Prevention of Zoonotic Diseases

II. IACUP OPERATIONS

B. Care and Handling of Animals and the Use of Protective Clothing in the Prevention of Zoonotic Diseases

PURPOSE

Zoonotic Diseases (Zoonoses) are diseases that are communicable from animals to people.  This standard operating procedure provides information on specific zoonotic diseases and procedures for the protection of faculty, staff and students who work with animals in the research laboratory, classroom, and field.

DEFINITIONS

Allergen- A substance—usually a protein—that can cause the immune system to react as if infected with a cold virus. Cats, rabbits, mice, rats, birds, and guinea pigs are the most frequently implicated allergy-causing species.

Biohazard- an organism, or substance derived from an organism, that poses a threat to (primarily) human health. This can include medical waste or samples of a microorganism, virus, or toxin (from a biological source) that can impact human health. It can also include substances harmful to animals and plants.

CDC- the Centers for Disease Control and Prevention is one of the major operating components of the Department of Health and Human Services (DHHS). The CDC’s mission is to protect America from health, safety, and security threats, both foreign and domestic.

NIOSH- the National Institute for Occupational Safety and Health is an agency of the CDC responsible for conducting research and making recommendations for the prevention of work-related injury and illness.

Care, Handling, Prevention & Protection


Review information on specific zoonotic diseases and procedures for the protection of faculty, staff and students who work with animals in the research laboratory, classroom, and field.
  • Occupational Animal Exposure

    Both research and non-research animals have the potential to cause injury, transmit zoonotic disease, and/or cause allergic reaction to those who have contact.

    These animal hazards can occur by either direct contact from handling an animal or just by being in close proximity, i.e., working or passing through an animal housing room, handling animals in the classroom, or during research in the field.

  • Training of Laboratory Animal Care Staff

    Faculty, staff, and students who have exposure to research and non-research animals need to be provided with the appropriate awareness training. Understanding routes of disease transmission, disease or allergy signs and symptoms, personal protective equipment, waste handling, and emergency contacts is very important.

    Persons working with animals or animal products shall receive individual training by their Principal Investigator, Classroom Instructor, or Supervisor in the safe handling of animals, the operation of any safety equipment and materials they may be required to use, and other procedures required to protect themselves and others.

  • Susceptibility

    Certain conditions might predispose the human body to increased susceptibility to zoonotic diseases. That is, the body might become infected more readily by the disease, or a worse form of the disease may develop. These include, but are not limited to:

    • Immune suppressive conditions (e.g., HIV, chemotherapy, corticosteroid treatments, concurrent diseases)- any condition that hampers the immune function lowers your natural resistance to other disease.
    • Pregnancy- pregnant workers are more susceptible to certain diseases, and the growing fetus is especially vulnerable to disease and the subsequent risk of possible permanent effects to full organ system development. Pregnant women should notify their supervisor as early in their pregnancy as possible, as the risk to the fetus with some hazards is greatest in the first few weeks.  If this is not possible they should consult a medical practitioner regarding the advisability of animal work as soon as possible after the pregnancy is confirmed.
    • Chronic smoking- chronic smokers are at greater risk of inhaled disease because of lung damage, and diminished mucociliary function.
    • Chronic alcoholism- alcohol consumption, acute or chronic, can decrease a specific white blood cell called a ‘monocyte’. The monocyte is responsible for fighting certain diseases. Chronic alcoholism further debilitates the immune system by decreasing several trace minerals and vitamins that are necessary for a normal immune function.

    Important:  If working with animals, faculty, staff, or students who have any of these conditions should consult their medical practitioner and advise their Principal Investigator, Class Instructor, or Supervisor.

  • Animal Bites, Scratch Exposure & Puncture Wounds

    Bites, scratches, and puncture wounds from needles used in animal research are potentially dangerous not only from the physical damage but also for the potential of contracting zoonotic disease or allergic reactions. Animal bites can become infected with a variety of bacteria that could lead to more serious problems.

    Important: If ANY animal bites you or you are punctured with a needle that has been used on an animal, thoroughly clean the wound with an antibacterial soap solution (such as a surgical scrub) and notify your supervisor and Public Safety immediately.

    To prevent bites, scratches and other puncture wounds, animal use and care staff must be trained in and knowledgeable of species-specific animal handling techniques. Training videos are available on the American Biological Safety Association (ABSA) website.  If needed, the Consulting Veterinarian will assist with training.

