03/23/2020
Novel Coronavirus Pneumonia Diagnosis and Treatment Plan (Provisional 7th Edition)
Part 2
IV. Clinical Characteristics
(1) Clinical presentation.
Based on the current epidemiological investigation, the incubation period is 1-14 days, and most often between 3-7 days.
The primary presentations are fever, dry cough, and fatigue. A minority of patients have symptoms such as nasal congestion, nasal discharge, sore throat, muscle pain, and diarrhea. Severe patients often suffer from dyspnea and/or hypoxemia one week after symptom onset, and severe patients can rapidly progress to acute respiratory distress syndrome, septic shock, difficult to correct metabolic acidosis, coagulation dysfunction and multiple organ failure. It is worth noting that severe and critical patients may have moderate to low fever or even no obvious fever during the course of the disease.
Some children and infants may present with atypical symptoms such as vomiting and diarrhea, or only with malaise and rapid breathing.
Patients with the mild form of the disease present only as low fever, slight fatigue, and so forth, with no lung inflammation.
Judging from the current cases, most patients have a good prognosis and a minority are in critical condition. The prognosis of the elderly and those with chronic underlying diseases is more poor. The clinical course of COVID-19 in pregnant patients is similar to that for patients of the same age. The symptoms of children are relatively mild.
(2) Laboratory examination.
1. General Examination
In the early stage of the disease, the total number of peripheral blood leukocytes is normal or reduced, and the lymphocyte count is reduced, and some patients may have elevated liver enzyme, lactate dehydrogenase (LDH), myoenzyme and myoglobin; some critically ill patients may have elevated troponin. C-reactive protein (CRP) and erythrocyte sedimentation rate increased in most patients, and procalcitonin was normal. In severe cases, D- dimer increased and peripheral blood lymphocytes progressively decreased. Inflammatory cytokines often increase in severe and critical patients.
2. Etiologic and serologic tests
(1) Etiologic testing: Use RT-PCR and/or NGS to detect 2019-nCoV nucleic acid in nasopharyngeal swabs, sputum and other lower respiratory tract secretions, blood, and stool samples. Testing done on lower respiratory tract samples (sputum or airway suction) is more accurate. After collection, samples should be sent for testing ASAP.
(2) Serologic testing: nCoV-specific IgM antibodies usually test positive 3-5 days after the onset of symptoms; the titre of IgG antibodies is elevated by 4 times or more in the recovery phase compared with the acute phase.
(3) Chest imaging
In the early stage, there are multiple small patches and interstitial changes, most notably in the outer lung. It further develops into multiple ground-glass opacity and infiltration shadows in both lungs; and in severe cases, consolidation of the lungs may occur, and pleural effusion is rare.
V. Diagnostic Criteria
(1) Suspected cases.
Comprehensively analyze combinations of the following epidemiological history and clinical presentations:
Epidemiological history
(1) Within 14 days prior to onset, had history of travel or residence in Wuhan or surrounding regions, or other communities reporting cases;
(2) Within 14 days prior to symptom onset, having had contact with patients infected with 2019-nCoV (positive nucleic acid test).
(3) Within 14 days prior to onset, had contact with patients who had a fever or respiratory tract symptoms that had come from Wuhan, its surrounding regions, or other communities reporting cases.
(4) Clustered onset (Within a span of 2 weeks, 2 or more cases with fever and/or respiratory symptoms appear in a small area, such as a family, an office, or a school class)
2. Clinical presentations
(1) Fever and/or respiratory tract symptoms;
(2) Having the imaging features of novel coronavirus pneumonia discussed above;
(3) During the early stages of the disease, white blood cell count is normal or reduced, while the lymphocyte count is normal or reduced.
Where there are any of the epidemiologic history items, and any 2 of the clinical presentions are met.
Where there is no clear epidemiological history, and at least 3 of the clinical presentations are met.
(2) Confirmed cases.
A 2019-nCoV diagnosis is confirmed if the suspected cases also have one of the following etiological or serological evidence.
Positive result in real-time fluorescence RT-PCR detection of novel coronavirus nucleic acid;
The sequence of the virus is highly homologues to that of 2019-nCoV.
Specific IgM and IgG antibodies against 2019-nCoV test positive in the serum; IgG antibodies specific to 2019-nCoV test positive after previous negative results, or increased by more than 4 times in the recovery phase compared to the acute phase.
