Q fever has no distinct clinical features and nearly 50% of patients have no symptoms. At presentation, the most common feature is a low grade fever.

Q fever may have an acute or chronic presentation. The acute form of the infection can present with a limited febrile illness, flu like symptoms, pneumonia, hepatitis, pericarditis or meningoencephalitis. Other features of the illness include a headache, muscle and joint pain. These symptoms may last 5-14 days. Pneumonia is a common feature with dry cough, vague chest discomfort and shortness of breath. In rare cases, it may become fulminant with progression to ARDs.

Hepatitis is a common presentation in Europeans who acquire Q fever; these patients may have mild elevations of liver enzymes. Other associated symptoms may include nausea, vomiting, diarrhea and right upper quadrant pain.

Cardiac presentation may include myocarditis or pericarditis. These patients may experience chest pain, palpitations and dyspnea.

Rash is not a common feature of Q fever but may present as erythema nodosum or maculopapular rash.

Other rare presentations include mediastinal adenopathy, thyroiditis, pancreatitis, orchitis, optic neuritis, Guillain Barre Syndrome and SIADH.

About 1-2 percent of patients with acute Q fever will develop chronic disease. This infection may not manifest for months or years after the initial acute infection. The chronic form of Q fever is a serious illness and usually involves the heart valves. In some cases, the infection may result in aneurysms. Patients may present with heart failure, arrhythmias, dyspnea, night sweats, fevers and chills. The same organ systems involved in acute Q fever can be affected in chronic disease.

Q fever during pregnancy can result in chronic uterine infection with relapse during subsequent pregnancies.

• Splenomegaly

  This case describes a man who, after extensive investigation for splenomegaly and pancytopenia by several specialties, was finally diagnosed with Q fever endocarditis after unexpected aortic valve abnormalities found during elective cardiac surgery. [ncbi.nlm.nih.gov]

  Marked finger clubbing, arterial emboli, hepatomegaly, splenomegaly, and a purpuric rash may occur. The case-fatality rate is only about 1% in untreated patients but is higher in those with endocarditis. [merckmanuals.com]

  Hepatomegaly splenomegaly (50%). Clubbing (30%). Purpuric rash (vasculitic) in 20% of cases. Abdominal pain. Chest pain. Night sweats. Hepatosplenomegaly. [patient.info]

• Fever

  Q fever management algorithm* Alternate Text: This figure shows a flow chart describing the management of acute Q fever and chronic Q fever. [cdc.gov]

  Other supportive treatments include the following: Antitussives NSAIDs for fever Oral hydration Antiemetics Management of acute Q fever Nearly 2/3rd of patients with acute Q fever have no symptoms. [symptoma.com]

  […] with Q fever. [ncbi.nlm.nih.gov]

  […] who present with unexplained fever. [doi.org]

• Fatigue

  […] comorbidity explaining the fatigue. [ncbi.nlm.nih.gov]

  Some people never get sick; however, those who do usually develop flu-like symptoms including fever, chills, fatigue, and muscle pain. [cdc.gov]

• Chills

  Some people never get sick; however, those who do usually develop flu-like symptoms including fever, chills, fatigue, and muscle pain. [cdc.gov]

  a disease characterized by high fever, chills, muscular pains, headache, and sometimes pneumonia that is caused by a bacterium ( Coxiella burnetii of the family Coxiellaceae) of which domestic animals serve as reservoirs and that is transmitted to humans [merriam-webster.com]

  Acute lower respiratory tract infection and chills were poorly associated with acute Q fever. Furthermore, 32% (95% CI: 24, 41%) of participants had a history of previous exposure to Q fever agent (past infection). [ncbi.nlm.nih.gov]

• Veterinarian

  A total of 108 veterinarians took part to this cross-sectional study, with a majority practicing with livestock animals. The overall seroprevalence was 45.4%, but it increased to 58.3% among veterinarians having contact with livestock. [ncbi.nlm.nih.gov]

