In the summer and winter, adults and children, low-income and frankly rich - enterovirus infections spare no one. The symptomatology of diseases that are associated with this pathogen has a wide range. The geography of viruses and their diversity is amazing. Let's try to understand the etiology, sources, routes of infection, methods of treatment and clinical recommendations for enterovirus infection.
Relevance of the topic
Epidemiological outbreaks recorded in different countries demonstrate the activation of enterovirus infections in the world. The geography of distribution of this group of pathogens is ubiquitous, clinical manifestations are diverse.
The peculiarity of infections of this kind is associated with the concept of virus carrier. This means that the virus can be in the human body, but manifests itself in special cases - with weakening of natural immunity. In addition, the virus carrier contributes to the formation of spores, leading to mass diseases and infection of a large number of non-immune recipients.
Pathogenicity and manifestation
This is a group of infections that are mostly asymptomatic or not too harmful to a person. But there are exceptions to any rule. Enterovirus infections are the second most common colds.
Infection can be extremely dangerous and affect all systems and organs, muscles, mucous membranes. This anthroponosis has two reservoirs:
- a person where the pathogen multiplies and accumulates;
- environment (water, air, food), where virions are able to maintain virulence for a long time.
The main route of transmission of enterovirus infections is airborne, the fastest and most unpredictable. No less effective is the route of infection in the human body through the alimentary canal and oral-fecal tract. There is a vertical route of infection - from the mother to the newborn. And it is with this phenomenon that many pediatricians associate sudden infant death syndrome.
What kind of beast is this?
Let's dwell on what microorganisms cause enterovirus infection. The pathogenic agent is viruses - extracellular life forms that parasitize in the cells of a living organism. The uniqueness of this group in the minimum of structural components outside the cell (virions) and the ability to start the synthesis of its own genetic material due to the resource of the host cell.
The main task of the virion is to penetrate into the cell, which is achieved by the specific structure of the envelope of viruses (capsids). After penetration, this parasite can behave differently, playing out scenarios that differ in the level of autonomy:
- The scenario is productive (of course, from the point of view of the virus): the parasite starts the synthesis of its own genetic material according to its own schedule, depleting the resource of the cell and leading to its death.
- Another scenario is conciliatory. Here, the parasite incorporates its genome into the genome of the host cell and already replicates its nucleic acids covalently with it.
Further development goes in two ways. In the first, the virus freezes, and only under certain conditions its genes turn on, producing a young generation of parasites that leave the dying cell. In the second variant of development, the virus genome is constantly replicated, but the cell does not die. The young generation of virions is pushed out by exocytosis.
Microbiology of Enteroviruses
The group of causative agents of enterovirus infections in humans includes representatives of the picornovirus family (Picornaviridae). This family includes more than 60 pathogens from the genus Enteroviruses (Enterovirus), Rhinoviruses (Rinovirus), Cardioviruses (Cardiovirus) and Autoviruses (Aphtovirus).
The genus of enteroviruses includes poliomyelitis viruses (3 forms or serotypes), Coxsackie viruses of group A (24 serotypes) and B (6 serotypes), ECHO (Enteric Cytopathogenic Human Orfhan - intestinal cytopathogenic human orphans, 34 serological types), hepatitis A virus and many unclassified enteroviruses. All of them have a number of similar structural features:
- These are small viruses (from pico - “small”), measuring within 28 nanometers.
- They have a cubic capsid type built of 4 types of proteins.
- They have a single complement-binding antigen common for the whole genus; serotypes differ in type-specific protein antigens.
- The genetic material is single-stranded linear RNA.
- External supercapsid membrane, carbohydrates and lipids are absent.
- They have high stability in the environment. That is why gastric acid does not kill them.
Pathogenicity and resistance
Representatives of this genus are ubiquitous, affecting plants, animals, bacteria. Enteroviruses enter the body in various ways, mainly through the digestive tract, reproduce in the mucosa and lymph nodes, penetrate the bloodstream and spread throughout the body. Lesions of one or another organ depend on the type of pathogen and the immune status of the recipient.
Enteroviruses are common on all continents of the planet. They remain contagious (infectious) in the environment for up to a month, and in feces for up to six months. Resistant to freezing, but die when heated to 50 ° C. They retain pathogenicity in acidic environments (they are not afraid of gastric juice), are resistant to 70% of alcohols, but are destroyed by ultraviolet radiation, ultrasound.
