Occupational exposure to zoonotic agents among agricultural workers in Lombardy Region, northern Italy

This study was conducted in Northern Italy with the aim of defining the risk of agricultural workers' contact with biological agents through the determination of serum antibodies against selected zoonotic agents. Immunity against tetanus was also investigated.

Two groups of agricultural workers consisting of 153 animal breeders (exposed) and 46 non- breeders (controls) were included in the study. In a first group of 103 workers (89 exposed and 14 controls) the serum concentrations of antibodies against Hepatitis E Virus (HEV) were measured, whereas in the second group of 96 workers (64 exposed and 32 controls) the serum concentrations of antibodies against Leptospira spp., Coxiella burnetii, Borrelia burgdorferi, Brucella spp. and Salmonella spp. were addressed. Imunization against tretanus was also studied in this group.

Animal breeders showed higher rates of IgG antibodies against Coxiella burnetii (50% vs. 31.2%), and Leptospira spp. (59.4% vs. 43.7%). Results of logistic regression analysis revealed that breeder workers showed a tendency to have higher prevalence of positivity for antibodies to Leptospira spp.and Coxiella burnetii than non-breeders (ORs ~ 3). Only one exposed subject showed antibodies against hepatitis E (none in controls), but when tested with another commercially available kit the percentage of anti HEV IgG positive subjects increased to 22.3% in the exposed, while none of the controls showed positive. None of the subjects showed antibodies against Salmonella spp. and Brucella spp. Italians and other European workers have better protection against tetanus (91%) compared to non-EU workers (81%).

The higher frequency of the presence of serum antibodies to zoonotic agents (e.g. Leptospira spp. and Coxiella burnetii) in animal breeders suggests that they are more exposed to biological agents than workers not involved in animal breeding activities. The risk of contact with HEV deserves further studies because the adoption of different assays can result in significantly different results. The promotion of immunization of agricultural workers might be a priority, in particular for migrants.