Department Head, Professor Texas A&M University College Station, Texas
Soft ticks (Family: Argasidae) are vectors of relapsing fever Borrelia in the United States, and are potential vectors of African Swine Fever virus, a pathogen that could have a devastating effect on the U.S. swine industry if introduced to the U.S. mainland. Much of the tick-borne disease research in the U.S. focuses on hard ticks, and less is known about the ecology of soft ticks. Some of the soft tick species found in the southern U.S. have a wide host range and may feed on cattle, swine, native and exotic ungulates, small mammals, reptiles, and humans. Because the feeding habit of most soft tick species involves taking short, repeated blood-meals, pathogen transmission among hosts is a concern both for human and animal health.
Sampling was carried out at four locations in south Texas in 2022 using modified dry ice traps placed in animal burrows and other sheltering cracks and crevasses that may provide refuge for soft ticks. Collected ticks were identified and subsequently screened for Rickettsia and Borrelia species and for host blood meal detection using conventional PCR and Sanger sequencing for pathogen and host species identification. One hundred thirteen ticks of two Ornithodoros species were collected. Borrelia species were identified in approximately 2.5% of samples. Blood meal detections were made in approximately 16% of screened tick specimens, representing 6 vertebrate host species. Results demonstrate that the soft tick species detected herein feed on a range of wildlife hosts in south Texas and are associated with agents of human disease.