Laboratory Animal Allergy (LAA) and Rodents

1. Laboratory Animal Allergy (LAA) and Rodents Note: Images used in this presentation are for educational, non profit use ONLY. Neil Grove Division Of Laboratory Animal Medicine University of North Carolina – Chapel Hill

2. What is LAA? • LAA can be defined as allergic rhinitis (inflammation and fluid production in linings of nasal passages, sinuses, and eyelids), asthma, and dermatological symptoms that may result from exposure to laboratory animals. • ILAR 2001

3. What are animal allergies? • Animal-related allergies and asthma are exaggerated reactions of the body’s immune system to animal proteins, also known as allergens. Sources of these allergens include animal dander, scales, fur, body wastes, and saliva. • NIOSH 1998

4. What about mice? • The major mouse allergen is Mus m 1, or mouse urinary protein. This allergen is found in urine as well as in hair follicles and dander. Mus m 1 is produced in liver cells, and males produce approximately four times more of it because gene expression is testosterone dependent. • ILAR 2001

5. What about rats? • Rats are responsible for symptoms in a large portion of people who have laboratory-animal allergy. The major sources of rat-allergen exposure appear to be in the urine and saliva of the animal. • NRC 1997

6. Who is at risk? • All animal handlers appear to be at risk for developing work-related allergy symptoms. • NIOSH 1998 Surprise, Surprise, Surprise

7. The estimated prevalence of allergic symptoms in the general population of regularly exposed animal-care workers ranges from 10% to 44%. An estimated 10% of laboratory workers eventually develop occupation-related asthma. National Research Council 1997

8. In a survey of 5,641 workers from 137 animal facilities, 23% had allergic symptoms related to laboratory animals. • Of the workers with symptoms: • 82% had nasal or eye symptoms • 46% had skin complaints • 33% had asthma • NIOSH 1998

9. Who is at heightened risk? • There is a correlation between atopy (an inherited, familial tendency to develop some form of allergy such as hay fever, asthma, eczema) and the potential for developing LAA, and a stronger positive correlation between atopy and development of lower respiratory symptoms (asthma). • CCAC

10. Workers who had symptoms or signs of allergies before they were employed as animal handlers are more likely to develop animal-induced asthma. Allergic workers, particularly those sensitized to domestic animals such as cats and dogs, are more likely to develop sensitivity to laboratory animals and asthma than non-allergic workers. • NIOSH 1998

11. Who is at heightened risk? Is it Capt. Kirk or Commander Uhura? • Sorry Kirk, males are more likely to be atopic than females (47% vs 37%) and so more likely to develop LAA. CCAC

12. What about smokers? • There have been some connections made between smoking and LAA. According to the Canadian Council on Animal Care “…if a smoker does develop LAA, they are 1.5-3 times as likely to get the lower respiratory symptoms (asthma).” • CCAC

13. How are we exposed to allergens? • The principle route of exposure to animal allergens is inhalation of aeroallergens. Direct skin and eye contact can also be a common route of exposure and, occasionally, ingestion. Percutaneous exposures may result from animal bites, needle punctures contaminated with animal allergens, or allergen contamination of wounds. • ILAR 2001

14. The principle route of exposure to animal allergens is inhalation of aeroallergens. • ILAR 2001

15. So this means you are breathing the allergen in. As stated earlier, the major mouse allergen is Mus m 1, (mouse urinary protein). If the primary mouse allergen is found in mouse urine, and the primary means of exposure is through inhalation, do you think that changing or dumping urine soaked mouse cages might be of concern for allergen exposure?

16. What do some of the hallways and animal rooms smell like here on a Monday morning or a Tuesday after a holiday weekend? How do some of those cages smell in cage wash on those days? How much allergen are you exposed to when you open the cage? Do you think your mask should always be covering your mouth and nose and conformed to fit properly?

17. Direct skin and eye contact  can also be a common route of exposure.

18. How are we exposed to allergens on our skin? Direct skin contact exposure occurs when: • An animal, or animal waste, touches your skin • Your skin comes in contact with any object that has been exposed to animals (dirty gloves, dirty bedding, dirty Tyvek)

19. How are our eyes exposed? • Any fluid (blood, urine, etc.) or exposed solid materials (soiled bedding) in the eyes can expose you to allergen, not to mention expose you to any possible zoonotic disease, or cause physical damage to the eye itself.

20. You can easily rub your eyes with your gloves and expose yourself to allergens. • Anytime you touch anything that has animal dander or dust on it, and then touch your eyes, you expose yourself. • Example: Those of you that wear PAPR (powered air-purifying respirators) - the battery packs accumulate dust while you are changing cages. After you have left a room and are carrying that battery pack in your bare hands, you will expose your hands to allergen, and if you touch your eyes, you’ve exposed them.

