2024 Data for Zoonoses in Ireland

Overview of 2024 Zoonoses Data 

Introduction 

Zoonoses refer to diseases and infections that can be transmitted between animals and humans. Transmission may occur through direct contact with animals or indirectly via exposure to animal excreta, such as faeces, which can contaminate food, water, or the environment. Foodborne zoonotic diseases arise from the consumption of food or water that has been contaminated with zoonotic pathogens, including bacteria and their toxins, viruses, and parasites. These pathogens typically enter the body through the gastrointestinal tract, where initial symptoms often manifest. Many of these microorganisms are found in the intestines of healthy food-producing animals. The potential for contamination exists throughout the food chain from the farm to the consumer. This necessitates effective prevention and control measures at every stage of the food chain. While anyone can be infected by a zoonotic pathogen, certain populations, particularly young children, the elderly, and individuals with compromised immune systems are more vulnerable and face a higher risk of severe health outcomes. 

The control and elimination of zoonoses in humans and animals presents challenges. However, the impact of zoonoses on health can be mitigated through: (i) monitoring the reservoirs of infectious zoonotic pathogens to better understand and manage their transmission; (ii) implementing hazard control measures along the food chain by businesses; and (iii) providing public education aimed at reducing the risk of infection. 

The European Union (EU) Zoonoses Directive (Directive 2003/99/EC) requires Member States to collect data on zoonoses. The Directive requires reporting at EU level on eight zoonoses (i.e. List A, Annex I) with reporting on additional zoonoses based on the epidemiological situation in the Member State (i.e. List B, Annex I). Annual EU summary reports are jointly published by the European Food Safety Authority (EFSA) and the European Centre for Disease and Prevention Control (ECDC). The latest report, at time of publication, is for the 2023 data (EFSA and ECDC, 2024). 

Ireland’s national zoonoses report is published annually by the FSAI, in collaboration with the Department of Agriculture, Food and the Marine (DAFM), the Health Service Executive (HSE), the Local Authority Veterinary Service (LAVS), the Sea-Fisheries Protection Authority (SFPA) and the Health Protection Surveillance Centre (HPSC). The report brings together the results of thousands of tests carried out on samples of food and feed, as well as tests on material of animal or human origin, in an effort to determine the pattern and extent of infection by zoonotic pathogens transmitted to humans from animals.  

Please be advised that the human zoonoses figures for 2024 are provisional and may be revised in the subsequent years. This is due to ongoing updates based on the notification data in the HPSC’s Computerised Infectious Disease Reporting (CIDR) system. 

The data presented in the 2024 tables concerning the results of testing conducted in Ireland on food, animal, and animal feed samples is categorised into four distinct types: routine, census, objective, and suspect sampling (EFSA, 2024): 

Routine sampling is considered as planned sampling, though it does not utilise statistically random methods.  

Census sampling refers to the comprehensive assessment of an entire population on which the data is based.  

Objective sampling involves the deliberate selection of a random sample that is statistically representative of the population under analysis.  

Suspect sampling is an unplanned approach where individual units are chosen based on recent judgment and experience related to the population, lot, or sampling frame, such as prior positive samples. The samples obtained from suspect sampling may have a higher likelihood of having pathogens present.  

Overview of 2024 data 

Brucellosis 

• In Ireland, there was 1 notified case of brucellosis in 2024, resulting in a crude incidence rate (CIR) of 0.02 per 100,000 population (HPSC, 2024). This disease ranked joint eleventh in terms of incidence among the various zoonotic diseases reported.
• During 2024, a total of 106,166 bovine herds, and 42,530 ovine and caprine herds, were tested for the presence of Brucella. None of the herds were identified as infected. All herds were classified with the status of being officially free from the disease. 
• In addition to the bovine, ovine and caprine herds tested, a total of 1,263 animal samples were tested in Ireland. None of the tested samples were positive for Brucella. 

Campylobacteriosis 

• In Ireland, a total number of 3,984 reported cases of human campylobacteriosis were reported in 2024, equating to a CIR of 74.05 cases per 100,000 population (HPSC, 2024). This disease ranked first in Ireland in terms of incidence compared to the other zoonotic diseases reported. 
• During 2024, a total of 190 routine food samples (meat n=187; other foods n=3) and 57 suspect food samples (meat n=30; other foods n=27) were tested for the presence of Campylobacter spp. Campylobacter was detected in: 
  • 127 (67.9%) of the 187 routine meat samples. Positive samples were obtained from broiler carcases (n=124), poultry carcases (n=2) and from fresh broilers (n=1). 
• During 2024, a total of 1,724 animal samples were tested for Campylobacter, 158 of which were positive (9.2%). Infected animals included calves under one year of age (n=134) and sheep (n=24). 

Cryptosporidiosis 

• In Ireland, there were 640 reported cases of cryptosporidiosis in 2024, resulting in a case incidence rate (CIR) of 11.9 per 100,000 population (HPSC, 2024). This disease recorded the third highest incidence compared to the other zoonotic diseases reported.