Adenovirus pneumonia
Introduction
Introduction to adenovirus pneumonia Adenovirus pneumonia refers to lung inflammation caused by infection with type 3 and type 7 adenoviruses, and occurs mostly in children between 6 months and 2 years of age. Adenovirus pneumonia infection symptoms are severe, pale and gray, 3 to 4 days after the onset of drowsiness, wilting, with the severity of the disease may be irritated, severe convulsions, coma, and even meningeal irritation. In the early stage of X-ray examination, the lung texture was thickened. On the 2nd to 6th day, small pieces or large patches of shadow were observed, and in the second week, pleural effusion was available. Treatment is mainly antiviral therapy and treatment and immunotherapy for concurrent bacterial infections. Adenovirus pneumonia is the most critical, especially in the northern provinces, and more severe cases than in the south. In North China, Northeast China and Northwest China, there was a large-scale adenovirus pneumonia epidemic in the winter of 1958 and the winter of 1963. The condition was extremely serious. Adenoviruses are generally transmitted through the respiratory tract, and adenoviral upper respiratory tract infections and pneumonia often occur simultaneously in collective children's institutions. Population serological studies have shown that adenovirus-specific antibodies transmitted from the mother are often retained in the first few months after birth, and thereafter until the age of 2 years, the antibody is deficient, and gradually increases after 2 years of age. This is in complete agreement with the clinical observation of 80% of adenovirus pneumonia in infants and young children from July to 24 months. It is worth noting that the more susceptible populations in different age groups, the more people with adenovirus respiratory infections occur, and infants and young children occur. The greater the chance of adenovirus pneumonia, adenovirus pneumonia is more common in winter and spring in northern China, only occasionally in summer and autumn, and more common in autumn in Guangzhou. This type of pneumonia accounts for 20% to 30% of viral pneumonia in Beijing. basic knowledge The proportion of illness: 0.0035% Susceptible people: infants and young children Mode of infection: respiratory transmission Complications: diffuse intravascular coagulation
Cause
Adenovirus pneumonia
Respiratory infections (35%):
It is known that there are 41 serotypes of adenovirus, many of which are closely related to human upper and lower respiratory tract infections. The pathogens of hospitalized children from all over the north and south of China have proved that adenovirus type 3 and type 7 are adenovirus pneumonia. The main pathogen, from the throat swab, feces or post-mortem lung tissue can be isolated from the virus, the serum antibody titer in the recovery period is more than 4 times higher than the early (onset 5 to 10 days or earlier), in some cases of measles complicated by pneumonia In the case, the same pathogen test results were obtained. The adenovirus type 11 was also found to be a common pathogen of pneumonia and upper respiratory tract infections in Beijing and other places (Pediatric Research Institute, 1964-1966). In addition, 21, 14 and 1, 2 , 5,6 and so on are also gradually appearing in mainland China, while Taiwan is mainly based on 1,2,5,6. Recently, Bethune Medical University conducted a genomic analysis of type 3,7 adenovirus isolated from 1976 to 1988. , prove that 7b leads to severe pneumonia.
Virus infection (33%):
Adenovirus is a DNA virus that mainly propagates in the nucleus. It is resistant to temperature, acid, and lipid-resistant solvents. In addition to pharynx, combined with membrane and lymphoid tissue, it is also intestines, which can be agglutinated according to its special animal red blood cells. The ability is divided into three groups, the group 3,7,11,14,21, which is easy to cause pneumonia in infants and young children, can agglutinate monkey red blood cells.
Prevention
Adenovirus pneumonia prevention
prevention
The oral attenuated live vaccine of adenovirus type 3,4,7 has been proven to have preventive effects through small-scale foreign application, but it has not been produced and applied on a large scale. During the epidemic, especially in the ward, efforts should be made to prevent cross-infection; In the work, more family treatments for infants and young children should be done. In child care institutions, special attention should be paid to early isolation and avoidance of nurses with colds to continue their nursing work to reduce communication opportunities.
