Date of Award
Rodrigo X. Armijos
Potential for sylvatic mammals and stray canines in transmission of leishmaniasis and Trypanosoma cruzi in Paso del Norte Border Area
Background. New World leishmaniasis is a zoonotic protozoal disease caused by various species of the genus Leishmania1. A number of mammalian species have been described as hosts for Leishmania2. Some of them also are considered to play important roles as disease reservoirs. Chagas' disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi, (T. cruzi)3. It is well recognized that T. cruzi is endemic in the United States, as evidenced by infections in domestic dogs and a wide range of mammalian wildlife species4.
Objectives and Hypotheses. This study will seek to identify T. cruzi and Leishmania mexicana (L. mexicana) through convenient sampling in wild mammals, which include rodents, raccoons, and also in stray canines in the El Paso County and surrounding areas (Regions 9 and 10). T. cruzi and L. mexicana are mainly affecting wild mammals in the southern portion of Texas and live in close proximity with traditional vectors of the parasites4.
Methods. The identification of T. cruzi and L. mexicana in tissue samples collected from selvatic mammals and stray canines will show that they are possible reservoirs of these parasites.10 stray canine tissue samples were collected once a week for ten weeks from October 2011 to July 2012 and 20 selvatic mammal samples were collected in October of 2011. DNA extraction and amplification of T. cruzi and Leishmania s.p. from wild mammal and stray canine heart, spleen, and skin tissue was conducted for the identification of L. mexicana and T. cruzi by polymerase chain reaction (PCR)5.
Results. A total of 10 (10%) PCR confirmed cases of T. Cruzi and no cases of L. mexicana were identified among 96 stray canine samples collected in the El Paso region and surrounding areas. A total of 13 (65%) PCR confirmed cases of T. cruzi and 1 (1%) case of L. mexicana was found among 20 selvatic mammals collected in the Mason Mountains. The presence of cases during the study period indicates that Chagas disease and leishmaniasis among dogs and sylvatic mammals in Texas is not a rare occurrence nor is it geographically constrained to a particular region within the state.
Conclusions. These data should serve to increase awareness regarding the prevalence of the diseases in selvatic and stray mammals among veterinarians and public health practitioners, leading to a greater emphasis placed on prevention methods that can be used to break the transmission cycle.
1. Centers for Disease Control and Prevention . Parasites- Leishmaniasis . 10 January 2013. 13 October 2013
2. Alvar, J., et al. "Leishmaniasis Worldwide and Global Estimates of its Incidence." Plos One 7.5 (2012): 1-12. Print.
3. World Health Organization . Chagas disease (American trypanosomiasis). March 2013. August 2012
4. Pung, O., et al. "Trypanosoma Cruzi in Wild Raccoons, Opossums, and Triatomine Bugs in Southeast Georgia, U.S.A. " The Journal of Parasitology 81.2 (1995): 324-326. Print.
5. Ferreira, E.C., et al. "Alternative PCR Protocol Using Single Primer Set for Assessing DNA Quality in Several Tissues from a Large Variety of Mammalian Species Living in Areas Endemic for Leishmaniasis ." Mem Inst Oswaldo Cruz, Rio de Janeiro 105.7 (2010): 895-898.
Received from ProQuest
Jacqueline Alyssa Mariscal
Mariscal, Jacqueline Alyssa, "Potential For Sylvatic Mammals And Stray Canines In Transmission Of Leishmaniasis And Trypanosoma Cruzi In Paso Del Norte Border Area" (2013). Open Access Theses & Dissertations. 1668.