Who is the carrier of causative agents of typhoid fever. Infectious disease typhoid fever. What anatomical damage does typhoid fever cause?

Typhoid fever- an acute infectious disease that affects the intestines and its lymph nodes. The disease is accompanied by an increase in the liver and spleen, severe intoxication with high fever and clouding of consciousness.

Although the frequency of the disease has decreased over the past hundred years, the problem still remains very relevant. About 20 million people are infected with typhoid every year in the world, and 800 thousand die from this disease. More often people get sick in developing countries, where there is not enough drinking water, low sanitary culture and street food trade flourishes. Therefore, tourists who go to Central Asia, Africa or South America should be extremely careful.

It is especially dangerous to swim in ponds that can be contaminated with sewage and buy ready-made meals in the markets. The highest risk is associated with dairy and meat products, in which the bacterium at a temperature of +18 C begins to actively multiply.

In Russia, thanks to sanitary control, it was possible to almost completely defeat typhoid fever. But in recent years, a new danger has emerged. Migrants who come to work and our tourists bring typhoid salmonella from other countries. One sick person can infect many people, especially if he works in the food industry.

You can get typhoid fever from a sick person and from a carrier who feels completely healthy. The route of transmission is fecal-oral. This means that the bacterium is excreted from the intestines of a sick person and enters the mouth of a healthy person through food, drinking water, dirty hands or household items.

Large outbreaks and epidemics occur in the summer-autumn period. At high temperatures, the typhoid fever bacillus multiplies rapidly. In addition, flies contribute to its spread.

Susceptibility to the bacterium that causes typhoid fever is high and people of any age can become infected. But according to statistics, children and young people under 30 are more likely to get sick. This is due to the fact that they are more active: they travel more often and eat away from home.

The causative agent of typhoid fever

Typhoid fever is distinguished from other diseases by the following symptoms:

• heat
• skin is pale and dry
• enlarged dry tongue, coated in the center and clean around the edges
• soreness and rumbling under the right rib
• slight rash in the form of red spots in the upper abdomen and lower chest (appear on days 8-9)
• decrease in heart rate at high temperatures
• signs of intoxication: weakness, lethargy, depression, lethargy, headache

General clinical tests

1. Hemogram or clinical (general) blood test. Determines the amount of all the elements that make up the blood. With typhoid fever, the following changes appear:
   • moderate leukocytosis - in the first days of the disease, the number of leukocytes slightly increases and the ratio of their types changes. but during the week their number sharply decreases.
   • leukopenia - low white blood cell count
   • aneosinophilia - the absence of eosinophils in the blood
   • relative lymphocytosis - an increase in the percentage of lymphocytes compared to all other leukocytes.
   • increased ESR - the erythrocyte sedimentation rate increases, but not significantly
2. General urine analysis. Urinalysis in the laboratory. The laboratory assistant studies the physicochemical characteristics and examines the sediment under a microscope. With typhoid fever in the urine are found:
   • erythrocytes
   • cylinders

For laboratory diagnosis, blood, urine, bile and feces are taken. They are inoculated on nutrient media and placed in a thermostat, where the temperature is constantly maintained at 37 C. If there are typhoid bacteria in the tests, they form colonies that can be examined under a microscope. Bacteria in the blood can only be found in sick people, and in feces and urine, salmonella can be found in both a sick person and a bacteriocarrier.

1. Hemoculture- isolation of salmonella typhoid fever from the blood. This is the earliest and most accurate diagnostic method. Bacteria appear in the blood during the incubation period and remain until the end of the disease. To detect them, blood (10 ml) is taken from the cubital vein and inoculated on Rappoport's liquid nutrient medium. A preliminary result can be obtained on the second day, but the entire study lasts 4 days.


2. coproculture- isolation of typhoid bacteria from feces. Salmonella in the contents of the intestine is found from 8-10 days of illness. In this case, dense nutrient media are used.


3. Urinoculture– detection of typhoid bacteria in urine. It is examined not earlier than on the 7th-10th day of illness.


4. bile culture- for the study of bile, a probe is inserted into the small intestine. Bile is collected in sterile test tubes and inoculated. This study is carried out after recovery.


5. Bone marrow culture- the sample is taken during the puncture in the second third week of illness. It is carried out if there is a suspicion that typhoid fever has severely damaged the bone marrow.

Serological testing methods

Starting from the second week, special antigens appear in the blood. These are particles of the shell and flagella of Salmonella typhoid. They can be detected using studies based on immune responses. For analysis, blood is taken from a finger and serum is separated from it.

1. Vidal reaction- determines whether there are O- and H- antigens in the serum of venous blood. After interacting with special substances, cells containing particles of typhoid bacteria stick together and precipitate. A positive result can be not only in a patient, but also in a person who has been ill, a carrier, or after vaccination. To know for sure that bacteria multiply in the blood, the reaction is carried out several times. In case of illness, the titer (level) of antibodies is 1:200 and is constantly increasing.
2. Passive hemagglutination reaction (RPHA with cysteine)- the blood serum of a sick person glues (aggluten) erythrocytes coated with antigens. This study also needs to be done several times to see if the antibody titer increases. In a sick person, it is 1:40 and can increase 3 times. The first analysis is taken on day 5, and then as needed with an interval of 5 days. Vi and H antibodies may be elevated in convalescents and carriers.

Treatment for typhoid fever

Treatment of typhoid fever goes in several directions at once.

Infection control

In severe forms, a combination of antibiotics Ampicillin and Gentamicin is used. Or new generation drugs Azithromycin, Ciprofloxacin.

If antibiotics do not work or are poorly tolerated, then antimicrobials of other groups are prescribed: Biseptol, Bactrim, Septrim, Cotrimoxazole. They are taken 2 tablets 2 times a day. The course is 3-4 weeks.

Fight against intoxication and dehydration

In a moderate condition, it is necessary to cleanse not only the intestines, but also the blood. To do this, glucose-salt solutions are administered intravenously so that toxins are quickly excreted by the kidneys. Use drugs: Lactasol, Quartasol, Acesol, 5% glucose solution. They are prescribed up to 1.5 liters per day.

If, despite all efforts, intoxication increases, then Prednisolone is prescribed in tablets for 5 days.
Oxygen therapy helps to fight intoxication well. Oxygen is administered through catheters into the nose or a special oxygen pressure chamber is used.

If the medicines do not help, and the condition continues to worsen for three days, then a blood transfusion is done.

Improvement in general condition

Angioprotector Askorutin helps to improve the functioning of small capillaries, normalize metabolism and blood circulation.

Tincture of ginseng, magnolia vine or eleutherococcus improves the general condition, gives strength and improves the tone of the nervous system. Natural herbal preparations are used together with a complex of vitamins: A, B, C, E.

Diet for typhoid fever

After discharge from the hospital (6-7 weeks of illness), the menu can be gradually expanded. Do not immediately lean on the forbidden smoked and fatty foods. Try small portions of new foods for 7-10 days.

Folk remedies for typhoid fever

For the treatment of typhoid fever during epidemics, decoctions of blackcurrant or rose hips, as well as coffee with lemon, were often used.

