Unraveling the chronic wasting disease mystery

The Ohio Division of Wildlife has found 11 additional white-tailed deer infected with CWD (Chronic Wasting Disease) in Marion and Wyandot counties — seven bucks and four does. CWD is a neurological disease which affects the brain and central nervous system of the infected animal. The disease was first discovered in the 1960s in the western U.S. It has currently been detected in free-ranging cervids in 29 states and three provinces and in captive cervid facilities in 18 states and three Canadian provinces. The total impact is 30 states and four provinces. The disease has also been discovered in Finland, Norway, Sweden and South Korea. It is caused by naturally-occurring proteins: labeled prions, which mutate, creating holes in the brain tissue. CWD is a proven death sentence to any infected cervid which includes whitetail deer, mule deer, blacktail deer, elk and moose. According to the Centers for Disease Control and Prevention, there's no strong evidence that CWD is transmissible to humans. In December 2020, Ohio confirmed its first CWD-positive wild deer in Wyandot County, a mature buck that was taken to a local taxidermist and was subsequently tested as part of routine CWD surveillance. In January 2021, a positive yearling doe was harvested during a controlled hunt on the Killdeer Plains Refuge. Eight hunter-harvested deer tested positive during the 2021-22 deer season in southern Wyandot and northern Marion counties and one additional positive deer was removed through targeted shooting in March 2022. Ohio's most recently diagnosed deer were discovered during the testing of deer killed by hunters during the 2022-23 deer season, as well as deer taken through the division's targeted removal efforts in February and March. The postseason deer removal is used in hopes of slowing the spread of the deadly disease by reducing deer numbers in areas where it has been detected. Since the fall of 2020, a total of 22 wild deer have tested positive in Wyandot and Marion counties (16 in Wyandot, six in Marion). You can find more information about CWD, including a map of known locations, at www.ohiodnr.gov/cwd As you would expect, both state and federal assets are being used to continue the study of this potentially herd-threatening disease. As is true of any investigation, a new twist in the plot can lead investigators in new directions. In the continuing work to unravel the CWD mystery, every avenue is being explored in the hope of discovering the silver bullet that may help limit its impact. According to information provided by Field & Stream Magazine's most recent newsletter, the University of Wisconsin, Johns Hopkins and the University of Montana have added CWD to the list of infectious diseases that ticks can carry and possibly transmit. F&S explained that a recently published article by the Scientific Reports Journal showed that black-legged ticks "harbor and even excrete the mis-folded proteins, or prions, that give rise to the always-fatal neurodegenerative disease in whitetail deer and other cervid species." Also in the report was the acknowledgement that it could be possible that deer could be spreading CWD amongst themselves by ingesting engorged ticks while grooming each other. The F&S column explained that the results came from "a sampling of some 2,000 hunter-harvested deer heads from Wisconsin ... Of those 174 were infested with ticks, and 15 of those tested positive for CWD … They examined the deer blood inside the ticks on the CWD-infected heads and found active prions in 6." It was noted that during the engorgement phase of the tick's feeding cycle, they may swell to 100 times their unfed body weight and "the parasites were excreting those prions back into their hosts' ear tissue." Could this study have uncovered how CWD is spread? I would give it a maybe, a yes, and a no. Insect-vectors are not new to animals, humans, nor to the scientific community. Throughout the world, mosquitoes are the most common and transmit many deadly diseases. Other common vectors include fleas, filth flies, sandflies, midges, and lice. In the U.S., guess what bug is the most common of the disease-carrying pests. If you guessed ticks, you win the prize. This arachnid isn't very mobile unless it is connected to a host. It can be a deer's back, your dog's ear, or your hairline. Without hitching a ride, ticks don't have much of an ability to travel. Therefore, the tick needs to catch a ride on an already infected deer to become part of the problem. Since it's already believed that cervids can become infected through exposure to feces, saliva, blood, or urine, either through direct contact or indirectly through environmental contamination of soil, food or water, ticks may just add another destructive layer of that exposure possibility in an area that is already suffering. The deer