Complication
Adenovirus pneumonia complications Complications, diffuse intravascular coagulation, myocarditis
In the course of adenovirus pneumonia, Staphylococcus aureus, Escherichia coli, pneumococcal, Klebsiella pneumoniae, Pseudomonas aeruginosa, etc. can be complicated, resulting in more serious disease. In the late stage of adenovirus pneumonia, the following points often indicate secondary bacteria. The presence of infection: 1 in the onset of 10 days or so, the condition does not improve, or once reduced and then worse; 2 turned yellow or Taomi water color; 3 other parts of the body have suppuration; 4 appeared empyema; 5X line examination showed a new shadow ; 6 increased white blood cell count and increased neutrophil ratio or left nucleus; 7 neutrophil alkaline phosphatase or tetrazolium blue staining increased.
In the extreme stage of severe adenovirus pneumonia (6th to 15th day), a small number of cases can be complicated by diffuse intravascular coagulation (DIC). Especially in the case of secondary bacterial infection, microcirculatory dysfunction occurs before DIC occurs. At first, it is limited to a small amount of bleeding in the respiratory tract and gastrointestinal tract; in the future, there may be extensive hemorrhage of the lungs, gastrointestinal tract and skin. The disease is screened by a preliminary screening test, a screening test and a confirmatory test to confirm the diagnosis. The primary screening test is positive for the fecal occult blood test. And the reduction of platelet count is an important indicator; affirmative diagnosis is due to thrombocytopenia, fibrinogen decreased, prothrombin time prolonged two of the three abnormalities or protamine paracoagulation test (three P test), ethanol gel test and excellent ball One of the three exceptions for protein solubilization time is correct.
Changchun Bethune Medical University found severe cases or complicated type 7 or type 3 adenovirus myocarditis, characterized by acute onset and rapid recovery, generally seen in the early 2nd week of the disease, with the elimination of myocardial hypoxia and edema, its recovery is faster However, due to combined heart failure, myocarditis is often missed; attention should be paid to the sudden appearance of paleness, excessive sweating, vomiting, abdominal pain, enlarged heart, rapid or slow heart rate, and hepatomegaly. Conventional electrocardiogram and myocardial enzyme examination to determine diagnosis.
Symptom
Adenovirus pneumonia symptoms common symptoms cyanosis convulsion relaxation heat high fever bloating dyspnea scarlet fever-like rash diarrhea nose wing fan face pale
Focal or fusion necrotic lung infiltration and bronchitis are the main lesions of the disease. Pneumonia can occupy the whole leaf, and the left lung is most common. The yellow and white necrosis can be squeezed from the solidified area on the lung section. The formed tubular type, the lung tissue other than the actualized body has obvious emphysema, the lesions seen by microscopic examination, centered on bronchitis and peribronchial inflammation, the inflammation often progresses into necrosis, and the exudate fills the entire lumen. There are also exudates in the alveolar space around the bronchi, mostly lymph, monocytes, serum, cellulose, sometimes accompanied by hemorrhage, while neutrophils are rare, alveolar walls are also often necrotic, and the edges of the inflammatory area are visible. Bronchoalveolar or alveolar epithelial hyperplasia, intranuclear inclusions are often seen in the hyperplasia and enlarged epithelial nucleus, the size of which is similar to normal red blood cells, the boundary is clear, the stain is partially acidic or dichromatic, and there is a transparent circle around it; the nuclear membrane is clear There is a small amount of chromatin accumulation on the inner surface of the nuclear membrane; but there is no inclusion body in the cytoplasm, and no multinucleated giant cells are formed. Therefore, it is morphologically compatible with measles virus pneumonia and lung giant cells. Han difference body disease, in addition, tissues and organs such as the heart and central nervous system are small blood vessels and interstitial inflammatory cell proliferative response.
According to the analysis of 245 cases of virologically confirmed infantile adenovirus pneumonia in Beijing from 1959 to 1963, the clinical features can be summarized as follows.
1, symptoms
(1) Onset: The incubation period is 3 to 8 days, and the general fever is frequent. The high fever of 39 °C or more occurs from the 1st to the 2nd day, and the high heat is usually reserved or irregular on the 3rd to 4th day; 3/5 The highest body temperature of the above cases exceeds 40 °C.
