What is Adenovirus Infection in Children?
Adenovirus infection is an acute respiratory disease, accompanied by mild intoxication, fever. Adenovirus infection affects the mucous membranes of the respiratory tract, often conjunctiva of the eyes and lymphoid tissue.
In the period between flu epidemics, 25 to 30% of young children infected with viral diseases of the respiratory tract suffer from adenovirus infection. Almost all children under 5 years old endure this disease at least once; half of those who have been ill get sick for the second time.
The source of adenoviruses are diseased people (regardless of the form of the disease – hidden, inapparent, obvious) and healthy vectors. The greatest risk of infection arises from contact with a patient in the acute period. At this time in the nasopharyngeal washes there is a very large amount of virus. Also, the virus is detected in the blood, conjunctiva and feces. The first two weeks, patients pose a threat to others. It is worth remembering that in some cases, patients can be carriers of adenoviruses up to 3 or even 4 weeks.
Like many other infections, adenovirus infection “migrates” by airborne droplets. It is also possible infection, similar in mechanism to infection with intestinal infections. Adenovirus infection belongs to the group of airborne and intestinal infections (according to the epidemiological classification of infectious diseases).
Infants up to 6 months of age have a chance to become infected, close to zero, because they have passive immunity. After the sixth month of life, children are already susceptible to the disease. After the child has had an infection once, he has an active immunity. Children older than five years are practically not susceptible to the disease.
Diseases are sporadic, but there may also be local epidemics in kindergartens, schools, and children’s health camps. Very rarely does an outbreak spread outside of an organized group of children. The largest outbreaks were recorded, in which the number of cases – up to 500. After the start of an outbreak on days 14-16, the number of cases is maximum. After 14-16 days, the flash begins to fade. The greatest chance for a child to fall ill is in the fall, winter and early spring. In the summer, rare sporadic outbreaks occur everywhere. In children, serotypes 1, 2, 3, 4, 7, 7a, 14 and 21 most often cause the disease.
Classification. The main clinical syndromes for adenovirus infection are: catarrh of the upper respiratory tract, tonsillopharyngitis, pharyngoconjunctival fever, keratoconjunctivitis, diarrhea and mesenteric lymphoadenitis. There are such forms of adenovirus infection: mild, moderate and severe (the latter happens with or without complications).
Pharyngoconjunctivitis is a typical and common variant of adenoviruses. It manifests itself as a pronounced catarrh of the upper respiratory tract, prolonged fever, the virus also affects the mucous membrane of the eyes and causes inflammation of the tonsils. Cervical lymph nodes are enlarged. Also, the spleen and liver of a child are sometimes enlarged. The course of pharyngoconjunctivitis is often long. During the first (and sometimes the second) week, the body temperature rises.
Tonsillopharyngitis. All forms of adenovirus cause changes in the oropharynx. But with tonsillopharyngitis, these changes are pronounced and prevail in the clinical picture. The child will complain of sore throat. If you ask him to open his mouth, you will be able to observe a raid on the tonsils, and the regional lymph nodes will be enlarged. Such symptoms are caused not only by the influence of the adenovirus itself, but also by the bacterial flora. This means that a sore throat with tonsillopharyngitis is viral and bacterial in nature.
Mesenteric lymphadenitis (mesadenitis) is a type of adenoviral infection that occurs quite often. The patient feels pains in the navel or in the right iliac region, which “come” attacks. The main symptoms of this type of adenovirus are also fever and vomiting. A rare occurrence of peritoneal irritation. In the analysis of blood detect the number of leukocytes in the normal range. If surgery does occur, doctors find significantly enlarged, swollen lymph nodes in the mesentery.
Qatar of the upper respiratory tract is the most common clinical variant of adenoviral infection in a child. The first days at the patient fever is observed. Symptoms of intoxication are moderate or mild (manifested as tracheitis, rhinitis and bronchitis). In some cases, developing croup syndrome, catarrhal pharyngitis. Cervical lymph nodes are enlarged – this can be determined not only by the doctor, but also by the parents themselves.
Diarrhea occurs in children younger than 1 year. Emptying occurs 4-5 times a day, and at an altitude of catarrhal phenomena even up to 7-8 times. In the fecal masses can be detected impurities of mucus, but without blood. When the airway catarrh falls down after three or four days, the stool returns to normal.
Keratoconjunctivitis is quite rare and has an acute onset. The body temperature rises, the child begins to have headaches. Also noted eye pain, conjunctivitis and photophobia. In the second week of illness, corneal clouding is added to conjunctivitis. The course of the disease is long, but for about 3-4 weeks the baby will be fully cured with timely and adequate treatment. Corneal ulceration is not.
There is a possibility of serous meningitis of adenoviral etiology.
