Gilpin County, Colorado –  Several dead beavers found in the vicinity of Snowline Lake have tested presumptive positive for tularemia, an infectious disease found in animals. At least three beavers, apparently from the same family unit, were found dead on April 24, 2010. Preliminary tests on the beavers were negative, however a second test performed at the Center for Disease Control Laboratory in Fort Collins were presumptive positive for tularemia. Additional testing is being conducted.

Tularemia, also called rabbit fever, is a bacterial disease caused by the bacteria Francisella tularensis and is associated with various animal species especially rodents, rabbits, hares and beavers. Water-borne tularemia is naturally occurring and commonly infects beavers, muskrats and other animals that spend a lot of time in the water. Humans can be infected with the bacteria, which is treatable with appropriate antibiotics.

Tularemia does not spread from person to person. Tularemia occurs year-round throughout the United States. In Colorado, there are generally two peak seasons: in May associated with tick bites and in October and November associated with rabbit hunting season. Colorado reports a few human cases of tularemia every year. “Tularemia is not uncommon in Colorado and the risk to the public is very low in this instance,” states JCPH Environmental Health Services Director and veterinarian, Dr. Jim Dale. “Washing your hands thoroughly for at least 20 seconds is one of the best ways to avoid getting sick.”

JCPH advises citizens to follow basic safety precautions to avoid exposure to animal-borne diseases, including:

• do not handle sick or dead animals, instruct children to leave wildlife alone
• wash hands thoroughly following recreational activities
• wear rubber gloves when skinning or handling animals, especially rabbits
• thoroughly cook meat from wild game, especially rabbit and squirrel meat, before eating
• use protective clothing and insect repellents to avoid deerfly and tick bites
• conduct frequent check for ticks
• avoid drinking untreated water

Symptoms usually appear 3-5 days after exposure and can include high fever, swollen lymph nodes and a sore or lesion at the site where the bacteria entered the body. In addition, if the bacteria are ingested, such as swallowing contaminated water, a person may have a sore throat, abdominal pain, vomiting or diarrhea. Persons who have handled dead animals in this area or swallowed water from the lake and have developed these symptoms should contact their physician.

Prevent Animal-Borne Diseases This Summer

Jefferson and Gilpin County Public Health reminds residents that with summer and warm weather upon us, so is the risk of contracting certain animal-borne diseases. Rabies, West Nile Virus, Western Equine Encephalitis, Hantavirus Pulmonary Syndrome, Bubonic Plague, Tularemia, and Colorado Tick Fever are all diseases that can be carried by various animals and insects (rodents, mosquitoes or ticks) and then transmitted to humans. They are also more common during the summer when people tend to be outdoors more often and wild animals and insects are active.

JCPH recommends everyone help control the presence of rodents and mosquitoes around their home; and, when heading outdoors, particularly to areas where wild animals and insects are active, wear insect repellant, appropriate clothing and protect your pets from fleas and ticks. Remember not to handle sick or dead animals or animal waste. A few precautions go a long way toward preventing animal-borne disease.

Rabies
Rabies is an infectious viral disease that affects the nervous system of humans and other mammals. People and domestic pets can get rabies from the bite of a rabies-infected animal (rabid animal). It is also possible, although rare, for persons to get rabies when infectious material, such as saliva from a rabid animal, gets into an individual's eyes, nose, mouth or open wound. Bats are by far the most common carriers of rabies in Colorado and Jefferson County. However, during the past year skunk rabies has made its way back into Colorado and the Denver metro area and could infect any other wild mammal.

Because of the deadly nature of rabies and the increased possibility that skunk rabies is circulating in the wild mammal populations, JCPH strongly encourages citizens not to allow their pets to roam free and to keep their pet cats, dogs and ferrets current on their rabies vaccinations. 

For more advice on how to avoid exposure and for information on symptoms and what to do if you or a pet has been exposed, see the Public Health Rabies page.

West Nile Virus and Western Equine Encephalitis (WEE)
These diseases are carried by mosquitoes and can be passed on to humans through the familiar mosquito bite. Both can also cause encephalitis or inflammation of the brain and lining of the brain and spinal cord. Most care needs to be taken for the mosquitoes that feed primarily in the few hours around dawn and dusk.

For more information on the best way to prevent mosquito-borne disease, a list of repellants and their effectiveness and symptoms if you've been exposed, please see the Public Health West Nile Virus page.

Bubonic Plague
Bubonic Plague is a disease caused by a bacterium named Yersinia pestis. These bacteria can be transmitted to humans by the bites of infected fleas or by direct contact with infected animals. Plague is frequently detected in rock squirrels, prairie dogs, wood rats and other species of ground squirrels and chipmunks. The best way to prevent plague is to control the presence of rodents and fleas in and around the home. Dogs and cats should be confined so they cannot prey on infected rodents and then bring the disease home with them.

For more information on the best way to prevent plague, symptoms of exposure or what to do if you've found a dead animal, see the Public Health Plague page.

Hantavirus Pulmonary Syndrome
Hantavirus pulmonary syndrome (HPS) is a serious respiratory disease caused by a virus (hantavirus). Hantavirus is carried by wild rodents, particularly deer mice, and is present in their droppings (feces), urine and saliva. These dried droppings or urine can be stirred up in dust and breathed in by people. People may get hantavirus when they breathe in air contaminated by the virus. The disease is not contagious and does not spread from human to human.

For more information on the symptoms of Hantavirus and preventing the disease, see the Public Health Hantavirus page.
 
Colorado tick fever
Colorado tick fever is caused by a virus that thrives in the environment through a rodent-tick-rodent cycle. The virus can be transmitted to humans by the bite of an infected Rocky Mountain wood tick. Ticks emerge in the mountains of Colorado in late March and are present throughout the summer with the peak season occurring in late May through early June. 

Symptoms: Colorado tick fever is the most common tick-borne disease in Colorado. However, it is believed that most cases go unrecognized. This viral illness is characterized by fever, headache, body aches, nausea, abdominal pain, and lethargy. Symptoms usually last 4-5 days, followed by an apparent recovery, and then a relapse with symptoms for 2-3 more days. Complete recovery can take 2 or 3 weeks. The disease is not life threatening and infection results in life-long immunity.

For on line information about tularemia, please visit the Gilpin County website at www.co.gilpin.co.us/Public%20Health/homedefault.htm or the Centers for Disease Control and Prevention web site: www.bt.cdc.gov/agent/tularemia/index.asp

For more information on animal borne disease and prevention please call JCPH Environmental Health Services Zoonosis Program at 303-271-5700 and ask for Dr. Jim Dale or Dave Volkel or visit the JCPH Zoonosis web page.

Information is also available on the Colorado Department of Health and Environment web site: www.cdphe.state.co.us or Centers for Disease Control and Prevention (CDC) at www.cdc.gov.