Legionellosis (Legionnaires' disease, Pittsburgh pneumonia, Pontiac fever) is an acute respiratory infection caused by Legionella bacteria. The disease is usually accompanied by fever, general intoxication of the body, damage to the nervous system, lungs, digestive tract. Legionella can cause and various lesions of the respiratory system - from mild cough to severe pneumonia.
Sources of infection
Legionella is a microorganism that is widely distributed in nature. Most often legionella is found in fresh water bodies and actively multiplies at a temperature of 20 to 45 degrees. Infection of a person occurs by aerosol, by inhalation of small drops of water containing legionella bacteria, but directly from one person to another, the infection is not transmitted.
In addition to the natural source of water (reservoirs), in the modern world there is an artificially created niche, which has comfortable conditions for this microorganism. This is a water supply system with a suitable temperature for breeding bacteria, air conditioning and humidification systems, closed in a single cycle, swimming pools, whirlpools, etc.
Actually, the name of the disease - legionellosis or "Legionnaires disease" - comes from the first recorded mass outbreak, which happened in 1976 at the congress of the "American Legion." The source of infection was the air conditioning system in the hotel, where the congress was held.
In home air conditioners, moisture does not have enough time to accumulate in order to become a source of contamination, so the threat is minimal on this side. Dangers can be represented by humidifiers of air, if they do not regularly change the water.
Legionella - symptoms
The incubation period of the disease, depending on the form, is from several hours to 10 days, on average 2-4 days. The symptomatology of the disease with Legionella infection is no different from the symptoms of severe pneumonia caused by other factors. In typical cases of the disease initially observed:
- general weakness;
- aching muscles;
- state frailty.
Then a rapid rise in temperature begins, to 40 degrees, which is weak or not at all resistant to antipyretics, chills, headaches are possible. First there is a weak dry cough , which rapidly intensifies, eventually becoming wet, possibly the development of hemoptysis. Less common are additional symptoms, such as:
- pleural and muscular pain;
- nausea;
- diarrhea;
- stomach ache.
The main complications of the disease include the development of respiratory failure, which occurs in about 25% of patients requiring hospitalization.
Legionella - diagnosis and treatment
Diagnosing legionellosis, like any other atypical pneumonia, is not easy. The analysis aimed directly at identifying the legionella bacterium is quite complex, lengthy and conducted only in special laboratories. Diagnostics often use serological methods
Despite the difficulties in the diagnosis, this disease can be treated with antibiotics . Legionella is sensitive to erythromycin, levomycetin, ampicillin, is insensitive to tetracycline and is absolutely insensitive to penicillin. To enhance the effect of the course of major antibiotics often combine with the use of rifampicin.
Treatment of legionellosis is carried out only in stationary conditions, taking into account the severity of the course of the disease and possible complications. Untimely hospitalization of the patient can lead to a fatal outcome.