Deer research warns of tick-borne disease

Published By: Latasha Ford May 24, 2022

Master of Public Health students Naifsat Isa and Dr. Caroline Obi create peripheral blood smears to detect or identify the presence of anasplasmosis in white-tailed deer blood specimen from counties in Georgia.

Georgia’s state mammal could be a danger to hunters, taxidermists and wild-game processors due to a transmissible disease.

Found throughout the state, white-tailed deer are popular for meat and sport during the fall’s deer season. However, Dr. Oreta Samples, program coordinator of Fort Valley State University’s Master of Public Health Program, is concerned about the spread of germs between these animals and humans.

Transmission of diseases due to encounters with ticks and other parasites may cause zoonotic diseases. Samples is working with her team of researchers, students and Department of Natural Resources (DNR) technicians to study the potential effect of some of these common diseases on humans that may occur during handling of white-tailed deer carcasses.

The licensed veterinary technician is using in part a $200,000 Evans-Allen grant to research anaplasmosis. This tick-borne disease could pose a problem for hunters, taxidermists and wild-game processors who routinely encounter white-tailed deer. Also, anaplasmosis could infect cattle through shared grazing areas and tick populations that may feed on both deer and cattle.

Coming from a long line of hunters in her family, Samples’ interest in this research stemmed from her recreation of a study on the potential for the spread of Lyme’s disease by ticks found on white-tailed deer carcasses. This research was originally done by her mentor, Dr. C. Ben Lowery, in FVSU’s Veterinary Science Department in 1992-1993. She brought the project to the 21st century by examining other diseases affecting humans today, utilizing a similar research model to the earlier study.

“The zoonotic factor lies not in an assumption that the deer are infecting humans with anaplasmosis, but that the tick species commonly found on deer in the southeastern U.S. that is infected with the blood-borne parasite Anaplasma could bite someone handling the carcass and facilitate a transmission of anaplasmosis,” Samples explained.

“Cattle are also susceptible to anaplasmosis. Deer love to graze with cattle because they are less likely to be hunted by predators. Therefore, they may share a few parasites with cattle, including tick-borne diseases and gastrointestinal nematodes.”

To bring this project to fruition, Samples first conducted a beta study that she self-funded during the 2020-2021 hunting season. She collaborated with colleagues Drs. Thomas Terrill, Lori Stose, and George McCommon; MPH graduate Dr. Kingsley Kalu; Burke County DNR technician Ryan Meckle; and Dr. Hemant Naikare, director of the University of Georgia’s Tifton Veterinary Diagnostic and Investigational Laboratory.

Research involved collecting fecal and blood samples from 133 white-tailed deer in Bibb, Burke, Crawford, Marion, Merriweather, Pike, Talbot, Taylor, Schley and Upson counties in October and November 2020 for testing.

“We discovered that deer in each county showed signs of parasitic infestation with Haemonchus contortus,” Samples said. “We also discovered that a small number of animals did have anaplasmosis as a result of tick bites, although the specific species of Anaplasma were not determined.”

This confirmed her hypothesis that there could be a potential for spread of the disease between deer, humans and/or cattle given the right circumstances and the presence of ticks on carcasses and will lead to identifying the specific species of Anaplasma that is present in future samplings.

Moreover, she and her team learned that 6 percent of the animals whose blood was tested showed signs of a bacilli bacterium that was suspected to be a clostridium-type bacteria. The awarded Evans-Allen grant allowed Samples to continue with her research, along with offering MPH students Naifsat Isa and Dr. Caroline Obi, both of Nigeria, the opportunity to engage in the study as part of their graduate level matriculation. 

Isa, 23, said this project is fundamental because it furthers her knowledge of how to make the environment and workplace safe for hunters. With a biology background, she aspires to pursue a doctorate, in addition to sharing her thesis on researching gossypol. Found in cotton seed, gossypol is useful for conditions such as HIV/AIDS and for birth control. 

“I want to help people regarding health and food insecurity,” the future researcher said.

Obi, 31, said the significance of this project is that hunters, veterinary technicians and wildlife processors are experts at what they do but may lack the public health knowledge of how to prevent emerging diseases.

“Coming from Nigeria, many of the diseases I was exposed to were vector-borne related, such as malaria. I wanted to take this project and tailor it to the human aspect,” she said.

Her role included gathering and analyzing samples, research writing and presenting at conferences.

“It is a good entry spot into a career I see for myself as a leader in preventive medicine, which is behind the scenes of what policies are going to place on how health care is being ran in the community, state or federal setting,” Obi said.

During the 2021-2022 deer season research, the team tested fecal samples of white-tailed deer for gastrointestinal parasites and blood samples for anaplasmosis, while transporting COVID-19 nasal swabs to the Tifton Veterinary Diagnostic and Investigational Laboratory for testing.

They collected samples from 46 deer in October 2021 in Burke and Talbot counties and continued to collect each weekend from either DNR quota hunts or processing houses nearby until the end of the season in January 2022.

Samples said they anticipate a final sample population over the course of the five-year process of no less than 500 animals. The team is also working with FVSU’s Department of Biology and Dr. Felicia Jefferson regarding organ examination for other diseases of interest in various wildlife species.

“We are also offering health education to hunters on site when they bring their deer in for processing on ways to safely handle carcasses to avoid contamination or infection,” Samples emphasized.

Additional research currently being done by Samples and her team includes a three-month study on North American raccoons and possums during summer 2021 and 2022. Using a $4,300 grant from Morehouse School of Medicine, Samples and her team discovered that both species were shedding salmonella in their feces, which could be problematic for humans and domestic animals such as dogs that may encounter these urban wildlife inhabitants.

Therefore, she is working with the institution to create public health educational brochures for hunters, taxidermists and wild-game processors on proper handling of the carcasses of these small wildlife species.