The Associated Factors of SARS-CoV-2 Reinfection by Omicron Variant - Guangdong Province, China, December 2022 to January 2023

First insight into eosinophils as a biomarker for the early distinction of COVID-19 from influenza A in outpatients

Coronavirus disease 2019 (COVID-19) and influenza A outbreaks have spread rapidly in China. It is difficult to accurately differentiate these two different respiratory tract infections on the basis of their similar early-stage symptoms and lymphocytopenia. In the present study, the age, sex and white blood cell, neutrophil, lymphocyte, monocyte and eosinophil counts, as well as the neutrophil-to-lymphocyte ratio (NLR) of 201 outpatients with confirmed COVID-19 and 246 outpatients with influenza A were investigated and compared. A receiver operating characteristic curve was drawn to determine the thresholds in distinguishing COVID-19 from influenza A Our study found that the monocyte count and NLR were significantly elevated, while the eosinophil count/percentage was higher in outpatients with COVID-19 than in those with influenza A (0.06±0.07 vs. 0.04±0.09, P=0.002; 0.95±1.12 vs. 0.56±0.95, P<0.001, respectively). Logit(P)=-1.11 + 1.29 x eosinophil percentage -12.07 x eosinophil count +1.10 x monocyte count, deduced from the eosinophil count/percentage and monocyte count, had the largest area under the curve at 0.67, with high specificity (80.1%) and a sensitivity of 47.3%. The present study demonstrated that a higher eosinophil count/percentage may be a potential biomarker to significantly differentiate early COVID-19 from influenza A.

Long-term outcomes of mesenchymal stem cell therapy in severe COVID-19 patients: 3-year follow-up of a randomized, double-blind, placebo-controlled trial

BACKGROUND

The long-term effects and outcomes of human mesenchymal stem cell (MSC) therapy in patients with severe coronavirus disease 2019 (COVID-19) remain poorly understood. This study aimed to evaluate the extended safety and efficacy of MSC treatment in severe patients with COVID-19 who participated in our earlier randomized, double-blind, placebo-controlled clinical trial, with follow-up conducted over 3 years.

METHODS

One hundred patients with severe COVID-19 were randomized to receive either an MSC infusion (n = 65, 4 × 107 cells/dose, on days 0, 3, and 6) or a placebo, with both groups receiving the standard of care. At 36 months post-MSC therapy, patients were followed up to long-term safety and efficacy, particularly the effects of MSC therapy on persistent COVID-19 symptoms. Evaluated outcomes included lung imaging results, 6-min walking distance (6-MWD), pulmonary function test results, quality of life scores based on the Short Form-36 (SF-36) health survey, Long COVID symptoms, new-onset comorbidities, tumor marker levels, and rates of COVID-19 reinfection.

RESULTS

Three years post-treatment, 46.94% (23/49) of patients in the MSC group and 34.48% (10/29) in the placebo group showed normal findings on computed tomography (CT) images (odds ratio [OR] = 1.68, 95% confidence interval [CI]: 0.65-4.34). The general health (GH) score from the SF-36 was higher in the MSC group (67.0) compared to the placebo group (50.0), with a difference of 12.86 (95% CI: 1.44-24.28). Both groups showed similar results for total lung severity scores (TSS), 6-MWD, pulmonary function tests, and Long COVID symptoms. No significant differences between groups were observed in new-onset complications (including tumorigenesis) or tumor marker levels. After adjusting for China's dynamic zero-COVID-19 strategy, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection rates were 53.06% (26/49) in the MSC group and 67.86% (19/28) in the placebo group (OR = 0.54, 95% CI: 0.20-1.41).

CONCLUSIONS

These findings support the long-term safety of MSC therapy in patients with severe COVID-19 over 3 years. MSC treatment may offer potential benefits for lung recovery and improved quality of life in patients experiencing Long COVID symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04288102. Registered 28 February 2020, https://clinicaltrials.gov/study/NCT04288102 .