  The veterinarian will also collect a tissue sample (e.g., from the placenta) and refrigerate it for later use as an inoculator. [petmd.com]

• High Fever

  We present a 70-year-old man from Dalmatia, Croatia, with a history of prolonged high fever diagnosed as Q fever endocarditis. As far as we know, this is the first case of chronic Q fever in Croatia. [ncbi.nlm.nih.gov]

  a disease characterized by high fever, chills, muscular pains, headache, and sometimes pneumonia that is caused by a bacterium ( Coxiella burnetii of the family Coxiellaceae) of which domestic animals serve as reservoirs and that is transmitted to humans [merriam-webster.com]

  There is high fever, headache, muscle aches and a form of PNEUMONIA causing cough and pain in the chest. [medical-dictionary.thefreedictionary.com]

  Flu-like syndrome is usually self- limited, lasts up to 3 wks, and may involve high fevers, headaches, and muscle aches. [stopticks.org]

  Signs and Symptoms Symptoms include high fever, headache, sore throat, malaise, nausea, diarrhea, chest pain, nonproductive cough, pneumonia, and hepatitis. [columbia-lyme.org]

• Cough

  The most frequent clinical manifestation of acute form is a self-limited febrile illness which is associated with severe headache, muscle ache, arthralgia and cough. [ncbi.nlm.nih.gov]

  Respiratory and pulse rates are usually increased, and a cough often develops. In cattle, the disease is known as pasture fever in many parts of Europe, including Finland, Norway, Austria, Spain, and Switzerland. [merckmanuals.com]

  There is high fever, headache, muscle aches and a form of PNEUMONIA causing cough and pain in the chest. [medical-dictionary.thefreedictionary.com]

• Dry Cough

  Common symptoms may include: Dry cough (nonproductive) Fever Headache Joint pain (arthralgia) Muscle pains Other symptoms that may develop include: Abdominal pain Chest pain Jaundice (yellowing of the skin and whites of the eyes) Rash A physical examination [medlineplus.gov]

  The symptoms are like having the flu such as: high fevers (up to 41 C ) with chills or sweats bad headaches general feeling of being unwell muscle aches dry cough nausea or vomiting diarrhoea abdominal pain chest pain Long loasting fatigue can follow [healthdirect.gov.au]

  cough chest pain on breathing nausea, vomiting diarrhoea abdominal pain. [sahealth.sa.gov.au]

  The most common manifestation is flu-like symptoms with abrupt onset of fever, malaise, profuse perspiration, severe headache, muscle pain, joint pain, loss of appetite, upper respiratory problems, dry cough, pleuritic pain, chills, confusion, and gastrointestinal [en.wikipedia.org]

  Pneumonia is a common feature with dry cough, vague chest discomfort and shortness of breath. In rare cases, it may become fulminant with progression to ARDs. [symptoma.com]

• Pleural Effusion

  Segmental or lobar opacification and occasional pleural effusions may be seen (all of which are non specific features on their own). Features can be slow to clear 4. [radiopaedia.org]

  Pneumopathy is mostly moderate but pleural effusion or acute respiratory distress may occur. Symptoms may last 10-90 days. [orpha.net]

  Patients with respiratory symptoms or signs require chest x-ray; findings may include atelectasis, pleural-based opacities, pleural effusion, and lobar consolidation. [merckmanuals.com]

  effusions or interstitial fibrosis if the lung is involved. [symptoma.com]

  Pleural effusion can also be present. Findings on the chest radiograph are nonspecific. The duration of symptoms varies from 10 to 90 days. The mortality rate ranges from 0.5 to 1.5%, depending upon the series ( 30, 180 ). (iii) Hepatitis. [jcm.asm.org]

• Painful Cough

  Symptoms of endocarditis include : a high temperature a new heart murmur aching muscles alterations in a heart murmur bleeding under fingernails or toenails broken blood vessels in the eyes broken blood vessels in the skin chest pains coughing headache [medicalnewstoday.com]

