Worry about pets and wildlife sharing their diseases with us?by Jim Chan.
(Updated: August 31, 2018)
Raccoon Rabies incident
Toronto Star news article reported that on December 4, 2015, a case of Raccoon Rabies was confirmed in Hamilton, Ontario in Canada. The outbreak resulted in 128 cases of raccoon strain rabies in both raccoons and skunks in Ontario, according to report from the Ontario Ministry of Natural Resources and Forestry. Ontario rabies outbreak linked to hitchhiking raccoon
Rabies is an acute disease, caused by a virus (Rhabdovirus), that can infect all warm-blooded animals. This is probably one of the most dangerous zoonotic diseases and almost without exception, rabies is 100% fatal once a person becomes infected with rabies virus and clinical signs develop. People can be exposed to rabies through close contact with the
saliva of an infected animal, most often from licks, bites or scratches . Animals involved may be wild animals such as skunks, raccoons, and bats, stray or feral animals such as cats and dogs,or house pets, even cattle and horses. Because of public health concerns surrounding rabies, most communities require the mandatory vaccination of dogs and cats.
Prevention and treatment of rabies:
- Prevention - People in jobs that are at high risk of exposure to rabies, such as animal control officers, animal handlers, and veterinarians should be vaccinated before potential exposure
- Vaccination of pets - Take pet to the veterinarian for check-up and rabies vaccination every year.
- First aid - Should provide first aid immediately to a person who has been bitten by or had contact with a potentially rabid animal
- Medical attention - Contact a physician, attend a hospital for immediate medical attention after exposure to a potentially rabid animal and to determine if treatment is needed.
- Report incident - Notify local health department as soon as possible for investigation.
How do pets and wildlife share their diseases with us?
There are many diseases (Zoonosis or Zoonoses) that affect pets and wildlife and can be dangerous to you no matter if you live in the country or urban areas. It is hard to know which animals around us could be carrying zoonotic diseases, especially since some infected pets or wildlife can be carrying the infectious microbes often look healthy and act normal. According to University of Guelph (OVC) Centre of Public Health & Zoonoses,
one-of-a-kind research centre aimed at preventing and controlling emerging animal-related diseases that threaten public health indicated that ''zoonotic diseases account for approx. 60% of known human pathogens and 75% of emerging human pathogens''.
Pets and wildlife remain a primary source of many reportable and non-reportable disease and a number of outbreaks have been linked to these animals.
Usually zoonotic diseases are spread from animals to humans from:
- contact with an animal's wastes such as feces or urine
- bite or scratch of an infected animal
- consuming meat of an infected animal
- bite of an infected insect
- direct contact with an infected animal
In my career as a public health inspector for 36 years in Canada, I have involved in many zoonotic disease investigations.
Flashback: In 1979, I investigated an outbreak of Psittacosis (Parrot Fever) in Ontario when a person died, the pet budgie tested positive for Psittacosis and was linked to a large shipment of budgies in a pet warehouse. In 1982, two little girls were hospitalized with Salmonella poona infection that linked to their pet turtle (Red-eared slider) at home, investigation revealed that fertilized turtle eggs from a Louisiana turtle farm were shipped to Canada as 'food', these eggs were hatched and distributed to pet shops and responsible for an Salmonella poona outbreak (Note: It is prohibited for pet trade business to ship live turtles to Canada except met CFIA requirements). In 1996, a race horse at a Toronto racetrack was infected with Rabies and resulted in over 30 people with direct contact with the horse have to get rabies shots
(post-exposure prophylaxis). Investigation revealed a possible link to an infected groundhog in the area (Photo left - newspaper article). In 2005, a young child was hospitalized and was confirmed by the hospital that the child was infected with Raccoon Roundworm, the investigation revealed that the young child with a history of eating dirt most likely to have ingested soil and sand in the backyard play area contaminated with raccoon feces that contained Raccoon Roundworm or Baylisascaris eggs. The environmental samples I collected from the backyard and play area (sand box) tested positive for Baylisascaris (Photo right - sample collection).
A. Zoonotic diseases from pets
When we think of pets, we often refer to dogs, cats, birds, hamsters and the odd rats, but the popularity
1. Toxoplasmosis is caused by a parasite (protozoan) that can infect different animals, including cats, and can pass on to people. Toxoplasmosis may cause severe fetal abnormalities and abortion when expectant mothers become infected during their pregnancy.
Pet cats can be the cause of this disease as the complete life cycle of the parasite occurs only in cats. Cats can become infected by preying on infected birds and rodents, and most cats do not show any symptoms of disease but able to pass the infection to human. One common mode of transmission is through contact with faces in cat litter boxes. Picking up cat feces, cleaning out litter box often and following good hygiene practises are the best defences against this parasite. Toxoplasmosis is also considered to be a leading cause of death attributed to foodbourne illness in the United States from eating raw or under-cooked meat of infected animals.