Herbal infusions help speed up the healing of ulcers in the intestines and cleanse the blood of toxins. Pour 1 tablespoon of burnet roots with a glass of hot water and boil for half an hour. Take every 2-3 hours for a tablespoon.

Pour 1 tablespoon of St. John's wort with a glass of boiling water and insist in a thermos for 1 hour. Drink in small sips throughout the day.

Prepare a mixture of centaury herbs, sage and chamomile. Pour 1 tablespoon of the collection with a glass of boiling water, leave for 30 minutes and strain. Drink 7-8 times a day for a teaspoon.

Folk remedies can be an addition to the treatment prescribed by the infectious disease doctor. But remember, do not try to defeat the disease on your own. During the treatment of typhoid fever, antibiotics are indispensable.

Dispensary observation

They can be discharged from the hospital no earlier than a month after the onset of the disease or 21 days after the temperature drops below 37 C. Before discharge, feces and urine are analyzed 3 times. In the event that salmonella typhoid fever is not found in the discharge, they are allowed to go home.

Typhoid fever has the insidious feature of "returning." This recurrence of the disease is called relapse. In order not to miss the new development of bacteria in the body and carriage, after discharge, the patient will often have to communicate with doctors and take tests.

The first two months, the inspection is carried out once a week. 10 days after discharge, you will need to pass feces and urine 5 times with an interval of 1-2 days. In the future, visits to the clinic will be much less frequent. After 4 months, it is necessary to pass an analysis of bile and blood for the reaction of RPHA with cysteine. If the result is negative and no traces of bacteria are detected, then the person will be removed from the register.

Prevention of typhoid fever

Vaccination or vaccine against typhoid fever

Who needs to be vaccinated?

Since children become infected more often, they need the vaccine more. Therefore, in areas where cases of the disease often occur (25 patients per 100,000 population), children 5-19 years old are vaccinated. Vaccination is also recommended for people at risk. For example, family members where there is a sick person and medical workers who encounter this infection.
In our country, general mandatory vaccination is carried out only during epidemics. In other cases, doctors recommend, but do not force, to be vaccinated against typhoid fever.

In recent years, tourists who are going to visit Asia, South America and Africa have also been vaccinated against typhoid fever. In countries dangerous in relation to typhoid fever without a certificate of vaccination may not be allowed. You can clarify this issue with tour operators. Vaccination must be done no later than 1-2 weeks before departure, so that immunity can form. It helps protect travelers and their families, as well as prevent the spread of this disease in Russia.

How effective are typhoid vaccines?

The efficiency of different manufacturers is slightly different, but approximately the same. It is 60-75%. This does not mean that the vaccine does not work at all on the remaining 25-40% of people. If they get sick, then in a milder form.
Remember that the vaccine does not guarantee against infection. Therefore, even if you were vaccinated before the trip, you still have to take precautions.

What vaccines are used?

Hygiene

But each of us must take care of our own health. Especially in countries where typhoid fever is common. Follow basic safety rules:

• drink only bottled water
• do not buy groceries on the streets
• if there is no other way, buy dishes that have been boiled / fried, and not salads or desserts with cream
• wash your hands after using the toilet and before eating
• do not swim in open water, where drains from sewers can get into

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The site provides reference information for informational purposes only. Diagnosis and treatment of diseases should be carried out under the supervision of a specialist. All drugs have contraindications. Expert advice is required!

Treatment for typhoid fever

Antibiotic therapy for typhoid fever (Etiotropic treatment)

Antibiotics prescribed in the treatment of typhoid fever

Other medicines used in the treatment of typhoid fever (symptomatic treatment)

In severe cases of typhoid fever, injections of prednisone are given. This drug has a pronounced anti-shock and anti-allergic effect. It is prescribed at a dose of 1 milligram per kilogram of body weight, which on average equals 60 milligrams per patient per day. Treatment is carried out in a short course - from 5 to 7 days under the constant supervision of a doctor. Also, in case of severe intoxication, courses of oxygen therapy are carried out daily for 2 sessions for 60 minutes.

The tactics of treating typhoid fever in case of intestinal bleeding include absolute rest, a cold compress on the stomach, stopping the patient from feeding. To stop bleeding, a 5% solution of aminocaproic acid (100 milliliters twice a day), a 1% solution of vikasol (1 milliliter intramuscularly twice a day) and a 10% solution of calcium chloride (10 milliliters intravenously twice a day) are prescribed. day). After the bleeding stops, the patient should not eat for another 12 hours.

Prevention of typhoid fever

Measures to prevent typhoid fever include:

• individual prevention;
• disinfection (in case of infection with typhoid fever);
• emergency measures in the epidemic of typhoid fever.

Individual prevention

Measures of individual prevention are:

• quality control of consumed products and drinking water;
• compliance with personal hygiene standards;
• organization of effective control of flies.

A common cause of typhoid is water from contaminated sources. You can become infected not only by drinking water, but also by using it to wash dishes and food.

The bacterium that causes typhoid fever is killed instantly when boiled. Therefore, to prevent this disease, care should be taken when consuming products that do not undergo heat treatment. The greatest danger of infection is pasteurized milk, which is consumed raw. Once in milk, the bacterium begins to multiply rapidly, as it does not meet competition from other microorganisms.

Preventive measures against alimentary and water infection with typhoid fever are:

• only boiled or bottled water is used for drinking;
• all products (especially perishable ones) should be stored in resealable containers;
• contact between raw foods and prepared foods should be limited;
• you should not purchase products in places of spontaneous trade (unauthorized markets, stalls at the roadsides);
• milk should be boiled, and cottage cheese made from raw milk should be subjected to heat treatment;
• fruits and vegetables eaten raw should be scalded with boiling water.

Organization of effective control of flies

Flies are a great danger, as they carry a large number of bacteria on their paws, seeding them with food and household items. In the prevention of typhoid fever, the fight against flies should be carried out in two directions - against insects in the pre-imaginal stages (eggs, pupae, larvae) and against adult flies.

The pest control measures are:

• proper storage (in closed containers) and regular collection of food waste;
• treatment of trash cans with disinfectants;
• if there are cesspools in the areas near the house - ensuring proper maintenance in accordance with sanitary standards;
• the establishment of special traps in places of large concentrations of flies;
• preventing insects from entering the premises (installation of protective nets on doors and windows);
• maintenance of cleanliness in the kitchen.

Disinfection for typhoid infection

Current disinfection
Current disinfection begins immediately after the fact of the disease is established and until the patient is hospitalized. After discharge, in the premises where the convalescent (convalescent) patient lives, current disinfection measures are carried out over the next 3 months. In houses or apartments where chronic bacillus carriers live, current disinfection is carried out constantly.

