Typhoid fever: pathogen, symptoms, transmission routes, diagnosis, analysis, treatment, prevention

One of the unpleasant pathologies associated with non-compliance with sanitary and epidemiological standards is typhoid fever.

The concept of

So, typhoid fever is an acute intestinal infectious lesion with intoxication and exanthema, which is characterized by a cyclic course with lesion of the intestinal lymphatic system.

Pathology develops as a result of active bacterial activity of salmonella.

Pathology is anthropogenic in nature, i.e.its causative agent can live and reproduce only within the human body.

Causes of the disease

Typhoid fever is most active in the hot summer months, as well as in the fall. In this case, the pathology quickly spreads to the scale of the epidemic.

Salmonella is rapidly spreading and is massively ejected from the body of the patient with each bowel movement. The disease can be hidden, and some people act as carriers - they do not get sick themselves, but actively spread pathogens.

Pathogen

Pathogenesis causative agent is the notorious salmonella. Such bacteria belong to the category of fairly resistant bacteria.

These bacteria secrete the strongest endotoxic substance, which determines the characteristic clinic of typhoid fever.

In addition, salmonella are able to go into a chronic state, in which they seem to fall asleep, but the pathological characteristics of them are preserved. When a person for any reason decreases immunity, salmonella resumes its activity.

Transmission routes

The mechanism of transmission of typhoid fever is fecal-oral, in which bacteria penetrate the patient through the oral cavity.

  • A person can eat contaminated food or drink water, because it is in these environments that salmonella can live long enough.
  • In children, it is possible to get infected with a contact-household method, but rarely. For example, if a child takes an object in his mouth, on which there will be salmonella( toy, etc.).
  • Then the pathogen gets to the intestine, where it populates the ileum.
  • Then, with lymph flow, salmonella spreads to other lymph nodes, where they also multiply.
  • When the number of bacteria reaches certain limits, they will begin to spread into the bloodstream.

The entire period, when the bacterium was in the patient's body prior to its penetration into the blood, experts call incubation, and when it ends, pathological manifestations appear. Seeping into the blood, salmonella provokes the development of bacteremia.

Video on the sources of infection in typhoid:

Pathogenesis

The pathogenetic picture of typhoid fever develops in several consecutive stages.

  1. First the bacterium penetrates into the digestive tract;
  2. Then it penetrates into the ileal tissue;
  3. The bacterium multiplies actively, after which it migrates to the lymph nodes;
  4. In the lymph nodes inflammation begins, with the population of bacteria growing rapidly;
  5. Salmonella penetrate the bloodstream and develop bacteremia, as a result of which the pathogen spreads through all organic structures. Bacteremia is of a primary and secondary nature. With primary bacteraemia, the pathogen first enters the bloodstream, where Salmonella perishes, releasing endotoxin, which has a neurotropic effect. At this time, from the intra-organic structures, new bacteria are being replaced in the bloodstream, which is called secondary bacteremia;
  6. Active infectious foci are formed in the hepatic tissues, spleen, etc.

Carrier

Salmonella is carried by a carrier - the person who himself does not suffer from typhoid fever but secretes salmonella bacteria with feces. This can continue for a fairly long time, up to several decades.

This feature is explained by scientists as a convalescence vehicle, when the patient is at the stage of recovery. With the abdominal type, this carrier can last for tens of years.

Clinic

Pathology develops in several consecutive stages, for each of which a certain pathogenesis is typical. During each pathological phase there is a definite clinical picture, which distinguishes them from each other.

Incubation period

First comes the incubation period, which lasts from the time the salmonella enters the body to the first manifestations. As a rule, the incubation period takes about one and a half to two weeks for typhoid fever, although it can last up to 25 days as much as possible.

During the incubation, salmonella multiply, and when they begin to seep into the bloodstream, the next stage of the pathological process occurs. When poisoning through food, incubation lasts for about a week, but when infected through water it can take a longer time.

