Prevent Animal-Borne Diseases This Summer

Jefferson County, CO--Jefferson County Public Health (JCPH) is reminding residents that along with warm weather this summer residents may be exposed to wild animals and insect that carry the following diseases.   Rabies, West Nile Virus, Western Equine Encephalitis, Zika Virus, Hantavirus Pulmonary Syndrome, Bubonic Plague, Tularemia, and Colorado Tick Fever.  There diseases can be carried by wild animals and insects (rodents, rabbits, squirrels, mosquitoes, fleas, and ticks) and then transmitted to humans. 

JCPH encourages everyone to protect their family and pets by taking the following precautions.  Always wear insect repellant and appropriate clothing when enjoying outdoor activities.  Control the presence of rodents and mosquitoes around their home by sealing all openings and removing standing water.  Vaccinate all of your pet cats, dogs, ferrets, and valuable livestock for rabies and provide fleas and tick protection.  Do not to handle sick or dead animals or animal waste, and contact your local animal control agency for assistance in dealing with domestic or wild life encounters.

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).   Any wild mammal, such as raccoon, skunk, fox, coyote or bat can have rabies and transmit it to people through a bite. 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 but skunk rabies has returned to Colorado and several skunks have tested positive for rabies in 2016 in Jefferson County.  Because rabies is a fatal disease and skunk rabies is now in the Denver metro area everyone should take steps to protect your family and pets against rabies.  The best and most economical way is to have a licensed veterinarian vaccinate all your domestic cats, dogs, ferrets, and valuable horses and livestock against rabies.  It’s important to vaccinate your pets even if they stay indoors because rabid bats have been found inside homes as well as outdoors.  Protect your home from wildlife and insects by making sure all windows, doors or other openings are always closed and have screens that are in good condition.  Keep your home and yard clutter free and seal any openings.

Bites and Exposures: If bitten by a bat, dog, cat, raccoon or other mammal, wash the affected area thoroughly and seek medical advice immediately. Contact your local animal control agency with the location of the animal so the animal can be collected to undergo appropriate testing or quarantine.  If your pet comes into contact with a wild mammal and is unvaccinated (and the wild animal is not available for rabies testing to rule out rabies) your pet is subject to euthanasia or, a strict 4 month quarantine at a secure facility such as an animal boarding facility or veterinarian clinic. 

West Nile Virus and Western Equine Encephalitis (WEE)
These diseases are carried by mosquitoes and can be passed on to humans through the a mosquito bite.  Both diseases can also cause encephalitis or inflammation of the brain and lining of the brain and spinal cord.  Encephalitis can be life threatening for anyone and is particularly serious for those whose ability to fight off infections is compromised. 

The mosquitoes of greatest concern concerning WNV in Jefferson County are Culex tarsalis and Culex pipiens, these mosquitoes feed primarily in the few hours at dawn and dusk.  Dead birds are no longer tested for WNV testing but residents can report dead bird findings to the Colorado Help Line at 1- 877-462-2911.

Preventing WNV: The best way to prevent mosquito-borne disease is to mosquito proof your home and backyard.  Prevent mosquito bites by wearing appropriate clothing and wear insect repellent according to the label directions when conducting all outdoor activities.  This is especially important during dawn or dusk, when Culex mosquitoes are active.  For a complete list of repellants and their effectiveness, please visit the JCPH website at jeffcou.us/public-health.

Culex mosquitoes breed in almost any source of standing water, including old tires, irrigated fields, flowerpots, tree holes, or any puddle of water that lasts for more than a few days.  Mosquitoes lay up to 250 eggs at a time in still water, which hatch into adult mosquitoes in as few as 2-3 days. Eliminating standing water every two to three days will keep mosquitoes from breeding.

Symptoms:  Although most people who are infected with mosquito-borne viruses do not become ill and have no symptoms, others may develop symptoms between 3 and 14 days after being bitten. Symptoms may include fever, headache, and tiredness lasting about 2-7 days. In some cases, the virus can cause a more serious brain infection such as aseptic meningitis or encephalitis. These infections begin with a sudden onset of high fever and a headache, and then may progress to stiff neck, disorientation, tremors, and coma. Severe infections can result in permanent impairment or death. There is no specific treatment for infection with these viruses except supportive care.