  In addition, infection of bones, joints, or the genitourinary tract may cause pain. Cough and chest pain also may be present. Symptoms often last three to six months and occasionally for longer than a year. [emedicinehealth.com]

• Nausea

  Here we present a 41-year-old male complaining of body ache, fever, nausea, malaise, bilateral knee pain and vomiting. Clinical examination revealed a notable erythematous blanching rash all over his body. [ncbi.nlm.nih.gov]

  Signs and Symptoms Symptoms include high fever, headache, sore throat, malaise, nausea, diarrhea, chest pain, nonproductive cough, pneumonia, and hepatitis. [columbia-lyme.org]

  Signs and symptoms can include: Abrupt fever Chills Sweating Severe headaches Malaise and fatigue Muscle and joint aches Sore throat, cough and chest pain Nausea and vomiting Diarrhoea Weight loss As many of these symptoms are typical of other infections [worldwise.co.nz]

  Most acute cases of Q fever begin with sudden onset of one or more of the following: high fevers (up to 104-105 F), severe headache, general malaise, myalgia, confusion, sore throat, chills, sweats, non-productive cough, nausea, vomiting, diarrhea, abdominal [health.ny.gov]

• Abdominal Pain

  Case 1: A 55-year-old man admitted due to abdominal pain, diarrhoea and fever. [ncbi.nlm.nih.gov]

  Common symptoms may include: Dry cough (nonproductive) Fever Headache Joint pain (arthralgia) Muscle pains Other symptoms that may develop include: Abdominal pain Chest pain Jaundice (yellowing of the skin and whites of the eyes) Rash A physical examination [medlineplus.gov]

  pain, and chest pain. [health.ny.gov]

  The symptoms are like having the flu such as: high fevers (up to 41 C ) with chills or sweats bad headaches general feeling of being unwell muscle aches dry cough nausea or vomiting diarrhoea abdominal pain chest pain Long loasting fatigue can follow [healthdirect.gov.au]

• Loss of Appetite

  The onset may be gradual but generally is sudden, and the disease is ushered in by fever, chills or chilly sensations, headache, muscle aches, loss of appetite, disorientation, and profuse sweating. [britannica.com]

  […] of appetite diarrhoea jaundice rash. [nt.gov.au]

  However, afflicted people can feel generally ill with loss of appetite for several weeks. [ccohs.ca]

  The most common manifestation is flu-like symptoms with abrupt onset of fever, malaise, profuse perspiration, severe headache, muscle pain, joint pain, loss of appetite, upper respiratory problems, dry cough, pleuritic pain, chills, confusion, and gastrointestinal [en.wikipedia.org]

• Chest Pain

  CLINICAL FEATURES animal encounters: sheep, goats, cattle, dogs, cats, birds, rodents and ticks occupations: farmers, laboratory workers, sheep and dairy workers and vets bacteria shed in birth products, faeces, milk and urine incubation 10-40 days SOB chest [lifeinthefastlane.com]

  Common symptoms may include: Dry cough (nonproductive) Fever Headache Joint pain (arthralgia) Muscle pains Other symptoms that may develop include: Abdominal pain Chest pain Jaundice (yellowing of the skin and whites of the eyes) Rash A physical examination [medlineplus.gov]

  Signs and Symptoms Symptoms include high fever, headache, sore throat, malaise, nausea, diarrhea, chest pain, nonproductive cough, pneumonia, and hepatitis. [columbia-lyme.org]

  Signs and symptoms can include: Abrupt fever Chills Sweating Severe headaches Malaise and fatigue Muscle and joint aches Sore throat, cough and chest pain Nausea and vomiting Diarrhoea Weight loss As many of these symptoms are typical of other infections [worldwise.co.nz]

• Heart Murmur

  In the late stages of the disease, a heart murmur may be heard. [medlineplus.gov]

  Symptoms of endocarditis include : a high temperature a new heart murmur aching muscles alterations in a heart murmur bleeding under fingernails or toenails broken blood vessels in the eyes broken blood vessels in the skin chest pains coughing headache [medicalnewstoday.com]

