Body
| EHD Epizootic Hemorrhagic Disease (Bluetongue) | CWD Chronic Wasting Disease | |
|---|---|---|
| Virus that spread by biting gnats in late summer. Symptoms include fever and internal hemorrhaging. | OVERVIEW | Disease of the central nervous system in which the brain deteriorates. |
| Doesn’t spread deer to deer, only through bites from infected insects. | TRANSMISSION | Does spread deer to deer through direct contact, bodily fluids, body parts of infected deer or infectious materials in soil. |
| Bucks and does of all ages are equally susceptible to being bitten by infected insects. | OCCURRENCE | Higher infection rates among mature bucks, likely because they cover more ground and frequently contact toher deer. |
| Viruses are found across North America, with outbreaks typically occurring in late summer, during droughts and extreme heat | LOCATION | Present in 35 states (as of 2024). Preventing spread of CWD is critical, as transporting infected deer can spread disease long distances. |
| Some deer survive infection. Herd immunity is higher in areas with longer historical exposure. | MORTALITY RATE | Always fatal! Infected deer become more vulnerable to predictors, cars, and other illnesses, but those that live long enough die from CWD’s effects. |
| For deer that die of the virus, death usually occurs within a few days. | SPEED OF DEATH | Incubates in infected deer for 1-2 years before symptoms appear, during which deer can spread CWD to other deer. |
| Viruses cannot survive outside the body of the insect vectors or the deer hosts. | DURABILITY | Infectious prions are shed in feces, urine, saliva, blood, and from carcasses of infected animals and remain viable in the environment for years. |
| Cannot infect people, either through insect bites or through handling or consuming infected deer. | HUMAN HEALTH | No evidence that CWD is a health issue in humans, but the CDC advises hunters in CWD zones to test harvested deer and wait for result before eating the venison. |
| Outbreaks vary locally from mild to serious, but deer populations rebound. | LONG-TERM | Except where active management keeps infection rates low, CWD threatens to cause significant declines in deer populations. |