Zika Virus

Zika virus is spread to people primarily through the bite of an infected Aedes species mosquito (Ae. aegypti and Ae. albopictus).  Local mosquito-borne transmission of Zika virus has been reported in the Commonwealth of Puerto Rico, the US Virgin Islands, and American Samoa. The number of Zika cases among travelers visiting or returning to the United States is projected to increase as we head into the spring and summer. 

The Centers for Disease Control (CDC) suspects that Aedes species mosquito could carry the Zika virus well beyond the Southeast during the summer into the Midwest and Northeast.  The Zika virus can also be spread during sex by a man infected with Zika to his male or female partners.  Some non-travelers in the United States have become infected with Zika through sex with a traveler.

Public Health’s top priority for the Zika response is to protect pregnant women and their fetuses. The range of health effects linked with Zika infection during pregnancy as well as how many and which pregnancies may be at risk of poor outcomes are essential pieces of information for the public health response to the Zika outbreak

Symptoms: Most people infected with Zika virus won’t even know they have the disease because they won’t have symptoms. The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis (red eyes). Other common symptoms include muscle pain and headache. The incubation period (the time from exposure to symptoms) for Zika virus disease is not known, but is likely to be a few days to a week. See your doctor or other healthcare provider if you are pregnant and develop a fever, rash, joint pain, or red eyes within 2 weeks after traveling to a place where Zika has been reported. Be sure to tell your doctor or other healthcare provider where you traveled. The illness is usually mild with symptoms lasting for several days to a week.

Preventing Zika:  Wear long-sleeved shirts and long pants. Make sure all windows and doors have screens in good condition or keep windows and doors closed.  Prevent Zika by avoiding mosquito bites. (See Fight the Bite) Use Environmental Protection Agency (EPA-registered insect repellents and always follow the product label instructions. Prevent sexual transmission of Zika by using condoms or not having sex.

Everyone should always practice the 4 Ds during the upcoming mosquito season to prevent any mosquito borne diseases such as WNV, Dengue, or Zika.   The most effective way to protect yourself from being bitten by mosquitoes is to use insect repellant for all outdoor activities, even to pick up the mail or going out to get in your car.

Resources: Colorado Department of Public Health and Environment

CDC Changes Reporting of Numbers of Pregnant Women affected by Zika Virus

Zika Virus and Pregnancy or Planning a Pregnancy

CDC’s recommendations for couples thinking about pregnancy

Areas with Zika: United States

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. It is also found in fox squirrels, a tree squirrel common in front range city parks and residential areas.

Symptoms: The incubation period for plague is usually 2-6 days. Typical symptoms include sudden onset of fever and chills, severe headache, muscle aches, nausea, vomiting and a general feeling of systemic illness. Lymph node pain and swelling is a suggestive symptom of bubonic plague. Treatment with antibiotics is effective during the early stages of disease. 

Preventing plague:  The best way to prevent plague is to control the presence of rodents and fleas in and around the home. In addition, people should avoid contact with any species of wild rodents, especially sick or dead rodents. Dogs and cats should be confined so they cannot prey on infected rodents and then bring the disease home with them. Pet owners who live close to rodent populations should use flea control products recommended by their veterinarian. Controlling fleas on pets will prevent the transfer of fleas to humans.  If these reasonable precautions are taken, the probability of contracting plague is extremely low.

If a dead rabbit, squirrel, prairie dog or other rodent is found, do not directly handle the animal. Use gloves and place in a plastic bag. Large die-offs of dead squirrels, prairie dogs, other rodents and rabbits should be reported to JCPH Environmental Health Services at 303-232-6301.

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. Hantavirus has not been shown to infect other kinds of animals, such as dogs, cats, or farm animals. The disease is not contagious and does not spread from human to human.

Symptoms: The incubation period (time between exposure and appearance of symptoms) varies widely, but ranges from 1 to 6 weeks, with an average of 2-3 weeks. First symptoms of HPS include fever, headache, and muscle pain, severe abdominal, joint and lower back pain, nausea and vomiting. A cough and shortness of breath usually develops 1 to 5 days after the onset of symptoms. The primary symptom of HPS is difficulty in breathing due to fluid build-up in the lungs. This can quickly progress to respiratory failure.

