Q FEVER

From Big Medical Encyclopedia

Q FEVER (English. Q-fever; the name on the first letter English query uncertain, not clear; synonym; Ku rickettsiosis, pneumorickettsiosis, Queensland fever) — the acute infectious disease with a natural ochagovost caused by Burnett's rickettsiae and which is characterized by a polymorphic clinical picture; perhaps subacute and chronic current.

Cool. it is widespread in Australia, in many countries of America, in Europe and Asia. Local focuses of the disease are revealed also in a number of geographical zones of our country.

History

Derrick (E. The N of Derrick) in 1937 described the disease observed since 1933 among working slaughterhouses of Brisbane (Australia) under the name «Q-fever». He allocated the activator and established that a source of an infection are sheep. The same year F. Vernet and Freeman (M. of Freeman) in detail studied the activator and carried it to rickettsiae, and Derrick in 1939 gave it a specific name — Rickettsia burneti, than emphasized F. Burnett's role in studying of a disease-producing factor. In 1938 Davis and Cox (G. E. Davis, H. R. Dried) reported that they allocated the microorganism which appeared by identical Rickettsia burneti at ixodic mites of Dermacentor andersoni and Amblyomma americanum. In 1947 — 1948 Filip (S. of Philip) combined them in the independent sort Coxiella and gave a specific name to Coxiella burnetii. In 1938 the first diseases in the USA (laboratory infections) were registered, then were noted and epid, flashes, generally among working slaughterhouses in Chicago and other regions of the country. In Europe Cool. Imkheyzerom is for the first time described in 1943 (To. Imhauser) under the name «Balkan flu» which was registered in the years of World War II among the German occupational troops in Greece, Bulgaria, Romania, Yugoslavia and in the Crimea. In the USSR studying Cool. began since 1952 when M. P. Chumakov established that the microorganisms allocated with A. I. Shifrin from the patient in 1951 are Burnett's rickettsiae. It gave the grounds to consider that being registered in 1944 — 1951 so-called Termez, or Central Asian, fever was Cool.

The etiology

the Disease-producing factor of Coxiella burnetii [Derrick, Philip, 1948 (a synonym of Rickettsia burneti)] belongs to the sort Coxiella this. Rickettsiaceae. These are gram-negative motionless small kokkovidny, rhabdoid or bipolar educations from 0,25 X 0,5 to 0,25 X 1,5 microns in size. Across Romanovsky — to Gimza are painted in an issinya-magenta color, and across Zdrodovsky — Makkiavello — in red. They are capable to pass through bacterial filters and even ultrafilters and to turn into L-forms under the influence of antibiotics (see. L-forms of bacteria ). Rickettsiae have a three-layered cover (Provatsek's rickettsiae have a five-layer cover) and a granular rikketsioplazma, inside a cut diffuzno in the form of spirals or granules the nucleoid representing accumulation of DNA is located. Page of burnetii — obligate intracellular parasites with autonomous, unlike viruses, systems of metabolism. Are grown up in culture of cells or in vitellicles of chicken embryos. The experimental infection is reproduced at different types a lab. animals. One of the major burnetii properties C. is the phase variation, or phase variability. Svezhevydelenny strains of S. of burnetii, as a rule, are in the I phase. Repeated browning through a vitellicle is followed by transition of a microbe from I in the II phase. There is enough, however, one passage through an organism of a Guinea pig to return the activator in the I phase. From rickettsiae of the I phase soluble antigen which it is possible to use, as well as corpuscular antigen I of a phase, in RSK, and also for immunization and as allergen for an intracutaneous test is emitted. Pages of burnetii are very steady against influence various physical. and chemical agents. ° 90 ° they maintain heating to t more than an hour, in milk perish only after ten-minute boiling. Rickettsiae keep viability in milk up to 125 days, and in cottage cheese and other dairy products remain virulent up to 30 days, in oil at its storage in the refrigerator — within 40 days. Survive during 1 days at influence of 1% of solution carbolic to - you, during 4 days — at action of 0,5% of solution of formalin. In 3 — 5% solution of phenol, 3% solution of chloroamine and 2% solution of formaldehyde perish in 1 — 5 min. See also Rickettsiae .