(2) Respiratory symptoms: Most sick children have coughing from the onset of symptoms, often with frequent cough or mild cough, and at the same time, pharyngeal congestion, but nasal symptoms are less obvious, difficulty breathing and cyanosis Beginning on the 3rd to 6th, it gradually worsened; in severe cases, there were nasal fan, three concave signs, wheezing (obstructive dyspnea with wheezing and hernia) and cyanosis of the lips and nails, and dullness was easy to be diagnosed; voiced parts accompanied by breath sounds Reduced, sometimes you can hear the tone of the tube, most of the initial auscultation first have a breath sound or dry rales, wet rales appear after the third to fourth day of the onset, increasing more, and often signs of emphysema, severe disease Children may have pleural reaction or pleural effusion (more common in the second week), no secondary infection of the exudate is grass yellow, not turbid; when there is secondary infection, it is a turbid liquid, the number of white blood cells more than 10 × 109 /L.
(3) symptoms of the nervous system: usually after 3 to 4 days after the onset of drowsiness, wilting, etc., sometimes irritability and wilting alternate, in the severe cases in the late stage of semi-coma and convulsions, some sick children head backwards, neck stiffness In addition to toxic encephalopathy, there is still an encephalitis caused by encephalitis, so sometimes need to be identified by lumbar puncture.
(4) Circulatory system symptoms: pale complexion is more common, heavy face graying, increased heart rhythm, mild generally no more than 160 times per minute, severe cases more than 160 ~ 180 times, sometimes more than 200 times, the ECG is generally expressed as Sinus tachycardia, severe cases with increased right heart load and T wave, ST segment changes and low voltage, some have 1 to 2 degrees of atrioventricular block, occasionally pulmonary P wave, 35.8% of severe cases Heart failure occurred on the 6th to 14th day of onset, and the liver gradually enlarged, reaching 3 to 6 cm below the ribs. The quality was hard and a few had splenomegaly.
(5) digestive system symptoms: more than half of the patients have mild diarrhea, vomiting, severe cases often have abdominal distension, diarrhea may be related to adenovirus reproduction in the intestine, but in some cases may also be due to serious illness, high fever and affect digestive function .
(6) Other symptoms: There may be catarrhal conjunctivitis, red papules, maculopapular rash, scarlet fever-like rash, and the appearance rate of lime-like white spots on the tonsils is not high, and it is also a special sign in the early stage of the disease.
2, the course of disease
According to the symptoms of respiratory system and poisoning, the disease is divided into mild and severe cases. The heat type is inconsistent. Most of the cases are not regressed above 39~40°C, followed by irregular fever. Relaxation heat is rare, and mildness is generally 711. The body temperature plummeted, and other symptoms disappeared quickly. Only the lung shadows took 2-6 weeks to fully absorb. In severe cases, there was obvious lethargy after the 5th to 6th disease days. The complexion was pale and gray, and the hepatomegaly was significant. The wheezing is obvious, the lungs have large consolidation, some cases have heart failure, convulsions, and semi-coma. The recoverers have fever on the 10th to 15th, and each of the retreats and gradual retreats account for half of them. Sometimes there is fever after the retreat. Aftermath, after 1 to 2 days, it will fall to normal. The recovery period of lung lesions is longer. It takes 1 to 4 months. After 3 to 4 months, there are many cases of atelectasis, which may develop into bronchial tubes in the future. Expansion, we had 3 to 7 years of adenoviral pneumonia after 1 to 5 years of follow-up, 30.1% had chronic pneumonia, atelectasis and individual bronchiectasis, and later 10 years of type 3,7,11 adenovirus pneumonia for 10 years Long-term follow-up, 45.3% of X-ray films had pulmonary interstitial thickening, fibrosis and chronic bronchitis Chronic pneumonia, bronchiectasis accounted for 3.8%; bronchiectasis and chronic pneumonia each accounted for 4.7%.
Adenovirus pneumonia in preschool and school-age children is generally mild, often with persistent high fever, but respiratory and neurological symptoms are not heavy, measles complicated or secondary adenovirus pneumonia, all symptoms are more serious, the condition is often easy Suddenly deteriorated.
We have observed the clinical manifestations of 34 cases (1964-1980) of type 11 adenovirus pneumonia, and there is no significant difference between the symptoms of type 3 and type 7 adenovirus pneumonia, but the severe and dead are similar to type 3, but more obvious than type 7 less.
Clinical features of small infant adenovirus pneumonia from January to May: We have observed 38 cases (20 cases of type 3, 12 cases of type 7 and 6 cases of type 11 and 1981 to 1983), 8 cases of bronchiolitis and 30 cases of pneumonia Mostly, low or moderate fever, short heat history, no signs of lung consolidation, chest radiographs with small shadows, wilting, lethargy and other neurological symptoms are less and lighter than infants in June, clinically impossible Different from respiratory syncytial virus or parainfluenza virus pneumonia, no case of this group was diagnosed as adenovirus pneumonia before the etiology report.
