TENNESSEE HAZARD ANALYSIS - ANIMAL & VECTOR-BASED HAZARDS

One of the "new" or "emerging" series of  threats to the state and its citizens are vector-based threats - bacteria, insects and other animals that pose a direct or indirect hazard to humans, their food supply, or the state's economy.  Although many people don't consider Foot and Mouth Disease to be a "threat" to them per se, an outbreak of the disease in Europe caused widespread concern over the safety of the continent's meat supply, as well as the possibility of resulting infections of humans.  Federal, state and local officials, including the emergency services community have developed plans and procedures for handling incidents involving these threats.  The following list provides some insight into threats now identified as having the potential for causing concern in Tennessee.

West Nile Virus
West Nile Virus is one of several mosquito-borne viruses in the United States that can infect people. The virus exists in nature primarily through a transmission cycle involving mosquitoes and birds. Mosquitoes become infected with West Nile Virus (WNV) when they feed on infected birds.

West Nile Virus is one of several mosquito-borne viruses in the United States that can infect people. The virus exists in nature primarily through a transmission cycle involving mosquitoes and birds. Mosquitoes become infected with West Nile Virus (WNV) when they feed on infected birds.

The vast majority of people that become infected with the West Nile Virus have no illness or experience only a mild flu-like illness that includes fever, headache and body aches lasting only a few days. Some persons may also have a mild rash or swollen lymph glands.  Less than one percent of those infected may develop meningitis or encephalitis, the most severe forms of the disease, which occurs primarily in persons over 50 years of age. Symptoms of encephalitis or meningitis may include severe headache, high fever, neck stiffness, stupor, disorientation, tremors, convulsions, paralysis, coma and sometimes, death.

· CDC West Nile Virus Q&A

· CDC West Nile Virus Home Page

· Tennessee Department of Health West Nile Virus Fact Sheet

Foot and Mouth Disease

FMD is a highly infectious, persistent and difficult to control disease of cattle, domestic sheep and swine. It also affects other cloven-hoofed mammals including wild sheep, goats, deer and pigs. Should an outbreak occur anywhere in the United States, routine livestock movements could rapidly spread the disease to all sections of the country making early detection, combined with immediate eradication of affected animals, crucial for controlling the disease. Left unchecked, the economic impact of FMD could reach billions of dollars in the first year. Deer and other wildlife populations would likely become infected and would be a source for re-infection of livestock. FMD is not known to cause illness in humans. The virus does not infect horses, mules, and burros.

The virus may also be transmitted mechanically by animals such as rodents and birds. While these animals do not become infected with the virus, experimental studies have also shown that the virus can survive for a short time on their bodies (up to 91 hours on the feathers of live birds). Experimental studies also demonstrated that the virus could pass unaltered through bird digestive systems. These findings suggest that these animals may facilitate the spread of virus for a short time and distance in the vicinity of an outbreak.

If FMD arrives in the United States, it will most likely be found first in domestic animals. Because FMD is highly contagious among cloven-hoofed animals, populations of cervids (deer, moose, elk), bison, antelope, peccary and feral pigs, would likely be targets for eradication in the vicinity of FMD outbreaks. During a 1922 outbreak of FMD domestic cattle grazing on U.S. Forest Service lands in California were suspected of spreading the disease to local deer populations. Over 22,000 deer were killed because of concern that they might serve as a reservoir of the disease.

How FMD is Spread:

Domestic animals, wildlife, people, or materials that bring the virus into physical contact with susceptible animals can spread FMD. This can occur when susceptible animals drink from a common source of contaminated water, when animals carrying the virus are introduced into susceptible herds, when susceptible animals are exposed to materials such as hay or other feedstuffs contaminated with the virus, when people wearing contaminated clothes or footwear or using contaminated equipment (including vehicles) pass the virus to susceptible animals, and when raw or improperly cooked garbage containing infected meat or animal products are fed to susceptible animals. One study found that the virus might be able to be spread up to 10Km by aerial transmission.

· Tennessee Department of Agriculture FMD Prevention Measures

· USDA Foot and Mouth Disease Information

· Emerging Infectious Disease Network

Animals, Pests, Vermin, Etc.

Fire Ants Anyone who has been bitten by a fire ant can tell you that these well-known agricultural pests can quickly become a human health hazard. Once fire ants clamp onto your skin with their powerful jaws, they inject a dose of venom that causes a burning sensation. These stings can cause blisters and infections, and can even cause anaphylactic shock or death in the most sensitive victims. It is also not uncommon for colonies of fire ants to attack and sometimes kill domestic animals and pets, as well as livestock and wildlife.  And that's just the threat these tiny little insects pose to humans and animals.

Fire ant mounds (or nests) can grow up to 2 feet high above ground and are unsightly hazards in yards, open fields, parks and other recreational areas where children and pets are present. Fire ant colonies can knock out entire fields of corn and soybeans and also like to feed on the young buds of ornamental plants and fruit trees.  These insects are capable of causing major damage, both in terms of human and animal harm and in crop damage.  Fire ants have invaded many of the southern Tennessee counties and continue a slow spread northward.

· Map of Quarantined Counties (USDA-APHIS)

· Fire Ant Management Techniques

· Texas A&M University Fire Ant Program