Initial period

The onset of pathology lasts rather slowly, even in severe forms of pathology, development occurs in stages.

  • First patients are concerned about weakness and some malaise, the patient feels some weakness;
  • Then the temperature rises and there is a pronounced weakness, headaches and a feeling of chill. The patient thinks that he has a cold;
  • The duration of such a state takes about a week;
  • During this time, headaches are aggravated, the adynamic and weakened condition is increasing, there are stool delays, no appetite;
  • Approximately to the end of the week, hyperthermia reaches 40-degree indices, which indicates the onset of the height of the pathology.

In very rare cases, the development of pathology takes only a day or two.

Symptoms of swelling

The height of the pathology begins about a week after the onset of the first symptomatology. In this period, the common intoxication manifestations are of maximum severity.

The toxin released by bacteria has a neurotropic effect, which leads to the onset of encephalopathy. At the patient the condition is braked, its consciousness as though is confused and clouded.

Usually in a similar condition, patients:

  1. They lie with their eyes closed, they react monosyllabically to questions;
  2. They have dry and pale skin, enlarged lymph nodes;
  3. heart rate and blood pressure lowered;
  4. The tongue of the patient is covered, there is a brown coating on it, teeth are imprinted on the edges;
  5. Approximately on the 9th day, there is a specific symptomatology of typhoid fever, which manifests itself in the form of enteritis, roseoleic rash and myocarditis of toxic origin.

Extinction

When the tongue begins to clear and the temperature decreases, it is said about the onset of the period of extinction. During this period, symptoms are eliminated, and the temperature decreases significantly, but does not reach the norm yet.

Recovery

When the temperature values ​​are finally normalized, the recovery stage begins. Usually its duration takes about 14-15 days.

Symptoms of typhoid in adults and children

Clinical manifestations of typhoid fever are quite diverse. Their intensity is determined by the phase and variety of the pathological process, as well as by the organic characteristics of the patient himself.

Characteristic manifestations of typhus include:

  • Temperature reactions and fever;
  • Signs of intoxication;
  • Intraorganic lesions affecting the intestine, spleen, liver and mesenteric lymph nodes.

The severity of symptoms at different stages differs somewhat, and some signs are completely absent.

Fever

Due to organo-toxic intoxication, patients with typhoid fever begin to develop severe fever. Hyperthermia is a response to the penetration of the pathogen into the bloodstream of the patient.

The temperature rests on a 39-40 degree mark for about 14-21 days, then the fever will begin to wave out.

Rash

Eruptions also relate to intoxication manifestations. Usually the rash with typhus is rosetose, its elements look round red spots 1-5 mm. They do not itch and do not flake, so they do not give patients any trouble.

Usually, rashes occur on the 8th-9th day of development of pathology and last for 3-5 days.

Photo of the rash in typhoid

Sometimes the rash disappears earlier, but then it shows up again. In severe cases, the rash acquires a petechial-hemorrhagic form, when the roseola is soaked with blood. Forecasts in this situation will be less favorable.

Intestinal bleeding

Against the backdrop of salmonella activity, afflicted with typhoid and GIT structures are affected, accompanied by a clinic of enteritis. At first, the stool is disturbed, but diarrhea soon appears. When palpating the abdomen, the patient experiences pain and tension. Vascular and trophic disorders are formed in the intestinal mucosa.

First, the follicles of the intestinal mucosa are enlarged, then they die, they are rejected and ulcers form, which gradually heal. About 3-4 weeks of development of the pathological bacterial process in patients begins bleeding. The patients suffer from acute pain.

Lesion of internal organs

When a bacteriemia phase occurs in a patient, salmonellae begin to spread quickly through the body, affecting various inorganic structures such as the heart, liver or kidneys, as well as the spleen. The endotoxin released by bacteria provokes the development of toxic myocarditis, which causes inflammation of the heart muscle.

Also, typhoid fever causes the development of a shock kidney of the lung. In a state of shock, all functions of the body are violated. With renal involvement, diuresis decreases, urea and creatinine increase.