When disinfecting rooms and objects, oxidizing agents (hydrogen peroxide and potassium permanganate), chlorine-based products, formaldehyde, which inactivate the pathogen, are used.
Diagnosis of enterovirus infections
The specifics of diagnosing the causative agents of this group of the disease is based on the identification of all pathogens present in the body. Material for research - bowel movements and urine, swabs from the affected areas of the mucous membranes, blood and cerebrospinal fluid. The following methods are used to diagnose enterovirus infections:
- Virological research. This technique uses cell cultures and laboratory animals. For example, in order to determine all serotypes of poliomyelitis virus, clinical material uses transplantable cultures of monkey renal epithelium. A polymerase chain reaction is also used.
- Serological tests. The method of paired serums and staging of color samples is used. The method is based on the ability of viruses to suppress metabolism in the cell, change the pH of the medium and, accordingly, the color of the test sample.
- Express method. Pretty complicated and not widespread. For diagnosis, a cardiological analysis (changes in the nuclei of the affected cells) is used.
Many pathogens - many manifestations
Forms of enteroviral infections in accordance with the modern classification:
- Intestinal, or gastroenteric. The disease lasts from one to two weeks. Clinical manifestations: rhinitis, swelling of the mucous membranes of the oropharynx, cough, flatulence, diarrhea and vomiting.
- Enterovirus fever. Symptoms: fever up to 40 ° C, weakness, muscle pain, redness of the sclera of the eyeball, nausea and vomiting, in rare cases - diarrhea. The disease lasts 3-7 days. Pathogens are enteroviruses of all subtypes.
- Catarrhal, or respiratory (herpangina). The disease lasts up to a week and proceeds as an acute respiratory one. It is caused by the Coxsackie A and B. viruses. Symptoms: short-term fever with a slight increase in temperature, sore throat, ulcers on the walls of the pharynx and tonsils, decreased appetite.
- Intestinal infection. The duration of the disease in young children is up to 2 weeks, in older and adults - 1-3 days. Only intestinal mucosa are affected. Clinic: abdominal pain, frequent and loose stools, diarrhea, possibly a slight increase in body temperature.
- Myocarditis. Disorders of the heart in connection with the defeat of its various layers. Symptoms are associated with rapid rhythm, fatigue, weakness, decreased pressure and chest pain. Pathogens - Koksaki B5 and ECHO.
- Exanthema. Within 3-5 days, a rash of the type of rubella on the face and body appears.
- Conjunctivitis. Symptoms: eye pain, blurred vision, lacrimation and hemorrhage, an increase in lymph nodes may be observed. The disease lasts up to two weeks. Pathogens: enterovirus serotype 70, Koksaki 24.
- Meningitis and encephalitis. The most severe form of enterovirus infection. Clinical manifestations: severe pain, fever, vomiting, delusional states, convulsions. The course of the disease passes through periodic outbreaks that can last up to 2 months. The causative agents of this form are Coxsackie B viruses and ECHO.
- Paralytic form. It is accompanied by unilateral or bilateral paralysis of the limbs, a decrease in muscle tone. Symptoms can persist for up to 8 weeks, with severe development, a fatal outcome is possible due to disorders of the respiratory center.
- Epidemic myalgia. A fairly rare disease, manifested in paroxysmal pain in the muscles, chest and abdomen. It is accompanied by fever and increased sweating. The duration of the course is up to 10 days. Pathogens - Koksaki B3 and B5.
- Encephalomyocarditis of newborns - in 60-80% leads to death. The causative agents are Coxsackie viruses of group B. Symptoms: lethargy, cramps, heart failure, breast failure.
The incubation period in all cases lasts from 2 to 15 days. The onset of the disease is always acute. There may be mixed forms of infection.
Pathogen Entrance Gate
Before wondering how to treat enterovirus infection in children, we will understand how it enters the body. The entrance gates in this case are the mucous membranes of the respiratory tract and digestive tract, where viruses enter the fecal-oral or airborne droplets.
When a pathogen enters the mucous membranes, a local inflammatory reaction begins. This will end the infection with a sufficiently strong immunity. But if the immune status is weakened, and the virulence of the virus is high and its quantity is quite large, then generalization of the infection occurs. It penetrates the bloodstream and is carried throughout the body in accordance with the tropic features of the pathogen.