Current disinfection measures are:

• Items for personal use(dishes, bed linen, towels). The patient is provided with separate dishes, towels and linen. Dirty linen and towels are stored in a separate closed container and washed separately. An effective method of disinfecting textiles is boiling in a solution of soda and soap (100 grams of soap and 30 grams of soda ash are taken per 10 liters of water). You need to boil for at least 2 hours. After use, the dishes are boiled for 15 minutes, adding any detergent to the water.
• Flies fighting. Disinsection is systematically carried out (destruction of flies with chemical preparations). Particular attention is paid to places where flies lay offspring (toilets, garbage bins). Protective nets are installed on the windows in rooms where the carrier of bacteria lives. The use of sticky tapes, poison baits, and other fly control agents is also recommended.
• Discharge of the patient. If the patient lives in conditions where there is no sewerage, his waste products (feces, urine) are covered with bleach powder and only an hour later they are poured into a cesspool. Items used for the toilet (pots, buckets), after each use, are immersed in a solution of chloramine or bleach for 30 minutes, after which they are boiled.
• Walls, floors and other surfaces. In the room where the patient is located, wet cleaning is done every day using hot water, to which laundry soap (grated) or any laundry powder is added. In the toilet, after visiting, the toilet bowl, floor and walls are treated at a height of 2 meters with a solution of chloramine or lysol.

All textiles (towels, sheets), as well as blankets, pillows, mattresses are sent to special disinfection chambers. The dishes are boiled.
All final disinfection measures are carried out under the supervision of a doctor (infectious disease specialist or epidemiologist). The quality control of the performed activities is carried out by representatives of the sanitary and epidemiological station.

Emergency measures in the epidemic of typhoid fever

Anti-epidemic measures include:

• increased attention to persons who may be sick with typhoid fever;
• accounting and registration of all cases of infection with the provision of information to the relevant authorities;
• survey of areas in which cases of the disease were detected (identification of the source of infection, transmission routes, conditions conducive to infection);
• verification of persons with whom the patient has been in contact (family members, work colleagues, classmates or classmates);
• timely hospitalization of patients;
• discharge of patients in accordance with existing rules (not earlier than 3 weeks after a three-fold study of urine and feces);
• observation of discharged patients (within 3 months they must be tested for typhoid fever);
• carrying out sanitary and educational work with the population.

Specific prophylaxis

Routine vaccinations against typhoid fever

Individuals who are routinely vaccinated against typhoid fever are:

• employees of infectious diseases hospitals and bacteriological laboratories;
• employees of catering networks and food retail outlets;
• personnel of services involved in the transportation and disposal of household waste;
• personnel of services servicing sewer networks;
• certain population groups at high risk of infection.

Vaccination against typhoid fever according to epidemiological indicators

Types of typhoid vaccines

Types of typhoid vaccines are:

• polysaccharide liquid vaccines;
• dry alcohol vaccine;
• attenuated live vaccine.

In most cases, people tolerate polysaccharide liquid vaccines well. The reaction to the administration of the drug may be manifested by redness at the injection site and slight soreness. A low temperature is also possible (not higher than 37.5 degrees), which can last 1-2 days.

The minimum age for vaccination with these drugs is 3 years for Vianvac and 5 years for typhoid wi. But doctors note that children under 5 years of age rarely get typhoid fever, so it is not recommended to vaccinate before this age. Both one and the other polysaccharide vaccine has some contraindications.

Contraindications for the use of Vianvac and Tifim Vi are:

• various infectious and non-infectious diseases in acute form;
• exacerbated chronic diseases;
• any terms of pregnancy;
• poor tolerance of the drug (due to past vaccinations).

After administration of the drug, a person may develop both local and general reactions. For 2 days after vaccination, a person may have a headache, general weakness can be observed, the temperature rises to 38.5 degrees. Redness at the injection site Before use, you should consult with a specialist.

Typhoid fever - an acute anthroponotic infectious disease characterized by ulcerative lesions of the lymphatic system of the small intestine, bacteremia, cyclic course, intoxication, fever, roseolous rash, enlargement of the liver and spleen.

Etiology. The causative agent of typhoid Salmonella Typhi belongs to the group D kind Salmonella. S. typhi has dimensions from 1 to 3 microns long and 0.5-0.8 microns wide, contains somatic (thermostable) O- antigen, flagella (thermolabile) N- antigen, which O- antigen contains 9 and 12 antigenic factors and Vi-antigen. There is another surface K-antigen. By ability to ferment individual carbohydrates S. typhi are subdivided into biochemical variants (biovars), according to sensitivity to bacteriophages, almost 100 fagovars are distinguished.

Salmonella typhoid is well preserved in the external environment. In the water of open reservoirs and drinking water, they survive 11-120 days, in sea water - 15-27 days, in soil - 1-9 months, in room dust - from 80 days to 18 months, in sausages - 60-130 days , in frozen meat - 6-13 months, in eggs - up to 13 months, in egg powder - 3-9 months, on frozen vegetables and fruits - from 2 weeks to 2.5 months.

The causative agents of typhoid fever are moderately resistant to high temperatures: at 57°C in a liquid medium, most of them die within 1-3 minutes, boiling kills them instantly.

Under the influence of disinfectants - a 0.5% solution of phenol, a 3% solution of chloramine, salmonella die within 2-3 minutes, but in a mixture of feces and bleach (1: 1) - not earlier than an hour later.

source of infection. The source of the causative agent of typhoid fever is a person (patient or carrier). Patients are sources of infection in 3-7%, bacteria carriers - in 93-97%. The most massive excretion of the pathogen with the feces of patients occurs within 1-5 weeks of illness with a maximum at the 3rd week, with urine - within 2-4 weeks. Carriage occurs in acute and chronic forms. The prevailing number of recovered patients excretes the pathogen within 14 days of convalescence. In 10% of those who have been ill, this process will continue for up to 3 months. Chronic carriers are 3-5% of those who have had typhoid fever, who secrete the pathogen constantly or periodically over a number of years. Isolation of the pathogen from the body of the source of infection occurs with feces, urine, sometimes with saliva, sputum, sweat.

Incubation period is 7-25 days, most often - 9-14 days.

Transfer mechanism - fecal-oral.

Ways and factors of transmission. The most likely routes of transmission are water and food. Contact-household transmission is observed mainly among children. As an intermediate transmission factor, flies are not excluded, on the legs of which S. typhi remain viable for up to 2 days, in the intestine - up to 7 days.

susceptibility and immunity. In experiments with volunteers, it was found that, depending on the dose of typhoid bacteria, the disease developed in 65-95% of cases. With mass infection in epidemic foci, up to 40-50% of people can get sick. Immunity is usually due to the presence of specific immunity as a result of an illness or vaccination. Immunity after the disease persists for many years, however, when infected with a large dose of the pathogen, repeated cases of the disease are possible.

Manifestations of the epidemic process. The incidence of typhoid fever is widespread. Isolated cases of typhoid fever are detected in Belarus. Risk time- characterized by summer-autumn seasonality. At-risk groups- with water outbreaks, adolescents and adults are more often affected, with dairy outbreaks - young children.

Risk factors. Lack of conditions for fulfilling sanitary and hygienic requirements, overcrowding, lack of hygienic knowledge and skills, access of a chronic bacteria carrier to food products, drinking water and direct public services.

