Typhus – rickettsiosis, occurring with destructive changes in the vascular endothelium and the development of generalized thrombovasculitis. The main manifestations of typhus are associated with rickettsiemia and specific vascular changes. They include intoxication, fever, typhoid status, roseolus-petechial rash. Complications of typhus include thrombosis, myocarditis, meningoencephalitis. Confirmation of the diagnosis is facilitated by laboratory tests (RPH, IFA). Etiotropic therapy of typhus is carried out with tetracycline group antibiotics or chloramphenicol; active detoxification, symptomatic treatment is indicated.
A75 Typhus fever
Typhus is an infectious disease caused by Provacek’s rickettsia, manifested by severe fever and intoxication, roseolus–petechial exanthema and predominant damage to the vascular and central nervous systems. To date, typhus is practically not found in developed countries, cases of the disease are registered mainly in developing countries of Asia and Africa. Epidemic rises in morbidity are usually noted against the background of social catastrophes and emergencies (wars, famine, devastation, natural disasters, etc.), when there is a massive overstocking of the population.
Rickettsia prowazeki is a small polymorphic gram-negative stationary bacterium. It contains endotoxins and hemolysin, has a type-specific thermolabile antigen and somatic thermostable. It dies at a temperature of 56 ° in 10 minutes, at 100 degrees in 30 seconds. In the feces of lice, rickettsias can remain viable for up to three months. They respond well to the effects of disinfectants: chloramine, formalin, lysol, etc.
The reservoir and source of typhus infection is a sick person, the transmission of infection is carried out transmissively through lice (as a rule, clothes, less often head lice). After blood sucking of a sick person, the louse becomes contagious after 5-7 days (with a minimum life span of 40-45 days). Infection of a person occurs during rubbing of feces of lice when combing the skin. Sometimes there is a respiratory transmission pathway when inhaling dried feces of lice together with dust and a contact pathway when rickettsias get on the conjunctiva.
The susceptibility is high, after the transfer of the disease, a stable immunity is formed, but relapse is possible (Brill’s disease). There is a winter-spring seasonality of morbidity, the peak falls on January-March.
The incubation period can last from 6 to 25 days, most often 2 weeks. Typhus occurs cyclically, in its clinical course there are periods: initial, peak and convalescence. The initial period of typhus is characterized by a rise in temperature to high values, headache, muscle aches, symptoms of intoxication. Sometimes prodromal symptoms may occur before this (insomnia, decreased performance, heaviness in the head).
In the future, the fever becomes constant, the temperature remains at 39-40 ° C. On day 4-5, there may be a short-term decrease in temperature, but the condition does not improve, and in the future the fever resumes. Intoxication increases, headaches, dizziness increase, sensory disorders (hyperesthesia) occur, persistent insomnia, sometimes vomiting, dry tongue, overlaid with a white coating. Disorders of consciousness develop up to twilight.
On examination, hyperemia and swelling of the skin of the face and neck, conjunctiva, injection of sclera are noted. To the touch, the skin is dry, hot, positive endothelial symptoms are noted from day 2-3, and on day 3-4, a symptom of Chiari-Avtsyn (hemorrhages in the transitional folds of the conjunctiva) is detected. On day 4-5, moderate hepatosplenomegaly develops. The increased fragility of blood vessels is indicated by spot hemorrhages of the palate, pharyngeal mucosa (Rosenberg’s enanthema).
The peak period is characterized by the appearance of a rash on the 5th-6th day of the disease. At the same time, constant or remitting fever and symptoms of severe intoxication persist and worsen, headaches become especially intense, pulsating. Roseolous-petechial exanthema manifests itself simultaneously on the trunk and limbs. The rash is thick, more pronounced on the lateral surfaces of the trunk and internal extremities, localization on the face, palms and soles is not characteristic, as are subsequent additional rashes.
Plaque on the tongue acquires a dark brown color, there is a progression of hepatomegaly and splenomegaly (hepatolienal syndrome), constipation and bloating often occur. Due to the pathology of the renal vessels, there may be soreness in the area of their projection in the lumbar region, a positive symptom of Pasternatsky (soreness during beating), oliguria appears and progresses. Toxic damage to the ganglia of the autonomic innervation of the urination organs leads to atony of the bladder, lack of a reflex to urinate, paradoxical diabetes (urine is excreted drop by drop).
