Typhus is transmitted. Causes and symptoms of typhus

Typhus (Typhus exanthematicus) – infectious disease, caused by Rickettsia prowazekii, accompanied by fever, specific rash, central nervous system damage and blood vessels. Anthroponosis.

Taxonomy. The causative agent of typhus is named after the American scientist N. T. Ricketts and the Czech scientist S. Provacek, who died while studying typhus. Rickettsia Provatsek belongs to the department Gracilicutes, family Rickettsiaceae.

Epidemiology. The source of infection is a sick person. The carrier of pathogens is the body louse, which becomes infected by sucking blood on a patient. Rickettsia multiply in the intestinal epithelium of the louse and are released into the lumen of its intestine. IN salivary glands, the sucking apparatus of lice does not contain rickettsia, therefore they are not transmitted with a bite. A louse bite is accompanied by itching. A person, scratching the bite site, rubs lice feces containing rickettsia into it, and thus becomes infected. Consequently, the occurrence and spread of typhus is associated with lice (pediculosis). Typhus has been known since ancient times, but was isolated as an independent disease at the end of the 19th century. Distributed everywhere. Typhus epidemics are accompanied by wars, famines, social upheavals, i.e. associated with a decrease in sanitary and hygienic levels and living conditions of people. Mortality reached 80%. Currently, sporadic cases are reported, mainly in the form of Brill's disease.

Pathogenesis. Rickettsia Provacek enters the blood, penetrates the endothelial cells lining blood vessels, multiplies in them, releasing endotoxin. Under the influence of the toxin, endothelial cells are destroyed, and rickettsiae enter the blood again. Mostly small vessels and capillaries are affected, which leads to disruption of microcirculation in the brain, myocardium, kidneys and other organs and the occurrence of meningoencephalitis, myocarditis, glomerulonephritis. In the body of patients, rickettsiae can persist for a long time even after recovery, which causes the appearance of recurrent forms of typhus.

Clinical picture. The incubation period averages 12-14 days. There is a distinction between lung and varying degrees severity of the disease. The disease begins with an increase in body temperature, painful headache, insomnia, and agitation; after 4-5 days a characteristic rash appears due to dilation of skin capillaries and their damage. At severe forms complications may develop in the form of damage to the heart and brain. Currently, cases of recurrent typhus are more common, differing more light current and called Brill's disease.

Microbiological diagnostics . Isolation of rickettsiae from the patient's body is difficult. The main diagnostic method is serological. RNGA, RA, RSK, RIF, ELISA are used to detect rickettsial antigen or antibodies in various materials taken from patients. Differential diagnosis typhus and Brill's disease is based on the phenomenon of immunological memory: with typhus, first IgM and then IgG are formed; with Brill's disease - fast education IgG.

Treatment. The most effective anti-rickettsial agents are tetracyclines, chloramphenicol, and rifampicin.

Prevention. Elimination and prevention of lice are necessary. Specific prevention has an auxiliary value. Currently in Russian Federation A dry chemical typhus vaccine is being prepared, which is a purified concentrated substance of the surface antigen of Provacek's rickettsia. Vaccination is carried out according to epidemic indications. Vaccinations are indicated for medical personnel working in epidemic conditions or in research laboratories.

Epidemic typhus – acute illness infectious nature with a predominantly transmissible mechanism of transmission of the pathogen, characterized by a tendency to mass spread, severe course with fever, intoxication and damage to various organs and systems.

This pathology belongs to anthropozoonoses. A person is quite susceptible to typhus, and neither gender nor age are particularly important. The spread of infection is facilitated by poverty, overcrowding, poor hygiene and sanitary conditions where people live. Epidemics of typhus have always accompanied wars, famines, natural disasters and were accompanied by high mortality. Currently, the disease is less common and can be either sporadic or group in nature. Thanks to the possibilities modern methods diagnosis and treatment has a more favorable prognosis.

The only source of infection is a sick person whose blood is contagious for at least 20 days: 2 days before the onset of the first symptoms, the entire period of fever and 2 days after it. The degree of blood infection depends on the timing and severity of the disease; it is most pronounced in its first week.

