Enterovirus EV71 infection mostly occurs in preschool children, especially in the age group under 3 years old. It can cause maculopapular rash and herpes on hands, feet and mouth, and individual patients can cause encephalitis, encephalomyelitis, meningitis, pulmonary edema and circulatory collapse. The source of infection is the current patients and the hidden infected, mainly through the crowd gastrointestinal tract, respiratory tract and close contact with secretions and other means of transmission.
I. Clinical manifestations
(A) General case performance.
Acute onset, fever, scattered herpes on oral mucosa, maculopapular rash and herpes on hands, feet and buttocks, inflammatory redness around the herpes, less fluid in the herpes. It may be accompanied by cough, runny nose, loss of appetite, nausea, vomiting and headache. Some cases present only with a rash or herpetic pharyngitis. The prognosis is good, with no sequelae.
(ii) Severe cases present.
A few cases (especially those younger than 3 years old) may develop encephalitis, encephalomyelitis, meningitis, pulmonary edema, circulatory failure, etc.
1. neurological system: poor mental health, drowsiness, headache, vomiting, easily startled, shaking limbs, weakness or paralysis; examination reveals meningeal irritation, weakened or absent tendon reflexes; critical cases may show frequent convulsions, coma, cerebral edema, brain herniation.
2. respiratory system: shallow and difficult breathing, altered respiratory rhythm, cyanosis of lips and mouth, white, pink or bloody foamy fluid (sputum); sputum sounds or wet rales can be heard in the lungs.
3. Circulatory system: pale face, increased or slow heart rate, shallow, rapid, weakened or even absent pulse, cold extremities, cyanosis of fingers (toes), increased or decreased blood pressure.
II. Laboratory tests
(A) Terminal blood leukocytes. Leukocyte count is normal in general cases, but can be significantly increased in severe cases.
(B) Blood biochemical examination. Some cases may have mildly elevated ALT, AST, CK-MB, and blood glucose may be elevated in severe cases.
(C) Cerebrospinal fluid examination. Clear appearance, increased pressure, leukocytosis (more polymorphonuclear cells than mononuclear cells in critical cases), normal or mildly increased protein, normal sugar and chloride.
(iv) Pathogenetic examination. Positive specific EV71 nucleic acid or isolation of EV71 virus.
(E) Serological examination. Positive specific EV71 antibody test.
Physical examination
(A) Chest X-ray: It may show increased texture of both lungs, grid-like, dot-like or large shadows, some cases are unilateral, and rapidly progress to large bilateral shadows.
(b) Magnetic resonance imaging (MRI): brainstem and spinal cord gray matter damage is the main cause.
(C) EEG: Some cases may show diffuse slow waves, and a few cases may show spiky (sharp) slow waves.
(iv) ECG: no specific changes. Sinus tachycardia or bradycardia with ST-T changes may be seen.
IV. Clinical diagnosis
The disease develops in the epidemic season, and is common in preschool children, and is more common in infants and young children.
(A) Diagnostic basis
1. Fever, maculopapular rash and herpes on hands, feet, mouth and buttocks are the main manifestations, which may be accompanied by symptoms of upper respiratory tract infection.
2. Some cases only show rash on hands, feet and buttocks or herpes pharyngitis.
3. In severe cases, neurological involvement, respiratory and circulatory failure may occur.
(II) Confirmation of diagnosis
On the basis of clinical diagnosis, positive EV71 nucleic acid test, isolated EV71 virus or positive EV71IgM antibody test, 4 times or more increase of EV71IgG antibody or change from negative to positive.
V. Indications for observation or hospitalization
(A) Indications for observation.
Infants and children under 3 years old with one of the following conditions should be kept under observation. If a township health center finds a patient who meets the indications for observation, they should be immediately transferred to a medical institution at or above the county level.
1. fever with hand, foot, oral, or perianal rash of less than 4 days duration.
2. herpetic pharyngitis with increased peripheral blood leukocyte count.
3. fever and poor mental health.
(B) Hospitalization indications.
Those with one of the following conditions requiring hospitalization should be immediately transferred to the designated medical institution
1. poor mental health/drowsiness, easily startled, irritable.
2. trembling or weakness of limbs, paralysis.
3. pale face, increased heart rate, poor peripheral circulation
4. Shallow breathing or chest X-ray suggesting pulmonary edema, pneumonia.
VI. Early detection of pediatric critically ill patients
Patients with the following characteristics are likely to develop into critically ill cases within a short period of time, and should be more closely observed for changes in their condition, carry out the necessary ancillary examinations, and do targeted rescue work.