  Because our patient was known to have a heart murmur, and because we knew that the estimated risk of developing endocarditis in patients with acute Q fever who have a valvular defect is 39% [ 6 ], a transoesophagal echocardiogram was performed. [dx.doi.org]

  Two of these patients had preexisting heart murmur (patients 13 and 15). One patient received a diagnosis of endocarditis during pregnancy, and maternofetal death occurred at 27 weeks of gestation (patient 15). [doi.org]

• Jaundice

  A 28-year-old woman, a park ranger, developed acute Q fever with associated sepsis, profound jaundice, disseminated intravascular coagulation and multiorgan failure necessitating prolonged admission to the intensive care unit for ventilatory support. [ncbi.nlm.nih.gov]

  […] cattle, dogs, cats, birds, rodents and ticks occupations: farmers, laboratory workers, sheep and dairy workers and vets bacteria shed in birth products, faeces, milk and urine incubation 10-40 days SOB chest pain clay coloured stools systemic symptoms jaundice [lifeinthefastlane.com]

  Common symptoms may include: Dry cough (nonproductive) Fever Headache Joint pain (arthralgia) Muscle pains Other symptoms that may develop include: Abdominal pain Chest pain Jaundice (yellowing of the skin and whites of the eyes) Rash A physical examination [medlineplus.gov]

  More rarely, it can cause yellowing of the skin and the whites of the eyes (jaundice). Cases of acute Q fever are usually self-limited. [rarediseases.org]

• Hepatomegaly

  The aborted foetus may show hepatomegaly, subcutaneous oedema and reddish fluid accumulation. On histopathology, the placenta is infiltrated by mononuclear cells and chorionic trophoblasts are necrotic. The exudate contains fibrin and neutrophils. [en.wikivet.net]

  Marked finger clubbing, arterial emboli, hepatomegaly, splenomegaly, and a purpuric rash may occur. The case-fatality rate is only about 1% in untreated patients but is higher in those with endocarditis. [merckmanuals.com]

  Hepatitis may cause abnormal enlargement of the liver (hepatomegaly). More rarely, it can cause yellowing of the skin and the whites of the eyes (jaundice). Cases of acute Q fever are usually self-limited. [rarediseases.org]

  Hepatitis can be associated and may be clinically asymptomatic or present with hepatomegaly and (rarely) jaundice. [patient.info]

• Hepatosplenomegaly

  The patient had a new onset of Melody valve dysfunction associated with the combination of hepatosplenomegaly and pancytopenia but was afebrile. [ncbi.nlm.nih.gov]

  Hepatosplenomegaly. Chronic Q fever is rarely reported in children, although when it does occur, osteomyelitis is one of the most common findings. [patient.info]

  There was no hepatosplenomegaly, enlarged lymph nodes, or peripheral stigmata of endocarditis. [doi.org]

• Photophobia

  Patients may develop one or more of the following symptoms: sudden onset of acute fever greater than 39ºC (usually lasts 1-2 weeks) chills or rigors profuse sweating non-productive cough chest pain severe headache photophobia confusion muscle pain fatigue [nt.gov.au]

  Signs and symptoms of acute Q fever include: fever, with a body temperature of at least 39.4 degrees Celsius, or 104 degrees Fahrenheit severe headache muscle pain joint pain sweats photophobia, or sensitivity to light weight loss skin rash, although [medicalnewstoday.com]

  Severe debilitating headaches are common, often retro-orbital and associated with photophobia. [patient.info]

  The headache might be retroorbital and associated with photophobia ( 6 ). [cdc.gov]

• Eye Pain

  Following entry into the eyes, pain, tearing, redness, and blurred vision occur. [emedicinehealth.com]

• Myalgia

  Clinical symptoms were nonspecific: myalgia (94%), fever (91%), headache (80%), acute fatigue (64%), and arthralgia (55%). Most cases (93%) were acute, and serology (immunofluorescence) was the main diagnostic modality. [ncbi.nlm.nih.gov]