Development mechanisms

The main route of transmission of infection is transmissible. It is realized through head and body lice. Moreover, infection does not occur through the bite itself (the saliva of carriers does not contain the pathogen), but as a result of scratching, traumatizing the skin after it, and rubbing rickettsiae found in lice feces into microdamages of the skin. The latter become infected when a sick person sucks blood; rickettsiae multiply in their digestive tract and after a few days appear in the feces. During this period, lice become infectious and remain so for more than 2 weeks until they die from rickettsiosis. Moreover, infection carriers are very sensitive to temperature conditions, so they quickly leave sick or dead people, crawling onto healthy ones.

There is also the possibility airborne infection typhus, but this route of infection is of secondary importance.

Thus, rickettsiae enter the human body through damaged areas of the skin, and in in rare cases– through the conjunctiva of the eyes and mucous membranes of the respiratory tract. After pathogens enter the body along the lymphatic pathways, they penetrate the bloodstream and multiply in the endothelial cells of blood vessels. It leads to:

• destruction of endothelial cells with a massive release of microbes and their toxins into the blood;
• inflammation vascular wall and the development of destructive changes in capillaries with the formation of blood clots and specific granulomas;
• impaired microcirculation and slow blood flow;
• hypoxia and metabolic disorders in tissues;
• functional disorders of the vascular apparatus in all organs and systems.

The process of introduction of rickettsia into healthy cells and reproduction in them occurs an indefinite number of times until the number of microbes reaches a certain threshold value at which specific immunity is developed in the patient’s body. However, it is non-sterile and rickettsia can persist in the human body for many years, waiting for some factors to weaken the immune defense.

Symptoms of the disease

Typhus has a rather bright clinical picture, however, there are various forms of it - both in severity and in flow. It depends on the:

• general reactivity of the body;
• age of the patient;
• his living conditions and nutrition (malnutrition, lack of vitamins);
• availability concomitant diseases and intoxications (alcoholism), etc.

During the course of the disease, it is customary to distinguish the following periods:

1. Incubation (continues until the first signs of the disease appear; from 6 to 21 days).
2. Initial (from the moment the temperature rises to the rash on the skin; 4-5 days).
3. The peak period (longer, characterized by the deployment of all clinical symptoms and ends with normalization of body temperature; 4-12 days).
4. Recovery (may have a varying duration until normal work ability is restored, on average 2-4 weeks).

The disease begins acutely with high body temperature with chills and dizziness. However, patients may not immediately seek treatment medical care due to euphoria. They often continue to do their work despite the fever. The latter in typhus has a constant or remitting character with daily fluctuations of 1-2 degrees. The fever increases over several days. Wherein general state getting worse. Appetite disappears, irritability and insomnia appear.

The patient's appearance becomes characteristic:

• puffy face;
• hyperemia of the skin of the neck and head;
• scleral vessels are injected;
• a conjunctival rash often appears (single petechiae or roseola on the transitional folds of the eyelid);
• eyes shine;
• the skin becomes dry and hot.

As it progresses pathological process the disease enters a period of height, which is characterized by:

• high fever and intoxication;
• roseola-petechial rash on the skin of the chest, lateral surfaces of the torso, flexor surfaces of the limbs (results from stasis of blood in the capillaries and local inflammation in them; disappears when the skin is stretched), in severe cases it appears on the head ears, hands and soles and may be hemorrhagic in nature (lasts longer);
• enanthema on the soft palate, anterior arches in the form of small, strictly delimited red spots (disappears after 1-2 weeks);
• enlarged liver and spleen;
• dark brown coating on the tongue (due to the formation of cracks in the tongue and protrusion of blood droplets);
• symptoms of damage nervous system(general cerebral, meningeal, vegetative);
• cardiovascular disorders (, and);
• mental disorders (delirium, disorientation in time and space, slurred speech).

From the 12th to 14th day of illness, the temperature drops critically, which is often accompanied by collapse. From this time on, a period of convalescence begins, and the condition of the patients begins to improve. The rash gradually turns pale and disappears, symptoms of intoxication decrease, and the size of the liver and spleen normalizes. After the illness, asthenic syndrome persists for a long time.

It should be noted that in addition to the classic course of typhus, there are other variants:

• heavy (with hemorrhagic syndrome, predominance of symptoms of meningoencephalitis);
• fulminant (pathological manifestations of the disease grow very quickly and often lead to death);
• erased (with short-term fever and absence of rash).