Prevention. Prevention of typhoid fever is associated with the provision of the population with good-quality drinking water and food, a reliable cleaning system, and the improvement of populated areas. The complex of listed measures includes the following: maintenance of water supply sources and distribution networks in accordance with sanitary norms and rules, purification and disinfection of drinking water; purification and disinfection of wastewater before discharging it into water bodies; regular cleaning and disinfection of garbage pits, outdoor toilets; elimination of unorganized landfills; compliance with sanitary norms and rules when collecting, processing, transporting, storing and selling food products; creation of conditions for the implementation of personal hygiene rules in places of public catering, mass concentration (stations, airports, theaters, cinemas, schools, beaches, etc.); identification of bacteria carriers, their registration, work on their hygienic education; vocational training for workers at epidemically significant facilities; health education of the population; preventive immunization of the population.

The currently used typhoid vaccines, if used correctly, can protect up to 80% of those vaccinated and alleviate the clinical course of the disease. However, immunization against this infection is only an additional tool in the system of preventive measures, since with a relatively low incidence of typhoid fever in most areas, it cannot have a significant impact on the course of the epidemic process.

Epidemiological characteristics of paratyphoids. Paratyphoid A and B occur with damage to the lymphatic system of the small intestine, bacteremia, intoxication, fever, skin rash, enlargement of the liver and spleen.

Etiology. The causative agents are independent species of Salmonella - Salmonella paratyphi A and Salmonella paratyphi B, morphologically indistinguishable from other members of the genus Salmonella. It is known that S. paratyphi B more stable in the environment than S.typhi and S.paratyphi A.

source of infection. The source of infection is the patient or the carrier. Carriage of paratyphoid bacteria is formed more often than typhoid, but it is shorter - up to several weeks, less often months, after recovery. Isolation of the pathogen from the body of the source of infection occurs with feces and urine, less often with other excretions. Paratyphoid A refers to anthroponoses, the causative agent of paratyphoid B in some cases can cause diseases in domestic and laboratory animals.

Incubation period- from 2 to 21 days, more often 6-8 days.

Transfer mechanism- fecal-oral.

Ways and factors of transmission. Most often S. paratyphi A transmitted by water S. paratyphi B- food, and milk is a more likely transmission factor.

susceptibility and immunity. The susceptibility of the population to paratyphoid pathogens does not differ from the susceptibility to S. typhi. The transferred disease leads to the formation of species-specific immunity.

Manifestations of the epidemic process. Incidence of paratyphoid AT is ubiquitous, the incidence of paratyphoid BUT found predominantly in Southeast Asia and Africa. In Belarus, isolated cases are occasionally detected. Diseases are recorded as sporadic cases or limited outbreaks. Risk time and at-risk groups- similar to those in typhoid fever.

Risk factors the same as in typhoid fever.

Prevention the same as in typhoid fever.

Anti-epidemic measures- table 2.

Acute cyclic intestinal infection caused by Salmonella typhi bacteria. The course of typhoid fever is accompanied by fever, general intoxication, roseolous rashes on the skin, a pathological increase in the size of the liver and spleen, and damage to the lymphatic system of the lower small intestine.

The causative agent of typhoid fever is Salmonella typhi. This is a bacterium of the species Salmonella enterica, subspecies enterica, serovar typhi. Like other Salmonella, it grows on normal nutrient media, but thrives especially on media containing bile. The optimal growth conditions are called a temperature of 37 ° C, and an acidity of pH = 7.2-7.4. To the environment, typhoid-paratyphoid salmonellae are relatively stable, they tolerate low temperatures well for several months. The survival of these pathogens in water depends on the conditions: in running water they persist for several days, in tap water for up to 3 months, and in silt of wells for up to 6 months. They are very well preserved in food products, namely in milk, cheese, sour cream, minced meat, vegetable salads, where they are capable of reproduction and with which they often enter the human body.

Salmonella typhi dies under the influence of high temperature - within 1 hour at 50 ° C, within half an hour at 60 ° C and instantly when boiled. Direct sunlight also has a detrimental effect on them. Conventional disinfectants cause their death in a few minutes.

The causative agents of typhoid and paratyphoid diseases, like other salmonella, are characterized by a wide range of enzymes that increase their aggressiveness (hyaluronidase, fibrinolysin, lecithin aza, hemolysin, etc.). Many properties of typhoid-paratyphoid bacilli (for example, virulence, agglutinability, lisability) are capable of changes under the influence of antibiotics, bacteriophages and other factors unfavorable for bacteria. It is noteworthy that in the course of the disease in one patient, the properties of the pathogen change.

Causes of typhoid fever are explained by its anthroponotic nature, that is, the source of infection is always a sick person or a carrier of these microbes. The mechanism of transmission of infection is fecal-oral:

• chronic bacterionosia, in particular those whose activities are associated with food, water supply sources;
• the feces of a sick person contain millions of microbes - the so-called urinary carriers are considered the most dangerous, since the act of urination is often not accompanied by sufficient hygiene;
• household contact route of transmission - through contaminated hands (direct route of transmission), dishes, linen, door handles (indirect route);
• contaminated water due to faecal contamination of water supplies - outbreaks are explosive
• food - mainly when consuming infected milk, dairy products, products with cream, ice cream, butter, mainly in the warm season; infection of finished food products occurs when sanitary norms and rules for processing raw materials, storage, transportation, and sale of finished food products are violated;
• transmission of infection involving insects, such as flies - they turn out to be a mechanical carrier of microbes on products consumed without heat treatment;

When 10 and microbial bodies enter the body, the disease develops in 25% of those infected, 105 - 50%, 108 - 100%. Since patients with severe typhoid-paratyphoid diseases are mainly identified and hospitalized, they are less likely to become a source of infection - usually only for those who deal with them or directly surround them.

Typhoid-paratyphoid diseases are characterized by summer-autumn seasonality, this period accounts for up to 75% of all cases. The seasonal increase in the incidence is due not only to a simplified mechanism of infection transmission, but also to the following factors:

• a decrease in the reactivity of the body under the influence of excessive insolation,
• swimming in open water,
• eating large amounts of carbohydrates
• violation of water metabolism,
• decrease in the barrier function of the stomach,
• decrease in bactericidal properties of blood,
• increased migration of the population in summer (tourism, recreation by the sea, etc.),
• consumption of unboiled milk, unwashed berries, fruits, vegetables.

The transferred disease, if the carriage has not formed, contributes to the emergence of long-term sterile immunity.

The pathogenesis of the abdominal type includes several stages. In the penetration phase pathogens enter the alimentary canal through the mouth. Due to their high resistance to the acidic environment of the stomach, they freely enter the lymphatic formations: Peyer's patches and solitary follicles of the small intestine, which serve as a barrier to other infections. Contribute to such a deep penetration of their stomach surgery, alcoholism with the formation of stable achlorhydria, the use of antacids, H2-hietamin receptor blockers or proton memory inhibitors. Sometimes microbes can even get into the lymphatic formations of the mouth of the throat.

