Morbidity rates in livestock dense areas

Abstract

TPS 751: Farms, antibiotics, infections, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM Background: There is ongoing debate and public concern regarding the possible effects of livestock density on human health. Two studies were performed based on longitudinal health data, to investigate the prevalence of infections/symptoms, chronic illnesses and medication among residents of livestock dense areas. Methods: In the first study prevalence of health outcomes was assessed for seven consecutive years (2010-2016), based on a sample of ±100000 individuals. Data were obtained from electronic health records registered in 26 general practices located in areas with intensive livestock farming in the Netherlands (provinces of North-Brabant and Limburg) (“study area”). These were compared with data from 22 general practices in rural regions with a low density of livestock farms or other major environmental exposures (“control area”). In the second study, a different “study area” was used (Gelderland, Overijssel and Utrecht) and analyses were repeated for the period 2014-2017 based on a sample of ±70000 residents. Results: The first study suggested a significantly higher prevalence of pneumonia, which was consistent over the years (2013: OR=1.5, 99% CI 1.03 – 2.17; 2014: OR=1.45, 99% CI 1.00 – 2.1; 2015: OR=1.58, 99% CI 1.09 – 2.3; 2016: OR=1.6, 99% CI 1.13 – 2.28). Lower respiratory tract infections, respiratory symptoms and vertigo were also consistently more common compared to the control area. Significant results were also observed for subgroups with respiratory conditions, children and the elderly. The second study verified the previous findings on respiratory outcomes, showing a consistently higher prevalence of pneumonia and acute respiratory symptoms in other livestock dense area(s). Both studies showed no significant differences in chronic conditions such as asthma and COPD. Conclusions: Respiratory infections and symptoms are more common in livestock dense areas. Assessment of temporal associations including individual exposure estimates and identification of causal pathogens based on serological analyses may shed further light.