The Q stands for query, as the causing agent of Q fever was unknown when it was first recognized as human disease in Australia in the year 1935. There are number of microbes around us in our environment. Some of them are bacteria. Q fever in human is caused due to encounter of Coxiella burnetii, a gram-negative intracellular bacterium. Having too much physical contact with animals and infected cattle can cause the encounter of Coxiella burnetii in human body through inhalation and several rare mode of transmission.
Let’s have a deep look into this bacterial disease, Q fever.
Q Fever: An Overview
Q fever is a bacterial infection caused due to encounter of a gram negative bacterium Coxiella burnetii, which affects both human and animals. Animals are the primary host of this bacterium. Cattle, sheep, goats, especially the dairy cattle have been found as a reservoir of C. burnetii.
Humans get infected due to close contact with the infected animals. Transmission of the C. burnetii from animals to human allows Q fever to show its signs and symptoms in the human body.
There are number of signs and symptoms of Q fever caused due to C. burnetii. However, the interesting fact is that, half of the human infected by C. burnetii do not show any sign of Q fever, and thus, the disease spreads easily from man to man.
Signs and Symptoms of Q Fever
Human develop a chronic illness within 2 to 3 weeks when Coxiella burnetii attacks human body. Following are the signs and symptoms of Q fever:
- High fevers with body temperature of 104-105°F
- Chest pain due to myocarditis or pneumonia
- Severe headache
- Abdominal pain with diarrhea
- Vomiting with nausea.
Epidemiology of Q Fever
The Q fever bacterium is found almost everywhere in the world except New Zealand. The bacterium is highly virulent and can sustain very high temperatures. A single bacterium is enough to cause an infection in an animal and cattle and also in human. Due to its high sustainability, C. burnetii was developed and is regarded as a biological weapon capable of causing massive emergency. The bacterium is least known to human and is ranked by CDC as “Category B” bioterrorism agent.
Causes of Q Fever
Transmission of the Coxiella burnetii from the infected goats, sheep, and dairy cattle is the primary cause of Q fever in humans.
The transmission from the infected cattle to humans may happen in several ways.
- Inhalation: Inhalation of aerosols from the contaminated soil and animal waste can result in transmission of C. burnetii to humans very easily.
- Tick Bites: Ticks act as vectors for the transmission of C. burnetii after they bite an infected animal and then a human. One tick bite is enough to transmit the bacteria into the human body.
- Ingestion of Dairy Products: Milk and other dairy products from an infected cow or goat can make an individual a victim of C. burnetii with symptoms of Q fever.
Complications Caused due to Q Fever
- Patients with Q fever recover well, but the complications can become worse with the symptoms mentioned above if the patient has any other disease or malfunction in the body.
- Few complications like inflammation of liver called granulomatous hepatitis may occur. Moreover, the complications of Q fever also worsen with pneumonia, inflammation of the heart tissue, called myocarditis and complications in the CNS (Central Nervous System).
- This bacterial infection also results in miscarriages of the pregnant women. Moreover, pre-term delivery is also possible in a patient.
- The rate of fatality is very low; very less number of people has been found dead due to Q fever i.e., < 2% of the hospitalized patients. Early diagnosis and right treatment with correct antibiotics can shorten the period of this acute illness.
Diagnosis of Q Fever
Early diagnosis is always helpful to start the treatment immediately. Diagnosis of Q fever is not easy for the clinicians and doctors as the disease comes with symptoms of many diseases, and thus makes it hard to distinguish Q fever from the other diseases. For this reason, doctors need to know and rely on patient’s history, about their job, recent visit to any animal firm etc. There is a high risk of chronic Q fever for a patient who has the history of acute Q fever.
Clinical Diagnosis of Q Fever
According to CDC (Centers for Disease Control) report, antibody tests are found negative within seven to ten days of Q fever. Doctors give opinions as per an individual’s clinical tests, histories, and symptoms.
Sometimes clinical diagnosis with low platelet count, normal WBC (White Blood Cells) count, and elevated level of liver enzymes (having symptoms of jaundice) indicates acute Q fever infection. During this acute phase of Q fever, PCR (Polymerase Chain Reaction) test helps doctors to be assured that the suspected one has been infected with C. burnetii.
Treatment & Recovery of Q Fever
Patients with milder phase of Q Fever recover without treatment, if they are not suffering from any other diseases or immunodeficiency.
Antibiotic is the only way to get rid of Q Fever. Deoxycycline is the antibiotic normally prescribed for adults and children who have been diagnosed with Q Fever. It normally takes two to three weeks to recover, but in case of chronic Q Fever an individual must continue the antibiotic course for 18 months.
Report says that the outcomes of the treatment with antibiotic are very effective, and fatality is very rare and uncommon. However, a patient of Q fever having myocarditis (inflammation of the heart tissue) takes 18 months to recover with the antibiotic course.
Prevention of Q Fever
In Australia, Q fever was first discovered and recognized as human disease in 1935, and in the early 1940’s it was also found in the United States.
Vaccine for Q fever is available in Australia, but currently is not obtainable in the United States. The vaccine prevents people from the bacterial infection of C. burnetii, who work in animal firms and high-risk environment.
- People who are not vaccinated yet, but visit the high-risk environment can get infected easily. They must take some precautions to avoid transmission of C. burneti.
- Be assured about the milk whether it is pasteurized or not, because milk and other dairy products without pasteurization can transmit C. burnetii to the human body.
- Routine check of the pets and animals whether they are infected or not must be done.
- Washing hands properly with sanitizer after handling animals and cattle.
- Immediate restriction of airflow from any animal firm, as air is an easier way of bacterial transmission through inhalation.
- Proper education and awareness about the source and symptoms of Q fever.
- Last but not the least, vaccination of individuals must be done, if the vaccine is available.
Q Fever due to bacterial invasion of Coxiella burnetii can be restricted firstly with simple awareness and education about the source and the result. Washing hands and the habit of cleanliness help in staying away from the contaminated soil, dirt, and air. Although rarely fatal, the disease must be taken care of at the earliest to prevent it from furthering. People with already established immunodeficiency must be more cautious while handling animals and cattle.