I have a small flock of Soay sheep and lambing season started today (too early, but better than the -30C weather from a few days ago). For someone like me, lambing season inevitably triggers thoughts about Q fever, a zoonotic disease that is most commonly associated with contact with small ruminants like sheep and goats (especially sheep). The disease is caused by the bacterium Coxiella burnetii. This organism is highly infectious – very few bacteria are required to cause infection – and is considered a potential bioterrorism agent. Coxiella burnetii can be transmitted by direct contact with an infected animal, or by inhalation of organisms in dust or dirt that get blown into the air. It can be carried by healthy animals several species, but the greatest risk of transmission is from sheep and goats around the time of birthing (lambing and kidding, respectively). At that time, large numbers of C. burnetii can be shed with the placenta and fetal fluids, and can also be found on the newborn animals. Close contact with the animal and these tissues during lambing, such as with our first lambing this morning – a stillborn lamb that was stuck at the shoulders and required some manipulation to free it – can result in transmission of C. burnetii.
On a happier note, the second lambing in our flock was unassisted, although I still handled the little guy to make sure he was okay.
Q fever can affect people of any age or health status. Disease can range from mild to life-threatening. More information on Q fever can be found on the websites of the Ontario Ministry of Health and Long-Term Care and the Centers for Disease Control and Prevention (CDC), as well as the previous Worms & Germs post entitled "Q Fever – From Goats to People (and Pets!)". The disease can cause miscarriage in pregnant women. People with heart valve disease or vascular grafts are also at high risk for serious disease from this infection.
- It is prudent to consider all sheep and goats Q fever–positive unless proven otherwise (which is difficult to do).
- Contact with newborn lambs and kids, placentae and fetal fluids of sheep and goats, and any area contaminated by these tissues should be avoided as much as possible. If contact is necessary, it should be done by low-risk people, and careful attention should be paid to hygiene, especially handwashing.
- Pregnant sheep and goats should not be used in petting zoos. Unfortunately, this is actually a common occurence.
- Live birthing exhibits, where sheep or goats give birth in public during fairs or similar events, should not be held. If they are held, they should be in an area where there is no direct or indirect contact with the public, unlike this picture (right).
- While we focus on sheep and goats, many different species can shed Coxiella burnetii, including cattle and cats. It is reasonable to consider all animals a risk around the time of giving birth, and ensure that hygiene practices are optimal.
- At my place, Q fever control consists mainly of careful attention to hygiene around newborn lambs and their ewes, and not allowing my kids to handle newborn lambs.
- Like most zoonotic diseases, hand hygiene is a critical infection control measure.