Worldwide distribution
Laboratory animal allergies (LAA) and asthma pose a significant occupational disease for a huge number of technicians, animal caregivers, physicians, and researchers whose job demands such exposure. Sensitization related to occupation may lead to the development of skin reactions, asthma, allergic rhinitis, rhinoconjunctivitis, and increased bronchial responsiveness (9). Clinical manifestation of LAA includes nasal symptoms (e.g., sneezing, congestion and watery discharge) and skin rashes. Asthma, accompanied by cough, wheezing, and shortness of breath, may affect 20% to 38% of laboratory technicians who are sensitized to LAA. Pre-existing allergies to pollens, molds and dust mites; exposure to LAA; and possibly the use of tobacco is considered to be the risk factors for acquiring LAA (10).
A cross-sectional study in Brazil that determined the prevalence of respiratory allergies in laboratory technicians found that the sensitization to work-related allergens was reported to be greater among animal handlers in comparison to non-animal handlers (16% vs. 3%, p<0.01). Out of 455 animal handlers, 10.8% (n=49) were exposed to guinea pigs. Furthermore, 9.6% (n=43) of these animal handlers reported asthma, 2.8% (n=12) reported work-related asthma, 58.1% (n=263) reported rhinitis, 29.6% (n=134) reported rhinoconjunctivitis, 34.3% (n=156) reported red and irritated skin, and 10.7% (n=48) reported LAA (9).
In a cross-sectional survey 169 individuals employed in Kochi Medical School, Japan was enrolled. The study group was instructed to fill out a questionnaire to assess the symptoms associated with exposure to laboratory animals. The results reported an overall prevalence of LAA to be 17.6%. Furthermore, the most commonly reported symptoms were allergic rhinoconjunctivitis (2.4%) and asthma (3%). Among the 22 guinea pig handlers, LAA was reported in 9.7% (11).
Risk factors
Allergic sensitization and reactions to guinea pigs have been frequently reported by laboratory animal handlers. The laboratory technicians exposed to guinea pigs have reported allergic symptoms, including asthma, allergic rhinitis and conjunctivitis (7)
Guinea pigs exhibit high allergenic potential, because of which they induce a high rate of sensitization in the laboratory animal workers, thus leading to various allergic symptoms. Hypersensitive manifestations are often severe (12).
Since the size of airborne particles derived from guinea pig urine, saliva and dander are minutes, allergic diseases such as asthma can easily occur in individuals sensitized to guinea pig (7).
Recent studies from Canada report that technicians working in animal research facilities are at a higher risk for developing LAA if they were atopic, had respiratory symptoms in the pollen season, were sensitized to dog or cat allergens, had baseline airway hyper-responsiveness, and/or had an increased hour of exposure with laboratory animals (10).
Risk factors for sensitization to pets (cats, dogs, and guinea pigs) were studied in 169 male individuals aged between 15 to 17 years. Of these individuals, 30.8% (n=52) reported recent or past history of contact with cats, 24.9% (n=42) with dogs and 11.8% (n=20) with guinea pig in their homes. Furthermore, clinically manifested allergy was observed in two individuals who showed allergic reactions to cats (one with asthma and the other with allergic rhinitis); and the other two being allergic to guinea pig (rhino-conjunctivitis). Three of the four individuals had past exposure to pets and one with allergic rhinitis to cats had never had any exposure to pets. A higher incidence of cat sensitization was seen in cat owners compared to individuals without direct exposure (26.9% versus 10.3%, p<0.01). No statistically significant difference in sensitization to dogs and guinea pigs was observed in either group (13).
