Legionella symptoms in children. Legionellosis. Disease of large cities

Today it will be:

Legionellosis is a rare disease of a bacterial nature, the main clinical manifestation of which is, proceeding with a pronounced intoxication syndrome and subsequent dysfunction of the structures of the central nervous system and organs of the urinary system.

The initial registration of legionellosis was carried out in 1976 in Philadelphia in the form of an outbreak of viral pneumonia, from which more than thirty patients died. It was then that infectious disease specialists first used the term "legionellosis", but at that time the causative agent of legionellosis had not yet been identified. Isolation of the causative agent of legionellosis from the patient's pulmonary parenchyma during autopsy was carried out only a year later and he was given the name Legionella pneumophilia.

Thus, "legionellosis" is a generalized diagnosis, which includes various clinical forms of this disease, provoked by the ingestion of various types of Legionella.

Legionellosis is characterized by the rapid progression of clinical symptoms, especially at the onset of the disease, and the early development of complications in the form of pulmonary failure, shock and acute renal failure. The recovery period for legionellosis is quite long, and therefore, the course of therapy is several months.

Legionellosis in children belongs to the category of rare pathologies. Among children, the risk group for this pathology is made up of persons suffering from suppression of the immune system, due to prolonged use of cytostatic or glucocorticosteroid drugs, and primary immunodeficiency. V Lately more and more often they began to register legionellosis in children of the newborn period, provoking the development of nosocomial pneumonia. The causative agent of legionellosis becomes the cause of development high level mortality in children.

After a retrospective serological study of patients with a latent course of clinical symptoms, it is possible to reliably establish the cause of pneumonia, which is the main clinical manifestation of legionellosis. With a detailed clinical picture, legionellosis is manifested by croupous pneumonia, which has an acute onset and a rapid increase in clinical symptoms in the form of a pronounced intoxication syndrome, progressive respiratory disorders. The accession of such nonspecific clinical manifestations as watery diarrhea, pain in abdominal cavity can simulate other diseases and make it difficult to diagnose legionellosis early.

The risk of death in legionellosis directly depends on the severity of clinical manifestations, the timeliness of drug treatment, and the individual level of immunity. According to world statistics, the mortality rate from legionellosis does not exceed 10%.

Legionellosis causes

The causative agent of legionellosis is a gram-negative aerobic bacterium of the genus Legionella, characterized by high mobility, but only 22 species of it are pathogenic in relation to humans. Bright clinical symptoms are provoked by L. Pneumophila, which is well cultivated on cell media, and the addition of cysteine and iron is required for growth on an artificial nutrient medium. The high pathogenicity of Legionella is due to a lipopolysaccharide complex (endotoxin) and a potent exotoxin.

The causative agent of legionellosis is highly resistant to environmental factors. So, in water, pathogenic legionella species persist for up to three months at a temperature of 25 ° C, and at low temperatures this period can increase. Only when exposed to chlorine-containing disinfectants, legionella die within one minute, so this is the most effective treatment of contaminated objects.

Freshwater reservoirs and contaminated soil act as a reservoir and source of infection. The most favorable conditions for Legionella habitat are algae, in which there is an increased water temperature, due to which the causative agents of Legionellosis actively reproduce together with other protozoa, for example, amoebas.

The maximum concentration of bacteria is observed in cooling systems, compressor devices, showers, swimming pools, decorative fountains, bathrooms for balneological procedures, and mechanical ventilation equipment. Due to the long stagnation of water in these structures and low water temperatures, conditions are created for the active life of Legionella. A person sick with legionellosis does not under any circumstances become a source of infection, therefore, when treating a patient, quarantine measures are not required.

The main mechanism of transmission of the causative agent of legionellosis is aerosol, that is, the entry of the pathogen occurs as a result of inhalation of contaminated water in the form of an aerosol. In addition, infectious disease specialists record cases of the air-dust mechanism of transmission of Legionella, which is observed with earthworks... A large concentration of the causative agent of legionellosis, accumulated in the soil during inhalation of dust, enters the upper respiratory tract. When a ventilator is infected with legionella, pathogens can quickly spread in the upper respiratory tract of patients and their concentration in the lungs, which implies an artifactual mechanism of infection.

There is no reliable data on the development of persistent post-infectious immunity, but infectious disease specialists have not registered a single case of recurrent legionellosis. This pathology occurs in different countries around the world, however, the maximum incidence is observed in urbanized states, with outbreaks of legionellosis more recorded in the summer season.

