Adenovirus Pneumonia

　　(One) Etiology

　　Adenovirus is a DNA virus, first isolated from human adenoid cells by Robwz et al. in 1953. The viral particles contain DNA and protein and replicate within the nucleus. Electron microscopy observation shows that this virus has a complete 20-sided body structure, with a nucleocapsid (capsid) visible in the section, without an envelope. The outer capsid has a diameter of about 60 to 90 nm, and the capsid is composed of 252 particles, of which 240 particles form 6-sided pyramids in groups of 6 to form the 20 triangular faces of the 20-sided body, and 12 particles are pentamers to form 12 apices. Each pentamer extends a 'filament' at its base, making the virus body similar to a communication satellite configuration. The double-stranded DNA genome has a molecular weight of (20 to 25) × 10^6, with terminal repeats, and the 5' end is connected with protein, which is infectious and replicates in the nucleus.

　　Adenovirus is very stable in the homogenate of infected cells, cold-resistant, and can maintain its infectivity for several weeks at 4°C and for several months at -25°C. It is relatively heat-sensitive, and its infectivity can be inactivated by ultraviolet radiation for 30 minutes. It has a wide tolerance range for acidity and alkalinity and temperature, and can maintain its highest infectivity under room temperature conditions with a pH of 6.0 to 9.5.

　　It is known that human adenoviruses have 42 serotypes (named adenovirus H1 to H42), which can be divided into 6 subgroups (A to F) or regarded as 42 types and belong to 6 species according to the homology of the genome, the potential for intragroup recombination, and other standards. Adenoviruses within the same subgroup have common pathogenic mechanisms and epidemiological characteristics. Adenoviruses can also be divided into 4 subgroups according to their agglutination characteristics with different animal red blood cells. Most types do not cause serious diseases in humans, but certain types can cause acute respiratory diseases in sensitive populations, especially in adults.
　　(Two) Pathogenesis

　　Adenovirus infection via the respiratory tract first invades epithelial cells in the eyes, nose, and pharynx mucosa, and after 3 to 5 days of replication, acute upper respiratory tract inflammation occurs, which can spread to nearby tissues, causing an ascending respiratory tract inflammation, and develops into pneumonia 5 to 10 days later. The virus can form viremia via the blood circulation, leading to systemic lesions, often damaging important organs such as the central nervous system and the heart, and causing severe symptoms in various systems. After the adenovirus invades the cell, it can lead to the following results: ① Replication within the cell, causing cell lesions, and releasing a large amount of virus from the cell to infect other cells, resulting in acute infection; ② The virus (such as Ad1, Ad2, and Ad5) can invade certain cells, such as tonsils, lymphocytes, or monkey epithelial cells, without symptoms for several years, and the release of the virus is also fluctuating, suggesting the potential for latent or chronic infection; ③ When the virus (adenovirus A and B subgroups) replicates within the cell, its DNA combines with the cell's DNA, promoting cell proliferation without forming infectious virus particles, and can cause carcinogenic changes in new-born rodents, but retrospective and prospective epidemiological, serological, virological, and biochemical studies have not provided evidence of causing human cancer.

　　Recently, Mistchenko et al. reported that in severe adenovirus infection, the levels of serum interleukin-6, 8 (IL-6, 8), tumor necrosis factor (TNF), and immunoglobulin IgM are elevated, suggesting that these cytokines and immune factors may play an important role in the occurrence and development of adenovirus pneumonia.

　　Lesional or confluent necrotic pulmonary infiltration, bronchitis, and interstitial pneumonia are the main pathological changes of this disease. Grossly, both lungs are involved, with a heavier impact on the lower lobes and the posterior edge of the spinal column. In severe cases, lesions may merge, feeling hard to the touch, with a uniform, dense, dark red cut surface. There are scattered or dense granular, grayish yellow foci centered around the bronchi in the lesion area. Necrotic tissue and inflammatory exudates in the epithelium of the trachea and bronchi fill the entire bronchial lumen, and there are often exudates in the alveolar cavities surrounding the bronchi, mostly consisting of lymphocytes, monocytes, serous fluid, and纤维素. Sometimes, hemorrhage is present, while neutrophils are rare. In the marginal inflammatory area, there is hyperplasia of bronchial or alveolar epithelial cells, and intranuclear inclusions can be seen in the nuclei of epithelial cells, which are approximately the size of normal red blood cells, with clear boundaries, eosinophilic or amphiphilic staining, and a surrounding transparent halo. The nuclear membrane is clear, with a small amount of chromatin accumulation on the inside, and there are no inclusions in the cytoplasm, nor the formation of multinucleated giant cells. Due to bronchial obstruction and severe inflammatory changes in the pulmonary parenchyma, ventilation and gas exchange are affected, leading to hypoxemia and carbon dioxide retention, which increases the frequency of respiration and heart rate. Due to increased depth of respiration and the involvement of respiratory accessory muscles, there are flaring of the nostrils and the three凹陷 phenomenon. Hypoxia and carbon dioxide retention, as well as increased acidic metabolic products, can cause metabolic acidosis and respiratory acidosis, and can cause reflexive constriction of small arteries, forming pulmonary hypertension, which加重s the burden on the right heart. Adenovirus and toxic metabolic products in the body directly act on the myocardium, causing toxic myocarditis. The myocardium has mild interstitial inflammation, vascular wall hyperplasia, leading to heart failure.