(a) Age less than 3 years.
(ii) Persistent high fever that does not subside.
(C) poor peripheral circulation.
(D) significantly increased respiration and heart rate.
(v) Poor mental health, vomiting, convulsions, trembling or weakness of the limbs.
(vi) Significant increase in peripheral blood leukocyte count.
(vii) Hyperglycemia.
(viii) Hypertension or hypotension.
VII. Clinical treatment
The treatment mainly includes 4 stages according to clinical manifestations.
(i) Hand, foot and mouth disease/herpes pharyngitis stage.
1. general treatment: pay attention to isolation, avoid cross-infection, proper rest, light diet, good oral and skin care.
2. Symptomatic treatment: give appropriate treatment for fever, vomiting, diarrhea, etc.
(ii) Neurological involvement stage.
Patients in this stage show neurological signs and symptoms, such as headache, vomiting, poor mental health, irritability, drowsiness, limb weakness, myoclonus, convulsions or acute delayed paralysis, etc.
1. Control intracranial hypertension: limit the intake, give mannitol 0.5~1.0g/kg/dose every 4~8 hours, 20~30min intravenously, adjust the interval of drug administration and dose according to the condition. Add tachyphylaxis if necessary.
2. intravenous immunoglobulin, total 2g/kg, given in 2 to 5 days.
3. Apply glucocorticoid therapy as appropriate, reference dose: methylprednisolone 1~2mg/(kg?d); hydrocortisone 3~5mg/(kg?d); dexamethasone 0.2~0.5mg/(kg?d), divided into 1~2 times. Short-term high-dose shock therapy may be given in severe cases.
4. other symptomatic treatment: such as hypothermia, sedation, anti-stunning (Valium, luminal sodium, chloral hydrate, etc.).
5. Closely observe changes in the condition, closely monitor and pay attention to serious complications.
(iii) Cardiopulmonary failure stage.
Sudden onset of shortness of breath, pallor, cyanosis, cold sweat, rapid heart rate, vomiting of white or pink bloody foamy sputum, appearance of increased pulmonary rales, markedly abnormal blood pressure, frequent myoclonus, increased convulsions and/or impaired consciousness, etc. as well as hyperglycemia, hypoxemia, markedly increased abnormal chest radiographs or manifestations of pulmonary edema on the basis of the original illness.
1. keep the airway open and administer oxygen.
2. ensuring patency of both intravenous routes and monitoring respiration, heart rate, blood pressure and oxygen saturation.
3. In case of respiratory dysfunction, use positive pressure mechanical ventilation by tracheal intubation in a timely manner. It is recommended that the initial adjustment parameters of the ventilator for pediatric patients should be: 80% to 100% of the inhaled oxygen concentration, PIP 20-30 cmH2O, PEEP 4-8 cmH2O, f20-40 times/min, and tidal volume about 6-8 ml/kg. Adjust ventilator parameters at any time later according to blood gases.
4. limiting fluid intake while maintaining stable blood pressure.
5. head and shoulder elevation of 15-30 degrees, maintaining neutral position; gastric tube insertion and urinary catheterization (compression of bladder for urination is prohibited).
6. drug treatment.
6.1 Application of cranial pressure-lowering drugs.
6.2 Application of glucocorticoid therapy and, if necessary, shock therapy.
6.3 Intravenous immunoglobulin.
6.4 application of vasoactive and other drugs: dopamine, dobutamine, milrinone and other drugs can be used according to the changes in blood pressure and circulation; application of cardiotonic and diuretic drug therapy as appropriate.
6.5 Sodium fructose diphosphate or creatine phosphate sedation.
6.6 inhibition of gastric acid secretion: intravenous application of cimetidine, loxacillin, etc.
6.7 Antipyretic treatment.
6.8 monitoring blood glucose changes, if necessary, subcutaneous or intravenous injection of insulin.
6.9 sedative drug treatment in case of convulsions.
6.10 effective antibiotics to prevent and control bacterial infections in the lungs.
6.11 Protect the function of important organs.
(iv) Vital signs stabilization period.
The vital signs are basically stable after resuscitation, but there are still patients with neurological symptoms and signs.
1. good respiratory management to avoid complications of respiratory tract infection
2. supportive therapy and drugs to promote the recovery of the functions of various organs.
3. functional rehabilitation therapy or combined Chinese and Western medicine treatment.