The risk category for the development of legionellosis is made up of elderly men suffering from immunodeficiency. The share of croupous pneumonia of legionella etiology accounts for no more than 5%, and the remaining 95% of cases of legionellosis are observed in the form of Pontiac fever, which is one of the etiopathogenetic forms of acute respiratory diseases.

Entry gates for the entry of Legionella are both the upper respiratory tract and the pulmonary parenchyma. The damaging effect on the epithelial cells of the respiratory tract is directly caused by the pathogen, and the intensity of these manifestations directly depends on the concentration of the pathogen, the size of the infected aerosol, and the individual state of the function of external respiration.

Like any infectious disease, legionellosis develops with a certain staging. So, the duration of the incubation period can vary significantly depending on the clinical form of this pathology and range from four to ten days. Such a long incubation period makes it impossible to reliably establish the fact of infection with Legionella.

The most pathognomonic manifestation of legionellosis is severe croupous pneumonia, the symptoms of which debut in the form of a prodromal period, manifested by headache, weakness, loss of appetite, and short-term diarrhea. The acute onset of the clinical picture of legionellosis is rapid rise body temperature more than 39 ° C, increasing signs of intoxication syndrome. The main complaints of the patient in this period are chills, intense diffuse, myalgia and arthralgia, severe sweating, progressive general weakness, inability to perform the usual physical work.

Signs of toxic damage to the structures of the central nervous system in legionellosis are the appearance in the patient of psychoemotional lability, lethargy, short-term episodes of loss of consciousness, hallucinations. With severe brain damage, focal symptoms in the form of ataxia, dysarthria, nystagmus, and paralysis of the oculomotor muscles can be observed.

During the height of the clinical picture of legionellosis, the patient develops a dry hacking unproductive, which is quickly replaced by a productive cough with the discharge of bloody sputum. Respiratory manifestations in legionellosis are the development of shortness of breath, intense pain in the chest cavity during breathing, which is a sign of fibrinous pleurisy. Objective signs legionellosis, manifested by pneumonia, is the dullness of percussion sound and auscultation of weakened breathing in the projection of the localization of pulmonary infiltrate at the onset of the disease, and the presence of a large number of rales of various sizes during the height of clinical manifestations. A sign of fibrinous pleurisy of a legionella nature is listening to the pleural friction noise.

Pneumonia in legionellosis is characterized by a severe course and resistance to the drug treatment used, and therefore, the risk of complications manifested by abscesses, exudative pleurisy, and infectious-toxic shock significantly increases. In view of the rapid increase in signs of respiratory and cardiovascular failure, it is advisable to carry out treatment in an intensive care unit.

Changes in the circulatory system in legionellosis consist in the development of a tendency to hypotension, bradycardia, which quickly changes to tachycardia. A fairly common symptom of legionellosis, which occurs in 30% of cases, is the occurrence of prolonged diarrhea, rumbling along the intestines, severe pain in the abdominal cavity, inflammatory changes in the internal organs, in particular, the liver. Kidney damage in legionellosis is so severe that it causes the development of renal failure. The period of convalescence in legionellosis is long and is manifested by prolonged symptoms of asthenic syndrome in the form of weakness, dizziness, memory loss, irritability, and X-ray skeletal signs in the pulmonary parenchyma and pleura persist for up to six months.

A characteristic manifestation of legionellosis is acute alveolitis, the signs of which appear from the first day of the disease with a dry cough against the background of fever. In the future, the cough becomes productive and is accompanied by the active release of mucopurulent sputum, increasing shortness of breath. In the absence of timely drug correction, there is a protracted course and the development of fibrotic changes in the lung parenchyma.

In a situation where legionellosis proceeds without damage to the lungs, the term Pontiac fever is used, which manifests itself in the form of a sharp increase in body temperature over 40 ° C, chills, diffuse intense headache and severe muscle weakness. Respiratory manifestations are localized in the upper sections respiratory tract by the type of rhinitis, laryngotracheitis and are combined with symptoms of dyspepsia. Manifestations of a neurological nature in Pontiac fever are impaired coordination, insomnia, and disturbances of consciousness. In the overwhelming majority, legionellosis, proceeding according to the type of Pontiac fever, is distinguished by a favorable course, a short period of the clinical picture and a long asthenovegetative syndrome during the period of convalescence.

Fort Bragg fever, which also belongs to one of the clinical forms of legionellosis, is extremely rare. A distinctive feature of this form of legionellosis is the appearance of large-spotted petechial exanthema, which are not localized in certain parts of the body, but are diffusely distributed. The leveling of the rash occurs evenly without the development of peeling.