　　Hypoxia and carbon dioxide retention can cause significant expansion and congestion of cerebral capillaries, with hyperplasia and swelling of endothelial cells, smooth muscle cells, and perivascular cells. The brain tissue surrounding the blood vessels is loose, showing mild demyelination. Neural cells exhibit acute swelling, and glial cells are generally hyperplastic. The pia mater, arachnoid membrane, and subarachnoid space vessels are highly dilated, with increased permeability of the blood-brain barrier, leading to symptoms such as convulsions, cerebral edema, and cerebral hernia.

　　Hypoxemia and the effects of toxins can also cause gastrointestinal dysfunction. The main changes in the liver are interstitial inflammation and fatty degeneration, and the kidneys often have cloudy swelling. There are significant acute inflammatory reactions and proliferative phenomena in lymphoid tissue, spleen, lymph nodes, tonsils, and other organs.

　　Co-infection with respiratory syncytial virus (RSV) or parainfluenza virus.

　　Parainfluenza virus is a member of the paramyxovirus genus, spherical in shape, with a diameter of 125 to 250 nm, has an envelope, single-stranded RNA, and has 4 types, which are further divided into A and B subtypes. This virus can be isolated from primary monkey kidney cells or primary human embryo kidney cells. Since the virus was isolated from a child who died in Sendai, Japan, it is also known as Sendai virus.

　　Acute respiratory diseases caused by adenovirus are most common in children as fever pharyngitis and pharyngoconjunctival fever, while pneumonia is more common in infants. The incubation period is 3 to 8 days, and onset occurs after upper respiratory tract infection, pharyngoconjunctival fever, or other respiratory infectious diseases. High fever is a characteristic, with an acute onset, the body temperature being mostly between 38 to 39℃ in the first 1 to 3 days, and then gradually increasing. Half of the cases may reach above 40℃ within 4 to 5 days, presenting as remittent fever or irregular fever pattern. High fever lasts for 7 to 10 days, with the severe cases reaching the peak in 2 weeks and then subsiding. In some cases, the fever can last up to 20 days. The toxic symptoms are severe, with listlessness, pale complexion, and grayish skin, which may be related to vasoconstriction of the peripheral blood vessels caused by toxicity and systemic lesions caused by viremia.

　　Based on the clinical manifestations, it can be divided into mild and severe cases.

　　Mild cases: Common in children before and during school age, with early symptoms of adenovirus infection such as conjunctivitis, pharyngitis, and rash, a short fever course of 7 to 14 days, mild toxic symptoms, and generally no complications such as heart or brain diseases. Pulmonary signs and symptoms are similar to those of general bronchopneumonia, with a course of 10 to 14 days. The high fever drops abruptly, and general symptoms improve quickly, with pulmonary shadows taking 2 to 4 weeks to completely disappear.

　　Severe cases: The toxic symptoms are severe, with high fever lasting for 3 to 4 weeks, and most have complications such as circulatory and central nervous system disorders and DIC. Pulmonary lesions last for 1 to 4 months, and pulmonary wet sounds do not disappear for a long time. In extremely severe cases, DIC may occur.