  […] dogs, cats, birds, rodents and ticks occupations: farmers, laboratory workers, sheep and dairy workers and vets bacteria shed in birth products, faeces, milk and urine incubation 10-40 days SOB chest pain clay coloured stools systemic symptoms jaundice myalgia [lifeinthefastlane.com]

  Acute illness symptoms range from fever, headache, myalgia, non-productive cough, and gastrointestinal upset to more serious illness such as pneumonia, hepatitis, miscarriage, or myocarditis. [dhs.wisconsin.gov]

  The clinical picture is often dominated by fever, headaches and myalgias 5. A cough, if present, is often nonproductive and may even be absent despite the presence of the pneumonia. [radiopaedia.org]

  Acute Q fever is usually characterized by flu-like symptoms such as high fevers, chills, muscle pain (myalgia), and headaches. In some cases, fevers do not occur. [rarediseases.org]

• Arthralgia

  The most frequent clinical manifestation of acute form is a self-limited febrile illness which is associated with severe headache, muscle ache, arthralgia and cough. [ncbi.nlm.nih.gov]

  Common symptoms may include: Dry cough (nonproductive) Fever Headache Joint pain (arthralgia) Muscle pains Other symptoms that may develop include: Abdominal pain Chest pain Jaundice (yellowing of the skin and whites of the eyes) Rash A physical examination [medlineplus.gov]

  Individuals with chronic Q fever may also experience a variety of nonspecific symptoms including prolonged fevers (although fevers are often absent), joint pain (arthralgia), muscle pain (myalgia), night sweats, chills, fatigue, and unintended weight [rarediseases.org]

  Acute cases may present with fever, sweating and chills, sever headache, myalgia and arthralgia, extreme fatigue, weakness and malaise. [health.nsw.gov.au]

• Headache

  The most frequent clinical manifestation of acute form is a self-limited febrile illness which is associated with severe headache, muscle ache, arthralgia and cough. [ncbi.nlm.nih.gov]

  a disease characterized by high fever, chills, muscular pains, headache, and sometimes pneumonia that is caused by a bacterium ( Coxiella burnetii of the family Coxiellaceae) of which domestic animals serve as reservoirs and that is transmitted to humans [merriam-webster.com]

The symptoms and signs of Q fever are not specific and hence some type of laboratory test is needed to confirm the diagnosis. The majority of labs do not have the capability to isolate C. burnetii. Hence serological tests are the most common means to diagnose the organism. Other tests used to detect C burnetii include indirect fluorescent antibody test and complement fixation. PCR is now also available to detect C. burnetii [6].

Other tests

• ECG may show evidence of pericarditis or myocarditis [7].
• CBC may show hemolytic anemia
• WBC
• Liver function may show mild elevation of transaminase
• ESR may be elevated
• Blood cultures are usually negative
• Lumbar puncture to sample CSF if patient has meningoencephalitis

Imaging

Depends on which organ system is involved:

• CXR may show opacification, pleural effusions or interstitial fibrosis if the lung is involved.
• CT brain is needed if patient has neurological symptoms
• Ultrasound to assess the liver
• Echo to look for function of heart valves, presence of vegetations and pericardial effusions

• Pulmonary Infiltrate

  Chronic pulmonary infiltrates associated or not with infective endocarditis is the most frequent clinical scenario in chronic Q fever 11,12,16. [scielo.br]

• Atelectasis

  Patients with respiratory symptoms or signs require chest x-ray; findings may include atelectasis, pleural-based opacities, pleural effusion, and lobar consolidation. [merckmanuals.com]

• Thrombocytosis

  Abstract We report a case of Q fever in a man who presented with fever of 40 days duration associated with thrombocytosis. Serological and molecular analysis (polymerase chain reaction) confirmed infection with Coxiella burnetii. [ncbi.nlm.nih.gov]

