A Brief Overview of Zoonotic Disease
This section focuses on zoonotic disease associated with animals used that The University of Montana including general methods to prevent disease transfer from animals to humans, and specific diseases associated with animals commonly used at The University of Montana. It is the responsibility of Principal Investigator (PI) to education their staff on zoonotic diseases of the animals that they are using in their research or teaching activities. The Attending Veterinarian is available for consultation and research concerning zoonotic diseases.
While most animals at The University of Montana are free of zoonotic diseases, it is important to be aware of pathogenic organisms that may be carried by animals. Upon request, additional information about specific types of animals and their associated disease conditions may be obtained from the Director of Laboratory Animal Resources.
Principal Investigators, Co-Investigators, and animal users are required to participate in training related to the program. Principal Investigators are responsible for educating staff and students who are in contact with animals as part of the Principal Investigator’s protocol(s) on the availability of the program (i.e., medical evaluations, recommended immunizations) and the hazards that may be required to undergo a Comprehensive Surveillance Questionnaire Evaluation and receive training about potential zoonotic agents as well as other potential hazards that may be encountered while working with or around animals. Incumbent employees are strongly recommended to participate.
Animals primarily used for research or teaching purposes at The University of Montana are mice, rats, frogs, guinea pigs, rabbits, birds and sheep. Allergies to animals are among the most common health problems affecting personnel who care for and use animals in research. Laboratory animal allergies are associated with the inhalation of allergens, such as animal dander and urinary proteins, into the lungs. Although allergies may be associated with any species of animal, in the laboratory most cases are due to contact with small rodents (mice and rats). Pre-existing allergies to dust mites, pollens and molds, and tobacco smoking are risk factors for the development of laboratory animal allergies.
Zoonotic Agents – Diseases Transmitted from Animals to Humans
A zoonotic disease is any disease that may be transmitted from an animal to a human under natural conditions. Zoonotic diseases pose a risk to University of Montana laboratory personnel, students and visitors who work with or around animals. Some of these diseases pose a significant health consequence. Zoonotic diseases that you may recognize are rabies and ringworm.
Transmission of zoonotic diseases can be prevented through a variety of means, including use of protective clothing, prevention of bites and scratches, proper sharps handling procedures, medical surveillance and vaccination programs, and post-injury treatment. The University of Montana Attending Veterinarian is responsible for veterinary surveillance of all animals used in the department of laboratory animal resources at The University of Montana-Missoula, including those animals that are housed outside the animal laboratory facility.
Zoonoses (diseases transmitted from animal to man) will be discussed thoroughly in your training lecture. Most of the animals purchased are specifically raised for biomedical laboratory research. These animals are less likely to have diseases since their environment and contact is controlled. However, occasionally animals come in contact with untrained personnel or other animals in shipment, etc. and thus may become infected with a disease. Finally, your own pets present a reservoir for infections that can be transmitted to the laboratory animals. The following are a few diseases to be especially aware of:
Tetanus is caused by a bacterium called Clostridium. Clostridium can live in environments of low oxygen. The Public Health Service Advisory Committee on Immunization Practices recommends immunization against tetanus. It is suggested that you keep your tetanus vaccination up to date at all times. Any puncture wound may require a booster.
Cats and rabbits can be asymptomatic carriers of the fungus that causes ringworm. In humans, the disease usually consists of small, scaly, semi-bald, grayish patches with broken, lusterless hairs, with itching. However, other symptoms may appear. It is usually associated with the hair which in each of these animals can be floating around in the room. Prevention is to wear proper clothing and practice good personal hygiene.
- “Q” Fever
“Q” Fever is caused by Coxiella burnetti and infects many animals including humans, dogs, cats, sheep, goats, etc. In some areas, about 1/3 of the human population have been exposed to the disease. Sheep, goats and cows have the highest infection rate. The organism is found in large numbers in placental tissues but can also be spread through the feces and urine or on the wool or coat. It can be aerosolized and inhaled. The highest chance of getting the disease is when working with pregnant ewes during fetal surgery of during birthing of lambs. There may be few or no symptoms, from a bad cold with fever and headache to becoming very sick. Persons who are pregnant or have a history of valvular hear disease are at increased risk for developing complications from the infection. Personal protective equipment (gloves, lab jacket or coveralls, show covers, etc.) should be worn. The University of Montana-Missoula makes every attempt to use only male or non-pregnant female sheep in research in order to minimize the risk of Q fever exposure to personnel.
Rabies is caused by a virus and occurs throughout the United States. It can infect virtually all mammals, including humans. Most laboratory animals are protected through vaccinations or isolation. However, PIs or their staff and students working with wild animals in field studies may be at risk of exposure to rabies. The rabies virus can be transmitted through bite wounds or contact with saliva.
Salmonella is a bacterial disease that occurs in a multitude of animal species, including non-human primates, cows, horses, and pigeons. It is transmitted through the feces. Animals may not show signs of the disease but can still infect other animals. Disease can be very mild diarrhea to stomach pain, fever, chills, headache, nausea and vomiting.
- Diseases of birds
Psittacosis is a disease that almost any bird can have including chickens, turkeys and pigeons. Birds may not show signs of the disease but can still transit it through their feathers, excreta, etc. Avoid contact with obviously infected birds. When working with birds, wear your protective clothing including a mask and gloves.
Newcastle Disease can be transmitted from birds to humans generally through the virus getting into your eye. Face masks and washing afterwards should help to prevent it.
- Rat bite fever
Asymptomatic in rodents and hard to culture. Infection comes from contaminated milk or food but other animals can carry it too such as the dog or cat.