Brucellosis--a persistent occupational hazard in Ireland

Area of Science:

• Veterinary Medicine
• Epidemiology
• Public Health

Background:

• Brucella abortus causes brucellosis, a zoonotic disease with significant public health and economic impacts.
• Occupational exposure is a primary transmission route in agricultural settings.
• Understanding seroprevalence in high-risk groups is crucial for targeted prevention strategies.

Purpose of the Study:

• To determine the seroprevalence of Brucella abortus exposure among technical and support staff in Ireland's Department of Agriculture.
• To identify occupational groups at increased risk of exposure.
• To assess the rate of seroconversion over a five-year period.

Main Methods:

• A cross-sectional seroprevalence study was conducted among 375 staff, with 281 (75% participation rate) providing samples.
• Complement fixation technique (CFT) was used to detect antibodies against Brucella abortus; titers >= 1:8 were considered positive.
• Results were compared with medical records to distinguish new from old infections and calculate conversion rates.

Main Results:

• Ten out of 281 participants (3.6%; 95% CI 1.7-6.5%) tested positive for Brucella abortus antibodies.
• Veterinarians, laboratory staff, and meat plant workers showed increased risk of exposure.
• Four of eight previously tested positive individuals had converted from negative to positive within five years, indicating a conversion rate of 8 per 1,000 employees per annum.

Conclusions:

• Brucella abortus exposure remains a significant occupational hazard for specific groups within the Irish agricultural sector.
• Continued vigilance and targeted control measures are necessary to mitigate exposure risks.
• The study highlights the importance of ongoing serological surveillance in high-risk professions.