2. Cat Scratch Fever (Bartonellosis) is caused by a bacterium, (either Bartonella henselae or Bartonella quintana) and is commonly acquired from cats, especially outdoor cats. Most people contract the disease after
being scratched or bitten by an infected cat, however, in some incidents, it is possible to contract the disease from petting or handling a cat and then rubbing the eyes since the bacteria may be present on cat fur.
Cat scratch fever is usually not a serious illness for healthy people but can be dangerous for people with weaken immune system. Common symptoms including malaise and enlarged painful lymph nodes as well as a local inflammation at the site of the wound.
3. Roundworms (Ascariasis) is caused by the parasitic roundworm Ascaris lumbricoides.
These intestinal parasites can infect dogs, cats, and many other animals such as raccoons.
This worm can also infect people causing illness, most people infected with Ascaris often do not show symptoms but some people may show mild abdominal discomfort. Heavy infections can cause intestinal blockage and impair growth in children is known as visceral and/or ocular larval migrans.
Keeping pets free of parasites, cleaning out litter boxes often and picking up and disposing pet feces, and following good personal hygiene practises are the best way to protect against this parasite.
can infect many species of animals, including dogs,cats, hedgehog, pet rats as well as most reptiles such as snakes, frogs, turtles, lizards, newts etc. These pathogens can be passed to people and cause illness. In addition, people (particularly children) handling pet food contaminated with Salmonella have been linked to illness and outbreaks and resulted in pet food recalls. Proper hygiene, especially hand washing and safe food handling techniques are the best way to prevent spread of these diseases (Food safety at home).
5. Ringworm (Dermatophytosis) is a skin disease caused by fungal infection in humans, pets such as cats and dogs, and domesticated animals such as sheep and cattle. Do not get confuse with the name as Ringworm
is not a worm or parasite, but a fungus. Ringwormmost often affects children, but can also affect people of all ages. This common skin disorder is very contagious and can be passed by direct skin-to-skin contact, or with contaminated items such as a comb, brush, hat, towel, clothing, and change room or shower floor of locker room, pool and spa. People can also catch Ringworm from an infected cat or dog as the infections are contagious and easily passed from pets to people and also from people to pets. Pets infected with ringworm should be handled carefully, preferably wearing gloves when handling and washing hands frequently and thoroughly. Image from:http://diseasespictures.com/ringworm-pictures/
B. Zoonotic diseases from wildlife
1. Raccoon Roundworm (Baylisascaris procyonis & Baylisascaris. columnaris) is an intestinal parasitic infection caused by contact with infected raccoon feces often by accidental ingestion or inhalation of the parasite eggs in the feces. The parasite can cause severe human neurological disease.
Raccoons defecate at the base of trees, patio decks, sand boxes, kid's play area and rooftops. Adult raccoons infected with Baylisascaris shed millions of eggs daily in the feces and the eggs hatch into larvae; these larvae are infective and can remain viable for years. After ingestion, larvae migrate through the host's body tissues including the brain, eyes and viscera. In this investigation, raccoon feces were found throughout the backyard of the patient's home, especially in the deck (Photo - right) where the patient spent many hours playing, as well as in the
sandbox. The environmental samples collected from the backyard and play area (sand box) tested positive for Baylisascaris (Photo left - sample collection).
To reduce risk of exposure to Baylisascaris infection, prevent accumulations of raccoon feces and remove raccoon feces regularly, take precaution while removing feces such as wearing disposable gloves, clean and sanitize exposed surfaces or furniture or toys with boiling water, common household sanitizers usually not effective to kill the parasite. Never feed raccoon as this will attract more raccoon to the property. Eliminate access to food sources such as
garbage, food wastes and pet food. Good hand hygiene is important as handwashing and good personal hygiene can reduce risk of communicable disease transmission, especially after outdoor play and before eating.
2. Lyme disease is an infection caused by the bacteria, Borrelia burgdorferi and is transmitted to humans by ticks. Ticks live and feed on wildlife such as rodents and birds. In Canada, there are approximately 40 species of tick and most of the ticks do not transmit Lyme disease. Blacklegged ticks are the only type of tick in Ontario that can transmit Lyme disease. Ticks feed on blood by inserting their mouth-parts through the skin of a person, or an
animal.Ticks feed slowly and their body gradually enlarges (Photo - right) as they feed, making it more visible for people to detect. It usually takes from 3 to 7 days for a Blacklegged tick to complete a blood meal. The longer a tick is attached to a person, it is more likely to transmit infection because the bacteria requires time to migrate from the tick's gut to its salivary glands. Therefore, prompt detection and removal of ticks is one of the key methods of preventing Lyme disease.