Typhoid-paratyphoid bacilli can easily penetrate into lymphoid cells and multiply there, while bacteria do not penetrate into the cytoplasm of immune lymphocytes obtained from the peripheral blood of vaccinated people and chronic carriers, but are located around the lymphocytes. Microbes multiply in these lymphatic formations, accumulate in sufficient quantities and enter the next protective barrier - the mesenteric lymph nodes, resulting in their hyperplasia, the formation of granulomas.

Into the breakthrough phase microbes in the bloodstream appear clinical signs of the disease:

• gradual excitation of the thermoregulatory center with an increase in typical cases of body temperature to febrile numbers during the first 3-5 days of illness;
• general intoxication manifestations;
• redistribution of blood - its accumulation in the vessels of internal organs with the appearance of some of their edema and a simultaneous decrease in blood flow in the vessels of the skin;
• weakening of salivation, which subsequently leads to problems in the oral cavity;
• retention of stool, urination may be due to the stimulating effect of endotoxin on the sympathetic part at the level of autonomic nodes of the abdominal cavity;
• a decrease in intestinal motility is also associated with the severity of mesadenitis;
• the work of the bone marrow is suppressed, causing a decrease in the level of leukocytes, neutrophils and platelets.

Occurs almost simultaneously parenchymal diffusion- microbes are carried to various organs and tissues, secondary foci of inflammation and granulomas are formed there. As a result, there are manifestations of damage to certain organs, which can distort the typical clinical picture (pneumonia, nephritis, meningitis).

Pathogen elimination phase from the body begins approximately from the second week of clinical symptoms. The microbe is excreted in urine and bile. Pathogens enter the intestines in large quantities from the gallbladder, where they can multiply and accumulate. Prior to this, as a result of the ingress of pathogens of typhoid-paratyphoid infections into the lymphatic apparatus of the small intestine during the incubation period, sensitization of antigens to them occurs. The process of repeated "passage" of microbes through the intestines is accompanied by a number of sequentially occurring morphological changes:

• 1st week - "brain-like swelling" of the lymphatic apparatus of the intestine as a reaction to repeated exposure to pathogens;
• 2 weeks - the formation of local necrosis in the area of ​​the follicles; necrosis can spread deep into, sometimes reaching the muscle layer and even the peritoneum;
• 3 week - rejection of necrotic masses and the formation of ulcers. If at the same time the wall of the blood vessel is damaged, bleeding is possible, with the formation of deep ulcers, intestinal perforations may occur;
• 4 weeks - complete cleansing of ulcers; bleeding, perforation are also possible;
• 5th week - healing of ulcers without the formation of scars, strictures.

There are several periods during the course of the disease:

• elementary- gradual onset, increased body temperature, general weakness, increased fatigue, a feeling of fatigue, worsening appetite, sleep disturbance. Paleness of the skin develops. Spasm of superficial vessels and their expansion in the internal organs lead to a gradual increase in the liver and spleen. Blood pressure drops, bradycardia occurs. Sometimes there may be coughing, especially when changing the position of the body from horizontal to vertical, which is due to squeezing of the vessels of the lungs. Due to slow blood flow and vasodilation of the central nervous system, cerebral edema (toxic encephalopathy) develops, due to which the headache becomes constant, annoying, and intensifies in the afternoon. There is a violation of the sleep formula - drowsiness develops during the day and insomnia at night. Strong general weakness makes the patient stay in bed, he gradually loses interest in the environment, reluctantly answers questions, the reaction is slow. The initial period lasts 4-7 days and ends when the body temperature reaches a maximum.
• peak period- without treatment lasts 2-3 weeks. The fever acquires a permanent character at the level of 39-40 ° C without chills. Intoxication increases to a maximum, sometimes very pronounced, to typhoid status. In a severe course, the patient develops confusion ("fuzziness"), he is restless, completely disoriented in space, delirious. The face is amimic. Sometimes there are hallucinations, aggressiveness. The signs developed at the initial stage acquire the maximum manifestation. Arterial pressure can decrease significantly, relative bradycardia can turn into absolute. Heart sounds are muffled, systolic murmur at the apex is possible. A small number of physically developed individuals may develop dicrotia of the pulse (feeling of an additional pulse beat immediately after the main one). Weakened breathing, single dry rales are heard over the lungs. The skin of the trunk and face is very pale, dry to the touch due to high body temperature. The tongue is thickened, at first it is covered with a white coating, except for the edges and the tip, so the impressions of the teeth along the edges are clearly visible. From the 2nd week, in the absence of oral care, it becomes covered with a black coating ("fulginous tongue"). Characteristic flatulence, enlarged liver and spleen, constipation. With percussion of the right iliac region, a noticeable shortening of the percussion sound is manifested. On the skin of half of the patients, a roseolous rash may appear with typical localization: the lateral surfaces of the abdomen, the lower part of the chest, sometimes the forearms, and the lower back. The elements of the rash are pink-red or pale pink spots with clear contours, which disappear when pressed, but reappear. A rash with a hemorrhagic component is a sign of a very severe course of the disease.
• regression period of the disease and the period of convalescence - the body temperature decreases both politically and critically, the symptoms gradually disappear. Prolonged low-grade fever during convalescence is often a harbinger of an exacerbation of the disease.

Not always, all the periods described above are clearly traced. The clinical course of typhoid and paratyphoid diseases has undergone a certain transformation over the past decades, which is explained by cardinal changes in living conditions and the significant use of antibiotics. More often, an acute onset of the disease is recorded with a rapid increase in body temperature and its critical decrease, a short febrile period, mild manifestations of intoxication, the rapid appearance of a rash with a very small amount of roseola; mild forms of the disease are more common. Early use of antibiotics in most cases significantly reduces the duration of typhoid-paratyphoid diseases, sometimes literally "breaks" their course.

In addition to the usual cyclic course, typhoid fever may differ:

• exacerbations;
• relapses.

An exacerbation is suspected if, against the background of a decrease in body temperature to subfebrile numbers and a significant improvement in the patient's well-being, a high fever occurs for several days, followed by the appearance of all leading clinical symptoms. Now the cause of exacerbations is most often the early cancellation of the antibiotic or a decrease in its dose.

Relapses can occur at any time after the normalization of body temperature, but more often at the 2-3rd week, that is, soon after the antibiotic is discontinued. However, later relapses are also described - 1-2 months after normalization of body temperature. With relapses, typical clinical signs of typhoid or paratyphoid fever also appear from the first days.

Features of paratyphoid A note:

• much more often than with typhoid fever (more than half of the patients), the disease begins acutely;
• often in the first days, patients show signs of damage to the respiratory tract (tickle, sore throat, slight cough);
• the skin and conjunctiva are often hyperemic, often there are signs of pharyngitis;
• the rash appears earlier (in most patients - already on the 5-7th day of illness); it is more often papular, sometimes morbilliform; abundant, located not only on the trunk, but also on the flexion surfaces of the arms;
• constipation and stool disorders in the initial period of the disease occur with the same frequency;
• chills, sweating are often observed.