Diagnostics of the legionellosis

Legionellosis, manifested by pneumonia, is difficult to verify solely by clinical and pathomorphological signs, therefore, laboratory and instrumental additional diagnostics is a good help in this situation. So, the hallmarks of legionellosis in the blood test is the detection of a sharp increase in ESR in excess of 60 mm / h.

The bacteriological method for identifying the causative agent of legionellosis is extremely difficult, therefore it is used extremely rarely in diagnostics. More widely used bacterial cultures of biological fluids of the patient on nutrient media with further determination of bacterial colonization.

TO laboratory methods diagnostics of legionellosis, with a high degree of reliability, include serological studies of the type of microagglutination reaction, due to which an increase in antibody titer is determined. The maximum informative value in relation to the rapid diagnosis of the causative agent of legionellosis is the PCR method.

Among the instrumental methods for diagnosing legionellosis, various radiation imaging methods are widely used in the form of chest x-ray, computed tomography, during which infiltrative changes in the pulmonary fields of a unilateral nature are found in the patient. More often than other pneumonia, legionellosis is rapidly accompanied by the development of pleurisy with the formation of effusion.

Legionellosis treatment

The fundamental link in the treatment of legionellosis is the use of medicines etiotropic values, among which antibacterial drugs of the macrolide pharmacological group are most often used (Erythromycin in daily dose 4 g orally, and in severe cases - intravenous drip in a daily dose of 1 g). In a situation where antibiotic therapy does not have the desired effect in the form of leveling the intoxication syndrome in the first two days of use, therapy with Rifampicin at a daily dosage of 1.2 g should be supplemented with a course of 14 days. In addition to antibacterial and anti-inflammatory therapy, the patient is shown the use of immunostimulating drugs.

Prevention of legionellosis consists in monitoring the cleanliness of the air conditioning system, the quality of tap water, which is used for hygiene and medical procedures, and the operation of the ventilation system. Prevention of legionellosis involves the use of various measures aimed at effectively reducing the concentration of the pathogen, and the main method of disinfection in this situation is thermal, as well as chemical. Specific methods for the prevention of legionellosis are not carried out due to the fact that this pathology does not belong to the category of anthroponous infections.

Legionellosis - which doctor will help? If you have or suspect the development of legionellosis, you should immediately seek advice from such doctors as an infectious disease specialist, a pulmonologist. Especially for: - http: // site

Legionnaires' disease (legionellosis) is a bacterial disease characterized by severe intoxication of the body, severe pneumonia, and impaired renal and central nervous system functions.

The causative agent of Legionnaires' disease

Legionellosis has been known since 1976. Then the disease manifested itself in the form of an outbreak of acute respiratory viral infections, accompanied by severe pneumonia and a high percentage of deaths among the participants of the American Legion convention in Philadelphia. 4400 people took part in the work of the congress, of whom 182 fell ill, 29 died. It was then that this infection was named "Legionnaires' disease."

The causative agent of this disease was isolated from the lung tissue of one of those who died a year later by D. McDade and K. Shepard - it was named Legionella pneumophilia.

Later, the clinical and immunological similarity of this disease was studied with several other cases of infection reported in the United States and Spain. On the basis of these studies, the term "legionellosis" was introduced into practice in 1982 - it combined all diseases caused by different kinds legionella.

So, the causative agent of Legionnaires' disease is aerobic motile bacteria of the genus Legionella of the Legionellaceae family, numbering more than 40 species of Legionella, 22 of which are pathogenic for humans. In 90% of cases, the causative agent is Legionella pneumophilia.

Epidemiology of Legionnaires' disease

The natural habitat of bacteria is freshwater bodies of water and soil. They multiply intensively at a temperature of 35-40 degrees in protozoa, for example, in amoebas, which protect them from the effects of negative factors for them, including from a high concentration of chlorine. Due to their high adaptive properties, Legionella successfully colonize compressor devices, cooling systems, swimming pools, showers, decorative fountains, etc. Moreover, in artificial structures, conditions for the survival of bacteria are usually more favorable than in natural habitats.

A person who has contracted Legionnaires' disease is not a source of the causative agent of the infection, even with close contact with it.

The main transmission mechanism of bacteria is aerosol, i.e. contamination occurs when a person inhales water aerosol from contaminated sources. Also, infection is possible by airborne dust (by inhaling soil particles containing bacteria), for example, during construction or excavation work.

