Coxiella burnetii Infections in Small Ruminants and Humans in Switzerland

Area of Science:

• Veterinary Epidemiology
• Zoonotic Diseases
• Public Health Microbiology

Background:

• Q fever outbreaks in Europe raise concerns for unaffected countries.
• Switzerland lacks recent data on Coxiella burnetii prevalence in animals and humans.

Purpose of the Study:

• To assess Coxiella burnetii seroprevalence in Swiss sheep and goats.
• To quantify bacterial shedding during ovine and caprine abortions.
• To analyze human Q fever infection trends in Switzerland.

Main Methods:

• Cross-sectional study utilizing commercial ELISA for small ruminant seroprevalence.
• Real-time PCR to quantify Coxiella burnetii in abortion samples.
• Analysis of human Q fever serology data from major Swiss laboratories (2007-2011).

Main Results:

• Herd-level seroprevalence: 5.0% sheep, 11.1% goats.
• Animal-level seroprevalence: 1.8% sheep, 3.4% goats.
• 13.4% of abortion samples showed high bacterial shedding (>10^4 bacteria/g).
• Human seroprevalence ranged from 1.7% to 3.5% (2007-2011) with no temporal trends.
• Higher human seroprevalence observed in regions with high goat populations and livestock density.

Conclusions:

• Coxiella burnetii is circulating in Swiss small ruminants.
• Significant bacterial shedding occurs during abortions, posing a potential transmission risk.
• While human Q fever is present, a direct link to animal infections requires further investigation.