Examine
Adenovirus pneumonia examination
X-ray examination
X-ray morphology is closely related to the disease condition and disease stage. The lung texture is thickened and blurred. It is an early manifestation of adenovirus pneumonia. The lung consolidation often begins on the 3rd to 5th day of the onset, and there may be flaky lesions of different sizes. Or fusion lesions, more common in both the lower lungs and the right upper lung, 6 to 11 days after the onset, the lesion density increased with the development of the disease, the lesions also increased, the distribution is wider, and the fusion, and the difference with the big leaf pneumonia is The lesions of this disease are not limited to a certain lung lobe. Most of the lesions are absorbed after the 8th to 14th days. Sometimes, if the lesions continue to increase, the condition is heavier, and there is a suspected mixed infection. Emphysema is quite common. Early and There was no significant difference in the extreme period, bilateral diffuse emphysema or peripheral emphysema, 1/6 cases may have pleural changes, more pleural reaction in the extreme stage, or effusion.
The total number of white blood cells decreased or normal in the early stage (1st to 5th day), about 62% of cases were below 10×109/L (10000/mm3), and 36% were (1015)×109/L (1000015000/ Mm3), no special changes in classification, the value of late leukocytes is similar to that of early stage, only increased after secondary bacterial infection, blood smear examination, neutrophil alkaline phosphatase and tetrazolium blue staining, generally more normal Children with pediatric or bacterial pneumonia are low. Although the total number of white blood cells is as high as 15,000, the white blood cell alkaline phosphatase index is still significantly reduced. Some patients have positive serum condensation test. During the fever, some cases have a small amount of protein in the urine test. In children with irritation, cerebrospinal fluid examination is generally normal.
Diagnosis
Diagnosis and identification of adenovirus pneumonia
diagnosis:
According to the epidemic situation, combined with clinical diagnosis, the typical early stage of adenoviral pneumonia in infants and young children is different from general bacterial pneumonia: 1 Most cases have persistent high fever at the onset or soon after onset, and are not treated by antibiotics; From the 3rd to 6th day of illness, there are neurological symptoms such as drowsiness and wilting. Sleepiness sometimes alternates with irritability. The complexion is pale and gray, and the liver enlargement is significant. Later, it is easy to see heart failure, convulsions and other complications. The above symptoms suggest that adenovirus pneumonia is not only Involved in the respiratory tract, other systems are also affected; 3 pulmonary signs appear later, usually in the 3rd to 5th day after the occurrence of wet rales, the lesion area gradually increased, easy to have percussion dullness and respiratory sounds, wheezing The second week of onset is getting worse; 4 the total number of white blood cells is low, the majority of sick children do not exceed 12 × 109 / L (12000 / mm3), neutrophils do not exceed 70%, neutrophil alkaline phosphatase and The value of tetrazolium blue staining is significantly lower than that of purulent bacterial infection, but it is increased if the septic bacterial infection is concurrent; the 5X line examination may have a larger flaky shadow in the lungs, with the lower left being the most See, in short, in the epidemic season, when infants and young children have severe pneumonia, and the X-ray and blood picture are more consistent, a preliminary diagnosis can be made. The conditional unit can carry out rapid diagnosis of the virus. Immunofluorescence technology (indirect method is more suitable than direct method), enzyme-linked immunosorbent assay and specific IgM assay, only these three methods can not classify adenovirus, which is the shortcoming, and the conventional throat swab Virus isolation and double serum antibody testing are only available in the laboratory as a retrospective.
Differential diagnosis:
Special attention should be paid to preschool and school-age children. The clinical manifestations of adenovirus and mycoplasmal pneumonia are almost the same. There are high fever, dyspnea and drowsiness. The symptoms of adenovirus pneumonia are common. Mycoplasma pneumonia has only X-ray shadows without roaring can help identify, and many cases can only rely on laboratory-specific diagnosis.
The clinical manifestations of adenoviral pneumonia in infants less than 5 months are significantly lighter than those in infants with adenovirus pneumonia. It is indistinguishable from respiratory syncytial virus and parainfluenza-induced pneumonia, only by rapid diagnosis or pathogen diagnosis.
