Respiratory diseases and allergy in farmers working with livestock: a EAACI position paper

Abstract

Farmers constitute a large professional group worldwide. In developed countries farms tend to become larger, with a concentration of farm operations. Animal farming has been associated with negative respiratory effects such as work-related asthma and rhinitis. However, being born and raised or working on a farm reduces the risk of atopic asthma and rhinitis later in life. A risk of chronic bronchitis and bronchial obstruction/COPD has been reported in confinement buildings and livestock farmers. This position paper reviews the literature linking exposure information to intensive animal farming and the risk of work-related respiratory diseases and focuses on prevention. Animal farming is associated with exposure to organic dust containing allergens and microbial matter including alive microorganisms and viruses, endotoxins and other factors like irritant gases such as ammonia and disinfectants. These exposures have been identified as specific agents/risk factors of asthma, rhinitis, chronic bronchitis, COPD and reduced FEV₁. Published studies on dust and endotoxin exposure in livestock farmers do not show a downward trend in exposure over the last 30 years, suggesting that the workforce in these industries is still overexposed and at risk of developing respiratory disease. In cases of occupational asthma and rhinitis, avoidance of further exposure to causal agents is recommended, but it may not be obtainable in agriculture, mainly due to socio-economic considerations. Hence, there is an urgent need for focus on farming exposure in order to protect farmers and others at work in these and related industries from developing respiratory diseases and allergy.

Keywords: Agriculture; Asthma; Farm animals; Rhinitis; Work-related.

Fig. 1

Mechanism PAMP-induced innate immunity responses to microbial agents. Examples for PAMPs (activators of the innate immune system) Endotoxin (LPS) signaling through TLR4-pathway expression TLR4 LPS induced inflammatory response (e.g. RSV increased TLR4) although LPS causes inflammation in everyone, people with asthma tend to be more sensitive several proteins are involved in LPS-response. Peptidoglycan signaling by TLR2 and, PGRPs (peptidoglycan recognition proteins), and NODs (nucleotide-binding oligomerization domain molecules) b(1 → 3)-glucans (polymers of glucose produced in fungi, plants and some bacteria) Dectin-1, expressed on macrophages and neutrophils, is the b-glucan receptor Dectin-1 may function as a T cell co-stimulatory molecule, suggesting that b-glucan stimulation may be a link between innate and adaptive immune response