  • Allergies

    Allergies can develop to any kind of protein, in any kind of workplace. Animal allergies can develop in pet owners, for example. Contact allergies are common in the laboratory animal industry and in the veterinary care industry, because of chronic exposure. Exposure to animal related allergens (fur, saliva, hair, dander, and protein from urine) may occur by inhaling contaminates or by direct contact.

    *Rodent contact allergy Workers with ongoing exposure to rodents are at higher risk of developing allergies to them.  The person is hyper-sensitized to the rodents mainly through exposure and inhalation of urine proteins that are aerosolized. Signs of allergies can vary tremendously, but include itching, hives, skin rash, flushing and inflammation; respiratory irritation and asthma; nasal, eye, or sinus symptoms; and in rare cases, shock.

    Important: Wearing gloves and a NIOSH approved, N-95 (or better) respirator can considerably diminish exposure to these antigens and theoretically reduce the chance of developing these allergies. If you suspect you have developed an allergy to something in the workplace, notify your Principal Investigator, Classroom Instructor, or Supervisor.

  • Personal Protective Equipment

    The Guide to the Care and Use of Laboratory Animals suggests that animal-care personnel wear appropriate institution-issued protective clothing, shoes or shoe covers, and gloves.  Protective clothing should not be worn beyond the boundary of the animal facility. Personnel working in areas where they might be exposed to contaminated airborne particulate material or vapors should be provided with suitable respiratory protection. 

    Protective clothing and equipment will be issued to animal care staff consistent with the risk associated with the research activities, hazards, and animal species involved.

    • Respirators- the CDC recommends that workers protect themselves from diseases potentially spread through the air (such as viruses, tuberculosis, and psittacosis) by wearing a fit-tested respirator at least as protective as a NIOSH-approved N-95 respirator. (The “N” means it is not resistant to oils and the “95” means that it will remove 95% of the particles in the air.)  Contact the Office of Environmental Health and Safety concerning what mask you need; EH&S will assure that you are supplied with the correct mask.
    • Gloves- gloves are recommended to prevent contact allergy to rodents and to prevent potentially infective material from getting on the skin or through cuts and breaks in the skin.  Two types of gloves in the healthcare industry: latex and vinyl. Vinyl is not as effective as latex against viral penetration. In case of toxin use, gloves must be also impervious to organic solvents or other diluents employed with the toxin. Non-latex gloves are available.

    *Latex contact allergy - workers with ongoing latex exposure, individuals with a tendency to have multiple allergic conditions, people with spina bifida, and people with allergies to certain foods such as avocados, potatoes, bananas, tomatoes, chestnuts, kiwi fruit, and papaya are at increased risk of latex allergies. Acute reactions are most common, but they can also be delayed, with a variety of symptoms surfacing hours or days later. These include itching, hives, skin rash, flushing and inflammation; respiratory irritation and asthma; nasal, eye, or sinus symptoms; and in rare cases, shock.  

    To reduce the chance of developing a latex allergy – do not use hand creams, perfumes, or cologne on the hands while using latex gloves (these cause the latex to deteriorate); wash hands after using latex gloves to remove any antigens on the skin; wipe down areas contaminated with latex dust.

    • Surgical Scrub- when washing hands, scratches or bites, a surgical scrub or soap that contains a medical grade disinfectant is necessary.  Follow label directions and use appropriate contact times.
    • Eye Protection- protective glasses will be made available if needed to prevent contaminated materials from making contact with eyes.  Based on the products’ MSDSs, contacts may not be permitted when working in the lab.
  • Preventive Measures

    Transmission of infectious agents from animals to persons in contact with them can largely be prevented by:

    • Thorough hand washing after handling animals or cleaning their enclosures
    • Not eating, drinking or applying cosmetics within the animal housing facility.

    For certain pathogens, immunization is an appropriate way of controlling the risks of acquiring a zoonotic disease.

  • Personal Protection in the Field

    Follow good safety and hygiene practices in the field as well as in the laboratory, including hand washing/sanitizing, careful animal handling, and wearing gloves, masks and eye protection as appropriate.

    Avoid Mosquito and Tick Bites

    Ticks and mosquitoes are the vectors for a number of zoonotic diseases including Lyme Disease, Rocky Mountain Spotted Fever, Dengue Fever, and West Nile Virus.

