PARMA, ITALY – The European Food Safety Authority (E.F.S.A.) has provided scientific advice on Q fever, an animal disease that can also be transmitted to humans, following a significant increase of human cases of Q fever in the Netherlands. The opinion addresses the significance of Q fever in animals and humans, different risk factors involved in the occurrence and spread of the disease and the effectiveness of possible control measures at the E.U. level.
Infection with Coxiella burnetii, the bacterium which causes Q fever, is widespread in cattle, sheep and goats in the E.U., E.F.S.A. said. Several factors can affect the spread of the infection between these animals, but the overall impact on their health is limited as they rarely develop the disease itself.
A combination of measures could be used to control Q fever in the long-term and short-term, with preventive vaccination of animals considered to be the most effective long-term option, the opinion suggests.
Q fever has a limited impact on public health, although it can be significant for some risk groups. Humans generally become infected through air-borne transmission of the bacterium. There is no evidence people can become ill by consuming contaminated milk or meat.
Infection with Coxiella burnetii can be present in a wide range of different farming systems. When it occurs, notably in sheep and goats, it may cause reproductive disorders, including abortion.
Numerous factors, including proximity to sheep and goats (especially when giving birth) and dry, windy weather, can affect the risk of human infection. However, there is considerable uncertainty about the relative importance of these risk factors, and it is likely that there is often more than one factor involved. No clear link was demonstrated between the spillover of infection from farms to humans and either the size of the farms involved or the virulence of different strains of infection.
The opinion identified measures that could be used to control Coxiella burnetii infection in sheep and goats, but stressed a combination of measures may be needed to deal with both farm-based and environmental routes of infection. Vaccination could be considered as a long-term control option, as it may not be effective in the short-term. Some options, including the culling of pregnant animals, were not considered suitable for long-term control but may have a role in the face of an outbreak. Antibiotic treatment of infected animals was not recommended.
The E.F.S.A. opinion included a number of recommendations, including the harmonization of data collection on Q fever in animals so as to enable comparisons over time and between countries. It also stressed the importance of the rapid identification and reporting of Q fever cases in animals, as well as the early exchange of information between veterinarians and public health practitioners.