COVID-19 is currently rampant all over the global and science is the sole panacea for this unknown health hazard. In addition to treating the COVID-19 patients, medical specialists from the First Affiliated Hospital of Zhejiang University School of Medicine are actively engaged into clinical research to deepen our knowledge on this novel virus and have published several research articles in international top journals.
On January 19, the research article entitled "Clinical findings in a group of patients infected with the 2019 novel coronavirus (SARS-Cov-2) outside of Wuhan,China: retrospective case series", co-authored by LI Lanjuan, academician of Chinese Academy of Engineering and director of the State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, and XU Xiaowei, deputy director of the Department of Infectious Diseases, was published online in BMJ.
On April 22, the research article entitled "Viral load dynamics and disease severity in patients infected with SARS-CoV-2 in Zhejiang province, China, January-March 2020: retrospective cohort study", co-written by Prof. LIANG Tingbo, Chairman of FAHZU and Prof. CHEN Yu, director of Laboratory Medicine, as corresponding authors, and Dr. ZHENG Shufa as the first author, was also published online in the BMJ.
On the same day, Science journalist Rodrigo Pérez Ortega covered a report entitled "Health care workers seek to flatten COVID-19's 'second curve'—their rising mental anguish". This report included an interview with Prof. HU Shaohua, a psychiatrist at FAHZU, who published a research earlier on symptoms of depression and anxiety among healthcare workers in JAMA Open Network.
Their study reveals that the duration of SARS-CoV-2 is significantly longer in stool samples than in respiratory and serum samples, highlighting the need to strengthen the management of stool samples in the prevention and control of the epidemic, especially for patients in the later stages of the disease.
The samples in this study were more systematic and comprehensive. It involved 96 consecutively admitted patients with laboratory confirmed SARS-CoV-2 infection: 22 with mild disease and 74 with severe disease. 3497 respiratory, stool, serum, and urine samples, including 1846 respiratory samples, 842 stool samples, 629 serum samples and 180 urine samples, were collected from patients after admission and evaluated for SARS-CoV-2 RNA viral load.
This study indicated that viral load differed significantly by sample type, with respiratory samples showing the highest, followed by stool samples, and serum samples showing the lowest. In respiratory samples, patients with severe disease had significantly higher viral loads than patients with mild disease.
Using a loess regression analysis, researchers also found that in the mild group, the viral load in respiratory samples was greater during the initial stages of the disease, reached a peak in the second week after disease onset, and was followed by lower loads. In the severe group, however, the viral load in respiratory samples continued to be high during the third and fourth weeks after disease onset.
When patients with severe disease were stratified, the duration of the virus was significantly longer in men than in women, and significantly longer in patients older than 60 years than younger, researchers found.
RNA was detected in the stool of 55 (59%) patients and in the serum of 39 (41%) patients. The urine sample from one patient was positive for SARS-CoV-2. The median duration of virus in stool (22 days, interquartile range 17-31 days) was significantly longer than in respiratory (18 days, 13-29 days; P=0.02) and serum samples (16 days, 11-21 days; P<0.001). The median duration of virus in the respiratory samples of patients with severe disease (21 days, 14-30 days) was significantly longer than in patients with mild disease (14 days, 10-21 days; P=0.04). In the mild group, the viral loads peaked in respiratory samples in the second week from disease onset, whereas viral load continued to be high during the third week in the severe group.
These findings suggest that reducing viral loads through clinical means and strengthening management during each stage of severe disease should help to prevent the spread of the virus.
(By ZJU Global Communications)