Legionellosis is widespread everywhere, but the incidence is higher in economically developed countries. Hotel residents and healthcare workers are more likely to get sick. Among the population, outbreaks usually occur in the summer-autumn months (they are infected through drinking water).

Legionnaires' disease symptoms

Legionellosis is characterized by a fairly rich symptomatology, however, there is not a single specific symptom of Legionnaires' disease that is characteristic only of this disease. This is the insidiousness of the infection.

The first signs include: pronounced fever, headache, general weakness, weakness, diarrhea, severe sweating, joint and muscle pain. Signs of toxic damage to the central nervous system appear: fainting, loss of consciousness, hallucinations, lethargy, delirium.

After the incubation period, which lasts from 2 to 10 days, a sharp deterioration in the human condition occurs: the temperature rises to 40 degrees, a dry cough occurs, which is replaced by a productive one. The sputum is viscous, purulent or mucous, less often with an admixture of blood. Patients complain of nausea, vomiting, diarrhea, shortness of breath, severe chest pain. In the lungs, areas of weakened breathing, dullness of percussion sound, a large number of wet and dry fine bubbling rales are detected. On the roentgenogram, focal infiltrates are visible, subsequently they merge and form extensive foci of pneumonia.

Pneumonia is severe and difficult to treat. Often the disease is complicated by the development of exudative pleurisy, abscesses and even infectious toxic shock. Despite the ongoing treatment, respiratory and cardiovascular insufficiency may progress, so the patient has to be transferred to artificial ventilation. Damage to the cardiovascular system is manifested by hypotension, tachycardia. Serious kidney damage is possible.

If a person during this period is not prescribed adequate treatment against the background of respiratory and renal-hepatic insufficiency, a lethal outcome occurs. The high mortality rate from this disease is due not only to the high pathogenicity of the pathogen, but also to the rather late diagnosis. And this, as mentioned above, is due to the absence of specific symptoms of Legionnaires' disease (most often diagnosed as pneumonia).

Diagnosis of Legionnaires' disease

The main thing in the diagnosis of legionellosis is to differentiate it in time from pneumonia of various etiologies, acute respiratory viral infections and other diseases characterized by lung damage. Pneumonia of Legionnaires' disease is characterized by severe intoxication, the development of toxic encephalopathy, and a tendency to complications.

It is very difficult to isolate the pathogen from sputum, blood, bronchial lavage and pleural fluid, therefore this method is practically not used in practice, although it is the most accurate.

In wide practice, methods for determining antibodies in the reactions of RNIF and microagglutination are used.

Legionnaires' disease treatment

Etiotropic treatment (aimed at eliminating the cause of the onset) of legionellosis involves the use of macrolide antibiotics. In particular, patients are prescribed erythromycin in a dosage of 2-4 g per day orally. In severe cases, the drug is administered by intravenous drip, 1-3 g per day.

In the absence of a clinical effect, treatment with macrolides is supplemented with rifampicin at a dose of 0.6-1.2 g per day.

The course of treatment for Legionnaires' disease is 2-3 weeks.

Pathogenetic treatment is carried out according to generally accepted rules. It is aimed at the mechanisms of the development of the disease, i.e. to combat bleeding, intoxication, renal and respiratory failure, shock conditions.

Legionnaires' disease or Legionellosis is a bacterial infection that most often manifests itself as a severe form of pneumonia. A characteristic expression of the disease is intoxication and impaired functioning of the central nervous system and kidneys. Sometimes, during illness, the respiratory and urinary systems are affected.

Legionnaires' disease is a very dangerous ailment, therefore, if it occurs, you must immediately consult a doctor. This disease is transmitted by airborne droplets, airborne dust or soil. Legionellosis most often manifests itself in the summer and autumn seasons.

Etiology

The main causative agent of this disease is a dangerous bacterium called Legionella. It is a gram-negative, aerobic, motile bacterium that has more than 40 varieties. Of these species, 22 lead to this disease.

The most common cause of legionellosis is Legionella pneumophila. This bacterium is very resistant in the external environment.

Common sites for Legionella infection:

fresh water bodies;
the soil;
various water tanks;
water pipes;
rooms for balneological procedures.

Also, the bacterium can be found in technical equipment, for example, in air conditioners and showers. Since there is a lot of moisture in such devices, this promotes the growth of bacteria and the formation of colonies.

Since the disease can be transmitted by soil, infection is possible during excavation.

Sometimes, legionella pneumonia can occur after the following treatment procedures:

whirlpool baths;
balneotherapy;
intubation;
therapy with ultrasonic disintegrators.

Often more susceptible to this infectious disease, people:

consuming alcoholic beverages;
smokers;
infected;
using drugs.

Classification

Legionellosis disease has several clinical forms:

(a serious illness that does not respond well to therapy);
fever Pontiac;
Fort Bragg disease;
acute febrile illness with exanthema.

Also, this ailment has subclinical and generalized forms. They appear quite rarely, but at the same time they can cause the development of serious complications.

Symptoms

The symptomatology of legionellosis depends on its form. In general, clinicians identify the following signs of the development of this infectious process:

the occurrence of prolonged diarrhea;
stomach ache;
muscle and joint pain;
severe headaches;
loss of appetite;
weakness appears;
the temperature rises to 39-40 ° С;
yellowness of the skin appears;
increased sweating.

Often, it is during the illness of legionnaires that symptoms of severe illness appear.

As the disease progresses, complications may occur, as a result of which the symptoms manifest themselves as follows:

lethargy;
fainting;
rave;
hallucinations.

Sometimes there may be paralysis of the oculomotor muscles and difficulty in pronunciation. Over time, the patient develops a cough, which may be with bloody sputum.

For an acute febrile illness with exanthema, the following manifestations are characteristic:

temperature about 40 ° C;
chills;
prolonged headache;
insomnia;
dizziness.

The most rare form of legionellosis is an acute febrile illness with exanthema. It often develops in the form.

The development of the clinical picture of each of the forms of the disease can last from two to ten days.

Diagnostics

To diagnose and treat this ailment, several doctors should go through. At the first stage of the disease, they usually turn to a therapist. If you have a cough and fever, you should consult a pulmonologist. It is important to consult an infectious disease doctor, since the cause of this disease is precisely the infection. In order to identify the presence of lesions, you need to contact the following specialists:

neurologist;
cardiologist;
gastroenterologist;
ophthalmologist.

Timely diagnosis is very important as it can prevent the development of complications.

Usually, a comprehensive diagnosis is assigned, which consists of the study of clinical and anamnestic data. To diagnose Legionnaires' disease, the following laboratory tests and studies are prescribed:

X-ray of the lungs;
bacteriological blood tests;
listening to noises in the lungs;
bronchoscopy;
microbiological examination of sputum and pleural fluid;
general and biochemical blood test;
cytological examination;
linked immunosorbent assay;
immunofluorescence analysis;
analysis for polymerase chain reaction.

Also, in order to make an accurate and correct diagnosis, you need to find out:

the presence of a burdened premorbid background;
multiple organ lesions;
seasonality of the disease.

It is very important to know in what way or as a result of what the infection was made.

To isolate the antigen of the causative agent of the disease, a polymerase chain reaction is performed. During PCR, material from the skin parts of the respiratory tract is examined.

Treatment

Legionnaires' disease requires immediate hospitalization and clinical measures, since there is a risk of serious complications, not an exception and death.

First of all, therapy is carried out, which is aimed at eliminating etiological factors. Also, procedures are carried out aimed at eliminating intoxication, combating, and.

The following drugs are prescribed to the patient:

nasal drops;
fever medications;
multivitamins;
anti-inflammatory drugs.

An important thing for the treatment of this ailment is detoxification therapy. The regimen, dosage and duration of taking the drugs are prescribed exclusively by the attending physician.

In order to eliminate water-electrolyte disturbances, patients can be injected with the following solutions:

sodium chloride solution;
plasma substitutes;
glucose solution.

If necessary, doctors carry out the correction of respiratory failure. For correction, mucolytic and expectorant substances are used.

Oxygen therapy or artificial ventilation is mandatory. Such measures are aimed at eliminating gas exchange disturbances. In case of occurrence, you need to consult a resuscitator.

Possible complications

Legionnaires' disease is very serious illness, which entails many complications. This ailment can provoke the appearance of heart, kidney and pulmonary failure. Sometimes it can occur. In addition, such pathological processes can develop:

abscess;
infectious toxic shock;

Prophylaxis

Prevention of legionellosis consists of the following measures:

avoiding dusty places, dirty bodies of water;
you can not swim in reservoirs during the flowering period;
sanitary and hygienic procedures for climatic technology should be carried out in a timely manner.

If a person has already suffered from this disease earlier, you should regularly undergo a medical examination and, in general, monitor your health.

Forecast

In rare cases, after suffering legionnaires' disease, foci may remain in the lungs.

If timely treatment is not carried out, the disease can be fatal.

Is everything in the article correct from a medical point of view?

Only answer if you have proven medical knowledge

Diseases with similar symptoms:

Lung inflammation (officially pneumonia) is an inflammatory process in one or both respiratory organs, which is usually infectious in nature and is caused by various viruses, bacteria and fungi. In ancient times, this disease was considered one of the most dangerous, and although modern means of treatment allow you to quickly and without consequences get rid of the infection, the disease has not lost its relevance. According to official data, in our country every year about a million people suffer from pneumonia in one form or another.

Legionellosis is an acute infectious disease from the sapronous group with an airborne transmission mechanism (the aerogenic pathway prevails), carried out by inhalation of infected dust or water aerosol. The source of the disease is not fully known, but it has been proven that transmission from person to person is impossible. Mostly legionellosis occurs in rooms equipped with air conditioning units (hotels or hospitals) and as a hospital infection (in intensive care units, hemodialysis centers). Legionellosis affects people of all ages, but the disease is common among smokers.

The main symptoms are:

an increase in body temperature up to thirty-nine degrees Celsius;
cough with sputum;
muscle and joint pain;
minor nasal discharge;
headache;
nausea and vomiting;
diarrhea;
violation of consciousness;
hallucinations;
impaired coordination of movements;
bleeding.

With the wrong or late prescribed treatment, complications arise in the form of lung abscesses, thromboembolism and kidney failure.

Definition of disease

Legionellosis or Legionnaires' disease is an infectious disease with an airborne transmission mechanism belonging to the sapronous group (a group of diseases in which the pathogen lives on environmental objects). It is characterized by damage to the upper and lower respiratory tract, central and peripheral nervous system. The main symptoms correspond to the site of the lesion and are manifested in the form of a cough with sputum production, chills, weakness and malaise, impaired consciousness, pain in muscles and joints, in the area chest... Complications in the form of a lung abscess or thromboembolism rarely occur.

Legionellosis is an acute sapronous infectious disease (photo: www.nebolet.com)

Etiology of the disease

The causative agent of Legionellosis is the Legionella bacterium. It is a gram-negative bacillus from the genus Legionella. Resistant to environmental factors. V tap water stored for more than a year. The bacterium is sensitive to the action of disinfected solutions. Legionella lives on the objects surrounding a person: air conditioners, a shower, a bathroom or a toilet room. The bacterium is dangerous by the release of endotoxin, which mainly affects the respiratory tract, nervous and digestive systems of a person.

Legionella is common on all continents. More often the disease occurs in the United States, Spain, Italy and France.

The source of the disease is not fully understood. It is only known that a person becomes infected when bacteria enter from objects of the external environment - a sapronous infection.

The transmission mechanism is airborne, carried out by inhalation of dust or water droplets with Legionella. People become infected in air-conditioned rooms: offices, hotels or hospitals.

Factors contributing to the development of the disease

Legionellosis is a disease with a low prevalence in our country, but still the risk of getting sick persists throughout the year. Contribute to the onset of the disease, both environmental factors (exogenous) and directly dependent on the person (endogenous).

Factors outside the human body include:

Long-term presence of a person in an air-conditioned room (hotel, hospital).
The presence of permanent legionella infection in the building (some hemodialysis departments, surgical departments).
Violation of the rules of sterilization and disinfection.
Insufficient information of the population.

The main factors associated with the human body:

The presence of chronic or acute diseases.
Violation of the rules of personal hygiene.
Hereditary diseases of the immune system.
Acquired diseases that lead to a decrease in immunity (AIDS, malignant neoplasms).

Important! The disease occurs everywhere, but mainly in countries with a high rate of development. It should be noted that the presence of factors contributing to the disease does not guarantee the occurrence of the disease in humans. But it still leads to an increased risk of bacterial growth and human infection.

Pathogenesis of the disease

Legionella enters the human body through the mucous membrane of the respiratory tract. The immune defense reacts to the pathogen and kills it, causing the bacteria to release endotoxin. Legionella enters the bloodstream and spreads through the organs and systems of the human body. The respiratory, nervous and digestive systems are affected. The bacterium destroys the cells of the bronchi, lungs, nerve cells, esophagus, stomach and intestines, which leads to pneumonia, bronchitis, neuritis, enteritis and gastritis. With the rapid multiplication of bacteria, complications can occur in the form of renal failure, lung abscesses, pleural empyema and thromboembolism.