Epidemiology

S.'s Parasitizing burnetii is revealed more than at 90 species of mammals, 72 bird species and 73 types of arthropods. The infection at mammals proceeds usually inapparantno, temperature increase, abortions are only sometimes noted. Vertebrate animals allocate rickettsiae to the environment with excrements in which they can remain before half a year, and at a low temperature — till 1 year. In epid, the relation domestic animals and some species of rodents are especially dangerous.

There are natural and agricultural (antropourgichesky) centers Cool.

A source of an infection in the suburban centers are wild hoofs (Middle Asian gazelles, deer), small mammals, generally rodents (hares, squirrels, sandworts, some species of voles and mice, hamsters, gophers, groundhogs, jerboas) and birds (sparrows, swallows, starlings, etc.). Transfer of activators happens in the transmissible way — mites, generally ixodic, in a smaller measure — argasovy, gamazovy and krasnotelkovy. During a krovososaniye mites allocate rickettsiae with excrements in which they remain many months. Iksodoidny (Ixodic and argasovy) mites differ in a long carriage of rickettsiae (up to 900 days and more) and their transfer on the course a metamorphosis and transovarialno. All this allows to consider iksodoidny ticks not only by carriers, but also tanks of activators in the nature. People catch in the natural centers rather seldom, but at close contact with hungry ixodic mites their attack on people and infection Cool. perhaps.

In the village - x. the centers sources of contagiums are large and small cattle, horses, camels, pigs, etc., and also dogs, rodents, poultry. Domestic animals allocate activators with excrements, milk, a placenta and amniotic liquid, nasopharyngeal slime. In the territory of the natural centers domestic animals catch through ticks more often, but the possibility of infection with an alimentary and aerogenic way (is not excluded at inhalation of dust, through the grass, water, a forage contaminated by allocations of the infected animals).

Infection of people occurs in the air and dust way — during the processing of wool, skin and fur of the infected animals, the cotton contaminated by excrements of rodents at inhalation of dust from roads, pastures, with contaminated by rodents of hay or straw; in the alimentary way — at consumption of milk and dairy products (the infected cows, goats, sheep allocate S. to burnetii with milk within 60 days and more), through the hands contaminated by allocations of animals; at contact with the infected animals during care of them, their slaughter and cutting of hulks.

Infection of the healthy person from the patient is not observed. Incidence is generally sporadic, professional and household character, arises in spring and aestivo-autumnal time more often, is registered preferential at cattle breeders, veterinary workers and working meat-processing plants.

At had Cool. there is a strong and long immunity, recurrent diseases are rare.

Pathogeny

Cool. — an acute infectious cyclic high-quality reticuloendotheliosis without development of a pan-vasculitis. The pathogeny of a disease can be schematically presented in the form of the following links: S.'s penetration burnetii in a human body in generally aerogenic, alimentary or contact way (implementation through mucous membranes or skin); a lymphogenous drift in blood; primary or small (premorbidal) rikketsemiya; dissimination of rickettsiae in parenchymatous bodies of reticuloendothelial system; reproduction and their development in histiocytes, and then in macrophages of reticuloendothelial system; secondary, or big, a rikketsemiya and a toxaemia with dissimination of the activator and formation of the new centers in reticuloendothelial system (the beginning and a heat of a disease); development of the allergic phenomena of different degree of manifestation depending on sharpness of process and duration of circulation of the activator; development of usually durable and long immunity, in case of a slow immunol, reorganization of an organism and weak nonspecific protection of an organism process can be dragged out with a tendency to hron, or to a recurrent current; recovery.

Rickettsiae, fagotsitirovanny leukocytes, are digested, but probably not always (in cases hron, currents). P.F. Zdrodovsky (1955) specified that burnetii taken by leukocytes, macrophages and histiocytes S. partially lyse (especially in leukocytes), and partially breed in them in a significant amount, i.e., unlike other rickettsioses, the phenomenon of incomplete phagocytosis is observed here.