  Reactive thrombocytosis and microscopic haematuria are common. Hyperglobulinaemia of up to 60 g/L is commonly found and a useful diagnostic sign. [patient.info]

  […] tests Acute Q fever may present with the following laboratory results: A complete blood cell (CBC) count usually shows a normal white blood cell (WBC) count (70-90%) (elevated WBC in as many as 30%), mild thrombocytopenia (25%) (followed by a reactive thrombocytosis [emedicine.medscape.com]

• Coxiella Burnetii

  Coxiella burnetii DNA was detected in 56 out of 202 samples (28%). Airborne Coxiella burnetii presence showed a clear seasonal pattern coinciding with goat kidding. [ncbi.nlm.nih.gov]

  […] pathogen was unknown Infection due to Coxiella burnetii (disorder) Infection due to Coxiella burnetii edit English Q fever disease caused by infection with Coxiella burnetii, a bacterium that affects humans and other animals; the most common manifestation [wikidata.org]

• Pleural Effusion

  Segmental or lobar opacification and occasional pleural effusions may be seen (all of which are non specific features on their own). Features can be slow to clear 4. [radiopaedia.org]

  Pneumopathy is mostly moderate but pleural effusion or acute respiratory distress may occur. Symptoms may last 10-90 days. [orpha.net]

  Patients with respiratory symptoms or signs require chest x-ray; findings may include atelectasis, pleural-based opacities, pleural effusion, and lobar consolidation. [merckmanuals.com]

  effusions or interstitial fibrosis if the lung is involved. [symptoma.com]

  Pleural effusion can also be present. Findings on the chest radiograph are nonspecific. The duration of symptoms varies from 10 to 90 days. The mortality rate ranges from 0.5 to 1.5%, depending upon the series ( 30, 180 ). (iii) Hepatitis. [jcm.asm.org]

Many patients with acute Q fever have a self-limited disease which can spontaneously resolve. Thus, the decision to start antibiotics requires clinical judgment and experience. In patients who have chronic Q fever, it is important to consult with an infectious disease expert. All patients who have endocarditis need evaluation by a cardiologist and a cardiac surgeon. Pregnant women need to be seen by an obstetrician.

However, because these is a remote chance that acute Q fever may become chronic, most healthcare providers do start a course of antibiotics.

Other supportive treatments include the following:

• Antitussives
• NSAIDs for fever
• Oral hydration
• Antiemetics

Management of acute Q fever

Nearly 2/3rd of patients with acute Q fever have no symptoms. Since the disease is self-limiting and resolves spontaneously in 7-14 days, the decision to treat remains questionable. Even if antibiotics are used, the disease period is only shortened by a few days if started at the onset of the infection.

• The drug of choice for Q fever pneumonia is doxycycline. The second line drug of choice is ciprofloxacin. The third line drugs of choice are the macrolides. All these agents have been well studied in prospective randomized trials and shown to be effective against Q fever. The chief reason why macrolides are drugs of 3rd choice is because of the gastrointestinal adverse effects. Both erythromycin and azithromycin have been proven to be effective against Q fever pneumonia. Patients who have respiratory distress need to be admitted to an ICU and be treated with a fluoroquinolone in such a setting.
• The optional duration of treatment is 14-21 days in an outpatient setting.
• In children the drugs of choice is macrolides or trimethoprim sulfamethoxazole.
• If the patient has hepatitis, adjuvant corticosteroid treatment may be of benefit.

Management of chronic Q fever

• Chronic Q fever is not easy to treat because of the multiple organ system involvement. In most cases admission to the hospital is required and a prolonged course of antibiotics needed. In most cases, combination antibiotic therapy is used because of high rates of relapse.
• The duration of therapy is not known but experts suggest at least 12 months. The treatment response can be followed by measuring antibody titers.
• If endocarditis is diagnosed, combination of doxycycline and hydroxychloroquinine/fluoroquinolone for at least 18 months is recommended to eradicate any remaining C burnetii and prevent relapses [8].
• Other organ system involvement may also require combination therapy for prolonged periods.