Complications

Previously, “classical” typhus predominantly had a severe course with various unwanted reactions. The modern version of the disease is milder with a shorter period of fever, with moderate intoxication and a less frequent development of complications. However, the latter are still possible, they include:

• thromboembolism;
• and etc.

Diagnostics

Early diagnosis of typhus is quite difficult due to the lack of specific symptoms at the onset of the disease. Therefore, when examining all patients with fever and intoxication, the doctor must be on guard. Indeed, to prevent the spread of infection, typhus must be detected as early as possible.

During the peak period, the diagnosis is usually not in doubt, with the exception of erased and atypical forms diseases. In such cases, it is crucial laboratory methods diagnostics For this purpose, various serological tests are carried out:

1. Complement fixation reaction (diagnostic antibody titers are determined in the blood from the 6-7th day of illness).
2. Indirect hemagglutination reaction (allows us to identify not only the total titer of antibodies, but also their belonging to different classes).
3. Linked immunosorbent assay.
4. (detection of specific fragments of the rickettsia genome).

Differential diagnosis is carried out with the following diseases:

• trichinosis;
• typhoparatyphoid diseases;
• sepsis, etc.

Treatment

All patients with typhus or suspected of having it are subject to mandatory hospitalization in an infectious diseases hospital, where constant and careful care is provided. At the source of infection, anti-epidemic measures are carried out with isolation of contact persons and monitoring of them for 25 days.

In the acute period of the disease, such patients are indicated bed rest observing a gentle diet for the entire period of fever.

The basis of treatment is antibacterial drugs. For this, tetracyclines or chloramphenicols are used, which are prescribed in medium doses until 2 days of normal temperature.

Also, the complex of treatment for typhus includes detoxification therapy. Other medications prescribed according to indications, these can be:

• antipyretics;
• analgesics;
• vascular agents;
• corticosteroids;
• psychotropic drugs.

With adequate treatment, the condition of patients quickly improves. 12 days after the temperature normalizes, they can be discharged home.

Typhus belongs to the category of acute anthroponotic diseases. It is characterized by severe intoxication of the body, feverish conditions, damage to the cardiovascular, nervous and other vital systems. important systems body.

The causative agent of epidemic typhus is Rickettsia Provacek. It penetrates the human body through the skin. The initial accumulation of harmful microorganisms occurs in lymph nodes, then they enter the circulatory system and spread to other organs. The most severe complications of typhus occur in the activity of the brain, adrenal glands and myocardium.

Epidemiology of infection

The carrier of the pathogens of epidemic typhus is an infected person, and the carriers are head and body lice, which multiply quickly in unsanitary conditions. It is for this reason that epidemic typhus is also known to us as “war fever”, because soldiers, often without the opportunity to wash themselves, suffered from this infection for several millennia. The mechanism of transmission of typhus is extremely simple. Lice move onto the body of a new host and, when bitten, inject him a large number of rickettsia, which are then rubbed even deeper into the skin when scratching the itchy area. The rapid spread of lice and the short incubation period of the disease often lead to epidemics, however, outbreaks of infection have not been recorded on the territory of the Russian Federation for more than half a century. This fact partly explains effective prevention typhus. It also has an impact on a noticeable increase in the quality of life of ordinary people.

Symptoms of typhus and clinical picture

Epidemic typhus begins acutely. Within several days, the patient’s body temperature rises to critical levels. Patients with typhus experience severe headaches, suffer from insomnia and constant vomiting. Sometimes they experience psychoneurological disorders, manifested in blackouts and euphoria. The facial skin of infected people is hyperemic, and the injection of scleral vessels is pronounced. Already in the first days after the appearance of the first symptoms of typhus, patients experience heart problems. Typhus leads to hypotension, severe tachycardia, and muted heart rhythms.

On palpation internal organs In patients with typhus, an enlargement of the liver and spleen is detected. In some cases, the development of typhus is accompanied by suppression of urinary reflexes. Urine is released literally drop by drop, which causes a person great suffering and worsens his psychological state.

On the 5th-6th day of illness, a characteristic rash appears on the skin of sick people. Its largest accumulations are observed on the lateral surfaces of the trunk and limbs. Severe course The disease promotes the spread of rashes to the face and neck and can lead to the development of meningeal syndrome. With adequate treatment, epidemic typhus is completely cured 1-2 weeks after the first symptoms appear.

