Enterovirus infections are a group of infectious diseases that develop when a person is infected with viruses of the genus Enterovirus, characterized by a variety of clinical manifestations. Infection with enteroviruses can occur by food, less often by aerosol. Characterized by high fever, malaise, diarrhea, polymorphic skin rashes. Enterovirus infections can occur in the form of herpangina, myalgia, viral meningitis. Rare forms include enterovirus pancreatitis, nephritis, encephalitis, pericarditis and eye damage. Diagnostics is based on the detection of the pathogen in biological environments. Treatment is mostly symptomatic.
ICD 10
B34.1 A08.4
General information
The term “enterovirus infections” refers to various diseases caused by Coxsackie and ECHO enteroviruses and occurring with damage to the mucous membranes, skin, muscles, and nervous system. The susceptibility is universal, but mass outbreaks are usually registered in children’s groups. Most children suffer at least one episode of enterovirus infection before the age of 5. In different regions, the percentage of healthy carriers varies between 17-46%.
Causes
Enteroviruses are RNA-containing viruses, many of them are pathogenic to humans: 23 types of Coxsackie A virus, 6 types of Coxsackie B. The same group includes the ESNO virus and from the 68th to the 71st types of enteroviruses. All pathogens of enterovirus infections are small in size (from 15 to 35 NM), resistant to freezing and some chemical disinfectants: ether, 70% alcohol, lysol. In feces, they can remain viable for more than six months.
Inactivation of enteroviruses occurs when heated to 50 ° C, dried, exposed to ultraviolet light, disinfection with a formaldehyde solution (0.3%), chlorine-containing agents. The reservoir and source of enterovirus infections is a sick person or carrier. Contagiousness is noted for weeks and months, the peak of the pathogen release falls on the first days of clinical manifestations. Enteroviruses are transmitted via the fecal-oral mechanism by food.
Most often, infection occurs when eating vegetables contaminated with viruses. Viruses get on vegetables and fruits when fertilized with uninfected sewage. Some enteroviruses are secreted with the secret of the mucous membranes of the respiratory tract, which can contribute to the implementation of an aerosol transmission mechanism. There are cases of infection by contact and household means (contaminated hands, household items, personal hygiene). In case of infection with enterovirus infection of a pregnant woman, vertical transmission of the pathogen to the child is possible. The natural susceptibility of a person to enteroviruses is high, immunity is usually type-specific, in rare cases there may be a cross.
Classification
Due to the polymorphism of clinical symptoms, there is no unified classification of enteroviruses. In our country, classification is used according to the forms of the disease: typical and atypical. Typical forms of enterovirus infection include herpangina, epidemic myalgia, exanthema, aseptic serous meningitis.
In addition, the disease can occur in a catarrhal, encephalic, spinal (polio-like) form. Atypical forms also include enterovirus uveitis, nephritis, pancreatitis, encephalomyocarditis of newborns, inapparant and small forms, mixed infections.
Symptoms
The incubation period of enterovirus infections can last 2-7 days. The clinic of the disease is so diverse that it is possible to assume the presence of several different pathologies. The most common signs are intoxication, fever, catarrhal and abdominal symptoms, polymorphic exanthema.
With an acute onset, fever can rapidly increase and reach 39-40 degrees, after which it persists for several days, accompanied by symptoms of general intoxication (weakness, headache, myalgia, vomiting and nausea of central genesis are possible). Enteric diarrhea may occur. Fever can occur in waves, especially with a recurrent course of infection. On external examination, hyperemia of the face is noted, injections of sclera, moderate redness is noted on the oropharyngeal mucosa, and granularity is noted on the back wall of the pharynx. There may be a variety of rashes.
Enterovirus angina
Enterovirus herpangina is characterized by hyperemia of the tonsils and palatine arches, which occurs against the background of a general febrile reaction. Soon, herpes-like bubbles form on the affected pharyngeal mucosa, which burst and form areas of erosion covered with a grayish coating and having a hyperemic rim along the edge. Bubbles and erosions tend to spread and merge. Over the following days, the elements of the enanthema gradually heal. Herpangina is often combined with serous meningitis.
Epidemic myalgia
Epidemic myalgia, which is also called pleurodinia, Sylveste-Finsen’s disease and Bornholsky disease, manifests itself, in addition to the general signs of infection, attacks of muscle pain (which are a symptom of myositis). Soreness is noted in the muscles of the chest, abdomen and extremities. The pain symptom in enterovirus lesion is quite diverse along the course. With the development of myositis of the pectoral muscles, breathing difficulties are possible, pain in the abdominal wall muscles sometimes imitates the clinic of the “acute abdomen”. As a rule, the pain lasts about 2-3 days, after which it subsides. There may be cases of recurrence of myalgia.
Enterovirus meningitis
Viral meningitis is the most common and severe form of enterovirus infection. Like any inflammation of the meninges, it is characterized by positive meningeal symptoms: rigidity of the occipital muscles, symptoms of Brudzinsky and Kernig. Patients are usually apathetic, lethargic, hypersensitivity to light and sounds may be noted. Sometimes convulsions, psychoemotional excitement are noted, consciousness, as a rule, is preserved. Meningeal symptoms and elevated body temperature usually persist for no more than 4-7 days.
