Clinical follow-up study of SARS-CoV-2 Omicron infection / 上海预防医学

ObjectiveTo observe the clinical course and explore the risk factors for SARS-CoV-2 RNA negative conversion duration （NCD） in asymptomatic and mild-symptomatic patients infected with the SARS-CoV-2 Omicron variant. MethodsClinical data were collected from 244 confirmed cases of corona virus disease （COVID-19） with Omicron variant infection admitted to a temporal makeshift hospital in Shanghai from April 9， 2022 to May 20， 2022. Demographic and clinical data were analyzed， with a primary focus on the time of COVID-19 nucleic acid conversion. Univariate and multivariate Cox regression analysis were used to determine identify risk factors associated with NCD. ResultsThe median duration of negative RNA conversion was 9 days （ranged 7‒12 days）. The percentage of patients with positive nucleic acid results on the 5th， 7th， 10th， and 14th days after confirmed infection was 68.4%， 47.1%， 20.1%， and 5.7%， respectively. Kaplan-Meier curves indicated a median nucleic acid conversion time of 12 days （ranged 10‒14 days） for patients with hypertension， 9 days （ranged 7‒11 days） in patients without hypertension， and 11 days （ranged 9‒13 days） for patients aged ≥60 years， and 9 days （ranged 7‒11 days） for patients aged <60 years. Multivariate Cox regression analysis showed that only hypertension was an independent risk factor of NCD （RR=1.60； 95% CI： 1.03‒2.49， P=0.036）. ConclusionIn asymptomatic or mildly symptomatic patients infected with the Omicron variant， 20.1% patients continue to exhibit positive viral nucleic acid on the 10th days of infection. The independent risk factor associated with the conversion of SARS-CoV-2 nucleic acid to negative is hypertension.

Comparative analysis of asymptomatic infection prevalence in Beta, Delta, and Omicron surges of COVID-19

Abstract Background The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had a devastating impact on the global population, with an estimated 650 million people infected and more than 6.6 million lives lost. Asymptomatic individuals have been shown to play a significant role in the transmission of the virus. Therefore, this study aims to investigate and compare the prevalence of asymptomatic individuals across three waves associated with the Beta, Delta, and Omicron variants of the virus. Methods This retrospective study was conducted between December 2020 and March 2022. The study population consisted of passengers on international flights who were referred to the Gerash Clinical and Molecular Diagnosis Laboratory. Real-time PCR was employed for the diagnosis of SARS-CoV-2. Results Out of a total of 8592 foreign travelers referred to our laboratory, 139 (1.16 %) tested positive for SARS-CoV-2 infection and were asymptomatic. During the Beta surge, 35 (1.49 %) out of 2335 passengers tested positive for SARS-CoV-2. In the Delta surge, 31 (0.6 %) out of 5127 passengers tested positive. However, during the Omicron surge, a significantly higher number of passengers, specifically 73 (6.46 %) out of 1130, had a positive result for the SARS-CoV-2 test. Conclusion Considering the significant role of asymptomatic transmission in the spread of COVID-19, it is imperative to reconsider health policies when dealing with future surges of the Omicron subvariants. Additionally, we strongly recommend that the World Health Organization prioritize the development and distribution of second-generation vaccines that target not only disease but also infection prevention.

Trends of humoral immune responses to heterologous antigenic exposure due to vaccination & omicron SARS-CoV-2 infection: Implications for boosting

Background & objectives: Vaccination and natural infection can both augment the immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but how omicron infection has affected the vaccine-induced and hybrid immunity is not well studied in Indian population. The present study was aimed to assess the durability and change in responses of humoral immunity with age, prior natural infection, vaccine type and duration with a minimum gap of six months post-two doses with either ChAdOx1 nCov-19 or BBV152 prior- and post-emergence of the omicron variant. Methods: A total of 1300 participants were included in this observational study between November 2021 and May 2022. Participants had completed at least six months after vaccination (2 doses) with either ChAdOx1 nCoV-19 or an inactivated whole virus vaccine BBV152. They were grouped according to their age (? or ?60 yr) and prior exposure of SARS-CoV-2 infection. Five hundred and sixteen of these participants were followed up after emergence of the Omicron variant. The main outcome was durability and augmentation of the humoral immune response as determined by anti-receptor-binding domain (RBD) immunoglobulin G (IgG) concentrations, anti-nucleocapsid antibodies and anti-omicron RBD antibodies. Live virus neutralization assay was conducted for neutralizing antibodies against four variants – ancestral, delta and omicron and omicron sublineage BA.5. Results: Before the omicron surge, serum anti-RBD IgG antibodies were detected in 87 per cent participants after a median gap of eight months from the second vaccine dose, with a median titre of 114 [interquartile range (IQR) 32, 302] BAU/ml. The levels increased to 594 (252, 1230) BAU/ml post- omicron surge (P<0.001) with 97 per cent participants having detectable antibodies, although only 40 had symptomatic infection during the omicron surge irrespective of vaccine type and previous history of infection. Those with prior natural infection and vaccination had higher anti-RBD IgG titre at baseline, which increased further [352 (IQR 131, 869) to 816 (IQR 383, 2001) BAU/ml] (P<0.001). The antibody levels remained elevated after a mean time gap of 10 months, although there was a decline of 41 per cent. The geometric mean titre was 452.54, 172.80, 83.1 and 76.99 against the ancestral, delta, omicron and omicron BA.5 variants in the live virus neutralization assay. Interpretation & conclusions: Anti-RBD IgG antibodies were detected in 85 per cent of participants after a median gap of eight months following the second vaccine dose. Omicron infection probably resulted in a substantial proportion of asymptomatic infection in the first four months in our study population and boosted the vaccine-induced humoral immune response, which declined but still remained durable over 10 months

Scientometric Research Mapping of OMICRON for Scientific Production: A Global Perception Analysis

Background: South Africa reported a new variant of SARS-CoV-2, named 'Omicron,' to the World Health Or-ganization on November 24, 2021. Scientometric analysis quantify all currently available written communica-tion, the authors of that communication, and their citation analysis. The study's goal was to use the Scopus and Web of Science databases to look at the research metrics of Omicron publications published between Jan-uary 1965 and March 2020. Methods:All scientific research outputs with the word 'Omicron' in the title were retrieved from the Web of Science (January 1965 to March 2022) and Scopus (January 1896 to March 2022) databases on April 10, 2022. The data was analyzed based on year-wise publications; leading authors; predominant journals in publishing, highly cited articles with citations; type of publications; subject classification, frequently used keywords, geo-graphical distribution of publication, language, and more contributed institutions. Results: There were 1229 research outputs for WoS and 655 from Scopus. The number of publications for WoS increased from 22 in 1965 to 265 in 2022, while Scopus increased from 1 in 1896 to 356 in 2022. Both the databases identified the author Yuen KY as the highest contributor; Journal of Virology and Nature as the predominant journals; the Lancet as highly cited journal; majority as original articles; frequently used key-words as 'SARS-CoV-2'; the United States of America as the most productive country; majority publication in English. The publications were mainly on the subjects Chemistry and Medicine by WoS and Scopus, respec-tively. The most productive institute was the ‘University of California Systems’ by WoS and the ‘University of Hong Kong’ by Scopus. Conclusion: The term 'Omicron' first appeared in the domain of Chemistry in the late 18th century. The growth pattern of publication was not consistent. The above research metrics will be helpful to researchers in the coming days.

Variante mexicana de COVID-19: ómicron BW. 1 o Xibalbá / Mexican variant of COVID-19: omicron BW. 1 o Xibalbá

Introducción: desde la aparición del COVID-19 a principios de diciembre del año 2019, en la ciudad China de Wuhan, esta enfermedad respiratoria empezó a avanzar a nivel mundial. El 30 de enero de 2020, la Organización Mundial de la Salud declaró a esta enfermedad con carácter epidémico y como una situación de emergencia a nivel mundial. El propósito de este estudio es presentar información de la variante ómicron BW.1 o Xibalbá. Conclusión: México está en un proceso de transición de pandemia hacia endemia, pero no quiere decir que no seguirán apareciendo nuevas variantes como ocurrió en la quinta ola (ómicron BA.5) o con subvariantes que emergieron como BW.1 «Xibalbá¼, BQ.1 «perro del infierno¼ y XBB «pesadilla¼. La población y los gobiernos deberán continuar con las medidas preventivas establecidas desde el inicio de la pandemia como son el uso de cubrebocas, el correcto lavado de manos y de ropa, los hábitos de higiene, limpieza, desinfección personal y de nuestro entorno, el aislamiento precoz ante alguna sintomatología y la vacunación (ya sea la primera o sus refuerzos subsecuentes).(AU)

Introduction: since the appearance of COVID-19 in early December 2019 in the Chinese city of Wuhan, this respiratory disease began to spread worldwide. On the thirtieth of January of the year two thousand and twenty, the World Health Organization (WHO) declared this disease to be epidemic and with a worldwide emergency situation. The purpose of the study is to present information on the Omicron BW.1 or Xibalba variant. Conclusion: Mexico is in a process of transition from pandemic to endemic but this does not mean that new variants will not continue to appear as they did in the fifth wave (omicron BA.5) or subvariants that emerged such as: BW.1 or «Xibalbá¼, BQ.1 «hellhound¼ and XBB «nightmare¼. The population and governments should continue with the preventive measures established since the beginning of the pandemic, such as: use of masks, proper hand and clothing washing, hygiene habits, personal and environmental cleaning and disinfection, early isolation in case of any symptomatology, and vaccination, either first or subsequent boosters.(AU)

Clinical characteristics and risk factors for perioperative lung surgery patients with SARS‐CoV‐2 infection / 中国胸心血管外科临床杂志

@#Objective     To investigate the clinical characteristics and risk factors for perioperative lung surgery patients with SARS‐CoV‐2 Omicron variant infection. Methods     The clinical data of patients who underwent lung surgery at the Department of Thoracic Surgery, Renmin Hospital of Wuhan University from December 1, 2022 to January 9, 2023 were retrospectively analyzed. The patients were divided into an infection group and a non-infection group according to whether they were infected with SARS-CoV-2. And the clinical data of two groups were collected and compared. Multiple linear regression analysis was used to explore the risk factors affecting the time of hospitalization. Results     A total of 70 patients were enrolled in this study, including 36 (51.4%) males and 34 (48.6%) females at a median age of 61.0 (49.0, 66.8) years. There were 28 patients in the infection group and 42 patients in the non-infection group. The proportion of preoperative abnormal coagulation function and the risk of postoperative pulmonary infection in perioperative patients infected with SARS-CoV-2 were higher than those in the non-infection group (P<0.05). Subgroup analysis found that patients with preoperative SARS-CoV-2 infection were more likely to have pulmonary infection after surgery, but did not prolong the time of hospitalization or increase the risk of severe disease rate. The patients with postoperative SARS-CoV-2 infection had worse clinical prognosis, including longer time of hospitalization (P=0.004), higher ICU admission rate (P=0.000), higher lung infection rate (P=0.003) and respiratory failure rate (P=0.000). Multiple linear regression analysis showed that gender and extent of surgery were independent risk factors for prolonged hospitalization time. Conclusion     Preoperative infection with SARS-CoV-2 Omicron variant will increase the risk of pulmonary infection, but it will not affect the clinical prognosis. However, postoperative infection with SARS-CoV-2 Omicron variant will still prolong the time of hospitalization, increase the ICU rate, and the risk of pulmonary complications.

Optimization of culture conditions of SARS-CoV-2 four Omicron variants in Vero cells / 中国生物制品学杂志

@#Objective To optimize the culture conditions of four vaccine candidates of severe acute respiratory symptom coronavirus 2(SARS-CoV-2) Omicron variants BA.1,BA.1.1,BA.2 and BA.5 in Vero cells.Methods The harvest time(24,48,72 and 96 h) and MOI(0.01,0.001,0.0001 and 0.000 01) of four Omicron variants cultured in Vero cells were optimized by using cytopathic effect(CPE),viral nucleic acid copy number and viral titer as evaluation indexes.Results The optimum harvest time of the four Omicron variants BA.1,BA.1.1,BA.2 and BA.5 in Vero cells was 72 h,and the optimum MOI was 0.001～0.000 01,0.001～0.000 01,0.01～0.000 01 and 0.01～0.000 01,respectively.Conclusion The culture conditions of four Omicron variants in Vero cells were optimized,which laid a foundation of the development of SARS-CoV-2 Omicron variant inactivated vaccine based on Vero cells.

The influence of COVID-19 infection on treatments of patients with acute type A aortic dissection / 中华胸心血管外科杂志

Objective:To investigate the differences in outcomes of surgical strategies and prognosis of patients with acute type A aortic dissection(ATAAD) during the period of COVID-19 Omicron variant epidemic compared with the non-epidemic period.Methods:Clinical data were retrospectively collected from ATAAD patients during the COVID-19 Omicron variant epidemic(December 7, 2022 to January 10, 2023) and during the non-epidemic period(December 7, 2019 to January 10, 2020) to compare the differences in surgical strategies, perioperative mortality, and perioperative complication rates in ATAAD patients during the two different periods.Results:There were 14 patients in the COVID-19 infected group and 43 patients in the control group. Patients in the infected group had a shorter mean aortic clamp time[(89.71±16.27)min vs.(110.09±28.99)min, P<0.01], a significantly higher postoperative mortality rate relative to the control group(21.43% vs. 2.33%, P=0.02), a significantly longer length of stay in the ICU(3 days vs. 2 days, P=0.04) and the duration of intubation time(34 h vs. 14 h, P<0.01), and the incidence of adverse events, mainly cerebral infarction, was higher in infected group(28.57% vs. 6.98%, P=0.03). Conclusion:During the COVID-19 Omicron variant strain epidemic, our center preferred a more conservative surgical strategy in COVID-19 infected patients. Although the COVID-19 infection increased the postoperative mortality and complication rate of ATAAD, patients still achieve a more satisfactory outcome. Therefore, surgical treatment should be timely performed for ATAAD patients.

Characteristics of digestive system symptoms and abdominal computed tomography imaging of patients infected with severe acute respiratory syndrome coronavirus 2 Omicron variant / 中华消化杂志

Objective:To investigate the characteristics of digestive system symptoms and its relation with the time of nucleic acid continuous positive in population infected with severe acute respiratory syndrome coronavirus 2 Omicron variant, and to analyze the abdominal computed tomography (CT) features of patients infected with Omicron variant.Methods:From April 11 to May 23, 2022, a questionnaire survey was conducted in patients infected with Omicron variant admitted to the Shanghai National Convention and Exhibition Center Fangcang Hospital. The questionnaire included basic information, the start time of nucleic acid positive, respiratory symptoms, digestive system syptoms and outcomes, etc.Combined with the clinical data, the relation between digestive tract symptoms and the time of nucleic acid continuous positive were analyzed. Thoracic and abdominal CT were performed for patients with continuous positive nucleic acid results ≥10 d, and the relationship between the abdominal CT imaging characteristics and the time of nucleic acid continuous positive was analyzed. Independent sample t-test and multivariate logistic regression were used for statistical analysis. Results:A total of 4 360 valid questionnaires were collected, including 2 475 males and 1 885 females, with a hospital stay of (6.8±4.9) d. Among the 4 360 patients, 1 979 patients (45.4%) had gastrointestinal symptoms such as loss of appetite, abdominal discomfort or pain, constipation and diarrhea. The time of nucleic acid continuous positive in patients with gastrointestinal symptoms was (7.4±5.5) d, which was longer than that of patients without gastrointestinal symptoms (6.5±3.6) d, and the difference was statistically significant ( t=3.78, P<0.001). During the isolation period in the Fangcang Hospital, the time of nucleic acid continuous positive in patients with complete remission of digestive tract symptoms was shorter than that of patients with no remission of digestive tract symptoms ((7.3±5.2) d vs. (8.5±5.7) d), and the difference was statistically significant ( t=2.25, P=0.025). The results of multivariate logistic regression analysis showed that the combination of gastrointestinal symptoms was an independent risk factor for continuous positive nucleic acid result ≥10 d ( OR=1.316, 95% confidence interval 1.294 to 2.205, P=0.046). Among the 299 patients with continuous positive nucleic acid results≥10 d, 187 cases (62.5%) had gastrointestinal symptoms, and 146 cases (48.8%) had abdominal CT findings of thickening of the gastroduodenal wall, thickening of the small intestinal wall, indistinct mesenteric vessels of the small intestine, and dilatation and pneumatosis of the colon. In patients with continuous positive nucleic acid results ≥10 d, abdominal CT indicated that patients with gastrointestinal imaging changes had a longer time of nucleic acid continuous positive than those without gastrointestinal imaging changes ((16.0±2.8) d vs. (13.0±2.1) d), and the difference was statistically significant ( t=2.62, P=0.009). Conclusions:Digestive system symptoms are common in patients infected with Omicron variant. The time of nucleic acid continuous positive in patients with gastrointestinal symptoms is longer than those without gastrointestinal symptoms. Some patients may have gastrointestinal lesions on abdominal CT.

Establishment and evaluation of a quantitative TaqMan RT-PCR for the detection of SARS-CoV-2 Omicron variants / 中华微生物学和免疫学杂志

Objective:To develop a rapid, simple and cost-effective quantitative TaqMan RT-PCR (RT-qPCR) that could be used as an alternative to sequencing for the detection of Omicron variants and to evaluate its performance.Methods:Primers and TaqMan probes targeting the conserved domains of SARS-CoV-2 ORF1ab and the high-frequency mutation sites in the S gene of Omicron variants were designed. Then a RT-qPCR for the detection of Omicron variants was established. The consistency of the method was verified using samples identified by whole-genome sequencing. The specificity and sensitivity of the method were also evaluated.Results:The established RT-qPCR could distinguish Omicron variants from early epidemic A strains and Alpha and Delta variants of SARS-CoV-2, and the results were consistent with those of whole-genome sequencing with a coincidence rate of 100% (28/28). There was no cross-reactivity with other six respiratory viruses or coxsackievirus group A16. For RNA standards, this method showed good linearity in the range of 10 9-10 3 copies/μl with a correlation coefficient ( R2) greater than 0.99 and detection sensitivity of 10 3 copies/μl. Conclusions:The RT-qPCR designed in this study for Omicron variant detection had good sensitivity and specificity and could be easily performed in laboratories, which would greatly facilitate the monitoring of Omicron variants.

Whole-genome characterization and traceability analysis of the first COVID-19 outbreak caused by Omicron variant in Henan Province / 中华微生物学和免疫学杂志

Objective:To analyze the whole genome of Omicron variants causing the first local Omicron outbreak in Henan Province and to investigate the mutations in the SARS-CoV-2 genome for source tracing.Methods:Respiratory tract samples from COVID-19 cases in the Omicron outbreak in Henan Province from January 7 to 29, 2022 were subjected to whole-genome sequencing and sequence alignment analysis. Whole-genome identity, variations and evolution of the Omicron variants were analyzed.Results:Through high-throughput sequencing, the whole-genome sequences of SARS-CoV-2 were obtained from 120 cases, which accounted for 25.64% (120/468) of all COVID-19 cases in Anyang during the same period. Compared with the genome of Wuhan reference strain (NC_045512.2), there were 57-59 nucleotide mutation sites in the 120 whole genome sequences, and one or two nucleotide mutation sites were added to the shared 57 nucleotide sites. All of the 120 strains were VOC/Omicron (BA.1.1) variants and shared high homology. The whole-genome sequence obtained from the first case A contained 57 nucleotide mutation sites, while apart from the 57 identical nucleotide mutation sites, one specific mutation site (C1594T) was found in the whole-genome sequence obtained from the first case B, suggesting that the two cases were in the same transmission chain. After comparing with the database of domestic and imported cases by the Chinese Center for Disease Control and Prevention and the Henan Provincial Center for Disease Control and Prevention, it was found that the current outbreak was linked with the same transmission chain as the existing local epidemics in other provinces. Moreover, epidemiological investigation showed that on January 2, case A had come into contact with her cousin and his family who returned from an affected area outside the province.Conclusions:Based on the gene sequencing results and epidemiological investigation, the COVID-19 outbreak in Anyang city, Henan Province was a local epidemic and the source of it was a college student who returned to Anyang city from other province on December 28, 2021. These infections were linked to the same transmission chain as the existing local infection in other provinces.

Research progress in site mutations of SARS-CoV-2 Omicron variants / 中华微生物学和免疫学杂志

SARS-CoV-2 Omicron variant (B.1.1.529) was first discovered in South Africa in November 2021 and has since become a mainstream strain worldwide. Omicron variant was defined as the fifth "variant of concern (VOC)" by World Health Organization on November 26, 2021. This paper illustrates the mutation trends of Omicron variants in terms of SARS-CoV-2 genome and protein structure as well as nucleic acid site mutations and amino acid site mutations, describes the features of Omicron mutation sites in terms of lineage comparison among the VOCs and Omicron sublineages, and further highlights the influences of Omicron site mutations from the aspects of immune escape, virulence and transmission ability. Moreover, this paper also reviews the development of direct antiviral agents, antibodies and vaccines, aiming to provide reference for further investigation.

Quick guideline for diagnosis and treatment of novel coronavirus Omicron variant infection / 中华临床感染病杂志

Novel coronavirus Omicron variant infection can cause severe illness and even death in certain populations. Omicron variant infection may lead to systemic inflammatory response, coagulation disorder, multi-organ dysfunction and other pathophysiological changes, which are different from other Novel coronavirus variants to a certain extent, so therapeutic strategies should not be the same. The National Medical Center for Major Public Health Events invited experts in fields of infectious diseases, respiratory medicine, intensive care, pediatrics and fever clinic to develop this quick guideline based on the current best evidence and extensive clinical practices. This quick guideline aims to standardize the diagnosis and treatment of novel coronavirus Omicron infection, and to improve the disease management abilities of clinicians.

Clinical characteristics of family clustering pediatric and adult cases with severe acute respiratory syndrome coronavirus 2 Omicron variant infection / 中华传染病杂志

Objective:To investigate the clinical characteristics of family clustering pediatric and adult cases with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infection in Shanghai City.Methods:A field investigation among the pediatric cases with Omicron variant infection and their household contacts from April 4 to April 30, 2022 in Children′s Hospital of Fudan University was conducted. The informations on case finding, clinical manifestations and SARS-CoV-2 vaccination status were collected. The epidemiological and clinical characteristics were compared between pediatric cases and adult cases. The independent sample t test or chi-square test was used for statistical analysis, and the relative risk ( RR) and 95% confidence interval (95% CI) were used to evaluate the protective effect of vaccination on the infection of Omicron variant. Results:There were 1 274 family members in 297 families including 370 children and 904 adults of whom 1 110(87.13%) were infected with Omicron variant, with 989(89.10%) symptomatic and 121(10.90%) asymptomatic. There were 355 children infected with Omicron variant, of whom 337(94.93%) were symptomatic, and the main manifestations were fever (96.74%(326/337)) and cough (40.36%(136/337)). Only one pediatric case with Rett syndrome developed critically severe pneumonia. A total of 194 pediatric cases had imaging examination, 64(32.99%) showed pulmonary inflammatory lesions. There were 755 adult cases infected with Omicron variant, of whom 652(86.26%) reported symptoms, and the main manifestations were fever (73.16%(477/652)) and cough (49.85%(325/652)). Among symptomatic cases, fever was more common in pediatric cases than in adult cases, while cough was more common in adult cases than in pediatric cases, and the differences were both statistically significant ( χ2=80.87 and 8.04, respectively, both P<0.01). The fever spike was higher in pediatric cases than in adult cases ((39.3±0.7) ℃ vs (38.6±0.6) ℃), and the difference was statistically significant ( t=9.85, P<0.001). The interval from the onset of symptoms to cycle threshold (Ct) value of the nucleic acid of Omicron variant≥35 was longer in pediatric cases than in adult cases ((13.0±3.1) d vs (10.9±3.6) d), and the difference had statistically significance ( t=2.97, P=0.004). Among 160 children aged 3 to 18 years, 54 (33.75%) received two-dose vaccination. Among the 904 adults, 388 (42.92%) received two-dose vaccination and 293 (32.41%) received a booster dose. In the adult cases, the risk of symptomatic infection was reduced by only 8% ( RR=0.92, 95% CI 0.86 to 0.98, P=0.014) following two-dose vaccination, and the risks of fever and cough following booster vaccination were reduced by 42%( RR=0.58, 95% CI 0.49 to 0.67, P=0.001) and 50% ( RR=0.50, 95% CI 0.34 to 0.78, P=0.001), respectively. Conclusions:Secondary attack rate and symptomatic rate of household infection are high in the context of the Omicron variant outbreak in Shanghai. Symptomatic infection is common in children and adults in household setting. Fever is the most common symptom and fever duration is short. Booster vaccination may provide certain protection against common symptoms caused by Omicron variant infection.

Clinical characteristics and pregnancy outcome of pregnancy complicated with novel coronavirus infection during the omicron epidemic period / 中国综合临床

Objective:To explore the clinical characteristics and pregnancy outcomes of novel coronavirus disease 2019 (COVID-19) in pregnancy during the prevalence of Omikjon.Methods:Retrospective analysis of the clinical data of 65 pregnant women (COVID-19 group) admitted to Beijing Friendship Hospital Affiliated to Capital Medical University from November 1 to December 24, 2022, who received COVID-19 in late pregnancy and delivered, including 64 mild cases and 1 medium case. In addition, 182 pregnant women with negative detection of novel coronavirus nucleic acid due to obstetric factors were selected as the control group. Compare the perinatal data, pregnancy complications, delivery related indicators, and neonatal outcomes between the two groups. To analyze the detection results of novel coronavirus in newborns delivered by COVID-19 pregnant women. The measurement data is represented by xˉ± s, and independent sample t-test is used for inter group comparison; Counting data is represented by examples(%), and comparisons between groups are conducted using χ 2 test or Fisher's exact probability method. Results:There was no statistically significant difference between the two groups in terms of delivery age, gestational age, pregnancy complications, cesarean section rate, perinatal bleeding volume and the amount of hemostatic medication used, newborn birth weight, neonatal asphyxia, and neonatal intensive care unit (NICU) transfer rate (all P>0.05). The proportion of amniotic fluid reduction in the COVID-19 combination was higher than that in the control group [7.69%(5/65) vs 0.55% (1/182)], with a statistically significant difference ( P=0.006). In COVID-19 group, 3 out of 5 pregnant women with amniotic fluid decrease had fever for 3-5 days before amniotic fluid decrease. After intravenous fluid replacement, the amniotic fluid index was >8 cm, and there was no recurrent amniotic fluid decrease during pregnancy. Among 65 newborns in COVID-19 group, 20 were negative for novel coronavirus nucleic acid detection after birth; 45 cases were negative for novel coronavirus antigen detection. After the birth of the newborn, the mother and baby were roomed together and breastfed. Among them, one case was transferred to NICU due to vomiting, one case was transferred to NICU due to nasal obstruction, one case was transferred to NICU due to the mother's fever at birth, and three cases were positive for new coronavirus nucleic acid detection. After general treatment, they recovered and discharged from hospital. Conclusions:During the prevalence of Omikjon, COVID-19 did not increase the risk of pregnancy complications and adverse pregnancy outcomes, and vertical transmission was not found in newborns delivered by COVID-19 pregnant women.

Analyze the clinical characteristics of mild and severe SARS-CoV-2 infected patients based on the local Omicron variant epidemic / 中华危重病急救医学

Objective:To analyze the epidemic characteristics and clinical key indicators of the patients infected with SARS-CoV-2 of the local Omicron variant epidemic, to understand the clinical characteristics of mild and severe patients, and to provide a scientific basis for the effective treatment and prevention of severe disease.Methods:From January 2020 to March 2022, the clinical and laboratory data of COVID-19 patients admitted to the Fifth People's Hospital of Wuxi were retrospective analyzed, including virus gene subtypes, demographic information, clinical classification, main clinical symptoms, and key indicators of clinical testing, and the changes of clinical characteristics of the patients infected with SARS-CoV-2.Results:A total of 150 patients with SARS-CoV-2 infection were admitted, 78, 52 and 20 in 2020, 2021 and 2022, including 10, 1 and 1 severe patient, and the main infected virus strains were L, Delta, and Omicron variants. The relapse rate of patients infected with the Omicron variant was as high as 15.0% (3/20), the incidence of diarrhea decreased to 10.0% (2/20), the incidence of severe disease decreased to 5.0% (1/20), and the number of hospitalization days of mild patients increased compared with 2020 (days: 20.43±1.78 vs. 15.84±1.12); respiratory symptoms were reduced, and the proportion of pulmonary lesions decreased to 10.5%; the virus titer of severely ill patients with SARS-CoV-2 Omicron variant infection (day 3) was higher than that of L-type strain (Ct value: 23.92±1.16 vs. 28.19±1.54). The acute plasma cytokines interleukin (IL-6, IL-10) and tumor necrosis factor-α (TNF-α) were significantly lower in patients with severe Omicron variant new coronavirus infection than those with mild disease [IL-6 (ng/L): 3.92±0.24 vs. 6.02±0.41, IL-10 (ng/L): 0.58±0.01 vs. 4.43±0.32, TNF-α (ng/L): 1.73±0.02 vs. 6.91±1.25, all P < 0.05], while γ-interferon (IFN-γ) and IL-17A were significantly higher than patients with mild disease [IFN-γ (ng/L): 23.07±0.17 vs. 13.52±2.34, IL-17A (ng/L): 35.58±0.08 vs. 26.39±1.37, both P < 0.05]. Compared with previous epidemics (2020 and 2021), the proportion of CD4/CD8 ratio, lymphocyte count, eosinophil and serum creatinine decreased in patients with mild Omicron infection in 2022 (36.8% vs. 22.1%, 9.8%; 36.8% vs. 23.5%, 7.8%; 42.1% vs. 41.2%, 15.7%; 42.1% vs. 19.1%, 9.8%), the proportion of patients with elevated monocyte count and procalcitonin was large (42.1% vs. 50.0%, 23.5%; 21.1% vs. 5.9%, 0). Conclusion:The incidences of severe disease in patients with SARS-CoV-2 Omicron variant infection was significantly lower than that of previous epidemics, and the occurrence of severe diseases was still related to the underlying diseases.

Diagnosis, treatment and prevention of severe acute respiratory syndrome coronavirus 2 infection in children: experts′ consensus statement (Fifth Edition)updated for the Omicron variant / 中华实用儿科临床杂志

China has classified the Corona Virus Disease 2019(COVID-19) as a statutory category B infectious disease and managed it according to Category B since January 8, 2023.In view that Omicron variant is currently the main epidemic strain in China, in order to guide the treatment of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in children with the times, refer to the Diagnosis and Treatment Protocol for Novel Coronavirus Infection (Trial 10 th Edition), Expert Consensus on Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fourth Edition) and the Diagnosis and Treatment Strategy for Pediatric Related Viral Infections.The Expert Consensus on the Diagnosis, Treatment and Prevention of Novel Coronavirus Infection in Children (Fifth Edition) has been formulated and updated accordingly on related etiology, epidemiology, pathogenic mechanism, clinical manifestations, auxiliary examination, diagnosis and treatment, and added key points for the treatment of COVID-19 related encephalopathy, fulminating myocarditis and other serious complications for clinical reference.

Primary assessment of the diversity of Omicron sublineages and the epidemiologic features of autumn/winter 2022 COVID-19 wave in Chinese mainland / 医学前沿

With the recent ongoing autumn/winter 2022 COVID-19 wave and the adjustment of public health control measures, there have been widespread SARS-CoV-2 infections in Chinese mainland. Here we have analyzed 369 viral genomes from recently diagnosed COVID-19 patients in Shanghai, identifying a large number of sublineages of the SARS-CoV-2 Omicron family. Phylogenetic analysis, coupled with contact history tracing, revealed simultaneous community transmission of two Omicron sublineages dominating the infections in some areas of China (BA.5.2 mainly in Guangzhou and Shanghai, and BF.7 mainly in Beijing) and two highly infectious sublineages recently imported from abroad (XBB and BQ.1). Publicly available data from August 31 to November 29, 2022 indicated an overall severe/critical case rate of 0.035% nationwide, while analysis of 5706 symptomatic patients treated at the Shanghai Public Health Center between September 1 and December 26, 2022 showed that 20 cases (0.35%) without comorbidities progressed into severe/critical conditions and 153 cases (2.68%) with COVID-19-exacerbated comorbidities progressed into severe/critical conditions. These observations shall alert healthcare providers to place more resources for the treatment of severe/critical cases. Furthermore, mathematical modeling predicts this autumn/winter wave might pass through major cities in China by the end of the year, whereas some middle and western provinces and rural areas would be hit by the upcoming infection wave in mid-to-late January 2023, and the duration and magnitude of upcoming outbreak could be dramatically enhanced by the extensive travels during the Spring Festival (January 21, 2023). Altogether, these preliminary data highlight the needs to allocate resources to early diagnosis and effective treatment of severe cases and the protection of vulnerable population, especially in the rural areas, to ensure the country's smooth exit from the ongoing pandemic and accelerate socio-economic recovery.

Epidemiological characterization of a cluster of COVID-19 caused by SARS-CoV-2 Omicron variant at a construction site in Qingpu District， Shanghai / 上海预防医学

ObjectiveTo determine the epidemiological characteristics of a cluster of SARS-CoV-2 Omicron variant at a construction site and provide evidence for further COVID-19 prevention and control. MethodsDemographic data of all COVID-19 cases at a construction site in Qingpu District， Shanghai， and basic information of the construction site were retrospectively collected through filed investigation. Descriptive epidemiology was used for the analysis. Basic reproduction number （R0） and time-dependent reproduction number （Rt） were calculated using R program. ResultsDuring April 12 and May 8， 2022， a total of 314 cases were reported at the construction site， with an attack rate of 60.62%. The attack rate significantly differed between workers and managers （χ2=10.868， P<0.001）， whereas did not differ statistically by gender （χ2=0.358， P=0.550） or by vaccination status （χ2=2.861， P=0.091）. The age of all cases ranged from 5 months of age to 68 years， with a media age of 49.0 years （interquartile range： 39.8， 54.0）. In all cases， male was predominant （83.44%）. Moreover， the epidemic was mainly concentrated in the workers’ dormitory area， with infected cases identified in all buildings of each dormitory area. The attack rate ranged between 33.33% and 87.50% across the buildings. Symptoms and signs were observed among 43.0% of all cases， of which major clinical manifestations included cough （33.33%）， fever （30.37%） and headache （17.04%）. Clinical manifestations did not differ by gender （χ2=1.275， P=0.259） or by vaccination status （χ2=0.186， P=0.666）. Additionally， R0 was estimated to be 6.08 （95% confidence interval： 4.49‒8.02）. The Rt showed a decline in the beginning， followed by an increase and a re-decline. ConclusionThe cluster epidemic of COVID-19 caused by Omicron variant at the construction site is highly contagious， spreads rapidly and quietly， causes mild symptoms， which finally resulted in a large number of infected cases. It warrants rapid and strict containment when an epidemic occurs at construction sites.

Spatiotemporal characteristics and prevention and control measures of SARS-CoV-2 Omicron pandemic in Shanghai / 上海预防医学

ObjectiveTo analyze the spatiotemporal characteristics and prevention and control measures of the pandemic caused by the SARS-CoV-2 Omicron variant in Shanghai in 2022， aiming to optimize future prevention and control strategies. MethodsDescriptive statistical method was used to analyze data on daily infections released by the Shanghai Municipal Health Commission from March 1 to June 30， 2022. ResultsAs of 30 June， a total of 627 110 infections and 588 deaths had been reported in Shanghai. Most of the cases were in Pudong New Area （35.47%）， Minhang District （10.18%） and Huangpu District （9.27%）. The cumulative infection rate was 8.78% in Huangpu District， which was the highest among all the districts. With the progress of the pandemic， the prevention and control measures were strengthened from a “precise prevention and control” strategy to “block and grid” screening， and then upgraded to city-wide lockdown. All daily new infections were identified from the quarantined population on April 29， 2022， reaching the goal of “clearance of community transmission”. ConclusionThe cumulative infections in Shanghai exceeded any previous epidemics in mainland China. Given the enhanced transmissibility and vaccine-induced immune escape of the Omicron variant， timely and strong public health measures are needed to suppress the pandemic under the general policy of "Dynamic zero-COVID".