Diagnosis of typhus

Possible complications

Since when typhus is diagnosed, the symptoms indicate damage to the heart, lungs and genitourinary system, complications are primarily localized in these organs. The most dangerous of them are adrenal insufficiency and infectious toxic shock. In addition, the development of pneumonia, thromboembolism and thrombophlebitis is possible.

Treatment of typhus

If there is any suspicion of epidemiological typhus, patients should be immediately hospitalized. They are prescribed bed rest, which is maintained until the patient has no symptoms. normal temperature for at least 5-6 days. Patients with typhus are prescribed tetracycline drugs and chloramphenicol. Simultaneously with etiotropic therapy, detoxification therapy is carried out by administering infusion solutions.

Prevention of typhus

The main measures for the prevention of typhus are aimed at registering cases of head lice, hospitalization of patients with fever of unknown etiology and timely serological examinations. Special attention deserve children's groups and people living in hostels. If typhus is detected, patients are subject to isolation with disinfection and disinsection of their personal belongings.

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At all times, infectious epidemics have been the cause of mass deaths. Typhus carries infectious nature and is manifested by severe intoxication of the body, skin rashes, nerve damage and vascular system. Today, the disease is rare in developed countries; outbreaks of the disease are localized in developing countries and occur at the peak of extreme disasters and emergency situations.

The main causative agents of typhus

The disease can spread quickly among people. The causative agent of the disease is the Provacek rickettsia bacteria. They can withstand high temperatures. Death begins when the temperature rises to 50 ᵒC. The dry type is divided into 2 types.

Epidemic typhus:

• Occurs in humans when bitten by fleas that have sucked on rat blood;
• Epidemics are typical for warm countries;
• The disease is transmitted by body lice and head lice.

Having sucked on the blood of a sick person, they become sources of infection. In the intestines of insects, an increase in rickettsia occurs. Healthy man It becomes infected when bitten and lice excrement gets into the wound.

Endemic typhus is caused by rickettsia and is also transmitted from a sick person to a healthy person through lice feces.

The pathogen has distinctive feature, even in a dried state it survives. This allows the virus to enter the body through clothing and bedding. Disinfection with chlorine, formaldehyde, acids and alkalis is destructive to bacteria.

Symptoms of typhus at different stages

The incubation period lasts from 1 to 3 weeks. The disease occurs cyclically and has 3 stages: the initial period, the height of the disease and complications of the disease. For initial stage characterized by a rise in temperature to 39 ᵒC, a depressed state, muscle aches, headache. A person begins to have sleep disturbances and general bad feeling. After 3 days, a feverish state occurs. On day 5, body temperature drops to 37 ᵒC. Intoxication of the body continues to increase. Disorders of the sensory organs appear, consciousness is impaired, the tongue becomes coated, and the mouth feels dry. Frequent vomiting occurs.

Symptoms of the initial stage:

• Low blood pressure;
• Redness of the skin;
• Rapid pulse;
• Bruising appears when the skin is pinched.

Bloody stars on the palate and mucous membrane indicate the fragility of blood vessels. oral cavity. The skin is dry and hot to the touch. The Chiari-Avtsyn symptom appears, hemorrhage of the small vessels of the eyes. On the 6th day, the height of the disease begins.

Rashes appear on the limbs, which gradually spread to the body.

Intoxication of the body increases along with symptoms of poisoning and constant fever. Headaches become throbbing. The tongue is colored Brown color. The height of the disease is characterized by speech impairment, tongue tremor, fixation of one pupil, hesitation eyeballs With high frequency, swallowing disorder. Further sleep disturbance occurs, with visions and hallucinations. The severe stage is characterized by clouding of consciousness, mental agitation, high talkativeness, and memory loss. Lasts acute period from 4 to 10 days. Then the symptoms gradually pass, and the recovery stage begins.

Epidemic typhus: complications, diagnosis and treatment

Complications often occur with typhus. The human blood vessels and nervous system are at risk. Diagnosis consists of laboratory and instrumental studies. Blood and cerebrospinal fluid are collected. Increased ESR in the blood speaks of inflammatory processes. The quantitative composition of platelets decreases. Cerebrospinal fluid determines lymphocytic cytosis.