Preventing Hantavirus: The best way to prevent the risk of hantavirus infection is to control the presence of rodents in and around the home. This includes sealing up rodent entry holes or gaps; trapping mice and rats; and, being careful not to create food sources for the rodents, i.e. keeping yard clean and putting away pet food. Hantavirus is often encountered when cleaning vacated sheds, cabins or other enclosed areas, so it is especially important that areas where rodents have been are cleaned cautiously and carefully. Areas should not be swept or vacuumed as this can stir up dust. Instead, use gloves and thoroughly wet contaminated areas with a bleach solution or household disinfectant. Once wet, contaminated materials can be taken up with damp towel and then mopped or sponged with bleach solution or household disinfectant.  Contaminated gloves should be disinfected before taking them off. After taking off the clean gloves, wash hands with soap and warm water.

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.

Rocky Mountain spotted fever

Rocky Mountain spotted fever is a rare disease caused by a bacterium, Rickettsia and transmitted to humans through the bite of the Rocky Mountain wood tick and American dog tick. Ticks can carry spotted fever organisms (rickettsia) and infect humans via a bite at any time during the year.

Symptoms: The initial symptoms, which follow an incubation period of 3 to 14 days, are "flu-like": there may be sudden onset of high fever, headache, chills, and muscle aches. A rash often appears a few days later. This rash spreads rapidly over the entire body and may even be seen on the palms of the hands and soles of the feet. Rocky Mountain spotted fever can be fatal if medical attention and treatment is delayed. The illness can be treated with antibiotics.

Prevention: When going to the mountains, people are advised to wear light-colored clothing, tuck trousers into the tops of socks and shirttails into trousers, and to apply a small amount of an insect repellant containing DEET on clothing. Frequent “tick checks” should be performed every two to three hours especially in key areas such as the back, scalp and behind the ears. Once embedded in the skin, a tick can be removed by using a pair of tweezers to grasp the tick and gently but firmly pull backwards, without crushing the tick or leaving the mouthparts in the skin. Avoid crushing tick between fingers as infection can occur if the rickettsia bacteria enter the skin. Washing hands and applying an antiseptic to the bite after removal is advised.  Ticks should always be removed carefully and as soon as possible to prevent disease transmission.

A tick must be attached for several hours for the disease to be spread.

Tularemia

Tularemia is bacterial disease associated with various animal species, especially rodents, rabbits, hares and beavers.  Tularemia is now being found every year in Jefferson County and has already been detected in several counties in Colorado in 2015. Humans can be infected with the bacteria, which is treatable with appropriate antibiotics. People can get tularemia from many different sources including through the bite of an infected insect (usually a tick or deerfly), handling infected animal carcasses, consuming contaminated food or water, or by inhalation of the bacteria.  Although this disease can occur throughout the year, the peak times correspond with tick season (in spring and summer and with the rabbit hunting season in early winter. Tularemia is not spread from person to person.

Symptoms:  Symptoms of Tularemia disease usually appear 3-5 days after exposure and can include a sudden high fever, headaches, swollen lymph nodes, muscle and joint pain, and a sore or lesion at the site where the bacteria entered the body.  In addition, if the bacteria are ingested, such as by swallowing contaminated water or eating improperly cooked/prepared rabbit meat, a person may have a sore throat, abdominal pain, vomiting or diarrhea.  If any of these symptoms are noted after handling dead animals or swallowing untreated drinking water (as you find in a creek), contact your physician.

Recommendations for avoiding exposure to tularemia include the following:

Do not handle sick or dead animals.  Instruct children to leave wildlife alone.  When mowing, gardening, or landscaping: don’t mow over sick or dead animals;  when possible, check the area for carcasses prior to mowing; Use of masks during mowing and other landscaping activities may reduce your risk of inhaling the bacteria, but this has not been studied. 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 “tick checks”.  Avoid untreated drinking water.  Use DEET or other tick repellant during the Colorado tick season. Ticks emerge in the mountains of Colorado in late March and are present throughout the summer with the peak season occurring generally in late May through early June.  

For more information on animal borne disease and prevention please call JCPH Environmental Health Services Zoonosis Program at 303-271-5700 or visit JCPH at jeffco.us/public-health.  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 .