Lyme Disease in Canada
Symptoms: Early symptoms (Mayo Clinic) include a flu-like illness with headache, slight fever, muscle or joint pain, neck stiffness, swollen glands, jaw discomfort, and inflammation of the eye membranes and a diagnostic rash. The red rash starts at the tick bite site and expands rapidly and often has a bulls-eye appearance. Additional smaller skin lesions may appear at other sites of the body and may last for days or weeks. Later symptoms, including heart, nervous system, and joint manifestations, may develop in untreated individuals. The joint pain and swelling usually occur one or more months after infection, may involve one or more joints, and may recur in different joints; the knee joint is most frequently affected. More information on worldwide problem, see Lyme disease data file - World Health Organization
3. Histoplasmosis is a respiratory disease in humans caused by inhaling spores from the fungus Histoplasma capsulatum. This fungus can be found in soil, in bat caves with decaying bat guano and bird droppings. The common sources for histoplasmosis infection include: (1) traditional bird roosts, (2) poultry farms, (3) enclosed buildings where birds or bats have roosted, and (4) natural or organic fertilizers.
In addition, histoplasmosis is the most common disease associated with urban pigeon problems. People can get the disease by breathing in the fungal spores that grow on the pigeon droppings accumulated in the area with an active pigeon infestation (Photo - left. Taken outside Toronto City Hall) Pigeons often leave a great quantity of droppings along sidewalks, walls, roofs, overheard shelters, building balconies and inside building, which can result in airborne health hazard. Problem with Histoplasmosis, see Histoplasmosis info.
4. Psittacosis, also called Ornithosis and Parrot Fever, is an infectious respiratory disease caused by Chlamydia psittaci, a viruslike organism that affects humans, pets, and livestock. According to the Centers for Disease Control & Prevention, this is a rare disease as there
have been fewer than 50 confirmed cases per year in the United States since 1996, although many cases may have gone undiagnosed or unreported. Pigeons are most commonly associated with the transmission of the disease to humans but pet birds (parrots, parakeets, macaws, and cockatiels) and farm poultry (turkeys and ducks) can also carry Chlamydia psittaci. Some birds can act as healthy carriers, shedding the organism in their feces, which later may become airborne as dust. Symptoms include including: fever and chills, nausea and vomiting, muscle and joint pain, diarrhea, weakness, fatigue, dry cough.
Other possible symptoms include chest pain, shortness of breath, and sensitive to light.
5. Diseases from rats to human Other than food poisoning, rats can also transmit some communicable diseases to humans via their urine, feces, fleas and bites. Many of these diseases are rather serious, and some can even be fatal. The following are some examples of diseases that can be transmitted by rats:
Rat-bite fever - Disease that cause by bites or scratches from infected rats, handling rodents with the disease (even without a bite or scratch), consuming food or drink contaminated with the bacteria. Symptoms of Rat-bite fever.
Plague - Caused by the bacterium Yersinia pestis. Humans usually get plague after being bitten by a rodent flea that is carrying the plague bacterium or by handling an animal infected with plague. In history, plague killed millions of people in Europe during the Middle Ages.Today, the risk of plaque can still be a risk in North America.
Leptospirosis - A bacterial disease that is spread by rat urine to humans. Symptoms including fever,
chills, jaundice, vomiting, muscle aches or rashes. If left untreated, leptospirosis can cause kidney damage and in rare cases, can even be fatal.
Hantavirus is a virus that can cause febrile illness in humans and sometimes kidney, blood, or respiratory ailments, and can sometimes be fatal. The symptoms include fever, headache, muscle aches, nausea, vomiting and lower back pain. Rodents such as rats and mice are the primary vectors for viruses in this group and these viruses are found across the US. Infected rodents leave viruses in their urine, feces and/or saliva and can remain chronically infected. The droppings from infected rodents are believed the be the source of both airborne and direct transmission to other rodents and humans.
flies and ticks that have been on dead rodents, including rats and rabbits. The disease can be transmitted through airborne transmission so even breathing the air around an infected animal can transfer the disease.The best prevention is to steer clear of wild rodent corpses, especially in the eastern part of the state.
For more information, see video and article: http://www.kotatv.com/news/wyoming-news/rabbit-fever-hits-wyo-and-you-do-not-want-to-catch-it/34324894
Other related links
Pet dog responsible for a plague outbreak in USA
Raccoon roundworm - rare case in Toronto
Rats in the city