This is the tenth of 16 student posts, guest-authored by Jean DeNapoli.
I own a small back yard flock of sheep and lambing season is the most exciting and rewarding time of the year. Nothing is more enjoyable than watching a lamb who takes a few wobbly steps and nurses for the first time as her mother nickers encouragement. Within a day, the lamb will be playing, bucking, running, and exploring her world.
Despite the pastoral wonders of the season, lambing is also inherently stressful. I must constantly check the barn to monitor for birthing problems and help out when necessary. This help might include repositioning a lambs stuck in the birthing canal, pulling a lamb when the ewe is unable to push it out herself, and cleaning the face and airway of a newborn when its mother is too exhausted to follow through on her own. Shepherds all over the world share the same experiences that I do. But what many of them don’t know is that they are probably being exposed to Q fever.
When the disease was first recognized it was given the temporary name Query fever (since very little was understood about it). We now know it is caused by a bacteria called Coxiella burnetii. It is found word wide and it is estimated that 15-20% of all cattle, sheep and goats have been exposed to it. The livestock rarely show signs of illness, but it can contribute to reproductive problems such as abortions.
In an infected animal, the organism can be found in milk, urine, and feces. But the greatest concentration of bacteria is in the amniotic fluid and placenta. Ticks can spread the disease, but much more frequently, it is passed directly to other animals at the time of birth. It can develop into a long lasting spore-like form and can then contaminate dust and be carried by the wind. Q fever is very easily spread and it takes only one organism to cause disease!
Q fever is zoonotic; it can be passed from animals to people. When people become infected, they may have fevers, headache and weakness. Fortunately, the fatality rate is low (<2%). But some people, especially pregnant women and those with heart disease or who are immune deficient, end up with a more chronic and severe disease. Q fever may also cause pre-term delivery or miscarriage if women become infected while pregnant.
I am not only a shepherd, but I am a veterinarian and it surprises me that few shepherds (at least the hobby farmers I know) discuss Q fever or take the recommended precautions. In research facilities, Q fever is a biosafety 3 organism (on a scale of 1-4), requiring special laboratory containment precautions. To put this in perspective, other level 3 organisms include tuberculosis, anthrax, SARS, and yellow fever. Yet many farmers routinely assist in births without any thought to their own health.
Q fever is fairly common and can be difficult to detect in healthy animals, so experts recommend treating all sheep as if they are infected. Pregnant women or women who may become pregnant should avoid working with sheep at lambing time. Other people at increased risk (people with impaired immune systems and heart valve abnormalities) should also stay away from the barn at lambing time.
Shepherds should wear disposable gloves when assisting lambing or handling newborn lambs. Masks should also be worn, especially in dusty conditions. Farmers should not eat or drink in the barn and should clean their footwear and wash their hands when leaving the barn.
Clothes have also been shown to carry the organism and they are capable of causing infection in people handling the laundry. Therefore, high-risk people should not handle clothing that has been worn in the barn until it has been cleaned.
Farmers should use good sanitation when handling birthing materials and bury or compost the placentas. Birthing areas should be cleaned frequently and in a way that will not cause excessive dust. It is very important that farmers understand biosecurity precautions in general and specific Q fever prevention protocols to keep themselves, their families and their neighbors safe.
Shepherds should also work closely with their veterinarian to keep their flock as healthy as possible. In the event of an abortion, the fetal material (placenta) should be submitted to the veterinary diagnostic laboratory for testing.
But what if you are not a farmer, do you need to be concerned? Well, you should at least be aware of the disease.
Although usually associated with farm animals, dogs and cats may also transmit Q fever to people, most commonly at and around the time of birth. Again, people who are most susceptible should avoid association with pets at those times. Coxiella burnetii has been found in milk, so dairy products should be properly pasteurized before being consumed.
The organism is easily transmitted through the air (it is even considered a possible bioterrorism risk for this reason). The Netherlands had a recent outbreak of Q fever in people living close to goat farms due to unintentional airborne transmission. However, the people who generally are at the greatest risk are farmers, veterinary workers and researchers. They are the people most likely to be near animals giving birth or handling the organism during the course of their daily work.
With education and reasonable safety precautions, a visit to the barn does not have to be a risky event. Through the simple sharing of information, we can keep future generations of farmers safe, healthy, and productive.
References:
Prevalence of Coxiella burnetii infection in domestic ruminants: A critical review. Raphael Guatteo, Henri Seegers, Ann-Freida Taurel, Alain Joly, Francois Beaudeau. Veterinary Microbiology 149 (2011) 1-16
Q Fever: Current State of Knowledge and Perspectives of Research of a Neglected Zoonosis. Sarah Rebecca Porter, Guy Czaplicki, Jacques Mainil, Raphael Guatteo, and Claude Saegerman. International Journal of Microbiology Volume 2011 (p 1-22)
Eurosurveillance, special issue on Q fever, vol. 17, 19 January 2012
New York Department of health Q fever facts sheet (2011) http://www.health.ny.gov/diseases/communicable/q_fever/fact_sheet.htm
World Organization for Animal Health (OIE) fact sheet on Q fever (2011) http://www.oie.int/fileadmin/Home/eng/Media_Center/docs/pdf/Disease_cards/Q-FEVER-EN.pdf
Center for Disease Control (CDC) Q fever information (2011) http://www.cdc.gov/qfever/index.html
Public Health Agency of Canada pathogen safety data sheet for Q fever (2010) http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/coxiella-burnetii-eng.php
Health Protection Agency Q fever information for farmers (2010) http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1210834106356
University of Florida IFAS Extension, The Herd Health Handbook for Goat Producers: Biosecurity at the Farm Level, Ray Mobley and Carmen Lyttle-N’guessan. (2009) http://edis.ifas.ufl.edu/famu006
Wyoming State Veterinary Laboratory, Q fever fact sheet (2004) http://www.uwyo.edu/wyovet/disease-updates/2004/files/qfever.pdf
Institute for Biosecurity, Saint Louis University School of Public Health, Q fever fact sheet (2001) http://www.bioterrorism.slu.edu/bt/quick/qfever01.PDF
Eurosurveillance Q Fever in the Netherlands: an up date on the epidemiology and control measures, W van der Hoek, et al. (2010) http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19520
Photographs are courtesy of Laura Cowperthwaite and Triple J Farm.
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