Features of paratyphoid B include:

• shorter than with typhoid fever and paratyphoid A, the incubation period;
• the onset in most cases is acute, sudden, with moderate nausea and vomiting, stool disorders;
• often in the initial period there are chills, sweating;
• fever is usually short-term (1-5 days), of a different nature - subfebrile, undulating;
• due to the short duration of the course, the rash may be absent, but sometimes appears on the 4-5th day; may be abundant, polymorphic.

How to treat typhoid fever?

Treatment for typhoid fever is etiotropic in nature, that is, it is aimed at eliminating the pathogen. Treatment is prescribed as soon as possible after typhus is suspected. The patient needs hospitalization. It is important to establish the epidemiology of the infection in order to stop its spread.

The main antibacterial agent is (chloramphenicol), to which the microbes circulating in our country are still sensitive. It is prescribed orally at 0.75-1.0 grams 4 times a day during the entire febrile period and up to the 10th day of normal body temperature. Parenteral administration of levomycetin should be used for typhoid status or certain complications (meningotitis) due to poor penetration of the drug into the lymphatic formations of the intestine during this route of administration.

Fluoroquinolones are the second-line drugs in the treatment of typhoid fever:

• or
• - inside of 0.4 g 2 times a day for 7-14 days.

In the event of certain complications, typhoid status, these drugs can be prescribed parenterally.

However, now for the countries of Eastern Europe, WHO recommends starting treatment with the above-mentioned fluoroquinolones - first-line drugs (in case of complications, administer them parenterally), but as second-line drugs (i.e. with resistance or intolerance to first-line drugs) in uncomplicated cases inside apply:

• - 0.5 g on the 1st day, 0.25 g on the 2nd-5th days;
• - 0.75-1.0 g per day for 7-10 days;
• cefixime - 0.2 g 2 times a day for 14 days.

In complicated cases, with typhoid status, second-line drugs for these regions are:

• - 1.0-2.0 g every 4-6 hours parenterally;
• - 2 g 4 times a day;
• - 1-2 g 2 times a day.

For the treatment of a patient who has become infected in a region with multidrug-resistant typhoid-paratyphoid pathogens (South and East Asia), WHO recommends in uncomplicated cases as a first-line drug to prescribe cefixime (0.2 g 2 times a day for 14 days) in combination with ciprofloxacin or ofloxacin (0.2-0.4 g 2 times a day for 7-14 days), and as a second-line drug - azithromycin (0.5 g 1 time per day orally for 10 days) .

In complicated cases, first-line drugs in these regions include ceftriaxone (1-2 g 2 times a day or defotaxime 2 g 4 times a day) in a mandatory combination with ciprofloxacin or ofloxacin (0.2-0.4 g 2 times a day for 7-14 days parenterally). As second-line drugs in this region, it is recommended to prescribe (1-2 g 3-4 times a day) or imipine together with dilastin (0.5-1.0 g every 6 hours) in combination with ciprofloxacin or ofloxadine (0 ,2-0.4 g 2 times a day for 14 days) or (0.4 g per day for 7-14 days), or (0.5 g per day for 7-14 days). All second-line drugs are administered parenterally.

It is necessary to dynamically evaluate the effectiveness of the drug. In the case of the use of levomycetin, the effect indicating the sensitivity of pathogens should be assessed on the 4th day of using the drug, with all other antibiotics - on the 2nd day. If insensitivity is suspected, a quick replacement of the antibacterial agent is needed. According to the WHO recommendations, the occurrence of an exacerbation or recurrence of typhoid-paratyphoid infection does not require the replacement of an antibacterial drug that previously had an effect, but encourages the search for other causes that led to an inappropriate course of the disease.

All patients are prescribed strict bed rest during the entire febrile period and another 5 days after normalization of body temperature. In case of non-compliance with the regimen before this period, the occurrence of such complications as collapses, bleeding, perforations is very likely. Patients need to be constantly monitored, cared for (regular treatment of the oral cavity, skin), with constipation - lactulose preparations, cleansing enemas. Diet No. 1 is prescribed from the first day, its gradual expansion is possible only after normalization of body temperature, but not earlier than the 5th week of illness. Food should contain a sufficient amount of vitamins and potassium salts. You can not consume carbonated mineral water, rosehip infusion, choleretic herbs.

In the presence of toxicosis in patients, the use of detoxification therapy is important. If the required amount of liquid (up to 40 ml/kg of body weight per day) cannot be provided orally, including with food, intravenous balanced polyionic solutions can be prescribed (in order to compensate for water and electrolyte disorders), glucose-salt mixtures, mixtures of salts and others. carbohydrates, 5-10% glucose solutions, reopoliglyukin.

Prolonged use of antibiotics can be the cause of the development of candidiasis, dysbiosis. Therefore, throughout the course of antibiotic therapy, patients should receive either other antifungal drugs and agents that correct the intestinal microflora.

In the event of intestinal bleeding, cold is urgently prescribed on the stomach, special diets, antihemorrhagic agents, if necessary, transfusion of erythrocyte, platelet mass, cryoprecipitate. If within 2 days conservative treatment of intestinal bleeding does not give an effect, surgical intervention is necessary to repair bleeding ulcers. As a rule, the last 70 cm of the small intestine, where such ulcers are concentrated, are subject to revision.

What diseases can be associated

Chronic carriage as a result of an acute form of typhoid-paratyphoid infection should be considered a kind of chronic form of the course, because in this category of people throughout life there are short-term cases of fever with a short appearance of the pathogen in the blood. In chronic bacterial carriers, the gallbladder, kidneys, and bone marrow are a common site of pathogen localization. Contribute to this or, the presence of urinary, etc. Such persons make up 3-6% of all patients. After removal of the gallbladder in "bilious" carriers, Salmonella is often eliminated from the body.

In addition, typhoid fever provokes the following complications

• intestinal bleeding- develops in 25% of patients with typhoid fever and in 7-10% of patients with paratyphoid fever, but the degree of blood loss is different; in most patients, bleeding is not clinically pronounced, and therefore is diagnosed only by examining feces for occult blood; in a certain number of cases, bleeding leads to pronounced hemodynamic changes (tachycardia, an even greater decrease in blood pressure), a sudden decrease in body temperature, sometimes below 37 ° C, which is noticeable in the temperature sheet; such massive bleeding is observed with numerous intestinal ulcers;
• bowel perforation- occurs more often in the 3rd week; the perforation site is usually not large in size, covered by the peritoneum, due to which, unlike the perforation of gastric and duodenal ulcers, which are accompanied by dagger pain, pain during typhoid-paratyphoid perforations is usually absent and appears only with the development of diffuse peritonitis. Therefore, the patient and medical staff must constantly be vigilant. If any unusual sensations appear in the patient in the right iliac region, the resistance of the abdominal wall is detected there, positive symptoms of peritoneal irritation, these signs should potentially be regarded as suspicions of intestinal perforation. Rarely, peritonitis may result from mesenteric lymph node necrosis.

Other complications of typhoid fever should include any clinically pronounced signs of infectious lesions of certain organs - piyevmotif, meningotif, myocarditis, nephrotif, osteomyelitis and others.

