Q fever - Symptoms

Unlike other rickettsioses, Q fever symptoms are characterized by pronounced polymorphism, which depends on the mechanism of transmission of the pathogen, the infecting dose of rickettsia and the state of the macroorganism. The most severe symptoms of Q fever occur with airborne infection, however, it is a cyclical infection, during which the following periods are distinguished: incubation, initial (3-5 days), peak (4-8 days) and convalescence. Q fever has the following forms:

• acute (disease duration 2-4 weeks) - in 75-80% of patients;
• subacute or protracted (1-3 months) - in 15-20% of patients:
• chronic (from several months to one year or more) - in 2-30% of patients;
• erased.

Acute, subacute and chronic forms are divided into mild, moderate, severe and very severe. Criteria for severity are the level of fever, severity of intoxication and organ pathology.

Q fever has an incubation period that lasts 3-30 days (on average 12-19 days).

In 95% of cases, Q fever has an acute onset: chills, a rapid increase in temperature to 39-40 °C and general toxic syndrome. A strong, persistent, non-relieved by analgesics diffuse, less often localized (forehead, back of head) headache occurs. Typical symptoms of Q fever occur: dizziness, weakness, sweating (up to profuse sweating), fatigue, arthralgia, myalgia, pain on palpation.muscles. From the first days of the disease, most patients experience hyperemia of the face and neck, injection of the scleral vessels, and hyperemia of the pharynx. Sometimes enanthem, herpes labialis or herpes nasalis, and sleep disorders up to insomnia are noted. Sharp pain in the eye sockets and eyeballs is very characteristic, increasing with their movement. Some patients experience dry cough, nausea, vomiting, nosebleeds, and loss of appetite.

In severe cases, the following symptoms of Q fever are possible: agitation, delirium. Rarely(1-5% of cases) on the 3rd-16th day of the disease, roseolous or maculopapular exanthema without permanent localization occurs.

The main and most constant symptom of Q fever is fever, the duration of which varies from several days to a month or more (on average 7-10 days). Usually the temperature reaches 38.5-39.5 °C. Fever can be constant, remittent, irregular. Its significant fluctuations are characteristic, detected during three-hour thermometry (especially in severe and moderate cases of the disease). Morning rather than evening temperature rises are often more pronounced. Fever is accompanied by chills (shivering), sweating throughout the disease. Temperature decreases lytically or by the type of shortened lysis within 2-4 days. In some patients, subfebrile temperature remains after its decrease, which may be a harbinger of a relapse.

Cardiovascular damage in Q fever is inconstant and non-specific. Muffled heart sounds, relative bradycardia, slight decrease in blood pressure, systolic murmur at the apex of the heart (sometimes) can be detected. In some patients, when the infection becomes chronic, specific rickettsial endocarditis can develop, which is more often observed in previous rheumatic heart disease and congenital heart defects. In this case, murmurs and expansion of the heart borders occur. Coxiella endocarditis is a chronic process lasting from 5 months to 5 years. In most cases (up to 65%), it ends fatally.

Q fever is characterized by respiratory system damage. Tracheitis, bronchitis, and pneumonia may occur. The incidence of pneumonia, according to different authors, varies from 5 to 70% and depends on the routes of infection. They develop mainly with airborne infection; isolated cases of pneumonia may be caused by a secondary bacterial infection. Patients complain of cough (dry, then productive, with viscous serous-purulent sputum), a feeling of discomfort and a burning sensation behind the breastbone: sometimes shortness of breath occurs. Physical data are scanty. It is possible to detect areas of shortening of percussion sound, harsh breathing, dry and then wet wheezing. On the radiograph, an increase in the pulmonary pattern, a decrease in the transparency of the lung fields are determined. small focal cone-shaped infiltrates, localized mainly in the lower parts of the lungs and the root zone. These changes are characteristic of interstitial pneumonia. Usually, pneumonic foci are defined as a gentle cloud-like darkening. Even with the formation of massive darkening, cavities are not formed, the acute process does not become chronic. With an increase in bronchial and paratracheal lymph nodes, the roots of the lungs expand, compact and deform. Very rarely, pleuropneumonia with dry pleurisy is detected, as a result of which the disease can take a protracted or recurrent course. The course of pneumonia is torpid. Resorption of inflammatory foci occurs slowly (within 6 weeks).

