Q Fever - CSU

Q Fever
Fact Sheet No. 8.022

Livestock Series|Health

by D. Van Metre*
Q fever is an infectious disease of animals
and humans caused by a species of bacteria
called Coxiella burnetii. This organism is
very durable – it can survive for months in
the environment. Sheep, goats, and cattle can
carry the organism. The bacteria can be shed
by these animals in feces, urine, milk, and in
the birthing fluids and membranes. Animals
that carry this organism and shed it into the
environment usually do not show any signs
of disease.

Quick Facts
• Q fever is an infectious
disease of animals and
humans caused by a species
of bacteria called Coxiella
burnetii.
• Sheep, goats, and cattle can
carry the organism.
• Animals that carry this
organism and shed it into the
environment usually do not
show any signs of disease.

Q Fever in Animals
Coxiella burnetii is most frequently found
in ruminants (cattle, sheep, and goats) but
can also be detected in wildlife and pets.
Sheep appear to be infected most frequently,
followed by goats and less frequently, cattle.
Ticks can carry the disease, but ticks are
considered to be of minor importance in
transmission of Q fever among animals
and people.
Coxiella burnetii can be shed in feces,
urine, and milk of infected animals. However,
the vaginal secretions and uterine fluids
released from infected ewes and does during
birthing carry the highest number of Coxiella
burnetii. Shedding of Coxiella burnetii in the
vaginal secretions can continue for days to
weeks after birthing. It is important to note
that the dam, the offspring, and the birthing
membranes and fluids can appear perfectly
healthy while the organism is being shed in
these materials.
Occasionally, infection does result in
visible signs of disease, usually in sheep and
goats. Infected ewes and does may abort or
give birth to weak offspring, and Q fever
should be considered as a possible cause
of outbreaks of abortion in flocks and goat
herds. When ewes or does abort because of
Q fever, the causative organism is present in
D. Van Metre, DVM, DACVIM, Colorado State University
Extension specialist (Veterinarian) associate professor,
College of Veterinary Medicine and Biomedical Sciences,
Clinical Sciences. 12/2014
*

extremely high numbers in the uterine fluids,
placenta, and aborted fetuses. Aborted fetuses
lack any characteristic findings, but the
placenta may be visibly thickened in cases of
Q fever abortion.
Diagnosis of Q fever abortion requires
testing of the fetuses and placentas from
aborted animals. Veterinary diagnosticians
typically identify the organism by the use
of special stains applied to microscopic
sections of these tissues, and/or through
the use of tests to detect the presence of the
organism’s DNA.
Abortions caused by Q fever typically do
not recur in sheep, but goats may abort again
in subsequent pregnancies if infection recurs.
There is currently not a licensed vaccine to
prevent Q fever in livestock in the United
States. Once Q fever is confirmed as a cause
of abortion in a herd or flock, treatment
of pregnant animals with tetracycline may
reduce the risk of further abortions, but is
unlikely to eliminate the problem entirely.
Prevention of Q fever in animals is
difficult, since infected animals may show

©Colorado State University
Extension. 5/10. Revised 12/14.
www.ext.colostate.edu

no signs of infection with the organism.
Isolation of any newly purchased animals
from pregnant ewes or does is advised
until all pregnant animals have birthed.
Isolate any animals that abort from the
remainder of the herd, and consult a
veterinarian to discuss diagnostic testing.
Dispose of bedding and equipment
contaminated with tissues and fluids from
an abortion in a sealed trash bag, buru, or
burn. Individuals handling these materials
should take protective precautions (see
below). Clean contaminated equipment and
facility surfaces with soap and water and
disinfect with a phenolic disinfectant (e.g.
Lysol®). More precautions for people are
described below.

Q Fever in Humans
Infection in humans occurs most often
in those individuals who come into contact
with cattle, sheep, and goats on a regular
basis. Therefore, occupational exposure
to Coxiella burnetii is a common source
of infection for humans; this occurs most
often in farmers, veterinarians, livestock
workers, slaughter plant personnel,
and individuals who work with sheep,
goats, and cattle in a research setting.
Occasionally, however, Q fever develops
in individuals with no known exposure to
livestock. Wind-borne transmission of the
organism and contact with contaminated
soil or clothing are other potential routes
for people to become infected.
Most people become infected by
inhalation of Coxiella burnetti that
become aerosolized (airborne) when an
infected animal gives birth or experiences
a spontaneous abortion. Ingestion of the
causative bacteria can occur if people ingest
non-pasteurized milk or milk products
derived from infected animals – remember,
infected animals can appear normal.
Pasteurization eliminates the organism
from milk and milk products. Aging
non-pasteurized milk into cheese may not
inactivate all C. burnetti bacteria.
Many people infected with Q fever
develop no symptoms of infection and
eliminate the infection with an effective
immune response. If symptoms do develop,
most people experience flu-like illness
within one to three weeks after exposure
to the organism. Affected individuals may
have a fever, headache, tiredness, muscle
aches, cough, vomiting, and diarrhea.
Pneumonia and rarely, liver infection are
potential complications. Most cases resolve

