# Risk assessment for Brucella suis biovar 2 in Danish pigs

## TL;DR

This study assesses the risk of Brucella suis biovar 2 in Danish pigs, focusing on public health concerns for workers and consumers.

## Contribution

The study provides a semi-quantitative risk assessment for Brucella suis biovar 2 in Danish pig production under EU legislation.

## Key findings

- The human health risk from B. suis biovar 2 is low for contact with outdoor-reared pigs.
- The meat-borne transmission risk and contact with indoor-raised pigs are negligible.
- Pig producers should monitor outdoor-raised pigs for symptoms like enlarged testicles.

## Abstract

In Denmark, the number of uncastrated finishing pigs is on the increase, due to a wish to improve animal welfare and productivity. According to the EU legislation, all parts of a slaughter animal must be subjected to official inspection, with the penis as an exception if already discarded. The question is what the risk associated with not detecting abnormal testicles is for people working with pigs and consumers eating pig meat. To address this, we undertook a semi-quantitative risk assessment following WOAH guidelines, assuming two different transmission pathways (contact/meat-borne) and two different pig populations (indoor/outdoor) using Denmark as a case.

Brucella spp. was identified as the only relevant public health hazard. Brucellosis is a notifiable zoonotic infection, among others resulting in enlarged testicles in infected boars. Denmark is officially free from B. abortus and B. melitensis, whereas B. suis biovar 2 has been detected on a few occasions during the last 50 years. No human cases have ever been detected in Denmark, and only few cases are found elsewhere. Pig meat is not ascribed to transmission of infection unless the meat comes from acutely infected animals.

The human health risk related to B. suis biovar 2 was assessed as low in case of contact with outdoor-reared pigs and negligible for the meat-borne route and contact to indoor raised pigs. Therefore, pig producers and veterinarians should focus on outdoor-raised pig production and react immediately upon presence of relevant symptoms such as enlarged testicles or abortions.

The online version contains supplementary material available at 10.1186/s40813-025-00471-4.