Q fever

Q fever: symptoms, treatment and prevention

Q fever is an acute rickettsial disease characterized by intoxication, fever and frequent lung damage. It is a zoonosis and can be transmitted through vector-borne, contact, nutritional and airborne dust routes.

Etiology and pathogenesis

Q fever is caused by Burnet's rickettsia, which is stable in the external environment and is not inactivated by drying. The gateway to infection is often the mucous membrane of the respiratory tract or digestive tract.

The route of infection determines the clinical manifestations. When airborne dust infection occurs, damage to the bronchi and often peribronchial inflammation of the lung tissue occurs. Other organs are also affected hematogenously.

Symptoms and course

The incubation period lasts from 3 to 32 days, most often 14-20 days. The disease begins acutely. Body temperature rises to 38-39 °C, fever lasts 1-2 weeks, although in some cases it can last up to a month. Characterized by large daily temperature variations, accompanied by chills and sweat, muscle pain, headache, and soreness of the eyeballs. The skin of the face and neck is hyperemic, the vessels of the sclera are injected.

Hypotension and bradycardia are observed. Symptoms of damage to the respiratory system usually appear from the 2-4th day of illness: dry cough, rawness behind the sternum, dry, and then fine moist rales, less often shortening of the percussion sound is detected. X-ray changes in the lungs are predominantly of an interstitial (peribronchial) nature, against the background of which focal infiltrative changes occur in some patients.

By the end of the week, the liver and spleen enlarge. During the period of convalescence, asthenia persists for a long time; full restoration of working capacity occurs in 2-4 weeks. There may be relapses of the disease.

Complications

Complications may include endocarditis, hepatitis, encephalopathy, myocarditis, arthritis and diseases caused by a layer of secondary infection.

Diagnostics

When diagnosing, stay in an endemic area is taken into account. Differential diagnosis is carried out with influenza (in the first days of illness), pneumonia, bronchitis, acute respiratory viral infections and other diseases with which clinical manifestations may coincide.

Laboratory diagnostics include the determination of antibodies to rickettsia using ELISA, RNP, RIF, ELISA, and PCR methods.

Treatment

Treatment is carried out in a hospital setting. Antibiotics of the tetracycline group (doxycycline, minolcycline) are prescribed for 7-14 days; in severe cases, gentamicin or chloramphenicol may be used. It is important to ensure the correct dosage and duration of treatment to avoid relapses and the development of a chronic form of the disease.

Symptomatic treatment is aimed at reducing temperature, eliminating pain, improving respiratory function and cardiac activity.

Prevention

Preventive measures include limiting contact with the pathogen, maintaining good hygiene when working with animals, and using protective clothing and personal protective equipment.

There is no vaccine to prevent Q fever, so special attention should be paid to the prevention of tick bites, which are vectors for the transmission of rickettsia. This requires the use of repellents, long sleeves and pants, and regular body checks after being in forested areas.