Incidence, severity, risk factors and outcomes of SARS-CoV-2 reinfections during the Omicron period: a systematic review and meta-analysis

Background

Our previous systematic review estimated the cumulative incidence of SARS-CoV-2 reinfections as 1.16% (95% CI = 1.01-1.33%) during the pre-Omicron period. The Omicron variant that emerged in November 2021 was significantly genetically distinct from the previous SARS-CoV-2 variants and thus, more transmissible and posed an increased risk of SARS-CoV-2 reinfections in the population. We, therefore, conducted a fresh systematic review and meta-analysis to estimate the SARS-CoV-2 reinfection burden during the Omicron period.

Methods

We searched CINAHL, Medline, Global Health, Embase, and WHO COVID-19 in October 2023 for studies reporting the SARS-CoV-2 reinfection incidence during the Omicron period. The quality of the included studies was assessed using the Joanna Briggs Institute checklists. Random effects meta-analyses were conducted to estimate the incidence, and requirement of hospitalisation of SARS-CoV-2 reinfections. Symptomatic severity of reinfections and case fatality rates were analysed narratively.

Results

Thirty-six studies were included. The reinfection cumulative incidence during the Omicron period was 3.35% (95% CI = 1.95-5.72%) based on data from 28 studies. The cumulative incidence was higher in 18-59-year-old adults (6.62% (95% CI = 3.22-13.12%)) compared to other age groups and in health care workers (9.88% (95% CI = 5.18-18.03%)) compared to the general population (2.48% (95% CI = 1.34-4.54%)). We estimated about 1.81% (95% CI = 0.18-15.87%) of the reinfected cases required hospitalisation based on limited and highly variable data.

Conclusions

There was an increased risk of reinfections during the Omicron period compared to the pre-Omicron period. The incidence was higher in 18-59-year-old adults and health care workers and generally less severe during the Omicron period. However, data were limited on disease severity and long-term outcomes.

Registration

PROSPERO: CRD42023482598.

Characteristics and risk factors associated with COVID-19 reinfection in Hong Kong: a retrospective cohort study

We aimed to identify risk factors related to COVID-19 reinfection in Hong Kong. We performed a population-based retrospective cohort study and reviewed case-based data on COVID-19 infections reported to the Centre for Health Protection from 8 January 2020 to 29 January 2023. We analyzed the epidemiology of COVID-19 infections and performed a Cox regression analysis. In this period, 3.32% (103,065/3,106,579) of COVID-19 infections recorded were classified as reinfection. Compared with primarily infected cases, a higher proportion of re-infected cases had chronic diseases (33.54% vs. 27.27%) and were residents of residential care homes (RCH) (10.99% vs. 1.41%). The time interval between the two episodes ranged from 31 to 1,050 days (median 282 days). Cox regression analysis of Omicron cases with the adjustment of covariates showed that being female (Hazard Ratio [HR] 1.12, 95% CI 1.11-1.13), chronic diseases (HR 1.18, 95% CI 1.16-1.20) and RCH residents (HR 6.78, 95% CI 6.61-6.95) were associated with reinfection, while additional vaccination after primary infection was protective (HR 0.80, 95% CI 0.79-0.81). Further analytical studies on the risk factors and protectors of COVID-19 reinfection are needed to guide targeted interventions.

Prevalence of infection and reinfection among health care workers in a hospital of Northern China between BA.5/BF.7 and XBB.1.5 wave

BACKGROUND

To analyze the epidemiological characteristics of the SARS-CoV-2 infection and reinfection associated with the emergence of Omicron variant in Healthcare workers (HCWs).

METHODS

We enrolled 760 HCWs who received 2-4 vaccination doses of COVID-19 and followed by BA.5/BF.7 and/or XBB.1.5 breakthrough infections between December 2022 and July 2023. Serum sample from each individual were collected approximately 1,3 and 6 months after last exposure. IgM, IgG and Total antibodies against SARS-CoV-2 were measured by chemiluminescent immunoassay. Meanwhile, we created an Enterprise WeChat link for HCWs to self-report SARS-CoV-2 infections, symptoms and post COVID-19 conditions.

RESULTS

Our study revealed that the reinfection rate among HCWs reached 26.1%. The main symptoms were fever (91.2% vs 60.1%), cough (78.8% vs 58.0%), and sore throat (75.4% vs 59.6%) during infection and reinfection in Omicron BA.5/BF.7 and XBB.1.5 wave, and the interval for reinfection ranged from 91 to 210 days (median 152). Fatigue (23.6%), memory loss (18.8%) and coughing (18.6%) were the most prevalent long COVID symptoms, with a higher prevalence among female HCWs.