Generalization inf. process at Cool. is a consequence of constant escaping of the destroyed histiocytes and macrophages of a large number of rickettsiae in intercellular spaces. Here a part them perishes with release of endotoxin, and from remained one get into new cellular elements, and others — in a circulatory bed where also perish or disseminate in the new centers reticuloendothelial system (see).

The disease at the same time can proceed sharply, cyclically with bystry recovery (at most of patients) or acyclicly with long and even hron, a current, including and recurrent. As a result of long parasitizing of S. of burnetii and owing to a sensitization the products of metabolism which are formed at their lysis allergization of an organism as one of important links of a pathogeny (at acute process allergization of an organism is insignificant) develops.

The pathological anatomy

In lungs is observed intersticial pneumonia, in a liver — focal puffiness with infiltration by eosinophils and monocytes, the centers of injury of hepatocytes. The hyperplasia of a pulp of a spleen, increase limf, nodes with detection of granulomas from epithelial cells is noted. In kidneys swelling of a canalicular epithelium is found. In a brain — a perivasculitis and dot hemorrhages around vessels. Sometimes find blood clots, the bulked-up endothelium in capillaries.

With patogistol, the points of view of Ku - l. differs from other rickettsioses in lack of primary defeat of endothelial cells of small vessels and other parts of cardiovascular system. Vasculites are more inherent, according to Volbakh (S. Wolbach, 1948), hron, to disease, than acute. And then changes of vessels are presented in the form of a perivasculitis, but not a pan-vasculitis as it is observed at other rickettsioses. Perhaps nek-swarm growth of cells of a neuroglia. Encephalitis with ektrapiramidny frustration and meningitis, an endocarditis with dissimination of rickettsiae in all parenchymatous bodies is described.

The clinical picture

the Incubation interval proceeds 7 — 30 days, 14 — 20 days are more often. The clinic of a disease is characterized by polymorphism.

The disease begins sharply with feeling of heat, a severe headache, weakness and weakness, perspiration and even profuse sweats more often; loss of appetite, dry cough is observed. Further the sleep disorder up to sleeplessness is noted, mialgiya, sometimes arthralgias, eye-socket pain and eyeglobes, retrobulbar pains, there are also nasal bleedings, dizziness and vomiting. Less often the disease begins gradually with an easy indisposition and chilling, moderate perspiration, weakness and a headache. At a part of such patients in 3 — 6 days the disease comes to an end.

In the first days of a disease the hyperemia of the person and an injection of vessels of scleras, sometimes herpes, a hyperemia of a pharynx with possible enantemy comes to light, the wet and laid-over by a grayish-white plaque language, can be bradycardia and hypotension, the liver and a spleen early increases. In an onset of the illness occasionally there can be phenomena of a meningism and encephalitis with nonsense and hallucinations. Temperature from the first days high — 39 — 40 °, seldom hyperpyrexial. Qualitatively it various — constant, remittiruyushchy, wrong, wavy and even intermittent. Duration of fever at most of patients does not exceed 2 — 3 weeks (seldom to 4 weeks). Decrease in temperature happens as a krizolizis more often (see. Crisis ). Without treatment can be antibiotics 5 — 7-day subfebrile condition and a recurrence coming in 4 — 8 days after normalization of temperature, sometimes several such waves which are followed by oznoba (or chilling), perspiration.

At the height of a disease all listed symptoms become more expressed. Occasionally during the period between the 3rd and 16th day of a disease rash with non-constant localization in the form of rozeolezny, rozeolezno-papular, papular and vesicular, rozeolezno-petekhialny and petekhialny elements is registered. Development of rash is connected with an allergy in a pathogeny of a disease especially as it appears at a long current and is quite often combined with an arthralgia and a mialgiya. There is no definiteness in changes from cardiovascular system — bradycardia, a normokardiya or tachycardia, hypotension and a normotenziya come to light. Muting of cardiac sounds is more constant, elektrokardiografichesk only decrease in a voltage is registered. There are single messages on development in patients rickettsial myocarditis, a pericardis with the advent of which process accepts a long current. Seldom found rickettsial endocarditis developing generally at patients with the previous rheumatism proceeds chronically.

Pneumonia at Cool. meet no more than in 10 — 13% of cases in the form of the centers (is more often in the lower share of the right lung) or plevropnevmoniya. Also tracheitis, a tracheobronchitis, bronchitis are noted. Their involution begins together with temperature drop, and complete cessation physical and rentgenol, aberrations in lungs occurs within 6 weeks.

Patients complain of moderate pains in the field of an epigastrium, in ileocecal area or diffuse pains on all stomach. There can be also attacks of an acute pain, as at appendicitis that contacts the spastic phenomena in intestines owing to disturbance of a vegetative innervation. All these phenomena stop to 10 — to the 15th day of a disease.

Language usually wet is also laid over by a white plaque, not edematous. In hard cases it dry, is edematous (with prints of teeth) and is laid over by a serogryazny plaque.

The hepatomegalia at most of patients is observed with 3 — the 4th day of a disease and at the height of it. At a part of patients the spleen increases. As well as the liver, a spleen is reduced to the normal sizes during the first 5 — 7 days of the period of reconvalescence and is very rare in later terms. The combination gepato-and splenomegalies is registered approximately at 55% of patients.

The headache, sleeplessness and anorexia are noted at all or almost at all patients, perspiration — almost at a half, pain in eyeglobes, especially at the movement by them, a back pain, diffusion muscle pain, an adynamy — at a third of patients. The general adynamy, the suppressed mood, loss of interest to surrounding is noted. Sometimes sick eyforichna, are excited, emotionally unstable, tearful, ipokhondrichna, are possible visual and auditory hallucinations, a delirium.

The picture of blood is not certain, the leukopenia with a neutropenia is more often noted, the eosinopenia, band shift, a relative lymphocytosis, raises ROE.

Usually quickly there comes reconvalescence with improvement of the general state, normalization of temperature and a complete recovery of health. Without therapy by antibiotics Cool. can sometimes proceed as a long or recurrent disease. In this case in 11 — 15 days after the main wave temperature increases again and the same symptomatology develops generally. Duration of a recurrence — 9 — 10 days; more than three recurrence do not happen. In cases of a long recurrent current Cool. are noted asthenic syndrome (see) and vegetative disturbances.

The disease can proceed in acute, subacute, chronic and it is difficult for the differentiable erased form. The current at the first three forms can be easy, medium-weight, heavy and very heavy, and at the erased form — usually easy.

The acute form — the most typical, is registered more often than other forms and 2 — 3 weeks last. Are characteristic the expressed toxicosis with an acute onset of the illness, temperature increase in the first 2 — 3 days to high figures and the subsequent feverish reaction in the form of constant, remittiruyushchy or wrong and even wavy fever. Disease most often medium-weight, is rare — heavy and is even more rare — very heavy. At slight toxicosis Cool. proceeds easily.

The subacute form is noted less often, its duration to 1 month. Temperature reaction various, from high to subfebrile. Disease usually medium-weight, heavy is observed seldom, and the lung is registered in 25 — 30% of cases.

The chronic form is observed seldom and several months, sometimes about one year and more proceed. Usually the disease begins sharply, and then owing to various reasons process gets a torpid, sluggish current with periodically changing symptom complex though damage of lungs or heart with development of rickettsial myocarditis and even endocarditis prevails more often. Process can continuously proceed or in the form of several recurrence. This form Cool. meets very seldom.

The erased form comes to light only at planned inspection of the centers Cool. with the help serol, tests which serve as the only way of diagnosis.

Complications during the carrying out causal treatment are very rare. In cases of heavy and very heavy disease, especially at late begun treatment, are possible pancreatitis (see), pyelonephritis (see), epididymite (see), pleurisy (see), bronchiectasias (see), a heart attack of a lung (see. Lungs ), thrombophlebitis (see).