21. Another example: Someone has placed a dirty cage on top of a PPE bin and you pick it up with your bare hands to move it to the dirty cage cart, and then you touch your eyes, you have now exposed your eyes.

22. Another example: Changing the pre-filter of a dump station without PPE can easily expose you. Dirty pre-filters hold extremely fine and allergen-concentrated dust particles that can easily get in your eyes, on your skin, on your clothes, and can easily be inhaled.

23. How are we exposed percutaneously? Percutaneous (through the skin) allergen exposure is another concern. • Bite wounds, needle sticks, and allergen exposure to open wounds are all examples, and pretty avoidable if caution is taken. Is it important to be trained on how to handle animals properly and always be alert while handling them? Is it important to be very cautious when handling sharp objects that have been exposed to animals, to use the sharps containers properly, and to never recap needles? Should open wounds always be properly dressed and not exposed?

24. What are the symptoms of LAA? • Symptoms of LAA are the result of the release of biochemical mediators and the generation of inflammation in the tissues induced by IgE (immunoglobulin E) response. The nature and intensity of the symptoms are dependent on the level of exposure to the laboratory animal allergen by the individual. These symptoms can range from mild skin reactions to severe asthma. • ILAR 2001

25. The most common symptoms are related to allergic reactions involving the nose and eyes and are known as allergic rhinitis and allergic conjunctivitis, respectively. Nasal symptoms include congestion, runny nose, sneezing, and itching; ocular symptoms include redness and itchy, watery eyes. Up to 80% of workers with LAA report nasal symptoms. • ILAR 2001

26. Skin reactions include hives (urticaria)  at the site of contact with animal urine or dander and as a result of scratches from rough tails and claws • ILAR 2001

27. Other rashes include maculopapular (measles-like) rashes, which are typically quite itchy and occur in about 40% of symptomatic individuals

28. Asthma may affect 20 to 30% of symptomatic workers exposed to laboratory animals. Symptoms of asthma consist of cough, wheezing, and shortness of breath. It is important to recognize that symptoms related to laboratory animal exposure may continue for several hours after exposure to the animals ceases. In addition, individuals may experience symptoms of asthma when exercising and when exposed to cold air, dust particles, or strong odors. • ILAR 2001

29. Systemic allergic reactions, known as anaphylaxis, can occur (albeit rarely) as a result of an animal bite or from puncture wounds (e.g., needles contaminated with animal proteins). These reactions can manifest by generalized itching, hives (urticaria), swelling (angioedema) of the lips, eyes, and/or extremities, respiratory distress due to edema of the larynx, hypotension (shock), or acute asthma attacks. These reactions are potentially fatal. Occasionally, a milder form of systemic reaction can manifest in which the allergic individual develops a maculopapular rash or hives under protective clothing as a result of a respiratory exposure to laboratory animal allergens. • ILAR 2001

30. How long does it take to begin to develop symptoms if I am allergic? • Time from the onset of exposure to development of symptoms is variable but generally occurs within 3 yrs of beginning employment. Approximately one third of individuals will develop symptoms in the first year and 70% within 3 yrs. • ILAR 2001

31. In a study from the United Kingdom, the mean duration of employment before the onset of nasal symptoms was 214 days, 335 days for skin symptoms, and 365 for the development of chest symptoms (asthma). • ILAR 2001

32. How can we minimize exposure? Exposure can be minimized by: • Protecting ourselves from exposure with the proper use of PPE. • Protecting ourselves from exposure through good hygiene and housekeeping

33. Proper PPE use is essential! • The main source of exposure to allergens is through inhalation; therefore, respiratory protection is the most important step that can be taken to protect oneself from LAA. Wearing a properly fitted respirator mask of the appropriate type is essential to ensure that allergens are not being inhaled. • labanimal.com 2004

34. PPE • The National Institutes of Health recommends that employees with known allergies to animals wear National Institute of Occupational Safety and Health (NIOSH)–approved N-95 dust/mist respirators. (these are our standard masks) When properly fitted and worn correctly, these masks filter out at least 95% of the particles that are capable of transporting animal allergens. • labanimal.com 2004

35. PPE • In cases when the N-95 respirator is not sufficient, a PAPR can be provided. ("PAPR") devices, marketed as the air helmet and air hat provide 100% HEPA-filtered air to control exposure and relieve symptoms for sensitized workers” • ILAR 2001

36. Protection of skin and hair from contact with animal allergens through the use of protective clothing is an effective means of prevention. Use of dedicated clothing when in the facility also helps prevent the distribution of allergens outside of the facility into offices or public areas, or to the employee's home. • labanimal.com 2004