    • Use insect repellents. Repellents containing DEET, picaridin, IR3535, and some oil of lemon eucalyptus and para-menthane-diol products provide longer-lasting protection. To optimize safety and effectiveness, repellents should be used according to the label instructions.
    • Use products that contain permethrin on clothing. Treat clothing and gear, such as boots, pants, socks and tents with products containing 0.5% permethrin. It remains protective through several washings. Pre-treated clothing is available and may be protective longer.
    • Wear long sleeves, long pants, and socks.
    • Bathe or shower as soon as possible after coming indoors (preferably within two hours) to wash off and more easily find ticks that are crawling on you.
    • Examine gear. Ticks can ride into the home on clothing, then attach to a person later, so carefully examine outer clothing and day packs.
  • Classification of Zoonoses

    The most commonly encountered zoonoses are organized by symptomatology in humans. This is a brief overview of the main features of select zoonotic diseases. Comprehensive information on zoonotic diseases is available from the CDC. In addition, resources organized by type of animals are listed at the end of this document.

    As with other hazardous materials and biohazards, contraction to these zoonotic diseases occurs primarily through infectious material absorbed through the skin, through cuts in the skin, in the mouth, in the eyes, or by inhalation of aerosolized particles.

    Organisms Primarily Causing Diarrhea

    The following organisms may cause diarrhea and dehydration. While working with laboratory animals, most of these diseases can be prevented by good hygiene which includes wearing protective gloves, washing hands before and after using the bathroom, not eating and drinking in the lab, and washing hands at the conclusion of work. 

    • Salmonella is a very common bacterium usually associated with birds and reptiles. However, many animals may be responsible for its transmission. Rodents have been reported to shed the disease. It usually presents with abdominal cramps, nausea and vomiting that may develop into diarrhea. It may also be accompanied by fever, muscle aches, and malaise.
    • Escherichia coli (E. coli) is a very common bacterium. Diarrhea would be the main sign of the disease and is more commonly associated with farm animals and chickens, but is possible in any species; humans are the main shedders of this disease.
    • Vibrio parahaemolyticus is a bacterium that lives in brackish saltwater and seawater. It typically causes gastrointestinal illness in humans. V. parahaemolyticus naturally inhabits coastal waters in the United States and Canada and is present in higher concentrations during summer; it is a salt-requiring organism.
    • Cryptosporidium paryum is a protozoan (single eukaryotic cell) that may produce profuse, watery, diarrhea. Sometimes abdominal cramping, nausea and fever may develop. It is primarily carried by cattle, chickens and turkeys, and humans. It is possible that any animal associated with humans could shed the disease.
    • Campylobacter is a bacterium usually associated with cattle and birds, but also can be transmitted by feces of other animals. In humans, it may also cause hepatitis, meningitis, fever, and rarely, abortions, and premature delivery.
    • Rotavirus enteritis usually occurs only in children, and is more common during winter. It is extremely common in humans with 60% of children worldwide exposed by their first birthday. It may be associated with nursing mice and is usually self-limiting in humans, but has been reported to cause death in children.
    • Shigella is a rare bacterium (except in non-human primates). The resulting diarrhea might include blood and mucus. Shigella is probably very rare in other animals, but possible.

    Organisms Causing Primarily Respiratory Disease

    Signs of primary respiratory disease might include difficulty breathing, a pain in your chest while inhaling, asthma-like symptoms, ocular redness or itching, and fever. While working with laboratory animals, most of these diseases can be prevented by good hygiene which includes wearing latex gloves, wearing a NIOSH approved N-95 (or better) respirator, and washing your hands at the conclusion of work.

    • Chlamydia psittissi is a bacterium that causes the disease, Psittacosis. It is associated with inhaling feather dust and dried droppings of birds of all types.  Symptoms include fever, headache, myalgia, and pneumonia-like respiratory illness.  It may also cause chronic conjunctivitis (inflammation of the conjunctiva, the clear membrane that covers the white part of the eye and lines the inner surface of the eyelids), commonly called ‘pinkeye.’
    • Hantavirus a virus that has been associated only with the deer mouse, cotton rat and rice rat in the Southeastern United States and the white footed mouse, elsewhere. However, it has been theorized that it is possible for any rodent to carry it. It can cause ‘hantavirus pulmonary syndrome’ and symptoms of fever, deep muscle aches, and severe shortness of breath.
    • Mycobacterium avium is a bacterium that is mostly associated with chickens and people that work with chicken manure, but might be associated with any kind of bird. It can cause pneumonia.
    • Pasteurella is a bacterium that may rarely cause respiratory disease in humans. It mainly causes contaminated skin wounds. A more detailed description is given in the next section.

    Organisms Causing Primarily Skin Disease

    Persistent red lesions, itchy skin or bumps, or non-healing wounds might indicate exposure to one of the following zoonoses. While working with laboratory animals, most of these diseases can be prevented by good hygiene which includes wearing latex gloves, washing any bite wounds immediately in an antibacterial soap (such as a surgical scrub solution), and washing your hands after you complete your work.