spontaneously or respond to treatment
with particular antibiotics. Fatalities are
uncommon when complications are not
present.
People who have impaired immune
systems – for example, those receiving
chemotherapy for cancer, pregnant women,
recipients of organ transplants, and those
infected with the HIV virus – are more
likely to develop more serious disease with
potential complications. Further, people
with abnormal heart valves or coronary
vascular grafts are at particularly high
risk of developing endocarditis, which is
infection of the interior lining of the heart
and heart valves. Endocarditis often does
not arise until several months after the
infection is established.
Q fever can be treated with certain
antibiotics. Consult your health care
provider if you have symptoms that might
indicate Q fever. Ill individuals who work
with sheep and goats must communicate
clearly with their health care provider about
their previous exposure to these animals
and their facilities, bedding, or manure.
This crucial step – communicating about
potential exposure – very important in
helping your health care provider to make a
diagnosis.

Prevention
1. Eat and drink only pasteurized milk
and milk products from cattle, sheep,
and goats.
2. Limit exposure to sheep and goats
during birthing. People who are at high
risk of serious complications from Q
fever include pregnant women, organ
transplant recipients, abnormal heart
valves, individuals on medications that
suppress immunity, and individuals
suffering from immune deficiency
diseases. Such individuals should
seriously consider avoiding contact with
sheep and goats, particularly during
lambing or kidding time. Consult with
your health care provider to determine
if you are at high risk for contracting
Q fever.
3. Protect yourself. Gloves, eye protection,
and a protective mask can be worn
when handling sheep or goats, their
manure, bedding, or soil from premises
where these animals have been kept.
Given that the organism can be shed
by otherwise healthy sheep and goats
at birthing, wearing this protective gear
may be warranted when administering

Once Q fever is confirmed as a cause
of abortion in a herd or flock, treatment
of pregnant animals with tetracycline
may reduce the risk of further
abortions, but is unlikely to eliminate
the problem entirely.
Most people become infected by
inhalation of Coxiella burnetti that
become aerosolized (airborne) when
an infected animal gives birth or
experiences a spontaneous abortion.

obstetrical assistance to these animals,
or when handling the bedding, birthing
fluids, or birthing membranes.
Consult your physician or health care
provider to determine if you are able to
wear an “N95” mask to limit the chances
that you might inhale the organism when
working with sheep or goats. These masks
are available at most hardware stores.
Particular care must be taken when
handling aborted fetuses or birthing
membranes from sheep or goats that are
known to be infected, as these materials
can contain large numbers of the organism.
These materials should be burned, buried,
or disposed of as hazardous infectious
waste. Work clothes contaminated with
birthing fluids or manure from sheep and
goats should not be handled by people at
high risk for Q fever and its complications.

Resources
Rodolakis, A. Q Fever in Dairy Animals.
Ann NY Acad Sci 1166: 90–93, 2009.
Cutler, S.J., Bouzid M., Cutler R.R. Q Fever.
J Infect 54: 313-318, 2007.
Hartzell, J.D., Wood-Morris R.N., Martinez
L.J., et al. Q Fever: Epidemiology,
Diagnosis, and Treatment. Mayo Clinic
Proc 83: 574-579, 2008.
McQuiston, J.H., Childs, J.E. Q Fever in
Humans and Animals in the United
States. Vector Borne Zoonotic Dis 2:
179–191, 2002.
Kim, S.G., Kim, E.H., Lafferty, C.J.,
Dubovi, E., Coxiella burnetii in Bulk
Tank Milk Samples, United States.
Emerg Infect Dis April, 2005.
Colorado State University, U.S. Department of
Agriculture and Colorado counties cooperating.
CSU Extension programs are available to all without
discrimination. No endorsement of products mentioned
is intended nor is criticism implied of products not
mentioned.