Chagas and Other Protozoal Parasites in Bats

The parasite Trypanosoma cruzi causes Chagas disease in humans, dogs, and other mammals. Its insect host is the kissing bug, which can transmit the parasite to animal hosts by biting and subsequently defecating near the site of the bite. Chagas disease is endemic throughout central and South America and is increasingly recognized as both a human and veterinary (mainly dogs) health concern in the southern United States. The prevalence of trypanosomes infections in bats has not been reported in the United States.

The East Foundation conducts research that focuses of factors that most threaten the productivity of native rangelands – factors such as diseases in wildlife, humans, and livestock. Here we aimed to determine whether bats, which are capable of long-distance migrations, are carriers of Chagas disease.

We sampled bats for trypanosomes in 34 counties across Texas (Figure 1). In 29 counties, bats were collected near homes and in 4 counties, bats were collected from rangelands, including the San Antonio
Viejo and Santa Rosa ranches of the East Foundation.

We recorded and analyzed:

  • 474 bats near homes
  • 119 bats from rangelands
  • 8 species of insectivorous bats (80% of bats were Mexican free-tailed bats)

We found:

  • One bat positive for T. cruzi (0.2%)
  • Nine bats positive for T. dionisii (1.5%) – a protozoal blood parasite similar to Chagas disease that has not previously been documented in the United States
  • Five bats positive for Blastocrithidia spp. (0.8%) – a protozoal blood parasite similar to Chagas disease that has not previously been reported in mammals 

Our findings represent the first report of T. cruzi in a bat in the United States, of T. dionisii in North America, and of Blastocrithidia spp. in mammals. The low prevalence of Chagas disease in bats suggests that bats are not as important as other wildlife species, such as striped skunks, raccoons, and rodents, in the United States.

Partners: College of Veterinary Medicine and Biomedical Sciences at Texas A&M University, Biodiversity Research and Teaching Collections at Texas A&M University, and the Texas Department of State Health Services

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