Treatment of typhoid fever at home

Treatment for typhoid fever contraindicated at home for two reasons:

• firstly, the disease requires constant medical monitoring and repeated diagnostic procedures, which is more convenient and efficient in a hospital setting;
• secondly, the disease is infectious in nature and poses a danger to persons in contact with the patient.

The patient is discharged from the hospital on the 21st day of normal temperature, given that it goes down as soon as possible with adequately selected treatment.

Be sure to conduct a control examination before discharge: 2 days after the antibiotic is discontinued, stool and urine cultures are prescribed for 3 days in a row and bile cultures (biliculture) once. With negative results of cultures of feces, urine and biliculture, the patient is discharged.

Subsequently, at home, it is important to lead a healthy lifestyle with a balanced diet and the exclusion of bad habits. Personal hygiene items used by patients before the disease must be sanitized or destroyed.

What drugs are used to treat typhoid fever?

First line drugs:

• - inside of 0.75-1.0 grams 4 times a day during the entire febrile period and up to the 10th day of normal body temperature;
• - inside of 0.2-0.4 g 2 times a day for 7-14 days;
• - inside of 0.4 g 2 times a day for 7-14 days;
• - inside of 0.2-0.4 g 2 times a day for 7-14 days.

Second-line drugs in uncomplicated cases:

• - inside 0.5 g on the 1st day, 0.25 g on the 2-5th day;
• - inside, 0.75-1.0 g per day for 7-10 days;
• Cefixime - inside 0.2 g 2 times a day for 14 days.

Second-line drugs in complicated cases:

• - parenterally 1.0-2.0 g every 4-6 hours;
• - inside 2 g 4 times a day;
• - inside 1-2 g 2 times a day.

Typhoid brought from the southern regions is susceptible to the following medicines:

• - parenterally 1-2 g 3-4 times a day;
• Imipinem - parenterally 0.5-1.0 grams every 6 hours;
• - inside of 0.2-0.4 g 2 times a day for 7-14 days;
• - inside of 0.2-0.4 g 2 times a day for 7-14 days;
• - parenterally, 0.4 g per day for 7-14 days;
• - parenterally, 0.5 g per day for 7-14 days.

Treatment of typhoid fever with folk methods

The use of folk remedies in typhoid fever treatment is not able to provide a sufficient antibacterial effect, therefore it can be used for other purposes, but at the final stage of treatment. Herbal preparations recommended for use have a bactericidal, immuno-strengthening, anti-inflammatory effect, help to relieve pain and restore the function of the liver and gastrointestinal tract. Any prescription should be discussed with the attending physician and used with his consent, and not as part of self-treatment.

In the treatment of typhoid fever folk remedies are used:

• burnet roots- 1 tbsp. l. crushed roots pour 1 cup boiling water, boil for 30 minutes, cool, strain and take 1 tbsp. l. 5-6 times a day;
• currant juice- freshly squeezed 100 ml 2-3 times a day;
• herbal collection- combine 4 parts of the roots of Rhodiola rosea and lure high, brown rose hips, 3 parts of blood-red hawthorn and leaves of nettle dioica, 2 parts of St. John's wort; 2 tbsp collection, pour 200 ml of water, boil for 15 minutes, strain, take 1/3 and 1/2 cup of broth 2-3 times a day;
• melissa and mountaineer- combine 2 parts of lemon balm and 5 parts of highlander; 1 tbsp place the collection in a thermos, pour a glass of boiling water, strain after 10 hours; take 2-3 glasses during the day.

Treatment of typhoid during pregnancy

Treatment for typhoid fever during pregnancy is a difficult task, since the doctor's goal is not to harm the health of the woman and her fetus, but at the same time to select sufficiently effective drugs.

• personal hygiene (especially clean hands),
• prevention of contamination of food, water, household items,
• compliance with the conditions of preparation and storage of food.

According to the indications (most often an outbreak of typhoid-paratyphoid disease in a separate territory, travel to areas unfavorable for these infections), vaccinations are carried out with a complex trivaccine TAB at a dose of 0.5 ml subcutaneously (three times with intervals between injections of 10 days). After vaccination, immunity lasts up to 10 years. In the territory where an increase in the incidence is recorded, revaccination is carried out every 3 years.

Travelers to endemic countries are advised to avoid consuming raw fruits or vegetables that may have been soaked in dirty water; in addition, they should not drink plain water, but only bottled from well-known manufacturers or, at worst, boiled.

If pregnant women have an elevated temperature of unclear origin, it is recommended to conduct a blood test for the Vidal, Weil-Felix reaction and for the presence of Obermeyer's spirochete. With typhoid fever, the percentage of premature termination of pregnancy is high (up to 80%), and in most cases it occurs at the 2-3rd week of the disease. The course of the birth act does not change significantly. The course of the disease itself under the influence of pregnancy is often more protracted.

Which doctors to contact if you have typhoid fever

The beginning of diagnostic procedures occurs with an assessment of epidemiological criteria - fever, pallor of the face and skin of the body, a tendency to bradycardia and hypotension, a tendency to inhibition of the nervous system, a violation of the sleep formula, an annoying headache, changes in language, and bloating.

In the general analysis of blood, leukopenia with lymphocytosis, aneosinophilia, in severe cases, thrombocytopenia, moderate hypoplastic anemia are characteristic of the height of typhoid-paratyphoid diseases. Even in the absence of signs of bleeding in 20-25% of patients, the reaction to occult blood from the 3rd week becomes positive. In the case of complications, there are signs of acute posthemorrhagic anemia with intestinal bleeding, with perforation - leukocytosis and neutrophilia. Other changes in laboratory and instrumental parameters correspond to those organ complications that arose during typhoid-paratyphoid disease.

A positive bacteriological culture of feces, urine, bile is not a confirmation of the severity of the process, but makes it possible to first diagnose a possible bacteriocarrier. Sowing of bile taken during duodenal sounding can be carried out exclusively during the period of convalescence, because during the height of the disease, this diagnostic technique can lead to undesirable complications - intestinal bleeding, to a greater extent to perforation.

In the leading countries of the world, PCR diagnostics is used to diagnose typhoid.

The serological method is applicable to confirm the diagnosis from the 2nd week of the disease; studies must be carried out in dynamics at intervals of 5-7 days:

• RA (Vidal reaction) - diagnostic titer - not less than 1,200, in the future, an increase in titer is possible;
• RIGA - more specific, becomes positive on the 6-7th day;
Treatment of bronchiectasis

The information is for educational purposes only. Do not self-medicate; For all questions regarding the definition of the disease and how to treat it, contact your doctor. EUROLAB is not responsible for the consequences caused by the use of the information posted on the portal.

Typhoid fever is an infectious disease from the group of anthroponoses with a fecal-oral transmission mechanism, caused by one of the varieties and occurring with a predominant lesion of the lymphatic apparatus of the small intestine against the background of pronounced toxic manifestations.