　　In the case of adenovirus pneumonia, if the fever persists for more than 10 to 14 days after onset without improvement, or if the fever has decreased but then rises again, or if the condition once improves but worsens, one should be aware of the possibility of secondary bacterial infection. Korppi's observation report states that in respiratory adenovirus infections involving the lower respiratory tract, especially in pneumonia, bacterial infection is common. At this time, the sputum is yellow, and bacterial cultures of sputum or throat swabs are positive, with common pathogenic bacteria including Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, and others. At this time, X-ray examination may show an increase in pulmonary lesions or the appearance of new lesions. The peripheral blood leukocyte count and neutrophil count increase, with left shift or the appearance of toxic granules in granulocytes. The condition is more severe than general adenovirus pneumonia.

　　In addition, children with adenovirus pneumonia may also be complicated with respiratory syncytial virus (RSV) or parainfluenza virus infection, and the child's condition may be more severe than that with simple adenovirus pneumonia.

　　The severity of the disease and the prognosis are related to age, the virulence of the virus type, immune function, and whether secondary bacterial or other viral infections occur. Younger children with adenovirus infection are more severe than older children; type 7 is more severe than type 3; type 21 can cause long-term lung damage, such as atelectasis and pulmonary fibrosis, which may be caused by obliterative bronchiolitis.

　　The clinical characteristics of measles complicated with adenovirus pneumonia, in addition to the general characteristics of adenovirus pneumonia, are all severe, with a prolonged course, slow recovery, and a high incidence of severe complications, especially myocarditis and laryngitis are the main causes of death. The mortality rate is higher in the younger age group. Some cases may not have atypical rash, but pneumonia is the main manifestation, which should be paid attention to.

　　1. Respiratory symptoms are common in most children, with frequent coughing from the onset, respiratory secretions being thick and difficult to cough up. After 4 to 6 days, symptoms such as shortness of breath, cyanosis, nasal flaring, tracheal retraction, obstructive respiratory distress, or respiratory failure may gradually appear. The late appearance of physical signs in the lungs is a characteristic of adenovirus pneumonia. Early in the disease, the respiratory sound is rough, and physical signs in the lungs may not appear until 4 to 5 days after the onset of fever. The percussion sound is dull, the respiratory sound is reduced or dry, and when the lung becomes consolidated, tubular breathing sounds can be heard. Later, wet rales or crepitus can be heard, and they increase day by day, with signs of emphysema. In some severe cases, pleural reaction or a small amount of pleural effusion may occur in the second week, and adenovirus can be isolated from the pleural effusion.

　　2. Neurological symptoms may appear 3 to 5 days after onset, including listlessness, irritability, and alternating with drowsiness. With the progression of the disease, seizures, coma, and toxic encephalopathy may occur. Sometimes, there may be meningeal irritation, adenovirus meningitis, or unequal size of pupils, changes in respiratory rhythm, and the appearance of cerebral edema and cerebral hernia. Cerebrospinal fluid generally shows no significant abnormalities.

　　3. Symptoms of the circulatory system often include pale, gray, or cyanotic complexion, mottled skin, cold extremities, increased heart rate, muffled heart sounds, and can be complicated by myocarditis. About 30% to 50% of severe pneumonia develop heart failure within 6 to 14 days after onset: oliguria, edema, increased heart rate, and enlargement of the liver and spleen. Electrocardiogram findings: generally sinus tachycardia, changes in T waves or ST segments, and low voltage. Some may experience 1 or 2 degrees of atrioventricular block, and occasionally, pulmonary P waves.

　　4. Adenovirus in the digestive system reproduces in the intestines, persistent high fever and hypoxia both affect the function of the digestive system. In severe cases, the permeability of gastrointestinal capillaries increases, more than half of the adenovirus pneumonia patients have mild vomiting, diarrhea, decreased appetite, and in severe cases, there may be abdominal distension, toxic enteroparesis, or gastrointestinal bleeding, vomiting coffee-like substances, and positive occult blood test in feces.

　　5. The urinary system has reported that adenovirus pneumonia of type 11 can appear with slight proteinuria and a small number of cells during the acute phase, and severe cases can cause acute hemorrhagic cystitis, with symptoms such as frequent urination, dysuria, hematuria, and the urine can isolate adenovirus.

　　6. In the early stage of the disease, the reticuloendothelial system may show liver and spleen enlargement and varying degrees of enlargement and slow regression of systemic lymph nodes. In some cases, serum protein levels may decrease and transaminases may increase, indicating liver damage.

　　7. Other cases may present with early red macules, maculopapular rash, and scarlatiniform rash. Early diagnosis is often misdiagnosed as measles, scarlet fever; the incidence of calcareous white spots on the tonsils is not high, but it is a relatively special sign in the early stage of the disease.

　　The main criteria: ①Infants and young children aged 6 months to 2 years; ②Persistent high fever, remittent fever, or稽留热type, pharyngitis, conjunctivitis, and measles-like rash; ③Severe toxic symptoms, with drowsiness early on; ④Lung signs appear late, generally after 4 to 5 days of high fever, moist rales can be heard; ⑤Antibiotic treatment is ineffective; ⑥When lung signs are not obvious, X-ray examination has shown patchy shadows; ⑦The total white blood cell count is low, most cases do not exceed 12.0×109/L, and the neutrophils are often less than 0.7, the alkaline phosphatase of neutrophils and the tetrazolium blue staining are lower than those of purulent bacterial infections.

　　When the above clinical manifestations appear, it is suspected to be adenovirus infection. If conditions permit, perform throat swab virus isolation and double-serum antibody tests or immunofluorescence techniques, various enzyme techniques, radioimmunoassays, and hemagglutination and cell adherence techniques for early rapid diagnosis to determine the diagnosis. However, the final diagnosis depends on the comprehensive analysis of clinical, virological, and serological findings.

　　In 1985, Beijing Children's Hospital proposed the following clinical classification: ①Mild: fever around 38℃, lasting for 5 to 7 days; with mild drowsiness, irritability, and other neurological symptoms; no obvious complications. ②Severe: fever of 39～40℃, lasting for 7 to 10 days; with alternation of irritability and drowsiness, consciousness disorders, delayed reactions, tachycardia, liver enlargement, abdominal distension, and other symptoms; with varying degrees of respiratory distress symptoms and hypoxia; with intrapulmonary and extrapulmonary complications, such as pleurisy, toxic myocarditis, and others. ③Very severe: persistent high fever for more than 11 to 14 days; with severe respiratory distress and cyanosis and other symptoms.

　　Strengthen nursing care and physical exercise to prevent respiratory tract infections. During the epidemic period, prevent cross-infection within the hospital; when adenovirus infection occurs in child care institutions, isolation measures should be taken, observe the duration of positive pharyngeal virus, and the isolation period should be more than 2 weeks. In addition, the oral live vaccine against adenovirus types 3, 4, and 7 has been shown to have a preventive effect, and the recombinant adenovirus live vaccine will be an ideal live vaccine, which can induce immunity against adenovirus respiratory tract infections and also produce local immunity against rotavirus in the intestines.

　　1. Blood count

　　The total white blood cell count is below 10.0×109/L in about 62% of cases, and between (10～15)×109/L in 36% of cases. The classification is mainly lymphocytes. The total white blood cell count and neutrophils can increase in secondary infections. Blood smear examination: The alkaline phosphatase and azurophilic blue staining of neutrophils are generally lower than those in normal children or bacterial pneumonia.

　　2. Virological examination

　　Since adenovirus infection is common and its clinical features are extremely similar to those of other viral infections, it is difficult to make a final diagnosis of adenovirus infection based on clinical manifestations alone. Therefore, specific diagnostic methods are required.

　　(1) Virus isolation: This is the earliest method of studying the virus, and its success rate depends on whether it is possible to collect a sufficient amount of live virus samples and to find sensitive tissues. The best time to collect the specimen is on the day of onset, with a positivity rate of 86%. The positivity rate decreases to 15% after 6 to 10 days. The specimen can be throat, nasal, oropharyngeal swabs, or nasal lavage fluid. The collected specimens are quickly inoculated into sensitive primary or secondary epithelial cells such as human embryonic kidney, Hela, KB, or HEp-2, which are sensitive to adenovirus. Characteristic cytopathic changes appear a few days to several weeks after virus infection, the timing of which varies depending on the virus type and the amount of virus infection. The characteristic changes are that the cells first become rounded and then spherical, with increased light refraction. Many of the cytopathic cells cluster together resembling a cluster of grapes.

　　(2) Paired serum hemagglutination inhibition test: The neutralization test is performed on acute and convalescent sera, and a fourfold increase in antibody titer is diagnostic. Although it only provides a retrospective diagnosis, it still has value.

　　(3) Rapid diagnostic methods: Virus isolation and serological examination, after decades of research and application, the results are relatively reliable, but it takes a long time, and can only be used for retrospective diagnosis, so rapid diagnostic methods have been developed abroad.

　　①Immunofluorescence technique: The direct and indirect immunofluorescence labeling of antibodies with fluorescent dyes is one of the early rapid diagnostic methods for adenovirus pneumonia in children. The technique involves preparing a smear of the shedding cells from the nasopharynx of the child, with each slide containing more than 50 scattered and intact cells. The direct method involves marking the specific antibody globulin against the virus with fluorescent dye and directly combining it with the viral antigen in the specimen. Under a 20W high-pressure mercury lamp and a special fluorescence microscope, positive cells exhibit yellow-green fluorescence at the sites where specific antigens and antibodies combine. The indirect method involves marking the fluorescent dye, FITC, onto the second antibody against the antiviral antibody globulin and detecting the complex of antiviral antibody and viral antigen antibody. The direct method is simple and highly specific, but less sensitive than the indirect method. The indirect method can detect multiple viral antigens with just one labeled second antibody, making it more sensitive than the direct method. After 1979, the research on the diagnosis of adenovirus pneumonia virus antigen using immunofluorescence technology was carried out in Changchun area, with a reported direct positivity rate of 74.4% and an indirect positivity rate of 88.6%.

　　② Immunoenzyme technique: To improve sensitivity, foreign countries have combined antiviral antibodies labeled with fluorescent substances with isotopes 125I or enzymes to form radioimmunofluorescence technology and immunofluorescence enzyme technology. This is a new immunological technology developed in recent years. Its basic principle is the same as that of immunofluorescence technology, but it uses chemical methods to replace fluorescent substances with enzymes labeled on the virus antibody globulin or the second antibody globulin of antiviral antibodies. These enzyme-labeled reagents can specifically bind to corresponding antibodies or antigens while maintaining the activity of immunoenzyme and enzymatic activity. When the enzymes on the immunecomplex encounter the corresponding substrate, they catalyze the colorless substrate to hydrolyze, oxidize, or reduce it, generating soluble or insoluble colored products. The appearance of these products indicates the presence of enzymes, thereby indicating the occurrence of antigen-antibody specific reactions and making a diagnosis. Immunoenzyme technology is divided into: A. Immunoenzyme staining or immunoenzyme histochemistry: Used to detect antigens, antibodies, and other components in biological tissues or cells, B. Immunoenzyme assay: Used to detect antigens, antibodies, and other components in biological body fluids and tissue culture fluids, a. Enzyme-labeled antibody method: This method is used to detect adenovirus antigens in the oropharyngeal exfoliated cells of children. The entire operation process only takes 2-4 hours. According to the report from Changchun, this method has a coincidence rate of 83% with the traditional laboratory method of virus isolation and hemagglutination inhibition test with two serum samples, direct method 83%, indirect method 89.7%, b. Enzyme-linked immunosorbent assay (ELISA): This method is more reliable than the enzyme-labeled antibody method in terms of spectrophotometric determination, and its sensitivity is similar to that of radioimmunoassay.

　　Salomon et al. compared three diagnostic techniques: immunofluorescence, immunoenzyme linked, and tissue culture. The results show that immunoenzyme linked and immunofluorescence are reliable methods for diagnosing most respiratory viruses, but they are less sensitive than tissue culture for diagnosing adenovirus.

　　③ Polymerase Chain Reaction (PCR): It is currently the most sensitive and specific molecular biological technology in the world, which can be used to detect adenovirus DNA. It is more sensitive, rapid than virus isolation, and can detect adenovirus in any sample, whether it is the adenovirus causing pneumonia or the difficult-to-culture enteric adenovirus. As long as there is adenovirus in the sample, whether it is infectious or not, it can be detected by PCR. It can also be used to study the molecular biological characteristics of adenovirus and the relationship between its genetic variation and pathogenicity.

　　3. Immune function measurement

　　Adenovirus pneumonia has different degrees of impact on the cellular immune and humoral immune functions of the body. In severe cases, the degree of cellular immune suppression is significant.

　　(1) Decreased phagocytic function of leukocytes: The degree of decrease is related to the severity of the illness, and there is a significant increase in the recovery period. The decrease in phagocytic function of leukocytes is a temporary inhibition related to infection.

　　(2) PHA skin test reaction weakened: Severe non-responders are all children with severe illness. As the condition recovers, the PHA skin test reaction can also increase to some extent.

　　(3) Radioactive isotope penetration method: The 3H-TdR incorporation rate in lymphocyte transformation test is low in the acute phase, and it decreases significantly in severe cases. A low 3H-TdR incorporation rate reflects the weakened proliferative response of T cells to PHA.

　　(4) Increased IgM in the acute phase, decreased IgG and IgA, and recovery to normal gradually.

　　(5) Serum complement C3: Higher in mild cases, lower in severe cases.

　　(6) Significantly increased serum lysozyme levels: During the state of infection, the turnover rate of neutrophils in the blood circulation accelerates and the metabolic activity of monocytes is enhanced, which has a certain significance in the defense mechanism of the body.

　　4. Blood gas analysis and blood lactate determination

　　For severe adenovirus pneumonia patients with respiratory failure, it is helpful to judge the prognosis. According to the observation of Beijing Children's Hospital, those with blood gas analysis pH less than 7.25, carbon dioxide partial pressure greater than 9.0 kPa, and severe hypoxemia (when inhaling more than 40% oxygen concentration, the oxygen partial pressure is less than 7.0 kPa) and/or hyperlactatemia (blood lactate detection value greater than the normal value + 2 standard deviations) have a higher mortality rate.

　　X-ray chest changes occur earlier than pulmonary signs. In the early stage, there is an increase in pulmonary vessels, which are blurred, followed by patchy lesions of varying sizes in the middle and inner parts of both lungs and the lower parts on both sides. With the progression of the disease, the density of the lesions increases, the number of lesions increases, and the distribution is wider. Some lesions may merge into large patchy lesions, with more on the right side than on the left. The shadow of the lungs usually begins to fade after 2 weeks and is completely absorbed after 3 to 6 weeks. Some cases may have pleural reaction or a small amount of pleural effusion and emphysema.

Therapeutic recipe:

　　Ingredients: Pomelo flesh 5 slices, dried Chinese cabbage 60 grams, Astragalus 15 grams, lean pork 250 grams.

　　Preparation: All the herbs are cooked into a soup and taken, once a day, taken in two doses.

　　Ingredients: Lily bulb 50 grams, Job's tears 200 grams

　　Preparation: Add 5 bowls of water, boil to 3 bowls, take 3 times, once a day.

　　Ingredients: Walnut kernel 30 grams, rock sugar 30 grams, pear 150 grams

　　Preparation: Grind together, add water to boil and take. Take 1 spoonful each time, 3 times a day.

　　Ingredients: Almond 10 grams (peeled, crushed), pear 1 to 2, rock sugar to taste.

　　Preparation: First, cut the pear into pieces and remove the core, then cook with almonds. When the pear is cooked, add rock sugar and drink it as tea.

　　What is good for patients to eat:

　　①Eat high-nutrient, easily digestible foods. Staple foods can include rice, noodles, steamed buns, bread, etc., and side dishes should include more meat, fish, eggs, poultry, and soy products. Generally, add 1 egg to breakfast, and 2-3 ounces of meat to lunch and dinner.

　　②Patients with high fever and loss of appetite can eat semi-liquid foods, such as rice porridge, buns, wontons, etc. Side dishes such as minced meat and egg, meat balls, steamed fish, etc., should be eaten 1 meal every 2-3 hours, for a total of 6 meals a day. They can also eat liquid foods such as milk, soy milk, rice gruel, malted milk, lotus root powder, meat soup, chicken soup, cooked eggs, etc., for a total of 6 meals a day. Since liquid foods supply insufficient calories and nutrients, they are not suitable for long-term use.

　　③Eat more fruits that clear heat and generate fluid, such as pears, watermelons, cucumbers, winter melons, water chestnuts, tangerines, etc.

　　What patients should not eat:

　　Avoid spicy and salty foods. Quit smoking and drinking.

　　(One) Treatment

　　The treatment of adenovirus pneumonia should adopt a combination of traditional Chinese and Western medicine and comprehensive treatment measures. Strengthen nursing care, ensure rest, nutrition, fresh air, and fluid intake, actively prevent and treat colds. For critically ill children, attention should be paid to correct hypoxia, encephalopathy, heart failure, water and electrolyte balance disorders, and other serious complications in a timely manner, including sedation, cough suppression, expectoration, cardiac strengthening, oxygen therapy, and correction of water and electrolyte disorders. The specific treatment methods are as follows:

　　1. General treatment

　　(1) Strengthen nursing care to avoid cross-infection: Keep the indoor air fresh, the environment quiet and tidy, room temperature 20-22℃, relative humidity 55%-56%. During the acute phase, the child should be kept quiet and rest to reduce the body's oxygen consumption.

　　(2) Maintain an unobstructed airway: Pay attention to clearing respiratory tract sputum, keep the child in a lateral position to avoid sputum blocking the airway and causing asphyxia. It is also necessary to often hold the child or change the position, turn over, to promote the absorption of pulmonary inflammation.

　　(3) Ensure fluid intake and pay attention to nutrition: Daily calorie intake of 209.2-251.0 kJ/kg, fluid intake of 60-80ml/(kg·d), the dosage for infants and young children can be slightly larger, while for older children, it should be relatively less. For children with high fever and wheezing or microcirculatory dysfunction, due to excessive insensible water loss, the total fluid volume can be higher. Children in the acute phase are prone to sodium retention, so the intake of sodium should not be excessive. Generally, for those without diarrhea, it should not exceed 3mmol [equivalent to 20ml/(kg·d) of physiological saline], and the infusion can be prepared as a 4:1 or 5:1 mixture of 10% glucose and physiological saline. The infusion rate should be controlled below 5ml/(kg·h). For children with obvious dehydration and metabolic acidosis, 1/2-1/3 isotonic sodium-containing fluid can be used to replenish the cumulative loss, and then the above fluid is used to maintain physiological needs.

　　(4) Early oxygen therapy: With mild respiratory distress, arterial oxygen partial pressure in blood gas analysis
　　2. Antiviral treatment

　　(1) Ribavirin: It is a synthetic nucleoside with certain antiviral activity against both RNA and DNA viruses. It can be inhaled by ultrasonic atomization, with a dose of 5mg/(kg·d), diluted with 10ml of distilled water and sprayed in 2-3 doses, for 15-20 minutes each time, 5-7 days as a course of treatment. It can also be administered intravenously or intramuscularly at a dose of 15-20mg/(kg·d), with a course of 5-7 days, and the concentration of intravenous infusion is 0.1%.

　　(2) Human blood leukocyte interferon: It is a class of broad-spectrum antiviral activity proteins produced by cells, which act by inhibiting the virus rather than killing it. It has inhibitory effects on both DNA and RNA viruses, and its inhibitory mechanism is to prevent the synthesis of viral proteins. Methods: interferon ultrasonic atomization inhalation, 50,000 U each time, twice a day; or interferon 100,000 U, intramuscular injection, once a day, 5-7 days as a course of treatment. It has certain therapeutic effects on mild cases or early adenovirus pneumonia, but due to its poor purity and low efficacy, the efficacy on severe cases is not certain. Some people have used interferon to treat severe adenovirus pneumonia and achieved certain effects.

　　(3) High-purity, high-titer equine serum against adenovirus: It has a good effect on the early treatment of adenovirus pneumonia. The use of high-titer 3,7 mixed adenovirus antibody serum is recommended: 6ml on the first day, 4ml on the second day, and 2ml on the third day. It can reduce fever quickly, relieve symptoms early, and has fewer sequelae, but attention should be paid to serum reactions.

　　3. Symptomatic treatment

　　(1) Antipyretic and sedative treatment: During adenovirus pneumonia, due to high body temperature (up to 39.5-42℃), children may become restless or have convulsions. Immediate antipyretic and sedative treatment should be provided. Methods include cold compress on the head, ice pack, alcohol sponge bath, or a bath with water 2-3℃ lower than the body temperature. Alternatively, antipyretic drugs can be used, and for severe cases of high fever, hypothermia therapy can be considered. Each dose of chlorpromazine and promethazine is 0.5-1mg/kg, administered intramuscularly or intravenously every 6-8 hours.

　　(2) Cough and asthma relief: Clear secretions, and consider the use of aminophylline, hyoscyamine hydrobromide, and isoproterenol; for those with respiratory obstruction, severe dyspnea, and severe toxic symptoms, short-term hormone therapy can be considered.

　　(3) Physical therapy: For children with persistent rales, phototherapy, electrotherapy, and ultrashort wave therapy can be used to reduce pulmonary congestion and promote the absorption of pulmonary exudates.

　　4. Treatment of complications

　　(1) Prevention and treatment of secondary bacterial infections: Early addition of antibiotics based on throat swab culture.

　　(2) Treatment of heart failure: Children with severe adenovirus pneumonia and those with congenital heart disease often suffer from heart failure. In addition to general treatments such as sedation and oxygen inhalation, early application of cardiotonic drugs is recommended. Commonly used ouabain is 0.007-0.01mg/kg per dose, administered intravenously with 10ml of 10% glucose slowly, and if heart failure is not controlled 1 hour later, the same dose can be repeated once. Digenin can also be used; the saturated dose is 0.03mg/kg for children over 2 years old and 0.04mg/kg for children under 2 years old. Half to one-third of the total dose is administered initially, diluted with 10ml of 5%-10% glucose and administered intravenously slowly. The remaining dose is divided into 3-4 doses, administered every 4-6 hours, and saturation is achieved within 24 hours. Other treatments include phentolamine and sodium nitroprusside. Recently, some studies have compared the therapeutic effects of the two on heart failure, suggesting that sodium nitroprusside reduces preload and cardiac index, while phentolamine reduces afterload and increases cardiac index, making it superior to sodium nitroprusside.

　　(3) Prevention and treatment of disseminated intravascular coagulation (DIC): The risk of DIC in children with severe pneumonia should be taken seriously. Some suggest using platelet count, changes in red blood cell morphology, and fecal occult blood test as initial screening tests for early diagnosis. Early application of blood-activating and blood-dispersing drugs, such as dipyridamole, heparin, and dextran 40 (low molecular weight dextran), should be considered.

　　5. Supportive treatment at the peak can be considered to transfuse blood or plasma at a dose of 5ml/kg each time, and sufficient vitamins should be given.

　　6. Immune regulation

　　(1) Thymosin: The main action is to induce T cell maturation, in addition, it also has an inductive effect on macrophages and NK cells. For children with immunodeficiency, due to the easy occurrence of viral or fungal infections, thymosin can improve cell-mediated immunity and significantly improve clinical symptoms.

　　(2) Transfer factor: Existing in sensitized lymphocytes in the human body, it is a low molecular weight RNA-polypeptide complex that can transfer cell immunity and improve the immune function of the recipient. It can treat immunodeficiency and infectious diseases caused by viruses and fungi.

　　(3) Intravenous immunoglobulin: Contains a wide range and effective antiviral antibodies, which have a comprehensive effect on the development and proliferation of the virus, and improve immunity by restoring the CD4/CD8 ratio, thus improving the condition, and has a certain therapeutic effect on preventing viral infection and secondary bacterial infection.

　　7. Traditional Chinese Medicine therapy for severe adenoviral pneumonia, due to the deep invasion of heat into the营 blood, consuming Qi and Yin, forcing blood to flow recklessly, causing excessive heat and blood stasis, red and purple tongue coating, thin coating, fine and rapid pulse, it is generally advisable to ventilate the lung and clear heat, relieve cough and asthma, and give modified San Nao Decoction with added Sang Ju Yin. For wind-heat affecting the lung, it is advisable to use acrid and cool to disperse the exterior, relieve cough and asthma, and give modified Mahuang Shigao Decoction with added Yin Qiao San. For the type with excessive heat in the lung and stomach, it is advisable to use acrid and cool to disperse the exterior, clear heat and resolve phlegm, and give modified Bai Hu Decoction. For the internal heat syndrome of the lung and stomach with excessive heat, it is advisable to clear the lung and stomach heat, and assist with cooling the营, and give modified Bai Hu Decoction with added Qing Ying Decoction. When the adenoviral pneumonia is at its peak with extreme heat and toxicity, and concurrent heart failure occurs with deficiency of heart Yang, it is advisable to clear the营 heat and rescue the Yang, and can give modified Ren Shen Bai Hu Decoction with added, and when concurrent DIC occurs with excessive heat and blood stasis, it is advisable to clear heat and cool the blood, activate blood circulation and resolve stasis, and can give modified Qing Ying Decoction with added Xue Fu Zhu Yu Decoction; when concurrent with toxic encephalopathy, the pathogenic heat invades internally, it is advisable to reinforce the body and expel the evil, open the orifices and wake the brain, and give modified San Jia Fu Mai Decoction with added, and add An Gong Nao Huang San 0.1-0.3g powder for 2 times a day for high fever and coma. When concurrent with respiratory failure, with sputum retention and Qi closure, it is advisable to reinforce the body and expel the evil to expand Qi and open the lung, and give modified Sheng Mai Powder. In the recovery period of the disease, with remaining heat not yet subsided, it is advisable to clear the remaining heat and nourish the lung Yin, and give Zhu Ye Shi Gao Decoction or Sha Shen Mai Dong Decoction.

　　(II) Prognosis

　　Severe infections and adenoviral pneumonia have poor prognosis and a high mortality rate.