All the above described variants of adenovirus can have a light, moderate and severe form. The mild form is characterized by a temperature of less than 38.5 ˚C with mild other symptoms. The body temperature reaches 39.5-40 ° C in the moderate form of the disease, moderately expressed symptoms of intoxication are observed. Severe forms of adenovirus infection are rare – hyperthermia, keratoconjunctivitis, severe pneumonia, symptoms of respiratory failure, etc., develop.
A sick child needs long-term treatment. But the temperature drops by 5-7 days of illness, although in some cases it may be elevated for 2 or even 3 weeks. Rhinitis lasts 1-4 weeks. Catarrhal conjunctivitis occurs up to a week, membranous – up to two weeks. Symptoms of catarrh of the upper respiratory tract pass from the 2nd to the 4th week of the disease.
Complications. Complications (as with flu or parainfluenza) occur only if a bacterial infection is introduced. Middle-aged children often suffer from sinusitis, otitis media, focal polysegmental serous-desquamative pneumonia.
If the adenoviral infection is not complicated, then the prognosis is favorable. Only if there are severe bronchopulmonary complications in toddlers of an early age, can a lethal outcome.
As already noted, newborns suffer from adenovirus infection in very rare cases, but if the mother did not have immunity, the newborns are susceptible to this disease from the first days of life. In newborns, adenovirus infection manifests itself differently than in older children. Body temperature reaches 37–37.5 ° C. Symptoms of intoxication in most cases are not observed at all. Among the catarrhal symptoms, there is a weak cough and nasal congestion in the child. Due to the fact that nose breathing is complicated, the baby begins to worry, does not sleep well and refuses to breast.
In infants up to one year, adenovirus disease is accompanied by loose stools. Lymph nodes are enlarged in rare cases, conjunctivitis is also rare. But there are frequent cases of bacterial complications – bronchitis with obstructive syndrome, pneumonia, etc. The body temperature in premature babies can be within the normal range and even lowered. The course of the disease in children under 1 year of age is severe, which sometimes leads to death.
Causes of Children’s Adenovirus Infection
There are 41 known serotypes of human adenovirus. The virus particles contain DNA, the diameter is 70-90 nm. Viruses are resistant to the environment. There are three antigens in the virion: A-antigen is a group-specific, common to all human adenoviruses; B-antigen is a carrier of toxic properties, and C-antigen, which characterizes the type-specificity of the virus.
Adenoviruses multiply well in primary and transplantable cell cultures of different origin. The first signs of cell damage are noted in the nucleus and appear as early as 12 hours after infection. Viruses have hemagglutinating activity.
Pathogenesis during Adenovirus Infection in Children
The infection enters the body through the upper respiratory tract, and sometimes through the intestines or conjunctiva. Next, the adenovirus reaches the cytoplasm, the nucleus of epithelial cells susceptible to the virus, and regional lymph nodes. Viral DNA is synthesized in the nuclei of affected cells, and mature virus particles form within 16–20 hours. This leads to the fact that infected cells stop dividing and die.
Some viral particles are released and enter non-infected cells and bloodstream. The mucous membrane of the nose is affected – first of all, and behind it is the posterior wall of the pharynx and tonsils. The mucous membranes swell, there is abundant serous discharge. If there is effusion with the formation of a delicate film on the mucous membrane, this means that the conjunctiva is affected.
Adenoviruses easily penetrate the human lungs, where they multiply in the epithelium of the mucous membrane of the bronchi and alveoli. These processes lead to pneumonia and necrotizing bronchitis (which is also sometimes observed in cases of influenza). Adenovirus can enter the intestines of a child.
Because of the spread of the virus in the bloodstream, the kidneys, liver, and even the spleen are involved in the process. If the outcome is lethal, in such cases it was affected and the brain (fix the swelling of the brain). In the pathogenesis of bronchopulmonary manifestations in adenovirus infection along with the virus is involved bacterial infection. Also, in case of lethal outcomes in the internal organs, impaired blood circulation, inflammatory and necrobiotic processes are found.
Symptoms of Children’s Adenovirus Infection
2-12 days the incubation period of the disease lasts. The disease has an acute onset, symptoms may appear consistently, rather than simultaneously. Immediately after the onset of the disease, it can be noted that the body temperature is elevated, catarrhal phenomena occur in the upper respiratory tract. Body temperature tends to increase. On days 2 or 3, it reaches a maximum (38–39 ° C, very rarely 40 ° C). Symptoms of intoxication moderately pronounced. The child may be a little lethargic, refuses to eat or eats little. Headaches are possible, muscle and joint pains are very rare. In some cases, patients complain of nausea, vomiting and abdominal pain.
The disease begins with serous nasal discharge. Gradually they become mucopurulent. The nasal mucosa swells, so the breathing of the nose becomes difficult. The front arms and palatine tonsils swell. In the mucous membrane of the posterior pharyngeal pharyngitis granulosis is noted, which doctors can distinguish by the edematous and hyperemic posterior wall with hypergenerated bright follicles. Enlarged lateral pharyngeal cushions.
One of the most common symptoms of adenovirus is cough. From the very first days of the disease it is wet. Small children have a strong cough. Doctors hear scattered moist and dry rales in the lungs, which are caused by exudative inflammation in the lower respiratory tract.
Affection of the mucous membranes of the eyes helps to accurately determine the adenoviral infection. There is catarrhal, follicular or membranous conjunctivitis from the very beginning of the disease, there are also cases when conjunctivitis begins on the 3rd, 4th or 5th day of the disease. First, conjunctivitis affects one eye, on the second day the other. Children who can speak can complain of stinging and burning in the eyes. There is a feeling of a foreign body in the eyes.
There is a moderate swelling of the eyelid skin, hyperemia. Eyes look half open. Conjunctiva sharply hyperemic, granular, edematous. Unlike diphtheria, the eyes of a film with adenovirus infection never extend beyond the conjunctiva. The appearance of membranous conjunctivitis allows clinically diagnosing adenoviral infection.
There is pastosity of the face of a sick child, swelling of the eyelids, eyes festering, flowing from the nose. Cervical lymph nodes are moderately enlarged, in rare cases the liver and spleen are enlarged. At the peak of the disease in children are intestinal disorders (emptying up to 4 or 5 times in 24 hours). The blood test shows normal white blood cell count. A small leukocytosis with neutrophilia can be observed only at the very beginning of the disease, lymphopenia is fixed. ESR increased slightly.
Diagnosis of Adenovirus Infection in Children
The main diagnosis of “adenovirus infection” is fever, symptoms of catarrh of the respiratory tract, hyperplasia of lymphoid tissue of the oropharynx, damage to the mucous membranes of the eyes, enlarged cervical lymph nodes.
The method of fluorescent antibodies is used as a rapid diagnosis. It allows you to detect a specific adenoviral antigen in the epithelial cells of the respiratory tract of a sick child. Serological diagnosis is carried out using the RAC and the reaction of delayed hemagglutination. The increase in antibody titer to adenovirus 4 times or more in paired sera in the dynamics of the disease confirms the etiology of the disease. Isolation of adenoviruses is carried out from nasopharyngeal washes (most often), feces and blood of a sick child.
Differential diagnosis. Doctors distinguish adenovirus and other respiratory infections by how affected the eye mucosa is. Also, a distinctive feature is that the clinical symptoms appear gradually as the disease progresses. Lymphoid tissue has a pronounced response. Exudative airway inflammation is pronounced.
Infectious mononucleosis is characterized in that the cervical lymph nodes are enlarged (determined by the doctor), catarrhal phenomena are absent. Nasal breathing is difficult because the nasopharyngeal tonsil is affected. In frequent cases, the occurrence of angina is recorded, the liver and spleen are significantly enlarged. Lymphocytic leukocytosis occurs.
Persistent catarrhal phenomena with no signs of exudative inflammation are characteristic of mycoplasma infection, the lungs are also affected at the very beginning of the disease, the ESR increases.
Treatment of Adenovirus Infection in Children
For the treatment of hospitalization is often not carried out. The child is treated at home. Bed rest is required, which allows you to save the strength needed to restore the body. Good nutrition is also important for children. As well as in the treatment of parainfluenza, apply erespal syrup, remedies that relieve symptoms. Doctors may prescribe a multivitamin, desensitizing drugs, such means as arbidol or anaferon for children (take according to the scheme specified in the instructions, or according to the scheme prescribed by the attending physician). In some cases, the doctor may prescribe the use of immunomodulating agents.
A 0.05% deoxyribonuclease solution is instilled into the nose (3-4 drops every three hours for two to three days). The nasal mucosa can be treated with liniment 5% cycloferon. Doctors do not usually prescribe antibiotics; they are recommended only if there are bacterial complications (with the appearance of sinusitis, pneumonia or tonsillitis). Imudon and IPC 19 are usually used if prevention of bacterial complications is necessary. Doctors may also prescribe interferon inducers to treat the child.
Treatment of the most severe syndromes is similar to treatment for influenza. Hospitalization is indicated for severe adenovirus infection and complications in young children.
Prevention of Adenovirus Infection in Children
Measures of specific prophylaxis are not developed at the moment. The patient is isolated, the room is aired and irradiated with ultraviolet light. Recommended wet cleaning of the room in which there is a sick child, weak solutions of chlorine, boiling dishes, linens and clothing.