Zoonotic diseases, or zoonoses, are diseases that can be transmitted from vertebrate animals to humans. Zoonoses are caused by bacteria, protozoa, fungi, viruses, parasites or prions, which are often part of an animal's natural flora (i.e., microorganisms that live in and on the animal) but can cause disease in humans. Infections can result from direct contact with animals or their products such as manure or placenta. Direct transmission can also occur through consumption of animal products (e.g., raw meat, raw milk, etc.) or through an animal bite. Humans can also become indirectly infected by contact with contaminated soil, food, or water. Farmers, ranchers, veterinarians, slaughterhouse workers, and other agricultural workers have a higher risk of contracting zoonoses because of their close contact with animals.
What are some examples of zoonotic diseases?
Some examples include:
Anthrax - a serious infectious disease caused by gram-positive, rod-shaped bacteria known as Bacillus anthracis. Anthrax can be found naturally in soil and commonly affects domestic and wild animals around the world.
Bovine tuberculosis - caused by Mycobacterium bovis (M. bovis), which is another mycobacterium that can cause TB disease in people and is most commonly found in cattle and other animals such as bison, elk, and deer. In people, M. bovis causes TB disease that can affect the lungs, lymph nodes, and other parts of the body.
Brucellosis - a bacterial infection with symptoms ranging from fever, mild headaches, muscle aches and rash to severe diarrhea and vomiting. Brucellosis can be fatal in rare instances. Both wild and domesticated animals can transmit Brucella bacteria by way of direct contact and through inhalation of infected aerosol.
Cryptosporidiosis - a diarrheal disease caused by the microscopic parasite Cryptosporidium.
Hantaviruses - a family of viruses that is spread mainly by rodents and can cause varied disease syndromes in people worldwide. Infection with any hantavirus can produce hantavirus disease in people. Hantaviruses in the Americas are known as “New World” hantaviruses and may cause hantavirus pulmonary syndrome (HPS). Other hantaviruses, known as “Old World” hantaviruses, are found mostly in Europe and Asia and may cause hemorrhagic fever with renal syndrome (HFRS).
Each hantavirus serotype has a specific rodent host species and is spread to people via aerosolization of the virus that is shed in urine, feces, and saliva, and less frequently by a bite from an infected host. The most important hantavirus in the United States that can cause HPS is the Sin Nombre virus, which is spread by the deer mouse.
Influenza viruses cause both seasonal flu and pandemic flu. Influenza can be transmitted from animals to humans, as occurred during the 2009 H1N1 (“swine flu”) pandemic. It is recommended that swine workers receive both the seasonal flu vaccine and, when necessary, vaccine for pandemic flu.
Leptospirosis - a bacterial disease that affects humans and animals. It is caused by bacteria of the genus Leptospira. In humans, it can cause a wide range of symptoms, some of which may be mistaken for other diseases. Some infected persons, however, may have no symptoms at all. Without treatment, Leptospirosis can lead to kidney damage, meningitis (inflammation of the membrane around the brain and spinal cord), liver failure, respiratory distress, and even death.
LA-MRSA (livestock-associated methicillin-resistant Staphylococcus aureus) infections of skin and soft tissues has been described in farmers who come in contact with pigs and cattle.
Psittacosis (Parrot fever) - caused by a type of bacteria Chlamydia psittaci that often infects birds. Psittacosis causes a wide range of symptoms, including fever, headache, and a dry cough. This illness can also cause pneumonia (a lung infection) that may require treatment or care in a hospital. Although rare, psittacosis can be deadly.
Q Fever - a bacterial infection caused by Coxiella burnetii from exposure to infected animals. Symptoms include fever, headache, muscle aches and cough. Infections can sometimes be serious, causing pneumonia or hepatitis.
Rabies - a fatal but preventable viral disease (caused by a rhabdovirus) that is spread to people if they are bitten or scratched by a rabid animal.
Because North Carolina is among the top five states for the production of poultry and pork products in the United States, workers in poultry and pork processing facilities in this state are at a greater potential risk of becoming infected by animal-specific zoonotic diseases such as psittacosis (parrot fever) and brucellosis than is the general working population.
What can I do to protect myself and others?
Proper personal protective equipment, especially gloves and eye and face protection should be worn whenever handling or otherwise processing meat from animals. Respiratory protection using HEPA filters may be necessary when working on the evisceration line of a poultry processing facility. Before eating or drinking and after removing gloves and other PPE, wash hands thoroughly with soap and running water.
Employers must perform a job hazard assessment and provide the appropriate PPE to employees, which may require implementing a respiratory protection program. In addition, they should train employees about how to protect themselves against infection and make available to employees vaccinations against zoonotic diseases. Adequate ventilation should be present to reduce the risk of airborne transmission of zoonotic diseases. Employers must also ensure that working surfaces and equipment used to process meat products are effectively cleaned and disinfected.
What resources are available to assist employers?
Safety and Health Programs
An example PPE hazard assessment and respirator program are available and can be customized to fit workplace conditions. Employers are required to perform a workplace hazard analysis to determine what personal protective equipment is necessary to protect employees from continued exposure to identified hazards.
Training and Outreach Services
Presentations on personal protective equipment and respiratory protection for general industry provides general safety and health information on personal protective equipment and should be modified to address site-specific conditions and hazards.
In addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request.
Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC).
A-Z Safety and Health Topics
The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.
Which standards apply?
OSH has adopted the following standards which are applicable to zoonotic diseases in North Carolina. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic.
29 CFR 1910 Subpart G - occupational and environmental control
29 CFR 1910.94 - ventilation
29 CFR 1910 Subpart I - personal protective equipment
General Duty Clause
Additionally, N.C. General Statute 95-129(1), commonly referred to as the General Duty Clause, may be applied for recognized serious hazards not covered by a specific NCDOL standard.
Other Applicable Standards
The Which OSHA Standards Apply webpage can help identify other standards that may be applicable to your worksite.
Where can I learn more?
- Industry Guide 49 - OSHA General Industry Standards Requiring Programs, Inspections, Procedures, Records and/or Training provides requirements for standards that can be applied to occupational exposure to zoonotic diseases in general industry.
If you would like to receive interpretive guidance on this or any other OSH standard or topic, you can submit your questions using the Ask OSH web form, by e-mail to firstname.lastname@example.org or by calling 919-707-7876.