Credit CDC
# 8656
Q fever is a zoonotic disease caused by exposure to the Coxiella burnetii bacterium - primarily carried by cattle, sheep, and goats – but that are capable of infecting a variety of animals, including humans. Bacterium are excreted though milk, urine, and feces - and during birthing - they can be shed in high numbers through the placenta and amniotic fluid.
Coxiella burnetii are environmentally very hardy; resistant to heat, desiccation, and many common disinfectants, allowing it to persist in the environment and spread to other hosts, often carried on barnyard dust which may be blown over a wide area.
The bacterium can also be transmitted through tick bites, ingestion of unpasteurized contaminated milk, or even (rarely) through human-to-human transmission. The CDC describes the symptoms of the disease and course of illness on their Q fever website:
Although most persons with acute Q fever infection recover, others may experience serious illness with complications that may include pneumonia, granulomatous hepatitis (inflammation of the liver), myocarditis (inflammation of the heart tissue) and central nervous system complications. Pregnant women who are infected may be at risk for pre-term delivery or miscarriage. The estimated case fatality rate (i.e. the proportion of persons who die as a result of their infection) is low, at < 2% of hospitalized patients. Treatment with the correct antibiotic may shorten the course of illness for acute Q fever.
While the number of cases diagnosed in the United States each year is small (avg 150), the infection is likely underreported here, and around the world. Between 2007 and 2010 we saw a protracted outbreak in the Netherlands, which affected thousands of people (see Q-Fever In The Netherlands).
Today, we’ve a report (h/t Gert van der Hoek on FluTrackers) out of France, where an outbreak of atypical pneumonia north of Marseilles is suspected to be due to Q Fever. This from La Provence.com.
Valréas / Published Thursday, 22/05/2014 at 2:43 p.m.
Since May 16, 23 people of all ages are presented to the emergency hospital Valréas (Vaucluse) for flu-like symptoms with high fever and a diagnosis of pneumonia .
Following all of these elements and different tips and recommendations ARS Paca, a warning and management system was immediately drawn to the emergency Valréas: it was established an early listing of patients for tracking and linking with the LRA. The establishment of a broad-spectrum antibiotic treatment in symptomatic patients awaiting serological results was ordered, suitable for children and people with allergies.
" To this day, even if arguments matching beam directed to an outbreak of Q fever from animal sources, we remain cautious in the absence of biological evidence , "says one official. Q fever is a zoonotic (transmissible from vertebrate animals to humans illness), common in farming areas.
If people experience the symptoms described, they must always go to the emergency room or make an appointment with their doctor. They must be treated to avoid complications.
Currently, this is a suspected outbreak, based on symptomology. Lab confirmation can take time.
According to the CDC : Doxycycline is the first line treatment for all adults, and for children with severe illness. Treatment should be initiated immediately whenever Q fever is suspected.
Lest anyone think that Q fever is a problem for places other than the United States, last December CIDRAP NEWS reported on the results of an investigation into a multistate outbreak in 2011.
Multistate 2011 Q fever outbreak had high rate of symptomatic cases
The first reported US multistate outbreak of Q fever, in 2011, involved 21 people, with an unusually high percentage of them having symptoms, according to results of a cross-sectional investigation published yesterday in Vector-Borne and Zoonotic Diseases.
Investigators queried people associated with the index goat farm in Washington state as well as 16 other farms that bought goats from the index farm or housed goats at the index farm for breeding.
Of 109 people contacted, 21 (19%) from Washington or Montana met the outbreak case definition and had a Coxiella burnetii phase 2 immunoglobulin G titer of 1:128 or greater by immunofluorescence assay. Of the case-patients, 15 (71%) were symptomatic. The authors said a typical symptomatic rate is about half of patients.
Evidence of C burnetii infection was detected in all 17 goat herds sampled (13 in Washington, 3 in Montana, and 1 in Oregon) by polymerase chain reaction, enzyme-linked immunosorbent assay, or both.
Goat-specific Q fever risk factors included direct contact with a newborn goat, exposure to a dead or weak newborn, living on a property with goats, and direct contact with "birth/afterbirth products."
The authors said that after their investigation Washington and Montana implemented a herd management plan to encourage best disease-control practices, reduce the possibility of future outbreaks, and promote communication between public health and agriculture officials.
Dec 18 Vector Borne Zoonotic Dis abstract
For more on the diagnosis and treatment of Q Fever, the CDC along with Medscape, produced an expert commentary last year:
