重型危重型新型冠状病毒肺炎危险因素分析

目的 分析重型危重型新型冠状病毒肺炎(简称新冠肺炎)发生的危险因素,为早期预测新冠肺炎轻型普通型进展为重型危重型提供依据。 方法 收集2020年1月17日—3月14日在长沙市第一医院收治的新冠肺炎确诊患者的基本情况、流行病学、临床和实验室资料。采用回顾性队列分析研究重型危重型新冠肺炎发生的危险因素,单因素χ²检验和多因素logistic回归分析相关指标。 结果 169例患者纳入研究,其中136例为轻型普通型,33例为重型危重型。单因素分析显示,重型危重型和轻型普通型在年龄、饮酒史、感染地为湖北、有明确接触史、合并慢性心脏病、高血压、总蛋白、白蛋白、淋巴细胞、血糖、乳酸脱氢酶、降钙素原、C反应蛋白差异有统计学意义(P＜0.05);多因素logistic分析显示,有饮酒史(OR=3.06)、有慢性心脏疾病(OR=15.26)、总蛋白偏低(OR=2.13)、入院时血糖升高(OR=4.91)、C反应蛋白升高(OR=12.34)为重型危重型新冠肺炎的独立危险因素(P＜0.05)。 结论 有饮酒史、有慢性心脏疾病、入院时总蛋白偏低、血糖升高、C反应蛋白升高为重型危重型新冠肺炎的危险因素。提示医师在诊疗过程中应重点关注有以上因素的轻型普通型新冠肺炎患者。     

Cellular Immunity in COVID-19 Convalescents with PCR-Confirmed Infection but with Undetectable SARS-CoV-2–Specific IgG

We investigated immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among a group of convalescent, potential blood donors in Germany who had PCR-confirmed SARS-CoV-2 infection. Sixty days after onset of symptoms, 13/78 (17%) study participants had borderline or negative results to an ELISA detecting IgG against the S1 protein of SARS-CoV-2. We analyzed participants with PCR-confirmed infection who had strong antibody responses (ratio >3) as positive controls and participants without symptoms of SARS-CoV-2 infection and without household contact with infected patients as negative controls. Using interferon-γ ELISpot, we observed that 78% of PCR-positive volunteers with undetectable antibodies showed T cell immunity against SARS-CoV-2. We observed a similar frequency (80%) of T-cell immunity in convalescent donors with strong antibody responses but did not detect immunity in negative controls. We concluded that, in convalescent patients with undetectable SARS-CoV-2 IgG, immunity may be mediated through T cells.     

Etiology of Severe Acute Respiratory Infections,Bangladesh, 2017

In April 2017, surveillance detected a surge in severe acute respiratory infections (SARI) in Bangladesh. We collected specimens from SARI patients and asymptomatic controls for analysis with multipathogen diagnostic tests. Influenza A(H1N1)pdm09 was associated with the SARI epidemic, suggesting that introducing vaccines and empiric antiviral drugs could be beneficial.     

Territorywide Study of Early Coronavirus Disease Outbreak,Hong Kong,China

Initial cases of coronavirus disease in Hong Kong were imported from mainland China. A dramatic increase in case numbers was seen in February 2020. Most case-patients had no recent travel history, suggesting the presence of transmission chains in the local community. We collected demographic, clinical, and epidemiologic data from 50 patients, who accounted for 53.8% of total reported case-patients as of February 28, 2020. We performed whole-genome sequencing to determine phylogenetic relationship and transmission dynamics of severe acute respiratory syndrome coronavirus 2 infections. By using phylogenetic analysis, we attributed the community outbreak to 2 lineages; 1 harbored a common mutation, Orf3a-G251V, and accounted for 88.0% of the cases in our study. The estimated time to the most recent common ancestor of local coronavirus disease outbreak was December 24, 2019, with an evolutionary rate of 3.04 × 10⁻³ substitutions/site/year. The reproduction number was 1.84, indicating ongoing community spread.     

Waning Antibody Responses in Asymptomatic and Symptomatic SARS-CoV-2 Infection

We investigated the kinetics of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies in 7 asymptomatic persons and 11 patients with pneumonia. The geometric mean titer of neutralizing antibodies declined from 219.4 at 2 months to 143.7 at 5 months after infection, indicating a waning antibody response.     

Risk for SARS-CoV-2 Infection in Healthcare Workers,Turin, Italy

We measured severe acute respiratory syndrome coronavirus 2 spike protein subunits S1/S2 antibodies by using capillary electrophoresis and a chemiluminescence immunoassay for 5,444 active healthcare workers in Italy. Seroprevalence was 6.9% and higher among participants having contact with patients. Seroconversion was not observed in 37/213 previously infected participants.     

Postmortem Stability of SARS-CoV-2 in Nasopharyngeal Mucosa

Analyses of infection chains have demonstrated that severe acute respiratory syndrome coronavirus 2 is highly transmissive. However, data on postmortem stability and infectivity are lacking. Our finding of nasopharyngeal viral RNA stability in 79 corpses showed no time-dependent decrease. Maintained infectivity is supported by virus isolation up to 35 hours postmortem.     

Strand-Specific Reverse Transcription PCR for Detection of Replicating SARS-CoV-2

We developed an assay that detects minus-strand RNA as a surrogate for actively replicating severe acute respiratory syndrome coronavirus 2. We detected minus-strand RNA in 41 persons with coronavirus disease up to 30 days after symptom onset. This assay might inform clinical decision-making about patient infectiousness.     

Experimental SARS-CoV-2 Infection of Bank Voles

After experimental inoculation, severe acute respiratory syndrome coronavirus 2 infection was confirmed in bank voles by seroconversion within 8 days and detection of viral RNA in nasal tissue for up to 21 days. However, transmission to contact animals was not detected. Thus, bank voles are unlikely to establish effective transmission cycles in nature.     

COVID-19 and Infant Hospitalizations for Seasonal Respiratory Virus Infections,New Zealand, 2020

In March 2020, a national elimination strategy for coronavirus disease was introduced in New Zealand. Since then, hospitalizations for lower respiratory tract infection among infants <2 years of age and cases of respiratory syncytial or influenza virus infection have dramatically decreased. These findings indicate additional benefits of coronavirus disease control strategies.