CONCLUSIONS

HCWs reinfection with SARS-CoV-2 causes milder symptoms, but high reinfection rate and short intervals. Strengthen infection prevention and control is crucial to mitigating infection risk and improving health services.

Predicting higher risk factors for COVID-19 short-term reinfection in patients with rheumatic diseases: a modeling study based on XGBoost algorithm

BACKGROUND

Corona virus disease 2019 (COVID-19) reinfection, particularly short-term reinfection, poses challenges to the management of rheumatic diseases and may increase adverse clinical outcomes. This study aims to develop machine learning models to predict and identify the risk of short-term COVID-19 reinfection in patients with rheumatic diseases.

METHODS

We developed four prediction models using explainable machine learning to assess the risk of short-term COVID-19 reinfection in 543 patients with rheumatic diseases. Psychological health was evaluated using the Functional Assessment of Chronic Illness Therapy Fatigue (FACIT-F) scale, the Patient Health Questionnaire-9 (PHQ-9), the Generalized Anxiety Disorder 7-item (GAD-7) questionnaire, and the Pittsburgh Sleep Quality Index (PSQI) scale. Health status and disease activity were assessed using the EuroQol-5 Dimension-3 Level (EQ-5D-3L) descriptive system and the Visual Analogue Score (VAS) scale. The model performance was assessed by Area Under the Receiver Operating Characteristic Curve (AUC), Area Under the Precision-Recall Curve (AUPRC), and the geometric mean of sensitivity and specificity (G-mean). SHapley Additive exPlanations (SHAP) analysis was used to interpret the contribution of each predictor to the model outcomes.

RESULTS

The eXtreme Gradient Boosting (XGBoost) model demonstrated superior performance with an AUC of 0.91 (95% CI 0.87-0.95). Significant factors of short-term reinfection included glucocorticoid taper (OR = 2.61, 95% CI 1.38-4.92), conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) taper (OR = 2.97, 95% CI 1.90-4.64), the number of symptoms (OR = 1.24, 95% CI 1.08-1.42), and GAD-7 scores (OR = 1.07, 95% CI 1.02-1.13). FACIT-F scores were associated with a lower likelihood of short-term reinfection (OR = 0.95, 95% CI 0.93-0.96). Besides, we found that the GAD-7 score was one of the most important predictors.

CONCLUSION

We developed explainable machine learning models to predict the risk of short-term COVID-19 reinfection in patients with rheumatic diseases. SHAP analysis highlighted the importance of clinical and psychological factors. Factors included anxiety, fatigue, depression, poor sleep quality, high disease activity during initial infection, and the use of glucocorticoid taper were significant predictors. These findings underscore the need for targeted preventive measures in this patient population.

Mapping knowledge structure and emerging trends of extracorporeal membrane oxygenation for acute respiratory distress syndrome: a bibliometric and visualized study

Introduction

With the discovery of extracorporeal membrane oxygenation (ECMO), it is considered as a valuable tool for supporting the treatment of severe acute respiratory distress syndrome (ARDS). It has gained increasing attention, particularly during the COVID-19 epidemic. However, to date, no relevant bibliometric research on the association between ECMO and ARDS (ECMO-ARDS) has been reported. Our study aimed to summarize the knowledge structure and research focus of ECMO-ARDS through a bibliometric analysis.

Method

Publications related to ECMO-ARDS from 2000 to 2022 were obtained from the Web of Science Core Collection (WoSCC). Research data underwent bibliometric and visual analysis by using CiteSpace, VOSviewer, and one online analysis platform. By analyzing the countries, institutions, journals, authors, the geographic distribution of research contributions as well as the leading institutions and researchers in this field were identified. Additionally, prominent journals and highly cited publications were highlighted, indicating their influence and significance in the field. Moreover, the co-citation references and co-occurring keywords provided valuable information on the major research topics, trends, and potential emerging frontiers.