Depending on the affected organ or tissues, the clinic and symptoms of the disease can be very diverse.
General symptoms and course of the disease
The severity and duration of the course of enterovirus infection depends on many factors. These include:
- The virulence of the pathogen (the ability to resist the protective mechanisms of the body).
- Features of tropism - the focus of the virus on the defeat of certain organs and tissues.
- The immune status of the infected. The higher it is, the more likely the victory of the body over the pathogen.
As already clear, viruses of this group can infect various systems and organs of our body. But regardless of the focus of infection, the common symptoms for such infections are the following:
- The temperature during enterovirus infection rises in the range from 38 º to 40 º.
- Swelling of the submandibular and other lymph nodes.
- Weakness and drowsiness.
- In some cases, a rash.
- Nausea, vomiting, and diarrhea.
Preventative measures
Special methods of prevention in this case do not exist. In order to avoid infection, it is necessary first of all to observe the rules of personal hygiene: wash hands and products, use boiled and purified water. During an outbreak, avoid visiting crowded places. But, perhaps, the main thing is to monitor the condition of the body and increase immunity. A healthy lifestyle, proper nutrition and physical activity will minimize the possibility of a viral attack.
In the case of the presence of an infected family member, all contactees should be more careful about preventive measures. Separate dishes and personal hygiene items for the patient and increased attention to personal hygiene for all family members should be a priority.
In outpatient institutions, quarantine is introduced during outbreaks of enterovirus infections, which is set for 14 days from the moment of the last contact, and anti-epidemic measures are carried out (disinfection). In maternity hospitals, quarantine is also introduced, and all employees who have contact with patients are sent on vacation for two weeks.
How to treat enterovirus infection in children?
It is children, because of their immune status, that are more susceptible to such diseases. If a child is suspected of having an enterovirus infection, it is necessary to consult a pediatrician and get a referral for studies necessary in a particular case. Sometimes it may be necessary to consult doctors of narrow specialties - a cardiologist, otolaryngologist or ophthalmologist.
Treatment of mild forms of the disease is carried out on an outpatient basis and only with suspicion of meningitis, myocarditis and other combined lesions, a child may be hospitalized. There are no special drugs for enterovirus infection. Treatment is to reduce negative symptoms, prevent dehydration and timely detection of side effects.
As a rule, the body copes with the infection on its own within a week, and there are no significant consequences of enterovirus infections. To maintain the body, usually prescribed drugs are symptomatic (for example, antipyretic) and pathogenetic in nature (sorbents and antiseptic ointments). There are no dietary restrictions, but it is worth remembering that the nutrition for enterovirus infection must be balanced and take into account the nature of the disease. So, during infection of the oropharynx, the food should not be hot or cold, which will ease the pain during swallowing.
Antibiotics are prescribed for secondary infections and complications of enterovirus infection, such as pneumonia, otitis media, myocarditis. With some forms of the disease, hormonal drugs are prescribed. But all these appointments should be made by the doctor after a thorough examination of the research results and taking into account the patient's condition.
The most common enteroviral diseases
It is impossible not to list the most common and considered typical infections that cause enteroviruses. These include:
- Summer flu. The most common infection when swimming in the rivers and at sea. Overheating and hypothermia contribute to the development of infection. Symptoms combine flu-like symptoms and an upset intestinal tract. The disease lasts from 3 to 7 days, accompanied by fever, diarrhea, sore throat, sometimes conjunctivitis.
- Herpangina. Herpes-like rashes in the back of the pharynx and tonsils. The disease goes away in 3-5 days.
- Viral pemphigus. The appearance of bubbles filled with liquid on the palms, between the fingers, on the soles. Fever accompanies infection in the first 1-2 days, within a week the symptoms disappear.
- The exanthema is viral. It is caused by echoviruses and is accompanied by a rash throughout the body like rubella. It does not occur so often, the symptoms disappear within ten days.
In conclusion, I would like to note that this group of diseases is characterized by such a phenomenon as virus carriage. Often adults do not get sick, but they are virus carriers. But children, with their not yet stable immune system status, are easily infected. Therefore, compliance with personal hygiene is mandatory for both adults and children. And remember - the key to the victory of the body over viruses that constantly attack it is strong natural immunity. Be healthy and take care of yourself and your children!