Radiological findings from 81 patients with COVID-19 pneumonia inWuhan, China: a descriptive study”
81 patients were admitted from December 20, 2019 to January 23, 2020. There were 42 males and 39 females with an average age of 49.5 years.
CT showed that 81 cases of pulmonary lesions involved an average of 10.5 lung segments, including 2.8 lung segments in subclinical stage, 11.1 lung segments in 1 week, 13.0 lung segments in 1-2 weeks, and 12.1 lung segments in 2-3 weeks.
The subclinical stage (n = 15) mainly showed unilateral and multicentric ground glass shadow (93%).
Within one week after the onset of symptoms (n = 21), the lesions were mostly bilateral and diffuse ground glass shadows (81%).
The symptoms appeared for 1-2 weeks (n = 30), the ground glass shadow continued to decrease (57%), and most of them were consolidation and mixed lesions (40%).
The symptoms appeared for 2-3 weeks (n = 15), and the ground glass shadow was significantly reduced (33%), mainly including consolidation and mixed lesions (53%).
Chest CT of patients with COVID-19 showed pulmonary infiltrative lesions, even in asymptomatic patients.
Within 1-3 weeks after the onset, the lesion rapidly progressed from unilateral and focal lesions to diffuse ground glass shadows in both lungs, and consolidation in the later stage.
The results showed that the virus load in throat swabs and sputum samples reached a peak about 5-6 days after the onset of symptoms, from 104 copies per ml to 107 copies.
This change pattern of viral load is different from that of SARS, which usually reaches its peak around 10 days after the onset of the disease.
The viral load of sputum samples is usually higher than that of laryngeal swabs.
Viral RNA was not detected in urine or stool samples of two patients.
Subsequently, the study group analyzed the respiratory tract samples (1 nasal swab, 67 pharyngeal swabs and 42 sputum) of 80 patients with different infection stages.
The viral load of these samples ranged from 641 copies per ml to 1.34 × 1011 copies, with a median of 7.99 for pharyngeal swab samples × 104, the median of sputum samples was 7.52 × 105。
The only nasal swab was collected 3 days after the onset of the disease, and the viral load was 1.69/ml × 105 copies.
Overall, the viral load in the early stage of onset was high (> 1 × 106 copies).
However, one deceased patient had the highest viral load in sputum samples on day 8 after onset, at 1.34 × 1011 copies.
It is worth noting that two people received positive tests due to their contact history. The results showed that the virus was positive on the day before the onset of the disease, indicating that the infected individuals had been infectious before the onset of symptoms.
Among the 30 pairs of throat swabs and sputum samples available, there was a significant correlation between the viral load of the two samples on days 1-3, 4-7 and 7-14.
Of the 17 confirmed cases of novel coronavirus infection (0-13 days after onset), 9 patients had positive stool tests.
The viral load in feces ranged from 550 copies per ml to 1.21 × 105 copies, lower than the respiratory tract samples, and precautions should be taken when handling fecal samples.