Results

A total of 1,565 publications from 60 countries/regions were retrieved. The annual publication number over time revealed exponential growth trends (R2 = 0.9511). The United States was dominant in ECMO-ARDS research, whereas the Univ Toronto was most productive institution. Prof Combes A published the most publications in this area. ASAIO Journal and Intensive Care Medicine were the most active and co-cited journals, respectively. Reference co-citation analysis showed that current research focus has shifted to COVID-related ARDS, multi-center studies, as well as prone positioning. Apart from the keywords "ECMO" and "ARDS", other keywords appearing at high frequency in the research field were "COVID-19", "mechanical ventilation", "extracorporeal life support", "respiratory failure", "veno-venous ECMO", "SARS-CoV-2", "outcome". Among them, keywords like "mortality", "veno-venous ECMO", "epidemiology", "obesity", "coagulopathy", "lung ultrasound", "inhalation injury", "noninvasive ventilation", "diagnosis", "heparin", "cytokine storm" has received growing interest in current research and also has the potential to continue to become research hotspots in the near future.

Conclusion

This bibliometric analysis offers a comprehensive understanding of the current state of ECMO-ARDS research and can serve as a valuable resource for researchers, policymakers, and stakeholders in exploring future research directions and fostering collaborations in this critical field.

The serological IgG and neutralizing antibody of SARS-CoV-2 omicron variant reinfection in Jiangsu Province, China

Background

It is important to figure out the immunity of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) reinfection to understand the response of humans to viruses. A serological survey for previously infected populations in Jiangsu Province was conducted to compare the antibody level of SARS-CoV-2 in reinfection by Omicron or not.

Methods

Reinfection with SARS-CoV-2 was defined as an individual being infected again after 90 days of the initial infection. Telephone surveys and face-to-face interviews were implemented to collect information. Experimental and control serum samples were collected from age-sex-matched reinfected and non-reinfected cases, respectively. IgG anti-S and neutralizing antibodies (Nab) concentrations were detected by the Magnetism Particulate Immunochemistry Luminescence Method (MCLIA). Antibody titers were log(2)-transformed and analyzed by a two-tailed Mann-Whitney U test. Subgroup analysis was conducted to explore the relationship between the strain type of primary infection, SARS-Cov-2 vaccination status, and antibody levels. Multivariate linear regression models were used to identify associations between reinfection with IgG and Nab levels.

Results

Six hundred thirty-one individuals were enrolled in this study, including 327 reinfected cases and 304 non-reinfected cases. The reinfection group had higher IgG (5.65 AU/mL vs. 5.22 AU/mL) and Nab (8.02 AU/mL vs. 7.25 AU/mL) levels compared to the non-reinfection group (p < 0.001). Particularly, individuals who had received SARS-CoV-2 vaccination or were initially infected with the Wild type and Delta variant showed a significant increase in antibody levels after reinfection. After adjusting demographic variables, vaccination status and the type of primary infection together, IgG and Nab levels in the reinfected group increased by log(2)-transformed 0.71 and 0.64 units, respectively (p < 0.001). This revealed that reinfection is an important factor that affects IgG and Nab levels in the population.

Conclusion

Reinfection with Omicron in individuals previously infected with SARS-CoV-2 enhances IgG and Nab immune responses.

Safety, immunogenicity and protective effect of sequential vaccination with inactivated and recombinant protein COVID-19 vaccine in the elderly: a prospective longitudinal study

The safety and efficacy of COVID-19 vaccines in the elderly, a high-risk group for severe COVID-19 infection, have not been fully understood. To clarify these issues, this prospective study followed up 157 elderly and 73 young participants for 16 months and compared the safety, immunogenicity, and efficacy of two doses of the inactivated vaccine BBIBP-CorV followed by a booster dose of the recombinant protein vaccine ZF2001. The results showed that this vaccination protocol was safe and tolerable in the elderly. After administering two doses of the BBIBP-CorV, the positivity rates and titers of neutralizing and anti-RBD antibodies in the elderly were significantly lower than those in the young individuals. After the ZF2001 booster dose, the antibody-positive rates in the elderly were comparable to those in the young; however, the antibody titers remained lower. Gender, age, and underlying diseases were independently associated with vaccine immunogenicity in elderly individuals. The pseudovirus neutralization assay showed that, compared with those after receiving two doses of BBIBP-CorV priming, some participants obtained immunological protection against BA.5 and BF.7 after receiving the ZF2001 booster. Breakthrough infection symptoms last longer in the infected elderly and pre-infection antibody titers were negatively associated with the severity of post-infection symptoms. The antibody levels in the elderly increased significantly after breakthrough infection but were still lower than those in the young. Our data suggest that multiple booster vaccinations at short intervals to maintain high antibody levels may be an effective strategy for protecting the elderly against COVID-19.