In the midst of typhus, bulbar neurological clinic is actively deployed: tremor of the tongue (Govorov-Godelier’s symptom: the tongue touches the teeth when sticking out), speech and facial expressions, smoothed nasolabial folds. Sometimes anisocoria, nystagmus, dysphagia, weakening of pupillary reactions are noted. Meningeal symptoms may occur.
The severe course of typhus is characterized by the development of typhoid status (10-15% of cases): a mental disorder accompanied by psychomotor agitation, talkativeness, memory disorders. At this time, there is a further deepening of sleep and consciousness disorders. Shallow sleep can lead to the appearance of frightening visions, hallucinations, delirium, oblivion may be noted.
The period of the height of typhus fever ends with a decrease in body temperature to normal numbers after 13-14 days from the onset of the disease and relief of symptoms of intoxication. The period of convalescence is characterized by a slow disappearance of clinical symptoms (in particular from the nervous system) and gradual recovery. Weakness, apathy, lability of nervous and cardiovascular activity, memory impairment persist for up to 2-3 weeks. Sometimes (quite rarely) retrograde amnesia occurs. Typhus is not prone to early recurrence.
In the midst of the disease, an infectious and toxic shock can become an extremely dangerous complication. Such a complication can usually occur on 4-5 or 10-12 days of illness. At the same time, the body temperature drops to normal figures as a result of the development of acute cardiovascular insufficiency. Typhus can contribute to the development of myocarditis, thrombosis and thromboembolism.
Complications of the disease from the nervous system can be meningitis, meningoencephalitis. The addition of a secondary infection can cause pneumonia, furunculosis, thrombophlebitis. Prolonged bed rest can lead to the formation of bedsores, and the lesion of peripheral vessels characteristic of this pathology can contribute to the development of gangrene of the terminal extremities.
Non-specific diagnosis of typhus includes a general blood and urine test (there are signs of bacterial infection and intoxication). The fastest method of obtaining data on the pathogen is RPH. Almost at the same time, it is possible to detect antibodies in ELISA.
RNIF is the most common method of diagnosing typhus due to the simplicity and relative cheapness of the method with its sufficient specificity and sensitivity. Back-sowing of blood is not produced due to the excessive complexity of isolation and seeding of the pathogen.
If typhus is suspected, the patient is subject to hospitalization, he is assigned bed rest until the normalization of body temperature and five days after. You can get up on the 7-8 th day after the fever subsides. Strict bed rest is associated with a high risk of orthostatic collapse. Patients require careful care, implementation of hygienic procedures, prevention of bedsores, stomatitis, inflammation of the ear glands. There is no special diet for patients with typhus, a common table is prescribed.
Antibiotics of the tetracycline group or chloramphenicol are used as etiological therapy. Positive dynamics in the use of antibiotic therapy is noted already on the 2nd-3rd day after the start of treatment. The therapeutic course includes the entire fever period and 2 days after the normalization of body temperature. Due to the high degree of intoxication, intravenous infusion of detoxification solutions and forcing of diuresis are indicated. A neurologist and a cardiologist consult the patient to prescribe complex effective therapy for the complications that have arisen.
With signs of the development of cardiovascular insufficiency, niketamide, ephedrine are prescribed. Painkillers, hypnotics, sedatives are prescribed depending on the severity of the corresponding symptoms. In severe typhus with severe intoxication and the threat of infectious and toxic shock (with severe adrenal insufficiency), prednisone is used. Patients are discharged from the hospital on the 12th day after the establishment of normal body temperature.
Prognosis and prevention
Modern antibiotics are quite effective and suppress infection in almost 100% of cases, rare cases of mortality are associated with insufficient and untimely care. Prevention of typhus includes measures such as the fight against pediculosis, sanitary treatment of foci of spread, including thorough treatment (disinsection) of housing and personal belongings of patients. Specific prevention is carried out to persons who come into contact with patients living in areas that are unfavorable for the epidemiological situation. It is produced using killed and live vaccines of the pathogen. With a high probability of infection, emergency prophylaxis with tetracycline antibiotics can be carried out for 10 days.