As a result, you may experience:

• Myocardial development;
• Thrombotic stasis;
• Meningitis;
• Pneumonia;
• Furunculosis.

If the vessels of the extremities are damaged, gangrene may develop. TO instrumental studies include ECG, ultrasound and chest x-ray. More often, specialists resort to specific analysis. Serological tests highly reliably determine the presence of antibodies to rickettsia.

The maximum reliability of the method is observed after a week of pathology development.

For treatment, use drug therapy, including the tetracycline group of drugs, antibacterial drugs, pathogenic techniques to reduce intoxication of the body, antihistamines. Additional drugs are painkillers.

Vectors of typhus - insects

The disease is transmitted by lice. Moreover, the main carriers of the virus are clothed individuals, less often heads. Pubic insects do not spread typhus. The body louse prefers unsanitary conditions, pleasant smells and natural fabrics.

A comfortable living environment is dirty clothes, so that part of the population that has unfavorable living conditions becomes infected.

Handling personal belongings requires compliance with certain rules:

• Washing at high temperatures;
• Adding insecticidal agents to the powder, if they are not available, you can replace the ingredients with vinegar or tar soap;
• Dry clothes under ultraviolet rays;
• A mandatory method of disinfection is ironing clothes;
• Pediculicides must be used for the body.

The disease can be prevented by following the rules of hygiene and sterilization. The typhus vector must be destroyed. To prevent head lice, you need to wash your hair and comb your hair frequently. If infected, carry out procedures to remove lice and nits from the hair. Prevention of typhus involves maintaining personal hygiene, frequent changes linen, using only personal clothing, regular ventilation and washing of pillows and blankets.

How is typhoid transmitted: sources of infection

Typhus can only be transmitted by body lice and head lice. The source of infection can be animals and an infected person. After sucking blood containing rickettsia bacteria, the insects end up on skin covering and hairy areas of the body. Carrying out their vital functions, they lay eggs and excrement.

After the penetration of rickettsia, the bacterium begins to rapidly multiply in the insect’s body. The incubation period is 4-5 days.

The insect bites a person, injecting toxins into the epidermis. Each time they suck blood, the lice have a bowel movement. The skin becomes irritated by the injected toxins, causing itching and scratching. When lice feces get into the wound surface of the epidermis, infection occurs circulatory system Rickettsia bacteria.

Routes of infection:

1. In some situations, infection may occur by air. Shaking bedding or underwear with dried mite feces can lead to infection. Once in the pulmonary tract, the bacterium wakes up and begins to actively multiply, affecting the circulatory and nervous systems.
2. Known infections with donor transfusion blood taken in the last stages incubation period infected person.
3. Lice are very sensitive to changes in body temperature and quickly move from a sick host with a fever or a deceased person, crawling onto other people.

Dried feces retain a long lifespan; in case of massive and prolonged gatherings of people and prolonged non-handling of things, a chain mechanism of disease transmission occurs in 90% of cases.

Lice incubation period: how to avoid disease

After infection with rickettsia, the insect continues to live and function normally. In the insect's body, bacteria begin to multiply at high speed. Rickettsia viruses are tenacious and are able to resume their activity even in a dried state. When they enter the human body, they begin to multiply quickly.

Already on the 5th day, feces release a huge number of rickettsiae, which are deposited on:

• Fabric surfaces;
• Epidermis;
• And hairy parts of the body.

Reaction immune system the patient begins only after 2 weeks, and symptoms begin caused by intoxication of the body, damage vascular membranes and the nervous system. Rash appears cutaneous manifestation diseases. It takes about 2 weeks from the moment of infection to the first symptoms, so turning to specialists occurs already at the height of the disease.

Reading the chronicles of past centuries, every now and then you come across information about outbreaks of a disease such as typhus. The disease decimated people mainly at the most unfavorable moments in history: during wars, crises, social conflicts. What kind of infection is typhus, and can it manifest itself in our time?

In contact with

The first patients appeared in the poorest areas of the city or in the troops. The disease spread very quickly over a large area, taking away a lot human lives. This was due to the fact that the carriers of typhus are typhus, which multiplied quickly in poor areas, soldiers' trenches and refugee camps. Weakened by malnutrition and bad living conditions people could not resist the infection. Currently, there are no large epidemics of this disease. Small outbreaks occur only in Asia and Africa.

The causative agent of this infectious disease is a polymorphic gram-negative bacterium Rickettsia prowazeki. It is able to maintain its vital functions outside the carrier’s body for up to 3 months.

It dies at temperatures above 50 O after 10 minutes, and when exposed to disinfectants.

How is the disease transmitted?

The main route of transmission of typhus is through lice bites. The source of the disease is a sick person. When bitten by lice, it becomes contagious within a week. Considering that the insect lives for about 1.5 months, and the speed of its movement from one piece of clothing to another is quite high, it is able to infect even a single person.

After a bite, a small infiltrate appears on the human body, which is usually very itchy. It is when he combs his unwashed body, which contains lice feces containing bacteria, that the person himself introduces the infection into his blood. Another method of infection can be respiratory. It is more susceptible to people caring for the sick, who, along with dust from the patient’s clothes, can inhale lice feces.

A person who has once had typhus receives stable immunity to the disease; very rarely a relapse can occur.

The disease has a pronounced seasonal nature, which lasts from autumn to spring.

The period from the moment of infection to the appearance of the first symptoms can last up to 25 days, but usually within weeks the following signs appear:

• the temperature rises sharply;
• are plagued by constant headaches;
• there is aching in the muscles and bones;
• nausea, dizziness and other signs of intoxication appear.

The second stage of typhus is characterized by the following clinical picture:

• temperature rises to 39−40 degrees;
• headaches and intoxication increase;
• loss of appetite, vomiting appears;
• suffers from insomnia;
• the tongue becomes covered with a white coating;
• possible disturbance of consciousness, delirium;
• swelling of the face and hands is observed;
• A rash appears on days 5-6.

The typhus rash can cover almost the entire body except the face. Most of it is on internal parts legs and arms. The rash is a small red rash with a small head filled with fluid that is very itchy, leaving the patient feeling uneasy.

The third stage of the disease is characterized by malfunctions of the liver and kidneys, which leads to constipation and bloating, as well as problems with urination.

Increasing insomnia and heat leads to persistent hallucinations and constant delusions.

On the 13th-14th day, a turning point in the course of the disease may occur: the temperature drops, signs of intoxication recede, and within 2-3 weeks the nervous system is restored.

Death possible with infectious-toxic shock. Usually, during the course of the disease, 2 crises are possible: on the 4th and 10th day of illness.

Complications can affect the cardiovascular and nervous systems. In rare cases, gangrene of the extremities may develop due to thrombosis.

At the first suspicion of the disease, the patient is hospitalized and prescribed bed rest, which lasts until the onset of the third stage of the disease and another five days. You are allowed to move independently around the ward only a week after the temperature has subsided.

Special diet patients are not required, they are assigned to a common table, but it is necessary to take into account its condition. Nausea and vomiting in the first days of illness can lead to lack of appetite. It is necessary to ensure that the patient eats well, receiving sufficient vitamins and necessary nutrients, necessary for the body to fight the disease. In addition, you should reduce the load on the liver and kidneys by reducing fried, spicy and salty foods from your diet.

Important! During this period, it is necessary to maintain hygiene, keep clothes and body clean, and prevent the occurrence of bedsores. Since the patient is not able to do this on his own, he needs good care.

Typhus is treated with tetracycline antibiotics and chloramphenylcol. This gives positive results already on 2-3 days. Kars treatment must be continued for another 2 days after the temperature drops to normal. Appointed intravenous systems detoxification solutions that significantly alleviate the patient’s condition 5% glucose,

Throughout the illness, the patient should be monitored not only by an infectious disease specialist, but also by a cardiologist and neurologist. Ephedrine and sedatives may be used if necessary.

In particularly severe cases, prednisolone may be used.

We can talk about final recovery only 2 weeks after the last manifestations of the disease.

Preventive measures

Knowing the epidemiology of typhus, prevention can be quite simple: combating head lice. This is the main method of protection against this disease. It is important to maintain personal hygiene, promptly wash clothes in water above 60°C, and also iron underwear.

If a sick person is identified, his personal belongings must be destroyed and household items must be thoroughly disinfected.

If you are at the source of the disease or in forced contact with a patient, you should undergo a ten-day course of treatment with tetracycline antibiotics.

The video details the causative agent of typhus: