A fairly common disease today is listeriosis. What it is? It's no secret that such a disease is extremely dangerous. But what is its cause? What are the main symptoms associated with it? Are there effective methods of treatment and prevention? Is there any way to protect myself? This information will be useful to everyone.
Listeriosis - what is it?
Listeriosis is an infectious disease. In medicine, it is known under various names, including neurellosis, Tiger river disease, listeriellosis, etc. It is worth noting that with such a disease, the infection affects primarily the lymphatic system and nerve tissues.
The pathogen was first described in 1911 by S. Halfes. In 1926, scientists at the University of Cambridge (the study was led by D. Murray) were able to isolate the pathogen for the first time from tissues taken from sick guinea pigs and rabbits.
Already in 1927, U Peary proposed calling the recently discovered group of microorganisms Listeria in honor of the scientist D. Lister, who at one time studied the nature of the disease in South Africa. And already in 1929, the pathogen was isolated from human tissues.
Brief description of the pathogen
Listeria is a rod-shaped bacterium that belongs to the group of facultative anaerobes. It is worth noting that this microorganism is resistant to environmental influences. Listeria is able to breed in water, in soil, as well as on plants or corpses of dead animals. These bacteria easily tolerate freezing. Even under the influence of direct sunlight, Listeria can retain their ability to live for two weeks.
Transmission routes
Of course, the issue of transmission is quite relevant today. As already mentioned, listeria are fairly stable microorganisms that can survive outside the host for a long time.
So how can you get this disease? In fact, the transmission methods of infection can be different - this is aerosol, and fecal-oral, and transplacental. The source of the pathogen can be an infected person, since bacteria are excreted together with feces, saliva, sperm and other fluids. Transmission from mother to child during pregnancy, childbirth or breastfeeding is also possible.
However, in most cases, infection occurs when eating meat or waste products of a sick animal. In fact, animal listeriosis is quite common. Infection can enter their body even with water. Most diseases are affected by poultry and animals, although wild mammals (raccoons, rodents, foxes, ungulates), as well as fish, are often carriers of listeria.
On the other hand, infection of the human body can occur with the use of contaminated water or unwashed fresh vegetables and fruits.
Are there risk groups?
It is immediately worth noting that this infection was detected in all countries of Europe and, of course, is quite common in other countries of the world. Normally, a healthy human body is not too susceptible to this type of infection. Nevertheless, the risk group should include people working in the livestock sector.
In addition, in this case, the state of the immune system is of great importance. Listeriosis in a person with reduced resistance is diagnosed much more often. For example, pregnant women, newborns, and the elderly are more susceptible to this kind of infection. The risk factors also include the presence of cancer, diabetes mellitus, or damage to the excretory system. Some drugs that inhibit the activity of the immune system can also increase the body's susceptibility to listeria. And at risk include patients with immunodeficiency.
By the way, immunity to this infection is also not developed - once a person who has become ill can become infected again.
The clinical picture and pathogenesis
Listeria enters the human body through the mucous membrane of the digestive tract, less commonly through cracks in the skin. From here, microorganisms along with blood flow can spread throughout the body. Most often, they settle in the lymph nodes, where they begin to multiply actively, which leads to the appearance of an inflammatory process.
By the way, Listeria can penetrate into the white blood cells of macrophages. Here they disguise themselves from the immune system and become immune to the effects of antibiotics. In places of active reproduction of bacteria, so-called listeriomas are formed, which are necrotic nodules. In some cases, extensive necrosis leads to the development of sepsis. In addition, Listeria often affects the nervous system, which leads to dangerous consequences.
Listeriosis: human symptoms
How to determine the presence of such a disease? What changes in the body should cause concern? It is immediately worth noting that the incubation period lasts from 3 to 45 days, after which listeriosis begins to appear. Symptoms in a person depend on which organs the bacterium infects. To date, several basic forms of this disease are known.
- The angina-septic form in medicine is considered the most common. In the initial stages, the clinical picture is similar to an ordinary sore throat. There is redness and swelling of the pharynx. Patients complain of pain when swallowing. You can observe the increase and soreness of nearby lymph nodes. In addition, the main symptoms of intoxication appear - fever (sometimes up to 40-41 degrees), headaches, weakness, muscle aches, chills. If untreated, necrosis may occur. And the infection can spread to the structures of the central nervous system.
- Extremely dangerous is nervous listeriosis. Symptoms in this case resemble the clinical picture with meningitis, abscess and meningoencephalitis. Meningitis is accompanied by severe headaches, vomiting, convulsions, delusional conditions, stiff neck muscles. With meningoencephalitis, the patient also has some other symptoms, including ptosis (drooping) of the eyelids and anicosoria (loss of size of one of the pupils).
- In newborn infected children, septic granulomatous listeriosis often develops. Its symptoms are varied - it is an increase in temperature, pain, damage to the nervous systems, paralysis, skin rash, etc. Often the infection affects not only the nervous system, but also the respiratory and cardiovascular system. A frequent complication with this form of the disease is purulent pleurisy and bronchopneumonia.
- There is also an ophthalmic glandular form of the disease, which is quite rare in modern medicine. Most often, this type of disease develops against the background of direct contact with infected animals. The clinical picture in this case resembles purulent conjunctivitis. The disease is accompanied by inflammation of the mucous membrane of the eye, swelling, redness and the appearance of profuse purulent discharge. Often patients complain of severe itching, burning and even soreness in the eyes. The hallmarks include a strong increase in temperature and the presence of symptoms of intoxication, which are not expressed with ordinary conjunctivitis. In addition, an increase in nearby lymph nodes can be seen.
In any case, only a doctor can diagnose listeriosis. Therefore, when the first symptoms appear, you should seek the help of a specialist.
Modern diagnostic methods
In fact, there are many diseases that, in their symptoms, resemble listeriosis. What is it and what are the rules for differential diagnosis? For example, in some cases, the disease resembles an infectious tonsillitis or mononucleosis, as well as various respiratory infections of a viral nature.
The medical history, of course, begins with a list of complaints made by the patient. Further analyzes are carried out. In particular, during laboratory testing of blood samples, a significant increase in the number of monocytes can be noticed. In a sick person, depending on the symptoms present, mucus is taken from the pharynx and nasopharynx, conjunctival discharge, cerebrospinal fluid. In some cases, a puncture of the lymph nodes is performed. If listeriosis is suspected during pregnancy, the doctor may prescribe a collection and examination of amniotic fluid or placenta samples.
In laboratory conditions, sowing is carried out on a nutrient medium. This procedure makes it possible not only to determine the nature of the pathogen, but also its sensitivity to a particular drug.
Serological analysis for listeriosis is also quite accurate, but sometimes it can give false results. Further research depends on the form of the disease. For example, if an abscess is suspected, the patient is sent for magnetic resonance imaging. The nervous form of listeriosis requires a consultation of a neurologist, as well as lumbar puncture and brain EEG.
How is listeriosis treated?
Naturally, the medical history is extremely important for drawing up the correct treatment regimen. So what does therapy look like with a similar disease?
First of all, antibacterial drugs are prescribed to the patient. Erythromycin, tetracycline and chloramphenicol are considered quite effective antibiotics to date. However, in some cases, the doctor may choose other drugs, since here everything depends on the degree of sensitivity of the bacterial strain to a particular substance.
Along with this, the patient is intravenously injected with an isotonic sodium chloride solution and diuretics are prescribed - this helps to get rid of harmful waste products and eliminate the main symptoms of intoxication.
Other methods of therapy depend on the form and severity of the disease. For example, with damage to the nervous system, benzylpenicillin is administered to patients. If the disease struck the eyes, then eye drops and sometimes anti-inflammatory corticosteroid ointments are used to treat it.
How long does listeriosis require? Treatment is carried out exclusively in a hospital setting, namely in the infectious diseases ward. As a rule, the main symptoms of the disease disappear after 2-4 weeks. After this, the patient must once again undergo examination - if the test results confirm the absence of Listeria, a person can be discharged. Nevertheless, those who have been ill with listeriosis for another two years should be registered in the infectious ward and undergo regular medical examinations.
Are complications possible?
In most cases, adequate treatment provided on time helps to quickly get rid of such a disease. But there are some complications with which listeriosis is associated. What it is?
To begin with, it is worth noting that newborns and people with a strongly weakened immune system are most prone to complications. During pregnancy, infection of the mother's body and, accordingly, the fetus can lead to fetal freezing, stillbirth, the appearance of some intrauterine malformations, etc. If the baby became infected during childbirth, then in the very first days the baby’s body may encounter complications such as purulent meningitis, impaired respiratory and vascular systems. Listeria can cause severe pneumonia, which most often ends fatally for the baby.
The nervous form of the disease is rather severely tolerated. In a child, this kind of ailment can lead to damage to the central nervous system, which, accordingly, entails complications such as mental retardation, epilepsy, and paralysis.
In adults, the most common consequences are endocarditis and hepatitis. But even in adulthood, the nervous form of listeriosis with no treatment ends lethally in 45 - 70% of cases. That is why in no case should you ignore the symptoms or self-medicate.
Recommended Prevention
Unfortunately, today there is no medicine that can permanently protect a person from a disease called listeriosis. Prevention in this case is complicated by the fact that the bacterium is extremely resistant to environmental influences and can enter the human body in different ways.
That is why the only truly effective way of protection is to carefully follow all sanitary and hygienic and veterinary sanitary recommendations. On farms and in farms engaged in raising animals, you need to regularly examine the animals and, if necessary, provide them with quality treatment. As for personal protection, you should not forget about the proper processing of food - you need to boil milk, meat, sausages and other meat products thoroughly fry.
A person with a diagnosed disease should be treated in a hospital setting so as not to become a source of infection for others. An extract is possible only if the results of the tests have confirmed complete recovery and the absence of the causative bacterium in the body.