themselves then become their own, traveling Typhoid Mary — carrying the potential of delivering their own body fluids and any hitchhiking infected ticks throughout their home range. Since it takes more that 16-months for the animals to show symptoms of the fatal infection, it becomes a difficult problem to address. Compounding the problem, deer ranges overlap, increasing the opportunity for CWD to jump to new areas. While there's not yet a definitive answer as to whether deer can get CWD from ingesting infected ticks, the odds seem to favor the possibility — especially considering that deer can get the disease from other body fluids. "In the laboratory, the team of scientists fed black-legged ticks a CWD-infected 'blood meal' and found that those ticks readily absorbed prions and excreted the prions once fully engorged. They even measured the prion loads from each fed tick and determined that the arachnids held "transmission-relevant amounts and may pose a CWD risk to cervids," the staff of F&S added. Ohio's wildlife division has been conducting routine surveillance since 2002 — testing approximately 39,000 deer. The division has monitored and tested deer in the Wyandot-Marion-Hardin County disease surveillance area since CWD was discovered in the wild in 2020. Sampling for CWD will continue in the 2023-24 deer hunting season. Special deer hunting regulations and hunting opportunities will once again be in effect in the disease that surveillance area. Additional testing will continue to try to determine if ticks are that next layer of this toxic cake which is spreading slowly across far too much of North America. Every piece of new knowledge discovered about CWD allows zoologists, wildlife biologists, virologists and epidemiologists to combat the disease's impact. More information about this disease is available at www.cwd-info.org "All interest in disease and death is only another expression of interest in life." — Thomas Mann Along the way It has been three years since the R100 National Archery Tour has come to Ohio, the last being held in Coshocton. This year, the immensely popular competition is returning to the Buckeye State but this time to Putnam County. On June 23 through the 25th, the 3D shoot will be held at the Leipsic Fishing and Hunting Club, 10605 Road H, Ottawa — and the National Bowhunter Education Foundation is inviting you to participate in the 2023 R100 National Archery Tour. NBEF is sponsoring the 2023 R100 National Archery Tour, celebrating 20 years of operating family friendly 3D archery events. R100 is continuing its work with local clubs and archery pro shops to host the events across the United States. NBEF partners with R100 to increase awareness of NBEF's safety and success-focused bowhunter education classes and to actively support the archery industry. All events are of the same format including two 50-target ranges (the Safari Range and the North American Range). On top of the two ranges, specialty shoots are provided each day. Pre-registration and complete information for the three-day event can be found at https://www.r100.org/shop/ottawa-oh-2023 If you're an archer, the amazing array of targets will be a challenge like no other on the 3-D circuit! Step outside •Thursday: Trap and Skeet Practice, open to the public. 4 p.m. UCOA, 6943 Marion Township Road 243, Findlay. •Friday: Casting for Recovery Fly Fishing Film Tour, Maumee Indoor Theater, 601 Conant Street, Maumee, Ohio, benefiting the Toledo Clinic Cancer Centers. Doors open at 6 p.m. for appetizers and a silent auction, films begin at 7 p.m. Tickets: $30. Visit: https://flyfilmtour.myeventscenter.com/browseByState/OH/1. •June 3: Youth Fun Day, noon–3 p.m. Mount Blanchard Gun Club, 21655 Delaware Township Road 186. Introduction of safe gun handling and shooting for kids 17 and under. All young participants must be accompanied by an adult. The event is free, ammunition and firearms provided. For information: Bob Yoder, 419-957-0459. •June 4: Trap Shoot, 1 p.m. Mount Blanchard Gun Club, 21655 Delaware Township Road 186. •June 10: Kalida Fish and Game Extravaganza. Help support a great club! Visit kalidafishandgame.com for information or purchase tickets at extravaganza.ticketbud.com/2023 •June 10: Ladies' Day, noon–4 p.m. Open to the public. Mount Blanchard Gun Club, 21655 Delaware Township Road 186. Introduction of safe gun handling and shooting. The event is free, firearms and ammunition provided. For information: Jackie Schnapp, 419-273-5057. •June 11: 3-D Archery Match, mixed animal targets. Field and Stream Bowhunters; 11400 Allen Township Road 109, Findlay. Registration opens at 8 a.m. Contact: Harold Spence, 419-423-9861. Abrams is a retired wildlife officer supervisor for the state Division of Wildlife in Findlay. He can be reached at P.O. Box 413, Mount Blanchard, OH 45867-0413 or via email at jimsfieldnotes@aol.com