Adenovirus disease (synonyms of the disease: pharyngoconjunctival fever) is an acute infectious disease caused by adenoviruses with airborne transmission, characterized by a predominant lesion of the mucous membrane of the respiratory system, conjunctiva and sclera, lymphadenopathy. The most typical form of the disease is pharyngoconjunctival fever.
Historical evidence of adenoconjunctival disease
The causative agent was discovered by a group of American virologists – W. Rowe, R. Huebner, L. Gilmore, R. Parrot, T. Ward, M. Hilleman, J. Werner (1953-1954), which, through prolonged cultivation of tissues of hypertrophic adenoids and tonsils, removed from healthy children, previously unknown viruses were discovered. Somewhat later, similar agents were isolated from nasopharyngeal swabs from patients with pharyngitis, SARS, conjunctivitis.
Etiology of adenoconjunctival disease
The large family Adenoviridae (from Mammaliadenovirus), pathogenic for animals, birds, reptiles, belongs to 41 serotypes pathogenic to humans. Virion contains double-stranded DNA, the replication of which occurs in the nuclei of sensitive cells. Genome integration is possible, accompanied by carriage, potential oncogenicity, which is proved in the experiment. Adenoviruses have both group-specific and type-specific (hemaglutinucci) antigens. According to the hemaglutin activity of erythrocytes in rhesus monkeys and rats, adenoviruses are divided into three subgroups (A, B, C), which is used for identification in rtga. Adenoviruses are reproduced in primary cultures of the human embryo kidney or diploid embryonic cultures, as well as transplantable cell cultures. Compared to other ARVI pathogens, adenoviruses are quite stable in terms of the external midpoint — they can withstand changes in pH from 5.0 to 9.0, heating to a temperature of ’56 ° C for 30 minutes, and are resistant to low temperatures, ether, and detergents.
Epidemiology of Adenoconjunctival Disease
The source of infection is a sick person or a virus carrier. The transmission mechanism is predominantly airborne, alimentary and airborne are also possible. The incidence is observed year-round, but outbreaks are more common in winter. Mostly sick children from the age of six months to three years. Adults get sick 5-6 times less often. There is a certain pattern in the distribution of individual serotypes of viruses in certain areas and age groups. In Ukraine, the 3rd, 4th, 7th and 14th serotypes are common.
Pathogenesis and pathomorphology of adenoconjunctival disease
The virus is primarily localized in the “nutrition of the upper respiratory tract, conjunctiva and, possibly, in the mucous membrane of the small intestine and regional lymph nodes. The reproduction of the pathogen occurs in the nuclei of cells, where the DNA of the virus is replicated. Due to inhibition of the activity of the mononuclear phagocyte system, viremia and generalization of the process occur, which coincides with the onset of clinical manifestations. Features of the pathogenesis of adenoviral disease, unlike other acute respiratory viral infections, are much wider primary damage to organs, various clinical manifestations. In addition to pharyngitis, conjunctivitis, rhinitis, as the most common forms of the disease, pneumonia, mesadenitis, and hepatomegaly are also observed. Possible, especially in young children, meningitis, encephalitis, exanthema, sometimes with the development of severe hemorrhagic syndrome.
Morphological changes are not well understood. Desquamation of the epithelium is observed, which is combined with exudative and inflammatory-proliferative changes in the mucous membrane of the pharynx, conjunctiva, sclera with the development of severe keratitis with clouding of the cornea. In lethal cases, rebronchial pneumonia with severe edema and necrosis of the wall of the alveoli and bronchi, glomerulonephritis, myocarditis, pericarditis, a mandatory increase and inflammatory changes in the tissues of adenoids and tonsils and sometimes changes in the mesenteric lymph nodes are found.
Clinic of adenoconjunctival disease
The incubation period lasts 1-13 days (more often – 4-7 days). The onset of the disease is acute, but clinical manifestations tend to gradually spread and deepen. Complaints of general weakness, chills, mild headache, sometimes joint and muscle pain. Body temperature rises within 3-4 days and rarely reaches 39 ° C. An essential sign is moderate general intoxication against the background of rather significant local symptoms of acute tonsillitis, pharyngitis, membranous conjunctivitis similar. In some patients, in the early days, moderate diarrhea and pain in the epigastric region are observed. A roseola or rash sometimes appears on the skin (in severe cases, a petechial), which does not have a clear localization, staging, and quickly disappears after 1-2 days. A characteristic feature is moderate polyadenopathy. Perhaps an increase in the liver and spleen. In the study of blood – of course normoitosis, sometimes lymphopenia; ESR may increase slightly.
Adenoviral disease is clearly divided into separate clinical forms, but changes in the oral part pharynxes are observed in all forms of the disease.
Pharyngoconjunctival fever is considered the most typical. This form is characterized by moderate catarrhal symptoms – a runny nose with mucous membranes, less often purulent-mucous secretions, swelling of the face and eyelids, lacrimation, hyperemia of the sclera and conjunctiva. In the throat – slight hyperemia of the palatine arches, tonsils, against which significant swelling of the tissues is observed, mottled, sometimes membranous deposits on the tonsils are possible, as well as hypertrophy of the follicles of the posterior pharyngeal wall with slight hyperemia. Mild sore throat, sometimes barking cough with pain behind the sternum. On the C-4th day of the disease, less often in the first days, dense yellowish-white films appear on the conjunctiva, swelling and redness of the eyelids grow. Characteristic bright significant injection of scleral vessels. Most often, the symptoms of pharyngitis are the first, but in some cases, rhinitis, conjunctivitis and pharyngitis appear as if separately, without a certain order. Damage to the cornea is possible. First, one eye is affected, and after 1-4 days, sometimes the second. The course of this form of the disease can be long.