On the part of the digestive system, a loss of appetite is observed, with severe intoxication - nausea and vomiting; constipation is possible. Some patients complain of such symptoms of Q fever as: flatulence and abdominal pain (due to damage to the autonomic nervous system), sometimes severe, of various localizations. The tongue is enlarged in volume, coated with a dirty-gray coating (the edges and tip are clean), with imprints of teeth along the edges (similar changes are noted in typhoid fever). Moderate hepato- and splenomegaly are very characteristic. Sometimes reactive hepatitis develops with all its inherent clinical and biochemical signs; the outcome is usually favorable. Long-term hepatosplenomegaly (after normalization of temperature) can be observed in a protracted, chronic or recurrent course of the disease.

Pathologies of the genitourinary system are usually not detected.

During the peak of the disease, Q fever symptoms often intensify, indicating damage to the central nervous system caused by intoxication. Vegetative disorders are clearly manifested. Meningism, serous meningitis, meningoencephalitis, neuritis, polyneuritis, infectious psychosis with delirium and hallucinations are possible. During the recovery period, a pronounced psychoasthenic syndrome usually persists.

Unusual symptoms of Q fever: optic neuritis, extrapyramidal disorders, Guillain-Barré syndrome, LDH hypersecretion syndrome, epididymitis, orchitis, hemolytic anemia, enlarged mediastinal lymph nodes (similar to lymphoma or lymphogranulomatosis), pancreatitis, erythema nodosum, mesenteritis.

Blood tests reveal normo- or leukopenia, neutro- and eosinopenia, relative lymphocytosis and monocytosis. slight increase in ESR. Thrombocytopenia is detected in 25% of patients, and thrombocytosis reaching 1000x10 ⁹ /l is often observed during recovery. This can explain deep vein thrombosis, which often complicates Q fever. Proteinuria, hematuria, and cylindruria are sometimes detected.

The convalescence period begins with the normalization of temperature, but already several days before this, patients note an improvement in well-being, sleep and appetite. In 3-7% of patients, relapses of the disease are recorded 4-15 days after the main wave.

During the recovery period, a pronounced psychoasthenic syndrome often persists.

The latent forms are characterized by scanty and atypical symptoms. They are detected during routine serological studies conducted in infection foci.

Asymptomatic infection is possible in endemic foci and during epidemic outbreaks of the disease due to the introduction of the pathogen with raw materials (cotton, wool, etc.) into production teams. Positive results of serological tests can be interpreted in different ways: as evidence of asymptomatic infection, latent infection without clinical symptoms, which can sometimes "break through" protective barriers and cause disease, as a result of "pro-epidemic" or "natural immunization" of the population in epidemic foci.

Primary chronic course of Q fever is not observed. Usually Q fever begins quickly, and then for some reason acquires a torpid course. In chronic course, lung or heart lesions, myocarditis, endocarditis predominate. Such forms of infection occur in patients with heart defects, immunodeficiency, chronic renal failure. High fever is usually absent, but subfebrile condition is possible. In case of combination of acquired heart defects with hemorrhagic rash of unspecified etiology or renal failure, Q fever should be suspected first of all. Endocarditis, apparently, has an autoimmune and immune complex genesis. Immune complexes are deposited on the cusps of the heart valves affected by infection, or on the growths of the endothelium (especially at the junction of the patient's tissues and the valve prostheses).

The form and course of the disease are determined by a number of factors. It is known that in sporadic cases the course of the disease is benign. In children, Q fever is milder than in adults. In infants infected through milk, the clinical course of the disease is the same as in other age groups. A number of infectious disease specialists note a more severe and prolonged course of Q fever in patients over fifty years of age. Combination with other infections (hepatitis, dysentery, amoebiasis, etc.) aggravates the course of coxiellosis, and the disease itself contributes to the exacerbation of chronic pathology (tonsillitis, otitis, colitis, etc.).

[ 1 ], [ 2 ], [ 3 ], [ 4 ], [ 5 ], [ 6 ], [ 7 ]

Complications of Q fever

With timely and properly administered antibiotic therapy, complications of Q fever are virtually absent. In unrecognized cases of Q fever or with late treatment (especially in chronic cases), complications may develop: collapse, myocarditis, endocarditis, pericarditis, thrombophlebitis of the deep veins of the extremities; respiratory system damage - pleurisy, pulmonary infarction, abscess (with superinfection). Some patients are found to have hepatitis, pancreatitis, orchitis, epididymitis, neuritis, neuralgia, etc.

[ 8 ], [ 9 ], [ 10 ], [ 11 ]