Follow up

All patients with a diagnosis of Q fever need follow up with a healthcare provider because the condition can become chronic. Serology is needed on a regular basis to ensure that the infection does not reoccur.

If the patient has endocarditis a follow up with a cardiologist and a surgeon is necessary because there is a possibility of valve replacement. If surgery is not undertaken serial echo is required to monitor heart and valve function. Echo and ultrasound may also be required to ensure that the patient is not developing thoracic or aortic aneurysms.

Patients who are receiving hydroxychloroquine also need a follow up with an ophthalmologist to assess the eye for retinal toxicity.

Q fever in pregnancy

Only a few reports exist on Q fever in pregnancy. If infection occurs, then therapy may be undertaken with doxycycline or rifampin. In addition the treatment must eb continued after pregnancy, while the infant must be clinically monitored with serology for signs of Q fever. The decision to treat the infant must be individualized.

Therapy with biological modifying agents

There are some patients who fail to respond to the conventional drugs and in such cases use of biological agents may help [9] [10]. Isolated reports indicate that use of interferon gamma can help kill C. burnetii in monocytes through an apoptotic mechanism that is mediated by tumor necrosis factor [8]. Patients who develop granulomatous hepatitis due to Q fever and have a prolonged illness often fail to respond to antibiotics. These individuals may benefit from prednisone.

There are no commercial vaccines to prevent Q fever. An experimental vaccine is only available from the U.S. Army Medical Research Institute for Infectious Diseases in Fort Detrick, Maryland.

Acute Q fever is a self-limited disease and the outcome is excellent in patients who are promptly diagnosed and treated. At least 50% of patients are asymptomatic and less than 2% of patients need admission. The mortality for acute Q fever is very low.

Chronic Q fever is a serious illness and most patients require admission and long term follow up. This infection is associated with frequent relapses and has a high mortality rate. The most common feature of chronic Q fever is the development of endocarditis, which can be fatal if left untreated. Even with treatment, the mortality rate approaches 10-20 %.

Other complications of chronic Q fever include the following

• Abortions
• Acute respiratory distress syndrome
• Chronic fatigue syndrome
• Congestive heart failure
• Meningoencephalitis
• Premature labor
• Reactivation of infection during pregnancy
• Spontaneous abortion
• Thrombocytopenia
• Vascular aneurysms

Several studies from England and Australia have shown at least 10% of patients with acute Q fever go on to develop fatigue that may last 6 months.

Q fever is acquired by inhalation of aerosolized particles containing the bacteria. The organism is often found in animal waste like urine, feces and placenta. When these products dry out, the bacteria enter a spore stage and dries up, making it easily prone to inhalation.

Sometimes it can be acquired by direct contact with parturient animals or the placenta. C. burnetii can sometimes be found in dust, soil or other contaminated environmental waste that are carried for long distances by wind. Once inhaled the microorganism starts to proliferate in the lungs and then invades the blood, especially in patients who are immunocompromised. Once in the blood stream, C burnetii can infect bone, heart valves or liver resulting in chronic Q fever.

Other means of acquiring C.Burnetii include tick bites and sexual transmission, which is rare. C.Burnetii is known to localize to animal reproductive organs and is readily excreted. The infection can also be acquired in people who have no known exposure to animals. This may occur in scenarios when farm vehicles carrying contaminated hay, animal feeds or manure come into contact with humans. Human to human transmission is very rare and only one documented case has been reported.

