Detection of abortifacient agents in domestic ruminants, with a specific focus on Coxiella burnetii

René van den Brom; Susan Neale; Elsa Jourdain; Anneleen Matthijs; Marcella Mori; Elodie Rousset; Katja Mertens-Scholz; Tom N McNeilly; Ana Hurtado

doi:10.12688/openreseurope.19270.2

Detection of abortifacient agents in domestic ruminants, with a specific focus on Coxiella burnetii

Open Res Eur. 2025 Jun 30:5:94. doi: 10.12688/openreseurope.19270.2. eCollection 2025.

Authors

René van den Brom¹, Susan Neale², Elsa Jourdain³, Anneleen Matthijs⁴, Marcella Mori⁴, Elodie Rousset⁵, Katja Mertens-Scholz⁶, Tom N McNeilly⁷, Ana Hurtado⁸

Affiliations

¹ Small Ruminant Health Department, Royal GD, Deventer, 7400 AA, The Netherlands.
² Penrith Veterinary Investigation Centre, Animal and Plant Health Agency (APHA), Cumbria, CA11 9RR, UK.
³ University of Clermont Auvergne, INRAE, VetAgro Sup, UMR EPIA,, Saint-Genès Champanelle, France.
⁴ Sciensano, Belgian Institute for Health, Brussels, Belgium.
⁵ ANSES, Sophia Antipolis Laboratory, Animal Q fever Unit, Sophia Antipolis, France.
⁶ Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, 07743, Germany.
⁷ Moredun Research Institute, Penicuik, EH26 0PZ, UK.
⁸ Animal Health Department, NEIKER - Basque Institute for Agricultural Research and Development, Bizkaia, 48160 Derio, Spain.

Abstract

Q fever is a widespread zoonotic disease caused by the bacterium, Coxiella burnetii. In ruminants, C. burnetii can cause abortions, stillbirths, premature births, and weak offspring. As part of the EU-funded Q-Net-Assess International Coordination of Research on Infectious Animal Diseases (ICRAD)-project, aimed at generating the most comprehensive understanding of C. burnetii genetic variation to date and determining the implications of this genetic variation for zoonotic risk, pathogenicity and control of C. burnetii infection, we have reviewed the protocols reported by the different project partners and/or countries to diagnose abortion in domestic ruminants. As a result of this review, we have developed guidelines for the detection of abortifacient agents in domestic ruminants, with a special focus on C. burnetii. They include a description of the essential and complementary samples needed for a definitive diagnosis, the analytical techniques to be used, and the interpretation and validity of each type of sample and technique. The most comprehensive diagnostic approach to identify an infectious agent as the cause of abortion in ruminants would include histopathology, including immunohistochemistry (IHC), on the fetus and placental membranes, complemented by bacteriology, serology, and real-time PCR analyses of different types of samples. For the specific diagnosis of C. burnetii as the causative agent of abortion, we provide guidelines based on expert opinions for the interpretation of laboratory test results in relation to their diagnostic value.

Keywords: Coxiella burnetii; abortion; diagnostics; ruminants.

Plain language summary

Q fever, caused by the bacterium Coxiella burnetii, can be transmitted from animals to humans. It may cause reproductive issues in animals, such as cows, sheep, and goats, including miscarriages and weak offspring. The EU-funded Q-Net-Assess project aims to understand the genetic variations in C. burnetii and their impact on disease spread, severity, and control. Researchers in this project reviewed European methods for diagnosing miscarriages in these animals and created guidelines to identify causative agents, focusing on C. burnetii. The guidelines specify the necessary samples, diagnostic techniques, and interpretation of the results. The best diagnostic approach involves examining fetal and placental tissues using immunohistochemistry (IHC) supported by bacteriology, serology, and real-time PCR tests. For diagnosing C. burnetii, expert advice is provided to interpret the lab results.