Enterovirus exanthema
It can manifest as an independent predominant symptom complex, and accompany other forms of enterovirus infections (serous meningitis, herpangina). The rash appears on the 2-3 day of fever and intoxication, localized mainly on the face, trunk, limbs, feet. The rash is polymorphic, may resemble an exanthema in measles, scarlet fever or rubella, be roseolous, spotty-papular, petechial. Often exanthema is accompanied by enanthema in the oral cavity. There may be symptoms of conjunctivitis, meningism.
Enterovirus fever
Enterovirus infection can occur without any local manifestations, the only symptom is fever and general intoxication. This form is also called a minor illness, or summer flu. According to the type of influenza lesion, a catarrhal (respiratory) form of enterovirus infection also occurs. Fever is accompanied by a dry cough, sore throat and moderate hyperemia of the throat, rhinitis with serous-mucous discharge.
Encephalomyocarditis of newborns
Encephalomyocarditis of newborns is the most severe. Fever can either be present (usually has a two-wave character) or absent. There is a general pronounced weakness, lethargy, drowsiness, anorexia, vomiting. The skin is cyanotic, shortness of breath, tachycardia. With percussion of the heart, there is an expansion of its boundaries, with auscultation, deaf arrhythmic tones, systolic noise are heard. The liver is enlarged, edema is noted. With encephalomyocarditis, there is a high probability of developing convulsive syndrome, coma. Enterovirus myelitis is quite difficult to diagnose with a paralytic form of polio. The main difference is a lighter and short–term course, often the subsequent restoration of motor function.
Enterovirus diarrhea
Viral gastroenteritis is characterized by multiple enteritic diarrhea on the background of subfebrility, less often – fever. Abdominal pain is noted (mainly in the right iliac region) with bloating, vomiting may occur. Enteritis symptoms are often combined with catarrhal phenomena. Hepatolienal syndrome may be detected. The disease usually lasts from a few days to two weeks.
Viral conjunctivitis
Enterovirus hemorrhagic conjunctivitis is characterized by an acute, sudden onset, pain in the eyes, lacrimation, photophobia. On examination, the conjunctiva is hyperemic, numerous hemorrhages are noted, serous or serous-purulent copious discharge, the eyelids are pronounced edematous. Initially, one eye is affected, later the disease spreads to the second.
In addition to the above-mentioned forms, enterovirus infection can manifest itself in the form of encephalitis, jaundice-free hepatitis, lymphadenitis of various groups of lymph nodes, affect the cardiac sac (pericarditis), intestinal mesentery, provoke the development of other diseases.
Complications
Enterovirus infection, occurring in the form of meningitis, meningoencephalitis, encephalomyocarditis of newborns, can be complicated by brain edema, epileptoid seizures, mental disorders. A severe infection can contribute to the development of pneumonia, acute respiratory failure.
Diagnostics
Isolation of the pathogen from the blood, secretions of the nasopharyngeal mucosa, cerebrospinal fluid or feces and virological examination is possible, but in wide clinical practice it is rarely used due to the complexity, duration and low diagnostic value, since the identification and identification of enterovirus is not always proof that this particular pathogen is the etiological cause of the disease (due to the high frequency of asymptomatic carrier enteroviruses among the population).
The main method of specific diagnosis of enteroviruses is to detect a 4-fold and greater increase in the titer of antibodies to the pathogen in paired sera. Antibodies are detected using IFT and HI.
Treatment
Etiotropic treatment for enterovirus infections has not been developed, therapy includes the use of detoxification therapy and symptomatic agents according to indications. A severe form of infection with damage to the nervous system is an indication for the appointment of corticosteroid drugs and diuretics to correct the water-electrolyte and acid-base balance. With the development of life-threatening conditions, intensive therapy and resuscitation measures may be required.
To stabilize vascular tone and improve the rheological characteristics of the blood, vinpocetine is prescribed, pentoxifylline is actively used vitamin therapy. Depending on the symptoms, analgesics and sedatives are prescribed. The development of a secondary bacterial infection is an indication for the appointment of a course of antibiotic therapy in accordance with the sensitivity of bacteria to drugs.
Prognosis and prevention
Enterovirus infections mostly occur easily, or in a moderate form, recovery occurs within a few days, up to 2-3 weeks. The prognosis worsens in case of severe course, development of complications. Some complications of enterovirus infection (mainly from the nervous system) can be fatal, or leave behind irreversible functional disorders.
The general prevention of enterovirus infections includes measures to control the contamination of environmental objects with sewage waste, compliance with sanitary and hygienic requirements for the neutralization of wastewater, providing the population with food products of the proper degree of epidemic safety.
Individual prevention consists in strict adherence to the rules of personal hygiene, the necessary food processing. Specific measures for the prevention of enterovirus infections have not been developed. Children under 3 years of age who have had contact with the patient are prescribed interferon and immunoglobulin intranasally for 7 days. A complex of disinfection measures is carried out in the focus of infection.