Unprotected exposures to infected poultry or wild birds, and/or to the related avian influenza virus (AIV)-contaminated environments, could account for AIV infection in workers. This study was aimed at highlighting the ecological interfaces related to domestic poultry and wild birds posing an occupational risk regarding AIV. A search of all the articles investigating the possible presence of AIV in workers attested through virological and serological techniques and published up to August 2019 was performed on PubMed and Scopus electronic databases. Ninety-four articles consisting of 11 virological, 67 serological, and 16 mixed (both virological and serological) studies were obtained. Both virological and serological evidences of AIV infection were mainly related to H5, H7, and H9 subtypes. In addition, one piece of virological evidence for H10 subtype was reported, whereas seropositivity to all hemagglutinin subtypes from H4 to H11 was detected by serological studies. The number of AIV subtype exposures inferred from serological results showed that workers from large-scale industrial poultry farms and markets were the most represented, whereas workers from small-scale and backyard poultry farms showed seropositivity to a greater number of AIV subtypes. Workers exposed to wild bird habitats tested seropositive to H5, H9, and H11. In the occupational settings, direct contact with infected poultry or wild birds could account for AIV infection in workers. This AIV spillover can result in severe health complications for the workers, also posing a potential pandemic risk to the general population. From a public health perspective, the surveillance and early detection of AIV in workplaces should be a priority faced by a one-health approach.

The exposure to biocontaminants in animal facilities represents a risk for developing infectious, allergic and toxic diseases. The aim of this study was to determine what factors could be associated with a high level of exposure to biological agents through the measure and characterization of airborne fungi, bacteria, endotoxin, (1,3)-β-d-glucan and animal allergens. Airborne microorganisms were collected with an air sampler and identified by microscopic and biochemical methods. Endotoxin, (1,3)-β-d-glucan, Mus m 1, Rat n 1, Can f 1, Fel d 1, Equ c 4 allergens were detected on inhalable dust samples by Kinetic LAL, Glucatell, and ELISA assays, respectively. Our data evidenced that changing cages is a determinant factor in increasing the concentration of the airborne biocontaminants; the preparation of bedding and distribution of feed, performed in the storage area, is another critical working task in terms of exposure to endotoxins (210.7 EU/m³) and (1,3)-β-d-glucans (4.3 ng/m³). The highest concentration of Mus m 1 allergen (61.5 ng/m³) was observed in the dirty washing area. The detection of expositive peaks at risk of sensitization (>2 μg/g) by Fel d 1 in animal rooms shows passive transport by operators themselves, highlighting their role as vehicle between occupational and living environments.

Scientists and technicians who work in contact with laboratory animals are exposed to complex biological mixtures from animals, bedding and feed. The main objective of this study was to characterize the exposures to endotoxins and animal allergens in a biomedical research institution located in Central Italy by means of air sampling in the breathing zone of the staff during daily work activities. Forty-two inhalable dust samples were collected for endotoxins and allergens analysis. Filter extracts were analyzed using a Kinetic-QCL LAL kit for endotoxins; ELISA assays were performed for Mus m 1, Rat n 1, Can f 1, Fel d 1 and Equ c 4 detection. Laboratory animal attendants (LAAs) showed endotoxin concentrations significantly higher (4.59 ng/m³) than researchers (0.57 ng/m³), researchers working only in an office (0.56 ng/m³) and technicians (0.37 ng/m³). Endotoxin concentrations exceeding the recommended occupational exposure limit proposed by the Dutch Expert Committee on Occupational Safety were found in the case of two subjects in the animal attendants category. With regards to rat and mouse allergens, a higher average dose was found for mouse than rat allergens. Also for these bio-contaminants, the LAAs are confirmed as the work category at higher risk of exposure (15.85 ng/m³), followed by technicians (10.67 ng/m³), researchers (2.73 ng/m³) and researchers in an office (0.08 ng/m³). Fel d 1 was also detected (average: 0.11 ng/m³) highlighting a passive transport between living and occupational settings. Our data could be useful to improve the control and preventive measures, ensuring lower levels of allergens and endotoxins in animal facilities.