Under Regulation 557 – Communicable Diseases, made under the Health Protection and Promotion Act, veterinarians have a legal obligation to report a suspect or confirmed case of a reportable zoonotic disease to their local Medical Officer of Health. Veterinarians practicing in Toronto must report animal cases of diseases (i.e. avian chlamydiosis, avian influenza, novel influenza, and Echinococcus multilocularis infection) to Toronto Public Health as follows:
Veterinarians practicing outside of Toronto should report cases of diseases to their local public health unit.
Background
Avian chlamydiosis (or avian psittacosis) is a zoonotic disease of birds, caused by the bacterium Chlamydophila psittaci. Although most, or all, species of birds are able to transmit the disease, the most common are psittacine (parrot-type) birds, especially cockatiels and budgerigars (commonly called parakeets or budgies). Avian chlamydiosis can also occur in poultry, pigeons and doves as well as canaries and finches, but is less frequently diagnosed in these birds.
Transmission in Birds
C. psittaci is transmitted between birds through inhalation of infectious dust or airborne particles (e.g. feathers) or ingestion of infectious material. Large quantities of the organism are excreted in feces, and can become aerosolized when the fecal materials dry.
Transmission to Humans
Birds can transmit avian chlamydiosis to humans, causing human psittacosis. The transmission of avian chlamydiosis to humans occurs when a person inhales dust or other dried secretions from birds. Bacterial infections caused by C. psittaci can cause severe pneumonia and other serious health problems in humans.
Background
Avian influenza is a zoonotic disease that can affect all species of birds. There are at least 15 types of avian influenza, and all are caused by various strains of type A influenza virus. Influenza A viruses are widespread and in wild aquatic birds. Although avian influenza A viruses circulates among birds, the viruses can occasionally infect other species.
Transmission in Birds
Birds transmit avian influenza to one another through secretions and droppings. Once the virus is introduced into a flock of birds, it is transmitted either from bird to bird, or flock to flock.
Transmission to Humans
Most avian influenza viruses do not cause disease in humans. However, there are two viruses that cause illness in humans. Although rare, transmission of these viruses to humans occurs through exposure to infected poultry or contaminated environments, such as live poultry markets.
Background
Novel influenza, is similar to avian influenza, however, it is defined as any influenza virus not already known to be endemically circulating in Ontario’s animal species. Similar to influenza A viruses in birds, there are influenza A viruses specific to mammals. For example, swine influenza viruses in pigs, equine influenza viruses in horses, and canine influenza in dogs.
Transmission in Animals
Transmission of novel influenza A viruses usually occurs within the same species, and in rare cases transmission between animal species can occur. Transmission usually occurs either by direct contact or when an infected animal coughs or sneezes and aerosol droplets spread through the air and come in contact with other animals.
Transmission to Humans
Swine, equine and canine influenza viruses rarely infect humans. Occasionally, these flu viruses can infect humans and it is believe that the 2009-2010 pandemic influenza virus was the result of swine influenza transmission to humans. Transmission of novel influenza viruses from animals to humans usually occurs when an infected animal coughs or sneezes and aerosol droplets spread through the air and come in contact with humans.
Background
Echinococcus multilocularis is a small zoonotic tapeworm found commonly in the northern hemisphere. E. multilocularis infections are rare, with only a few documented cases of infections of dogs and cats, in North America.
Transmission in Animals
While rodents are the intermediate hosts of E. multilocularis tapeworms, dogs (or wild canids, such as foxes and coyotes) are the definitive hosts. Cats can also become infected. E. multilocularis infection of animals occurs when an animal comes into contact with infective E. multilocularis eggs found in the environment or from other animals.
Transmission to Humans
Humans are also intermediate hosts for E. multilocularis tapeworms. E. multilocularis tapeworms cause alveolar echinococcosis (AE) in humans. Transmission to humans mainly occurs through ingestion of food or water contaminated with E. multilocularis tapeworm eggs.
The following resources may be useful for veterinarians with respect to reportable zoonotic diseases.
Accurate and complete reporting of zoonotic diseases to Toronto Public Health is required for several reasons. The most common reasons include: