Livestock Farming and Neighbouring Residents* Health: Part 3

Exposures which originate from livestock farms, such as dust, (zoonotic)
microorganisms, endotoxins, and ammonia are associated with adverse health
effects in neighbouring residents. Several distinct signals have been found
recently: increased respiratory symptoms and medication use in chronic
obstructive pulmonary disease (COPD) patients living near livestock farms,
acute airway obstruction associated with elevated ammonia concentrations, and
an elevated risk for pneumonia near poultry and goat farms, accompanied by a
shift in the respiratory microbiome. The underlying causes have not been
unravelled.
We hypothesize that the excess pneumonia risk results from either inhalation of
potentially farm-related pathogens, or, alternatively, from other farm-related
exposures that lead to changes in the composition and diversity of the upper
respiratory tract microbiome and virome leading to excess pneumonia risk
through dysbiosis. These hypotheses will be studied in the so-called VGO-3
study. While awaiting the results of the VGO-3 study, 9 of the 12 provinces
have stopped issuing building permits for new and existing goat farms.

A primary objective of the study is to explore the underlying causes of the
excess pneumonia risk in individuals living in the proximity of goat farms.
Another objective is to study associations between long-term exposure to
livestock farms and respiratory health, namely respiratory symptoms, atopic
sensitization, and lung function decline over a six-year follow-up period.

A secondary objective of the study is to to identify potential exposures
responsible for a decreased prevalence of asthma and allergy observed in
neighboring residents living close to a farm.

A cross-sectional analysis of the microbiome and virome of the oral and nasal
pharynx is performed in three different populations: (1) patients diagnosed
with pneumonia, living in an area with a high density of goat farms, (2) a
general population sample in a similar area (control group) and (3) employees
and owners of goat farms. Potential causative pathogens and shifts in the
respiratory microbiome and virome will be studied.

Burden: all subjects are requested to fill in a questionnaire and from all
subjects a swab from the nasal and the oral pharynx and a blood sample (1 * 10
mL) via venepuncture will be taken. In addition, participants in the control
group will perform a standard forced exhalatory spirometric lung function test.
From participants in the goat farmers group and a stool sample will be
collected. total time control subjects and goat farmers: 55 minutes.
Risks: This is an observational study, involving minimal risks for participants
(taking a single nasal and oral swab, a lung function test in 1600 control
subjects, and taking a blood sample in a subgroup of 150 participants).
Benefits: The study has no direct benefits for the participants. The study will
give relevant insight into the increased risk of pneumonia in areas with a high
density of (goat) farms as well as in environmental factors contributing to
this increased risk. Finally, the study will also contribute to a better
understanding of how (shifts in) the (respiratory) microbiome and virome
contribute to development of pneumonia and respiratory health in general.