Disease classification

Around the world, doctors use a single classification based on the following points:

Clinical forms:

Legionnaires' disease with severe pneumonia.
Acute respiratory illness without pneumonia (Pontiac fever).
Acute febrile illness with exanthema (Fort Bragg fever).

According to the severity of the patient's clinical symptoms:

Lightweight.
Medium severity.
Heavy.

By the presence or absence of complications:

No complications.
With complications (thromboembolism, lung abscesses, renal failure).

According to the rate of development of clinical symptoms:

Fulminant.
Fast.
Chronic.
The erased form.

The clinical picture of the disease

The manifestations are different and depend on the form of the disease. The incubation period is two to ten days.

Today, there are three clinical varieties:

Legionnaires' disease with manifestations more severe than pneumonia, begins acutely and has a rapid development. The main symptoms are:

Chills.
The temperature rises to thirty-eight to forty degrees Celsius.
Headache and malaise.
Pain in muscles and joints.
Cough with thick and viscous expectoration.
Decrease in blood pressure.
Some patients have complaints from the gastrointestinal tract: nausea, vomiting, stool disturbance.
When the nervous system is damaged, there is a disturbance of consciousness, hallucinations, and impaired coordination of movements.

A cough with sputum secretion is one of the main signs of legionellosis (photo: www.stopillness.ru)

Acute respiratory illness (Pontiac fever) is a form of Legionnaires 'disease that has symptoms similar to that of Legionnaires' disease with acute pneumonia, but without developing respiratory symptoms. Observed:

Fever.
Headache.
Pain in muscles and joints.
Scanty transparent nasal discharge.
Sometimes nausea and vomiting are observed.

Acute febrile illness with exanthema (Fort Bragg disease) is a form of legionellosis that has a distinctive feature from all previous ones: the presence of a petechial or large-spotted rash on the human body. There are also complaints about:

Temperature increase.
Chills.
Scanty discharge from the nose.
Minor dry cough.
Headache.

Doctor's advice! Legionellosis is a disease that has no characteristic distinctive features from other diseases, therefore - if you have any complaints listed above, you should immediately consult a doctor or call ambulance... It is important to get medical assistance in the first hours of the disease, when the bacterium has not yet managed to destroy a large number of cells of the human body

Complications of legionellosis

Complications rarely occur, since in most cases patients receive complex therapy from the first signs of the disease. But in people prone to pneumonia or bronchitis, patients with immunodeficiency conditions, complications may occur in the form of:

Long-term and sluggish disease.
Lung abscesses.
Empyema of the pleura.
Closed pneumothorax.
Thromboembolism.
Kidney failure.
Infectious toxic shock.
DIC syndrome.

After suffering a disease (including all forms), a person has a favorable prognosis for life and further employment. In the form of legionellosis with pneumonia, the mortality rate is twenty percent worldwide. In the presence of complications in a patient, treatment has a longer period, but the prognosis remains positive in relation to all areas of human activity.

Diagnosis of the disease

The diagnosis is established by a doctor on the basis of a comprehensive examination of the patient:

Epidemiological history (the presence of group outbreaks of the disease, often in the same organization or room).
Clinical picture diseases.
Comprehensive examination by a doctor.

Laboratory data:

General blood analysis.
Analysis of urine.
Examination of feces for helminth eggs.

Special diagnostics:

Bacterioscopic method (using blood, sputum, urine, pleural effusion).
Bacteriological method (using the Mueller-Hinton medium).
Immunofluorescence reaction.
Serological methods - microagglutination reaction.
Biological method.

Instrumental examination methods:

Chest x-ray.
CT scan.

Treatment of the disease

When the first symptoms appear (chills, fever, headache, malaise, weakness, nasal discharge, rash on the body), you should consult a general practitioner, a general practitioner or call an ambulance. Further, the patient will be referred to an infectious disease doctor who will conduct a comprehensive examination of the patient and determine the correct treatment in a particular case. Treatment of the disease can be carried out both in the infectious and in the therapeutic (in the absence of a specialized) department.

Treatment includes the following items:

Mode - ward with the ability to move around the department.
Diet - balanced diet: lots of fruits and vegetables. The food should include all vitamins and minerals. It is worth excluding food that is heavy for a person: fatty and fried foods, strong tea and coffee, white flour pastries, sweets, carbonated drinks. It is worth consuming plenty of water, fruit drinks, herbal teas.
Drug treatment: antibiotics - macrolides (Erythromycin), Rifampicin, Levomycetin.