Filmy conjunctivitis is sometimes observed as an independent form of the disease.
The most common form is acute respiratory illness (rhinopharyngitis, rhinopharyngotonzylitis, rhinofaringobronchitis). In most cases, it begins gradually, the body temperature is low, in adults it can be normal. The main symptoms are a runny nose, cough, slight pain and redness in the throat, in some patients – catarrhal conjunctivitis, signs of tracheobronchitis. Sometimes the development of croup syndrome, asthmatic bronchitis is possible, a moderate increase in the cervical lymph nodes is observed. The course is sometimes undulating.
One of the clinical forms is acute febrile tonsilopharyngitis. Slight sore throat, runny nose and cough, low-grade body temperature are observed within 5-7 days. Adenoviral pneumonia is noted atypical, prolonged (up to C-6 weeks), quite weak general intoxication against the background of very significant respiratory failure. Pneumonia has a focal “creeping” character. In the lungs, many rales of various sizes are heard with a clear shortening of percussion sound over individual areas. Shortness of breath, significant cyanosis. In young children (especially up to a year), the prognosis is very serious. The recurrent nature of pneumonia with a tendency to the spread of foci leads to high mortality, especially in cases of epidemic outbreaks in institutions.
As separate clinical forms describe mesadenitis, adenoviral diarrhea, lymphadenopathy. In fact, they are only additional symptoms (syndromes) of the main clinical forms.
Adenoviral diarrhea is observed mainly in children of the first year of life. At the height of signs of catarrh of the upper respiratory tract (day 2-3 of the disease), diarrhea develops (up to 4-5, sometimes 8-10 times a day), possibly with an admixture of mucus in the stool (no blood). In the event of catarrh of the respiratory tract, the diarrhea decreases, which indicates their general nature.
The severity of the course of adenoviral disease depends on age. The most severe forms are observed in early childhood. In adults, a manifest form rarely occurs, which, apparently, is associated with background type-specific immunity.
It is mainly caused by a secondary bacterial infection or an exacerbation of chronic diseases (pneumonia, sinusitis, otitis media).
The forecast is favorable.
Adenoconjunctival disease diagnosis
The supporting symptoms of the clinical diagnosis of adenoviral disease is characterized by a combination of catarrhal signs with symptoms of filmy tonsillitis and conjunctivitis. Erased, low-symptom forms of the disease are diagnosed almost exclusively with epidemic outbreaks.
Specific Diagnosis of Adenoconjunctival Disease
For virological confirmation of the diagnosis, material from patients (swabs from the nasopharynx, conjunctival secretions, sometimes feces) infect cell cultures. By the nature of the GPA and on the basis of the pH of the GPA type of pathogen. From serological methods, pH, RTGA are used, but RSK is most widely used. A significant increase in antibody titer is observed in the next two weeks. The advantage of CSCs is that one antigenic version of the diagnosticum allows the detection of antibodies to a group-specific antigen. In children, an increase in antibody titer in CSCs is less common. Confirmation of the diagnosis is an increase in antibody titer in paired sera by at least 4 times.
Differential diagnosis of adenoconjunctival disease
With common manifestations of acute respiratory viral infections of various etiologies (acute onset, catarrhal signs, cough, fever, manifestations of general intoxication), adenoviral disease is characterized by a relatively long course with elements of recurrence. The age of patients is important for differentiation – children under 3-5 years old and teenagers predominate. In typical cases (pharyngoconjunctival fever), the diagnosis is straightforward. Keep in mind the possibility of bacterial oh infection. The diagnosis of adenoviral pneumonia is based, unlike pneumonia of another etiology, in combination with pharyngitis, conjunctivitis, and diarrhea characteristic of adenovirus disease. An important diagnostic sign is also the “creep” of pneumonia, significant respiratory failure with weak general intoxication. Adenoviral disease must be differentiated from infectious mononucleosis, diphtheria.
Treatment of adenoconjunctival disease
The main measures are aimed at reducing catarrhal manifestations, improves the well-being of the patient. Rinsing the throat and washing the nose with solutions of furatsilin, sodium bicarbonate, UHF and UV radiation on the face helps well. Assign washing of the eyes and applications with tea infusion, instillation into the eyes of a 15-ZO% solution of sodium sulfacyl, in the nose of a 0.05% solution of deoxyribonuclease 3-4 drops every 3 hours. In case of severe keratoconjunctivitis, it is recommended to lay hydrocortisone ointment for the eyelids, the use of DNAase. In the presence of bacterial complications, complex therapy involves the use of antibiotics. Desensitizing, symptomatic agents, multivitamins are prescribed.
Prevention of adenoconjunctival disease
Personal protective equipment includes intranasal administration of leukocyte interferon, oxolinic ointment within 3-4 days from the moment of contact. The following preventive measures are the same as for influenza and other acute respiratory diseases. Specific means of prevention are not developed.