Q fever is a very common zoonotic infection. The animal reservoir depends on the country. By far the most common animal reservoirs include sheep, cattle and goats. Cats are the primary reservoirs for Q fever in Nova Scotia, Canada. In rare cases, dogs have also been identified as reservoirs. Except for Antarctica and New Zealand, Q fever has been reported in most parts of the globe. The precise numbers of people infected remains unknown because the symptoms are nonspecific, diagnostic tests are not always performed and reporting of the infection is not mandatory. With recognition of the disease, more cases have been reported in the USA in the past decade than previous ones. Q fever cases have also been reported in US military personnel deployed in the Netherlands and Middle East. Clusters of outbreak have been reported in Australia, Spain, UK, France and parts of Africa [3][4]. Q fever is endemic in the Middle East; the reason for this is the hot dry environment and livestock farming practices which make it easy for the organism to spread and thrive.

Q fever can occur at any age and is slightly more common in men compared to women, primary because the former are more likely to work outdoors. When Q fever occurs at a young age there is an increased risk of developing hepatitis and pneumonia. If the infection is acquired during pregnancy, there is a risk of low birth weight, spontaneous abortions or premature birth.

The causative agent of Q fever is C. burnetii. This small gram negative organism usually multiplies fast in acidic environments and can form spores, which explains its ability to survive for prolonged periods in hostile environments and the ability to develop resistance to a variety of chemical agents. C. Burnetii has two antigenic phases: phase I and phase ll. In animals it exists in phase 1 and is very infectious. Phase II is less infectious.

C. burnetii is known to infect many animal species. Once the bacterium is excreted from feces, milk, urine or placenta, the bacteria survives in the soil as a spore. C. burnetii is extremely infectious and only requires a few microorganisms to produce disease. Because of the ability to form spores, C. burnetii remains viable for prolonged periods. Once the spores are inhaled by the human, the organism thrives in the lung and may escapes into the systemic circulation and infects the bone, heart or liver.

The organism is known to proliferate in lysozymes and then transported to other organs. Because of its high infectivity, C. burnetii is classified as potential agent for bioterrorism [5].

To avoid Q fever, the following recommendations are made:

• Avoiding consumption of unpasteurized milk and other dairy products- especially cheese from goat;
• Avoiding contact with pregnant farm animals and their birth products;
• Avoiding contact with urine, feces and other fluids from farm animals;
• Encourage birthing of animals inside;
• Safely disposing birthing tissues like the placenta and aborted fetuses;
• Minimize exposure to farm animals, especially in dry arid areas. Wear proper garments when outdoors to avoid tick bites. Use tick repellants and other chemicals if needed;
• When animals are sick, get them seen by a veterinarian on time;
• Wear mask and gloves when handling sick farm animals.

To prevent Q fever it is essential to eradicate the reservoir. One approach is to use seronegative sheep in research facilities and minimize contamination of livestock. Isolation of patients who are infected with Q fever is not necessary since person to person transmission does not occur.

Q fever is a common zoonosis caused by the gram negative organism Coxiella burnetii. The primary reservoirs for this organism are sheep, cattle and goats but many other animal species may also be infected. Human transmission is primarily via inhalation of aerosolized particles from contaminated soil, dirt or animal water. In rare cases, the organism may be acquired following a tick bite and ingestion of unpasteurized milk. Human to human transmission has been reported but is extremely rare. Q fever occurs as an acute or chronic illness. The acute illness has nonspecific symptoms and spontaneously resolves in many cases. The chronic phase is a serious infection that primarily causes endocarditis. C.Burnetii is susceptible to several antibiotics including doxycycline, fluoroquinolones and macrolides [1][2].

Q fever is an infectious disorder acquired following an infection from the organism, C. burnetii. The organism is often found in sheep, cattle and goats and acquired in humans after inhalation of dried spores. Once in the lungs, the bacteria can spread to other parts of the body. In most cases the acute phase of the illness lasts 5-12 days and presents with non-specific symptoms. In about 1% of cases, the organism will persist and result in a chronic infection. This is a serious illness which primarily affects the heart valves. Q fever does respond to antibiotics, but close follow up with a healthcare provider is recommended to ensure that recovery is taking place.

1. Chmielewski T, Tylewska-Wierzbanowska S. Q fever at the turn of the century. Q fever at the turn of the century. Pol J Microbiol. 2012;61(2):81-93.
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