Antibiotics (Erythromycin) - the main drug in the treatment of legionellosis (photo: www.trungtamthuoc.com)

With a severe course of the disease - glucocorticosteroids (Dexamethasone, Prednisolone).
With kidney failure - diuretic drugs (Furosemide, Spironolactone).
Infusion therapy - physiological solution.
Vitamin therapy.
After recovery - physiotherapy. Spa treatment is recommended.
In case of complications - therapy aimed at treating the underlying disease and this complication.

Disease prevention

Legionellosis is a disease that can be avoided through prevention. There are only nonspecific preventive measures. These include:

Thorough sanitary inspection of water supply and air conditioning facilities.
Compliance with personal hygiene.
Correct disinfection of showers and bathrooms, common areas.
In medical institutions, sterilization and disinfection control is carried out.
Timely diagnosis, hospitalization and treatment of patients with legionellosis.

Personal hygiene is the main point of prevention of legionellosis (photo: www.mport.ua)

There is no specific prevention of legionellosis.

Symptoms

Legionellosis symptoms

The non-pulmonary form of Legionellosis (Pontiac's disease), which is an acute, self-limiting flu-like fever, usually lasts 2 to 5 days. The incubation period is short, lasting up to 48 hours. The main symptoms are fever, chills, headache, malaise, and muscle pain (myalgia).

The duration of the incubation period of the pulmonary form of Legionnaires' disease is from 2 to 10 days (on average, 5-7 days, but cases of a 16-day incubation period have also been described). The first symptoms of legionellosis are fever up to 40 ° C and above, loss of appetite, headache, general malaise. In some cases, muscle aches, diarrhea, nausea, vomiting, abdominal pain, and confusion may occur. A dry cough appears, then mucous or mucopurulent sputum begins to separate, in half of the patients with blood streaks. Hemoptysis is noted in 20% of patients.

Forms of legionellosis

There are the following clinical forms of legionellosis: Legionnaires' disease (occurs in the form of severe pneumonia); Pontiac fever (named after the city of Pontiac in Michigan, where an outbreak of the disease was noted, which was characterized by an acute onset, flu-like course of moderate severity, headache, fever, myalgia, but without signs of pneumonia); fever "Fort Bragg" ( characteristic signs- fever, skin rashes); other possible forms of the disease.

Legionellosis causes

The most likely source of the disease is artificial water systems that create conditions conducive to the growth and spread of bacteria.

The most common form of transmission is inhalation of contaminated aerosols. Sources of aerosols that have been associated with transmission of Legionella include air conditioning cooling risers, hot and cold water systems, humidifiers, and hot tubs. Infection can also occur from aspiration of contaminated water and ice, and from exposure of newborns to bacteria during water delivery. The infection does not spread directly from person to person.

Complications of legionellosis

The most formidable complication of Legionnaires' disease is respiratory failure. Almost 30% of hospitalized patients have symptoms of severe hyperventilation and hypoxemia. Almost half of them require intubation and mechanical ventilation. The cause of death is primarily respiratory failure, as well as collapse, shock with secondary renal failure.

Diagnostics

Diagnostics of the legionellosis

The epidemiological prerequisites, the severe course of pneumonia and the weak effect of traditional therapy for pneumonia give grounds to suspect the presence of this disease.

Routine tests, including bacteriological blood and sputum tests, are negative for Legionella. The diagnosis of legionellosis is most accurately established using special media, subject to careful sampling of material, which excludes the ingress of microflora from the oral cavity. Immunofluorescence diagnostic methods are considered less sensitive than cultural ones and are used less often.

Treatment

Legionellosis treatment

Many antibiotics are highly effective against Legionella bacteria. The two most effective classes of antibiotics are macrolides (azithromycin) and quinolones (ciprofloxacin, levofloxacin, moxifloxacin, gemifloxacin, trovofloxacin). Other agents that have been shown to be effective in the treatment of legionellosis are tetracycline, doxycycline, minocycline, and trimethoprim / sulfamethoxazole.

Prophylaxis

Prevention of legionellosis

Prevention of Legionnaires' disease consists in minimizing the multiplication of Legionella. This requires regular maintenance, cleaning and disinfection of the cooling towers; maintain an adequate level of biocides in swimming pools; keep the hot and cold water supply systems clean and maintain the hot water temperature at more than 50 ° С, and cold water below 20 ° С; carry out regular maintenance of air conditioning systems, ice makers, coolers.