. cruzi, ITS primers for Leishmania spp., and IRBP primers to identify mammalian cells in the extracted DNA samples. PCR samples were run in 1.8% agarose gels.

Results Out of the 146 collected samples, 114 where considered as viable samples given that thirty where negative for mammalian DNA. Of these, the total number of positive samples was thirty-three (40.24 prevalence) for T. cruzi and eighteen (21.95) for Leishmania spp. 9 (10.98) samples were identified as positive for both parasites. Regarding species, three striped skunks (12.50) tested positive for T. cruzi and none of samples tested positive for Leishmania spp.; eighteen gray fox samples (48.65) tested positive for T. cruzi, four (10.81) for Leishmania spp., and of those four (10.81) had both diseases; five raccoon (35.71) samples tested positive for T. cruzi, ten (71.43) for Leishmania spp., and five (35.71) for both; lastly, seven coyote (100.00) samples tested positive for T. cruzi, four (57.17) for Leishmania spp., and four (57.17) tissues samples for both.

Conclusions As seen in previous studies, the prevalence of Chagas' diseases in sylvatic animals in El Paso is higher than that of Leishmaniasis. However, the prevalence found for Leishmania spp. is higher than was reported in previous studies for the area of El Paso, Texas. The distribution map showed that positive samples for Leishmania spp. and T. cruzi where mostly found in suburban areas with low population density. Furthermore, active surveillance for these diseases is needed. Also, it is necessary to educate the El Paso community on how to prevent infections and what to do in case any of these symptoms are noticed. Health care providers should consider symptoms for other common diseases such as cardiomyopathy and lymphadenopathy as also a symptom for Chagas' disease or Leishmaniasis.




Received from ProQuest

File Size

63 pages

File Format


Rights Holder

Mariel Christina Matamoros