    • Pasteurella is a bacterium that can cause infected wounds resulting from bites and scratches mainly from cats and dogs, but also rabbits and occasionally rodents. Humans may also carry the disease. The first signs of pasteurellosis usually occur within 2 to 12 hours of the bite and include pain, reddening, and swelling of the area around the site of the bite. Pasteurellosis can progress quickly, spreading through the body from the bitten area. Untreated, this infection can lead to severe complications.

    Important:  Bites to the hand need special attention; if pasteurellosis develops in the tissues of the hand, the bacteria can infect tendons or even bones and sometimes cause permanent damage if appropriate medical care is not administered promptly. Red streaks and enlarged lymph nodes may indicate a very serious septicemia is developing.

    • Visceral larval migrans may be caused by nematodes (roundworms) that penetrate the skin and become ‘lost’ as they try to complete their life cycle in an unfamiliar host. The lesions tend to be small, ‘sigmoid’ (curvilinear) and can be itchy.
    • Dermatophtes- are a variety of fungi that cause ‘ringworm’. The resultant lesions may be shaped in a red ring, with possible itchy, tingly or burning red bumps or lines as well.
    • Mycobacterium is a bacterium that is associated with fish. It can be difficult to cure and is manifested by puffy, red, persistent, non-healing wounds.
    • Sarcoptic mange is caused by a mite that may be present on any domesticated animal. It is usually self-limiting and may cause itchy red bumps or lines.
  • Other Zoonotic Diseases

    • Dengue Fever is a viral disease transmitted by the bite of an infected mosquito most commonly found in tropical urban areas of the world.  The principal symptoms of dengue fever are high fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising). Generally, younger children and those with their first dengue infection have a milder illness than older children and adults.
    • Leptospirosis is caused by bacteria spread through the urine of infected animals, which can get into water or soils and survive there for weeks to months.  Many different kinds of wild and domestic animals carry the bacterium, but may show no symptoms of the disease.  In humans, symptoms may be quite varied, including fever, flu-like signs, muscle aches, nausea, a stiff neck, conjunctivitis, bruising and bleeding, and jaundice may occur.
    • Lyme Diseaase is caused by the bacterium, Borrelia burgdorferi, and is transmitted by ticks in the field.  Small mammals, especially rodents, often play a major role as reservoir hosts. Birds, lizards, and rabbits may also harbor certain Borrelia species and serve as reservoir hosts.  Early symptoms include a red, expanding rash called erythema migrans (EM) or “bull’s-eye” rash and fatigue, chills, fever, headache, muscle and joint aches, and swollen lymph nodes.
    • Rabies is a viral disease that is transmitted primarily from saliva to blood (as in the case of bite wounds) from an infected animal. Without treatment, it is nearly always fatal in humans.  The vast majority of rabies cases reported to the CDC each year occur in wild animals like raccoons, skunks, bats, and foxes. Domestic animals account for less than 10% of the reported rabies cases, with cats, cattle, and dogs most often reported rabid. Any mammal could theoretically carry the virus, but it is primarily a disease of carnivorous mammals, and exposure would be highly unlikely in the rodent lab environment.
    • Rat-Bite Fever is caused by Streptobacillus monilformis or Spirillum mino.  These organisms are in the respiratory tracts and mouths of rodents, especially rats. Most human infections are the result of a bite wound. Symptoms include chills, fever, malaise, headache, and muscle pain. A rash can develop along with painful joints, abscesses, endocarditis, pneumonia, hepatitis pyelonephritis, and enteritis.
    • Rocky Mountain Spotted Fever, Toxoplasma, and Brucella are zoonotic diseases more likely encountered in veterinary practice or in research in the field resulting from close contact with ticks, dogs, cats, and cattle. They are less likely to be encountered in a laboratory environment.
    • West Nile Virus is transmitted by the bite of an infected mosquito.  Most people have no symptoms; however about 20% develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Most people with this type of West Nile virus disease recover completely, but fatigue and weakness can last for weeks or months.

Resources

Marine Mammal Zoonotic Bacteria – UC Davis

Working with Aquatic Species – Texas State

Zoonosis Information Sheet for Fish and Amphibians - Cornell

Zoonosis Information Sheet for Birds - Cornell

Zoonosis Information Sheet for Reptiles - Cornell

Zoonosis Information Sheet for Wild Mammals - Cornell

Working with Wild Rodents - Cornell

Zoonotic Fact Sheet – American Biological Safety Association


Approved: April 19, 2006

Revised: October 24, 2014, September 27, 2019