Despite the fact that humanity in the last century has managed to significantly reduce the number of registered cases of typhoid fever, solved to the end, this problem cannot be called. The likelihood of developing the disease exists, especially in countries with a turbulent military situation and poor hygiene standards for life. Therefore, unsanitary conditions are the main condition for the spread of the disease.

Typhoid fever refers to diseases exclusively of the human population. Infection occurs after the release of pathogens into the environment with the feces of carriers and sick people. At the same time, they contaminate water, food, and household items. Not the least importance belongs to flies as external carriers of pathogens. A healthy person can become ill after eating contaminated food or after direct contact with a sick person.

In this regard, typhoid fever is characterized by the following features:

Predominant occurrence in the hot months and autumn;

Rapid spread with the transition to an epidemic;

The absolute susceptibility of the human body to the pathogen;

Rapid reproduction of salmonella with their massive release into the environment with each bowel movement;

The long course of the disease (about seven weeks) and the presence of its erased forms;

The presence of carriers of the pathogen. Such people do not get sick, but are contagious to others;

The pathogenesis of the disease and the spread of the pathogen in the body consists of several stages:

Entry of a sufficient concentration of pathogens into the terminal sections of the small intestine;

Introduction through the mucous membrane with the development of an inflammatory process in the form of enteritis;

Penetration into the lymphoid tissue, to which Salmonella has an initial tropism. First, Peyer's patches are affected, and then the regional lymph nodes of the mesentery (mesenteric) and retroperitoneal;

Bacteremia (the entry of pathogens into the systemic circulation). This occurs due to the inability of the lymphatic system to retain and neutralize the pathogen. This is manifested in the form of their strong increase. Once in the blood of the portal system, the pathogen primarily spreads to the liver and spleen. In the cells of the reticuloendothelial system of these organs, its further reproduction occurs. As a result - an inflammatory lesion and spleen;

The circulation of the pathogen in the systemic circulation triggers immune responses. In this case, a massive destruction of pathogenic bacteria occurs, which, along with bacteremia, causes toxemia due to toxins that are released from the destroyed pathogens.

All these links of pathogenesis are cyclical, constantly repeating until the immune mechanisms are strengthened enough to neutralize all pathogenic pathogens in the tissues of the lymph nodes, liver and spleen.

Symptoms of typhoid fever

The clinical picture of typhoid fever emerges from the above features of its pathogenesis and is given in the form of a table.

The dynamics of symptoms in typhoid fever allows you to combine them according to the stages of the disease:

Incubation period. It continues from the moment the pathogen enters the body until the first clinical manifestations appear. The duration of this period depends on the pathogenic properties of the pathogen and the body's defenses;

The period of onset of the disease. Lasts several days. Clinical it can be limited by the appearance of the first temperature reaction to its stable maintenance at a high level;

Expanded flow period. It is characterized by all the symptoms of damage to internal organs and intoxication;

Permission period. Presented by a stepwise regression of symptoms and a decrease in fever;

convalescence period. It represents a complete restoration of the body and the formation of stable immunity.

Not always such a clear sequence of flow is observed. The disease can acquire an unpredictable character with a lightning-fast transition from one stage to another or their undulating change.

The danger of typhoid fever lies in the possibility of developing complications that pose a direct threat to the life of the patient. In the case of disease progression, there is a high risk of progressive liver failure, which, against the background of intoxication, can turn into multiple organ failure.

Local complications are no less dangerous. Their occurrence is associated with necrotic and ulcerative lesions of the terminal part of the small intestine. Against this background, profuse intestinal bleeding and perforation of the intestinal wall very often occur. These conditions require urgent surgical treatment. Carrying out any operation at the height of intoxication and organ failure always leads to aggravation of the general condition of patients with typhoid fever.

The pathogen that causes typhoid fever is one of the Salmonella species, Salmonella typhi. It is a gram-negative bacillus from the family of enterobacteria, capable of reproducing exclusively in the human body. It has no morphological differences from other Salmonella. A strict aerobe, therefore, it can only exist in a living form, does not form spores. It is not demanding on environmental conditions and therefore it is well cultivated on ordinary nutrient media. This type of Salmonella is quite stable in the external environment, perfectly adapted to low temperatures and can survive even prolonged freezing.

Not resistant to high temperatures and instantly dies when boiled. It retains pathogenic properties well in running and stagnant water and food (dairy products, vegetables, minced meat).

The pathogenicity of typhoid Salmonella is due to their antigenic structure and endotoxin. The most important of these are the surface virulence antigen (Vi antigen) and the cell wall liposaccharide protein complex (endotoxin). If the first determines the ability of the pathogen to infect organs and tissues, as well as the intensity of the immune response, then the second is activated when Salmonella is destroyed by immune cells with a powerful release of their toxic components. The features of the virulence antigen of the causative agents of typhoid fever are such that they allow it to change its antigenic properties, passing into different forms, including L-forms that are resistant to the action of antibacterial drugs. This allows the pathogen to circulate for a long time, maintaining epidemic spread.

The life cycle of typhoid salmonella after entering a susceptible organism cannot pass without the participation of lymphoid and reticular tissues. Therefore, the entrance gate of the infection is the accumulation of intestinal lymphatic cells (Peyer's patches) in the submucosal layer. Of these, the bacteria spread to the mesenteric lymph nodes and into the portal circulation. The most important breeding site for typhoid salmonella is the liver and spleen. Over time, immune mechanisms are able to neutralize pathogens completely, as specific antibodies are produced.

Serological testing for typhoid fever

Considering that there are no distinctive microscopic features of typhoid salmonella, serological studies are the main method for diagnosing typhoid fever. Their basis is the detection of specific antibodies in the blood plasma.

You can do this in the following ways:

Agglutination reaction. The simplest and most ancient method to determine the presence of antibodies to the O-antigen of the pathogen. It becomes informative two weeks after the onset of the disease. The method is non-specific, since it can give a false positive result in other types of Salmonella infection;

The reaction of indirect hemagglutination. Helps in the diagnosis of typhoid fever already in the first week of the disease;

Fluorescent antibody reaction. A highly sensitive diagnostic method that allows you to determine any type of antibodies to the antigenic components of the pathogen. The method helps not only in assessing the dynamics of the disease, but also in monitoring carriers and in the convalescent period;

The basis for the diagnosis of typhoid fever according to serological diagnostic methods is the constant increase in the titer of specific antibodies. For this study, it is necessary to repeat in dynamics.

Vaccination against typhoid and paratyphoid

The main preventive measure for typhoid fever is vaccination against this disease.

For these purposes, two types of vaccines are used:

The introduction of typhoid salmonella components into the body in small doses leads to their recognition by immune cells. The result of this interaction should be long-term immunity, which will allow the body to resist real pathogens when it encounters them.

Indications for vaccination with any of the types of vaccines are:

Planning of stay in territories with epidemic typhoid fever;

The need for contact with patients with typhoid fever;

Direct work with pathogens of typhoid fever.

It is desirable that after vaccination for two weeks, the vaccinated organism does not come into contact with the true causative agent of the disease. This is necessary in order to develop appropriate immunity. Otherwise, vaccination will end with worsening of the symptoms of the disease.

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