The diagnosis

Polymorphism a wedge, pictures at Cool. does not allow to diagnose authentically it clinically, especially at sporadic incidence. It can be suspected of the local centers, and then to confirm the diagnosis with the help a lab. researches. Serol, methods specific antibodies at patients or had Cool come to light. For these purposes use reaction agglutinations (see), to-ruyu put with a corpuscular diagnosticum (antigen) from karbolizirovanny S. burnetii. Agglutinins in blood serum of patients are found more often with 8 — the 10th day of a disease in credits 1:8 — 1: 16 which are considered as diagnostic. With 15 — the 20th day of a disease their caption gradually accrues and to 30 — to the 35th day reaches 1: 32 — 1: 512 at 90 — 95% of patients. Later credits gradually decrease also in cultivation 1:8 — 1: 32 can come to light at several years which had within several months and even. Reaction of microagglutination is more sensitive (minimum positive credits it is considered to be 1:8, considerable 1: 32 — 1: 64 and high — 1: 128 and more).

Has high sensitivity and specificity widely used in a lab. to practice of RSK, with the help cover antibodies in diagnostic credits (1: 8 — 1: 16) come to light with 8 — the 10th day of a disease; in 1 — 5 month contents them decreases, but nevertheless they remain 3 — 7 and even 11 years. It is considered that at dynamic observation confirmation of the diagnosis requires increase of a caption of reaction by 2 — 4 times.

(Generally retrospective) the skin allergy test has important diagnostic value. For this purpose enter 0,1 ml of allergen into skin of an inner surface of a forearm (corpuscular antigen from autoclaved S. of burnetii or soluble antigen) and on existence of a hyperemia with hypostasis estimate it as positive. Bigger value for the diagnosis has S.'s allocation burnetii from blood, urine or a phlegm. For this purpose lab. animal (to Guinea pigs, mice, etc.) inoculate material from the patient.

Radiological the pneumonic centers are usually represented as gentle oblakovidny blackouts which never happen intensive. Can be involved in process regional limf, nodes, especially on the party of defeat, with consolidation of the drawing on roentgenograms.

The differential diagnosis

On a wedge, to a current in one cases Cool. reminds tifo-paratyphoid diseases, a brucellosis, a pulmonary form of a tularemia, pneumonia of various etiology, and especially an ornithosis, in others — flu, adenoviral diseases, a harvest fever, in the third, especially at a long current — pulmonary forms of tuberculosis, miliary tuberculosis, mycoplasmosis, etc. The onset of the illness, its duration, character of temperature, often observed adynamia and block of patients, the possible typhus status, bradycardia with a dicrotism of pulse, hypotension, feature of change of language, a meteorism and rumbling at a palpation of intestines, very frequent increase in a liver and spleen, change of blood remind symptoms typhoid (see) and paratyphus (see). But at Cool. toxicosis is less expressed, only occasionally there are rash and Padalki's symptom characteristic of tifo-paratyphoid diseases Vidal's reaction and reaction of indirect hemagglutination are negative. Muscular pains, lack of joint pains, the expressed toxicosis, locality of a headache, existence in all cases of tracheitis, short duration of feverish reaction (3 — 5 days at an uncomplicated current), the normal sizes of a liver and spleen, sharply expressed contageousness distinguish flu (see) from Cool. Characteristic symptoms brucellosis (see) in an acute phase are rather satisfactory condition of patients at high temperature, pouring, especially at night, sweats, the migrating joint and muscular pains, almost constant lack of the typhus status. Hron, forms of a brucellosis distinguish from Cool. on characteristic defeat of the locomotory device, a nervous system, internals, urinogenital system, etc. Differentiation Cool. with anicteric hay fever (see), especially at sporadic incidence, presents certain difficulties because of a community of the majority a wedge, symptoms. In these cases, as well as at another difficult differentiated inf. diseases, including at a pulmonary form tularemias (see), ornithosis (see), reliability of the diagnosis is solved by means of the corresponding laboratory tests. Differentiation Cool. with pulmonary forms of tuberculosis (see. Tuberculosis of a respiratory organs ) and by mycoplasmosis in view of variability of changes in lungs at all these nosological forms it is carried out by bacteriological (for an exception of tuberculosis and mycoplasmosis), serological (at differentiation Cool. with mycoplasmosis) and allergological (at differentiation Cool. and tuberculosis) researches, and also careful analysis rentgenol, data. The miliary tuberculosis proceeding almost always it is heavy, with sharp intoxication and the expressed feverish reaction, frequent increase in a liver and spleen, differs from Cool. the accruing asthma and the constant tachycardia expressed by cyanosis, considerable acceleration of ROE, characteristic changes in lungs at a X-ray analysis. The lymphocytosis almost always excludes miliary tuberculosis.

