Chapter 4 Clinical Characteristics

(1) Clinical Manifestations.

Based on the current epidemiological investigation, the incubation period is 1 to 14 days, mostly 3 to 7 days.

The main manifestations are fever, dry cough, and fatigue. A few patients have symptoms such as nasal congestion, runny nose, sore throat, myalgia and diarrhea. Severe patients often have dyspnea and / or hypoxemia one week after the onset of illness, and severe patients can quickly progress to acute respiratory distress syndrome, septic shock, difficult to correct metabolic acidosis and coagulation dysfunction and multiple organ Functional failure, etc. It is worth noting that in the course of severe and critically ill patients, there may be moderate to low fever, even without obvious fever.

Some children and neonatal cases may have atypical symptoms, manifested as gastrointestinal symptoms such as vomiting and diarrhea, or only manifested as mental weakness and shortness of breath. Mild patients showed only low fever, mild fatigue, and no pneumonia. Judging from the current cases, most patients have a good prognosis, and a few patients are critically ill. The prognosis for the elderly and those with chronic underlying disease is poor. The clinical course of pregnant women with new coronavirus pneumonia is similar to that of patients of the same age. Symptoms in children are relatively mild.

(2) Laboratory Inspections.

1. General Inspection In the early stage of the onset, the total number of white blood cells in the peripheral blood was normal or decreased, and the lymphocyte count was reduced. Some patients may have increased liver enzymes, lactate dehydrogenase (LDH), muscle enzymes, and myoglobin; some critically ill patients can see increased troponin. Most patients have elevated C-reactive protein (CRP) and erythrocyte sedimentation rate and normal procalcitonin. In severe cases, D-dimer increases and peripheral blood lymphocytes progressively decrease. Severe and critically ill patients often have elevated inflammatory factors.

2. Etiology and Serology

   • (1) Etiological examination: New coronavirus nucleic acids can be detected in nasopharyngeal swabs, sputum and other lower respiratory tract secretions, blood, feces and other specimens using RT-PCR or / and NGS methods. Detection of lower respiratory tract specimens (sputum or airway extracts) is more accurate. Submit specimens for inspection as soon as possible after collection.
   • (2) Serological examination: Most of the new coronavirus-specific IgM antibodies begin to become positive after 3-5 days of onset, and the recovery period of IgG antibody titers is 4 times or more higher than that of the acute phase.

(3) Chest Imaging.

Multiple small patchy shadows and interstitial changes appeared early, and the extrapulmonary bands were obvious. Furthermore, it develops multiple ground glass infiltration and infiltrates in both lungs. In severe cases, pulmonary consolidation and pleural effusion are rare.