With pulmonary involvement in the pulmonary alveoli, fluid accumulates, leading to edema. The patient becomes difficult to breathe, the symptoms of dyspnea intensively increase, etc.

Signs of various forms of the disease

Typhoid fever is able to flow in various forms, one of which is atypical, when there are no specific symptoms. There is also an abortive form, in which the disease has a classical beginning, but soon all the signs disappear, and the temperature indicators can be kept at the 38-degree mark.

Consequences of

Typhoid typhoid fever refers to serious pathological conditions, often resulting in unpredictable consequences.

Specific complication of

To complications of a specific nature are infectious-toxic shock, in which toxins trigger the release of adrenaline and other hormonal components causing vasospasm cramps into the blood.

Nonspecific complication of

To typical complications, specialists include pathological conditions that develop due to borony-typhoid lesions. This includes:

  1. Inflammatory venous lesions;
  2. Inflammation of lung tissue;
  3. Inflammation of the heart muscle;
  4. Peripheral neuritis and cerebral inflammation;
  5. Inflammation of renal pelvis and kidney tissue;
  6. Arthritis and periostitis, chondrites;
  7. Inflammatory prostatic lesions and cystitis.

Diagnosis

To detect an accurate diagnosis, it is often not necessary for the doctor to wait for the results of laboratory tests, as the clinical picture is quite characteristic and pronounced.

Assays

To confirm the diagnosis and identify the pathogen, patients are assigned:

  • Bakposaeff;
  • General clinical studies;
  • Serological tests.

The results of studies determine the presence of an inflammatory process.

How do they pass tests?

Laboratory tests for the development of typhoid fever are assigned to patients with the aim of accurately determining the pathogen and selecting appropriate therapy. In addition, laboratory diagnostics make it possible to assess the state of the organism affected by salmonella in general.

Traditional urine and blood tests, feces, urine and blood cultures, serological tests, etc. are prescribed.

How much is done?

The causative agent of the blood can be isolated at the earliest stages of pathological development by means of bacteriological inoculation. Results of general clinical tests are usually ready after 3-5 days after the study.

How much is it?

The price of the survey depends on the list of studies being submitted:

  • Urine sowing ≈ 930-980 rubles;
  • PCR study ≈ 230-270;
  • Fecal culture ≈ 850-920;
  • Consultation with infectious diseases will cost around 2000-3000 rubles, etc.

Crops

With the help of bacterial crops, typhoid fever can be diagnosed at its earliest stages. Bakposev is carried out with blood and feces, urine and bile, even with breast milk, if the bacteria affected a nursing woman or baby.

Serological examination

Serological tests for typhoid fever allow detecting in the patient's blood specific antibodies and antigens( H, O or Vi antigens).

Antibodies are specific protein compounds that are produced by immune structures to neutralize salmonella antigens.

If there are many antibodies, the patient has developed a permanent immunity to the typhoid, which is typical for the recovery or bacterial transport.

Vidal's reaction

The conduct of the Vidal's reaction is directed towards the determination of the blood O-antigen. A similar study is used to diagnose pathology, but not specific.

Differential Diagnosis

Typhoid fever must be differentiated from pathological conditions such as:

  • Other infections caused by salmonella;
  • Rickettsial pathologies( typhus fever, etc.);
  • Disseminated tuberculosis;
  • Leptospiroid;
  • Brucellosis;
  • Malaria;
  • Infectious hepatitis;
  • Tularemia;
  • Psytacosis;
  • Lymphomas, etc.

At the initial stages, the pathology is symptomatic similar to a viral or influenza infection of the urinary or respiratory localization.

Treatment of

Therapeutic measures for typhoid fever are conducted with patients exclusively in a stationary setting.

This is also necessary because the pathology is of infectious origin, i.e., it is easily spread between humans.

In general, the therapeutic package of measures involves the use of several methods: antibiotics, pathogenetic and symptomatic drugs, full-fledged care of the patient and diet therapy.

