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Diseases from Animals & Insects

Animal and Insect-Borne Diseases

Insects, pets, farm animals and wildlife can carry diseases that affect humans. You can protect yourself and your family from the most common risks from animals.

Insect and spider bites often cause minor swelling, redness, pain and itching. These mild reactions are common and may last from a few hours to a few days. Home treatment is often all that is needed to relieve the symptoms of a mild reaction to common stinging or biting insects and spiders.

However, sometimes animals carry diseases that are harmful to humans. Diseases like Lyme disease and West Nile virus are spread through insect bites. Diseases spread by wildlife or pets include rabies and toxoplasmosis.

Animal Contacts

B.C. is home to about 16 species of bats. They come out in spring when the weather warms and the bugs come out, and go into hiding for the winter when the bugs die off. Most bats do not carry rabies but some do. There are other animals that are considered a lower risk that could also carry rabies, including monkeys, skunks, raccoons, coyotes, bobcats, foxes and other wild animals. On rare occasion, cats and dogs can be infected with the bat strain rabies. Report any animal contact to an Environmental Health Officer to determine if you are at risk for rabies.

Rabies is a serious viral illness that can affect humans; it is fatal if untreated. Rabies can be transmitted to humans when infected saliva comes in contact with mucous membranes (eye, mouth and nose) or broken skin. This usually occurs through a bite or scratch. If a person has an encounter with an animal, a series of vaccines started shortly after the exposure can prevent rabies.

How to avoid getting rabies from bats

Bat-proof your home and/or cabin by using tight-fitting screens for windows and attic vents, and by keeping doors closed or screened. Visit the Ministry of Environment website for tips on bat management.
If you have bats in your house, barn, or property, please contact BC Community Bat Programs.
Avoid places where bats like to live, such as caves and abandoned buildings.
Never touch bats, whether they are healthy or sick, alive or dead.
Keep your pet’s rabies vaccination up to date, as they may come in contact with rabid bats.

When to report instances to public health

A bat has flown into your body, or has made contact with your body. You will not always be aware if you have been bitten or scratched by a bat, as you may often not feel it
A bat is known or suspected to have bitten or scratched someone, or someone has handled a bat with bare hands
A bat has been found in a room and you are not able to confirm that it did not have physical contact with a person (e.g., young child or developmentally challenged person)

Treating bites

Wash wounds with mild soap and flush the wound with copious amounts of water under moderate pressure
Expert opinion suggests washing should be done for at least 15 minutes. Evidence shows that effective wound first aid can significantly reduce rabies risk
Disinfect the wound with an iodine-containing or alcohol solution
Contact your doctor or nurse practitioner

Testing bats

Bats will only be tested if a person has potentially been exposed to the rabies virus. If the bat is found to be free of rabies, immunization against rabies is unnecessary.

How to trap a bat for testing if contact with humans is suspected:

Call a licensed pest control company in your area. If professional help is not available, adults (not children) should catch the bat - be careful and avoid direct physical contact.
Close all doors and windows in the area. Put on a hat, leather gloves, a long-sleeved jacket and pants. Using a blanket, net, broom or towel, catch the bat (without touching it and while protecting any exposed area such as your face) and put it in a container. Close the container and put it into the freezer, which will make the bat go into hibernation (deep sleep)
If human exposure may have occurred, contact the Environmental Health Officer at your public health unit to arrange for animal contact assessment and for the bat to be tested

Mosquitoes and West Nile Virus

The West Nile virus (WNV), originally from the West Nile region of Africa, has been spreading across North America since 1999. B.C. has seen many cases of the disease in people who have travelled to other parts of North America. In 2009, WNV was detected in British Columbia for the first time. Interior Health continues to work with the B.C. Centre for Disease Control to investigate and report confirmed human cases of WNV.

Symptoms and transmission

The virus can be transmitted to humans from the bite of an infected mosquito. Most people who get infected will not have any symptoms but the disease can be serious for one person out of about every 150 who are infected. Fortunately, you can lower your risk of infection by avoiding mosquito bites.

How to avoid mosquito bites

Take steps both here at home and when travelling to avoid mosquito bites:

Eliminate mosquito habitat (standing water) on your property. Clean out and empty eaves troughs, pool covers, old tires or any other materials that can collect water. Empty and clean bird baths weekly, and install aeration pumps on ornamental ponds and water gardens. Fit rain barrels with tight lids or screens and empty saucers under flower pots
Install good screens on doors and windows. Check to make sure screens fit into the frame and that there are no holes or tears
Try to avoid outdoor activities around dusk and dawn when mosquitoes are most active
Wear long-sleeved shirts, long pants and a hat. Choose light-coloured clothing since dark colours attract mosquitoes
Use repellent containing DEET or other suitable alternatives. Follow label instructions for use.

For more information on prevention and repellents:

Information on West Nile Virus Pamphlet (BCCDC)
Insect repellent - which kind should I choose? (BCCDC)

Resources

West Nile Virus (BCCDC)
West Nile virus (Public Health Agency of Canada)

Ticks and Lyme Disease

Ticks are tiny bugs that feed on blood. In B.C.’s Southern Interior, the most common species is the Rocky Mountain Wood Tick (Dermacentor andersoni). It’s about the size of a small pea and not known to be a carrier of Lyme disease.

While not considered common to the area, the deer tick (Ixodes pacificus or I. angustus) has been linked to a handful of Southern Interior Lyme disease cases. The adult deer tick is the size of a sesame seed (2.5-millimeter diameter), oval and has a flattened body before enjoying a blood meal. When engorged with blood, the eight-legged arthropod is about the size of a small pea and blue-black in color.

Most tick bites do not result in disease because most ticks are not infected with disease-causing germs. If a tick is carrying disease, the germs that cause the disease are injected with the tick’s bite. Tick bites, like any insect bite, should be treated seriously since infection can occur due to the break in the skin.

How to avoid ticks

Walk on cleared trails wherever possible
Wear light-coloured clothing, tuck your shirt into your pants and tuck your pants into your boots or socks
Put insect repellent containing DEET on all uncovered skin. Re-apply as frequently as directed on the containers. See BCCDC’s Insect Repellant Poster
Check clothing and scalp (covered or not) when leaving an area where ticks may live
Regularly check household pets for ticks

How to safely remove ticks

Do not do anything that can stress or crush the tick’s body. This may cause it to inject its stomach contents into your blood. Follow the steps below:

Use tweezers or forceps to gently get hold of the tick as close to the skin as possible. Don't touch the tick with your hands
Without squeezing the tick, steadily lift it straight off the skin. Avoid jerking it out. Try to make sure that all of the tick is removed
Once the tick has been removed, clean the bite area with soap and water, then disinfect the wound with antiseptic cream
Wash your hands with soap and water
If you find one tick, check very carefully for others
Notify your doctor if you notice any rashes or unusual health problems later