Treatment

Treatment complex with use of etiotropic, pathogenetic and symptomatic means. Antibiotics from group of tetracyclines less — groups of levomycetinum are especially effective. Tetracyclines at early appointment them on 2 g a day interrupt disease in the first 2 — 3 days. They are appointed within 7 — 10 days regardless of normalization of temperature and the general condition of patients. Tetracyclines in a dose of 2 — 2,5 g are usually effective also at treatment developing sometimes at Cool. hepatitis and endocarditis. In the absence of effect in the first 2 — 3 days at peroral purpose of tetracyclines treatment 3 times during 2 — 3 days supplement with parenteral administration them on 0,1 g. Appointment antiinflammatory and antihistamines (acetilsalicylic to - you, Rheopyrinum, Butadionum or steroid hormones) in average doses within 5 — 8 days is shown that, undoubtedly, improves therapeutic effect. In case of development of rickettsial hepatitis, myocarditis or an endocarditis reception of these drugs in combination with antibiotics is prolonged before achievement of necessary effect. Besides, transfuse blood or plasma, give cardiac glycosides and angiotonic means (ephedrine, a phenylephine hydrochloride, caffeine, noradrenaline, Phethanolum). Symptomatic means apply according to indications.

The forecast

the Disease usually comes to an end with recovery. The lethality at an antibioticotherapia is not observed.

Prevention

the dignity Is necessary a complex. - vt. and dignity. - protivoepid, actions.

Dignity. - vt. measures are directed to protection of livestock farms against a drift of an infection. Inspection and a karantinization of the animals who are again coming to herd, release of pastures from mites are necessary (disinsection). Important measure is disinfecting of allocations of animals, and during childbirth — placentae, amniotic liquid. For this purpose solutions of phenol or kreoline, 10 — 20% solutions of lime chloride, 10% solution of caustic soda apply 3 — 5%.

For care of the cattle (bird) in unsuccessful farms it is preferable to select people from among had Cool. or vaccinated against this disease. In such farms all personnel are provided with overalls: gumboots, dressing gowns (overalls), caps (kerchiefs), rubber gloves. Upon termination of work of a glove, boots and aprons wipe 3 — 5% with solution of lysol, 3% solution of chloroamine; the clothes are brushed, moistened in 3% solution of chloroamine, or ironed the hot iron. Stalls, floors, feeding troughs disinfect as well as allocations of animals.

Milk from unsuccessful farms surely is boiled as pasteurization does not kill a disease-producing factor. Preparation of kefir, cottage cheese, oil, etc. from not boiled milk is absolutely inadmissible.

At emergence of diseases carry out epid, inspection for the purpose of identification of a source of an infection, conditions of developing of diseases and definition of necessary actions for elimination of the center.

Specific prevention (vaccination) yields good result. N. F. Zdrodovsky and V. A. Genig in 1962 — 1964 offered the live vaccine M-44. Inoculations of the population in unsuccessful on Cool are shown. areas, especially the persons occupied in livestock farms (see. Immunization, table ) .



Bibliography: Zdrodovsky P. F. and Golinevich E. M. The doctrine about rickettsiae and rickettsioses, M., 1972, bibliogr • Kasatkina I. L. a Q fever, M.’, 1963, bibliogr.; Mullet K. M. Lihoradka Ku, M., 1975, bibliogr.; Fedorova N. I. Epidemiology and Ku rickettsios prevention, M., 1968, bibliogr GiroudP. e t With a p p about n i M. La fievre Q, ou maladie de Derrick et Burnet, P., 1966, bibliogr.


K. M. Loban.

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