Antibiotic therapy

Without the use of antibiotic drugs, the mortality rate of patients reaches 12%.If the treatment is scheduled in time, the death rate from typhoid fever is reduced to 1%.Typhus most often die of infants and elderly, as well as weakened patients.

As antibiotic therapy, preparations such as:

  • Ceftriaxone for one to one and half weeks are given by intravenous or intramuscular route;
  • Fluoroquinolones such as Gatifloxacin or Ciprofloxacin for two weeks;
  • Chloramphenicol every 6 hours, although resistance to Salmonella is rapidly increasing;
  • Levomycetin 10-day course;
  • Ciprofloxacin;
  • As an alternative, Amoxicillin or Trimethoprim-sulfamethoxazole, Azithromycin and the like are prescribed.

Symptomatic therapy

In addition to antibiotic therapy, symptomatic treatment and diet therapy are used. To eliminate acute intoxication, glucocorticoids are used, after application of which the general condition improves, and the temperature drops.

Prednisolone or equivalent drugs is prescribed, the intake is administered for 3 days. If the patient has a pronounced coma, delirium, or shock, high doses of stronger glucocorticoids like Dexamethasone are used.

Prevention of

Prevention of typhoid is important. It can be specific or nonspecific. Nonspecific preventive measures include compliance with the sanitary and epidemiological rules regarding water supply and hygiene measures.

Individual

Individual preventive measures are associated with the maximum possible limitations of contact with salmonella. The entrance gates for pathology is the oral cavity, so the best way to avoid infection will be hygiene of food and personal hygiene, as well as sanitary conditions of living.

It is necessary to monitor consumed water and products, personal hygiene and fly control. It is necessary to carefully heat the food, water, scald the fruit with boiling water. It is necessary to frequently wash your hands and fight flies, because these insects on the legs carry a lot of bacteria, including salmonella.

Disinfection

Also to preventive measures include disinfection. It involves the processing of objects, bed linen and clothing of the patient with special means.

The bathroom where the patient walks is treated daily with bleach.

The room in which the patient lived should be processed daily for a 3-month period. For treatment, solutions of Lysol or Chloramine are used. Dishes after the patient should be boiled, and bed linen and towels are disinfected in special cells.

Anti-epidemic measures

Anti-epidemic measures are also being undertaken, which are considered to be general preventive measures. Emergency antiepidemic measures are aimed at destroying infectious foci and preventing their spread. This is the responsibility of sanitary epidemiological services.

Specific prophylaxis of

Specific preventive measures include vaccination of the population in order to acquire special immunity to them in relation to Salmonella.

According to statistics, the vaccination efficiency is about 80%. But this vaccination is not included in the list of compulsory vaccines, it is only an additional measure.

Routine Inoculations

If the region has a high incidence of typhoid fever, then routine vaccination is required. Vaccinations are put to all people who live in conditions where the risks of typhoid infection are highest.

In addition, people who work with risk of infection, for example, employees of bacteriological and infectious hospitals, public catering, as well as workers of organizations that handle municipal sewage disposal facilities, etc., must be vaccinated.

Vaccination of

If there is a definite threat of an outbreak, Vaccination is carried out according to epidemiological indicators. Especially it is necessary for major accidents or natural disasters, etc.

Immunizations are subjected to all persons living and working in flash zones. In addition, it is necessary to vaccinate those who go to hyperendemic countries like Latin America, Southeast Asia or Africa.

Types of vaccines

Live and killed vaccines are used to immunize the population. In general, several types of vaccines are used:

  • Weakened live - TY21A, encapsulated preparation, ingested, course - 4 capsules, 5-year period of validity, not used in Russia;
  • Dry alcohol vaccines - Tifivac, introduced into the subscapular zone;
  • Liquid polysaccharide vaccines Tifim Vi or Vianvak are administered subcutaneously in the forearm. Immunity is formed after a week or two.

Video about typhoid:

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