37. For example, while in the animal facility one may wear a uniform or scrubs rather than street clothes, and a lab coat or disposable garments that can be shed at the facility door. Hair bonnets, shoe covers, and gloves are helpful in protecting contamination of skin and hair and, when shed at the facility door, prevent the dispersal of allergens to the outside. Eye protection can also be important to prevent exposure to allergens and the symptoms of itchy, watery eyes. • labanimal.com 2004

38. Protection from exposure through good hygiene is essential. Hygiene - • Good personal hygiene through frequent glove changing and hand washing can limit hand-to-nose or hand-to-mouth transmission. (and hand to eye) • labanimal.com 2004

39. If you use a PAPR, the filter must be monitored and changed frequently. The battery pack should be cleaned and kept dust free (it can expose you), and the face shield should be cleaned frequently and changed when necessary. • As stated when addressing PPE, scrubs should be worn whenever possible and taken off as soon as possible after working with animals.

40. Protection from exposure with good housekeeping is very important. • Animal rooms should be frequently cleaned using wet methods. Left in the room environment, aeroallergens will eventually either settle out onto horizontal surfaces or adhere to hard surfaces. These settled and adhered particles can become secondary sources of exposure, especially in the presence of poor cleaning habits or inappropriate cleaning methods. Dry sweeping, for example, can be a significant source of exposure because re-suspended aeroallergens are introduced into the worker's breathing zone only feet away from the point of emission. Compliance with accreditation agencies and concerns for animal health usually promote satisfactory cleanliness within the animal facility. • ILAR 2001

41. Precautions/Prevention • Is it clear now why we stress the following?: • When changing cages, scrubs must be worn, and not just street clothes under coveralls • Limit the number of people who wear scrubs out of the animal facility • Keep your work shoes at work • Safety glasses, safety glasses, safety glasses • Frequently sanitize floors, wipe down racks, and wipe off shelves above sinks

42. Recommendations • If you have any of the symptoms mentioned in this training, report it to your supervisor. The greater the exposure you experience, the more severe your symptoms will become. It is essential that the allergy is caught early. “With early identification of allergic reactions to animals and appropriate treatment, most people can avoid further injury or the development of asthma” NIH Pamphlet

43. “Exposure to airborne allergens may first result in nasal, eye, and throat irritation as well as skin hives. As many as 50% of workers with these symptoms go on to develop asthma symptoms such as recurrent episodes of coughing, wheezing, chest tightness, and difficult breathing. Nasal symptoms usually develop first, occupational asthma without nasal symptoms is uncommon.” NIOSH 1998

44. Wash your hands, wash your hands, wash your hands! • They touch everything and then they touch you – often without thinking you end up touching your eyes, mouth, and skin. Keep those hands clean. • Do not touch any part of your exposed body with dirty gloves. Touching your eyes, nose, mouth, or exposed skin with dirty gloves exposes you.

45. Report any ventilation issues in your animal rooms immediately • An essential element of reducing exposure to aeroallergens is proper ventilation and air flow.

46. Keep your environment clean • Dirty cages and bedding are sources of allergens – get rid of them – dirty cages should not stay in the animal rooms for any longer than they have to and dirty bedding should not be on the floor, carts, racks or other surfaces.

47. If you are in a room that has a workbench, use it. They are an excellent means of protecting you from allergens.

48. You have PPE – Use it – and then take it off • Keep allergens off your skin, out of your lungs, and out of your eyes. • Take off your scrubs at lunch time. They have been exposed to allergens. Leaving them on extends your exposure, especially while you are eating. • Common sense rules. If it touches or is exposed to animals or animal materials in any way, it can expose you to allergens.

49. Conclusion • It is up to you to protect yourself from allergen exposure by following procedures, reporting symptoms, and asking questions.

50. References • ILAR 2001 – ILAR Journal 42 (1) viewed at: http://dels.nas.edu/ilar_n/ilarjournal/42_1/ • NIOSH 1998 – NIOSH ALERT Preventing Asthma in Animal Handlers January, 1998 • National Research Council 1997 – “Occupational Health and Safety in the Care and Use of Research Animals” National Academy Press, 1997. • labanimal.com 2004 “Laboratory Animal Allergies: Overview of Causation and Prevention” viewed at: http://www.labanimal.com/laban/journal/v33/n10/full/laban1104-25.html • NIH Pamphlet NIH Pamphlet “Allergies To Laboratory Animals – A Significant Health Risk” • CCAC (Canadian Council on Animal Care http://www.ccac.ca/en/CCAC_Programs/ETCC/Module12E/module12-16.html#top