SARS-CoV-2 reinfection with Omicron variant in Shaanxi Province, China: December 2022 to February 2023

BACKGROUND

Prior to December 2022, there were no reports of reinfection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Shaanxi province, China. Since then, China has refined its strategy in response to coronaviruses. The purpose of this study was to determine the incidence of SARS-CoV-2 reinfections and its contributing factors, as well as to compare clinical characteristics between first and second episodes of infection in Shaanxi Province, China between December 2022 and February 2023.

METHODS

We conducted a cross-sectional study using an epidemiological survey system and electronic questionnaires to investigate the incidence of SARS-CoV-2 reinfection among previously infected individuals during the epidemic wave owing to the Omicron variant that began in December 2022. A logistic regression model was used to determine those factors influencing SARS-CoV-2 reinfections.

RESULTS

According to the virus variant that caused the first infection, the rate of reinfection for the Omicron variants was 1.28%, 1.96%, and 5.92% at 2-3 months, 4-5 months, and 7-9 months after the primary infection, respectively. The rate of reinfection for the Delta variants was 25.10% 11-12 months after the primary infection. Females, adults between 18 and 38 years and being a medical worker were associated with an increased risk of reinfection. Fever, cough, sore throat and fatigue were the four most common clinical symptoms during both first and second COVID-19 infections.

CONCLUSIONS

In our study, the rate of SARS-CoV-2 reinfection increased over time during epidemic waves predominantly involving the Omicron variant in Shaanxi province, China. Large-scale infections are less likely in subsequent Omicron epidemic waves. Nevertheless, it is essential to continuously monitor cases of infection as well as continue surveillance for emerging SARS-CoV-2 variants.

The Efficacy and Safety of Shashen-Maidong Decoction Combined with Western Medicine in the Treatment of Omicron Infected Individuals Over 85 Years Old: A Retrospective Study

Background

During the Omicron variant outbreak of COVID-19 (2022-2023), Chinese healthcare institutions combined traditional Chinese medicine (TCM) with Western medical practices to treat COVID-19 patients, especially the elderly. The efficacy and safety of this approach, especially for individuals aged over 85, need further investigation.

Methods

In this retrospective study, a cohort of 62 patients aged over 85 years, diagnosed with COVID-19 infection, was examined. Among them, 34 patients were administered Shashen-Maidong decoction in conjunction with Western medicine (SMD+WM group), while the remaining 28 patients received only Western medicine (WM group). Comparative analysis was conducted between the two groups, encompassing parameters such as the duration for the nucleic acid test to turn negative, length of intensive care unit (ICU) stay, mortality rate, utilization of high-flow nasal cannula oxygen (HFNC), occurrence of endo-tracheal intubation, frequency of recurrent respiratory infections within three months, and various laboratory indicators.

Results

There were no significant differences observed between the two groups in terms of the duration for the nucleic acid test to turn negative, the length of ICU stay, mortality rate, utilization of HFNC, performance of endo-tracheal intubation, or the frequency of recurrent respiratory infections within three months (P > 0.05). However, in comparison to the WM group, the SMD+WM group exhibited notably lower growth rates in white blood cell (WBC) and neutrophil (NEUT) values. Additionally, the SMD+WM group demonstrated superior improvement in cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP) values.

Conclusion

In contrast to the administration of Western medicine alone, the combined use of Shashen-Maidong decoction with Western medicine significantly suppresses the increase in WBC count, particularly in NEUT levels, in elderly patients diagnosed with COVID-19. Moreover, this combined treatment exhibits a protective effect on cardiac function and demonstrates a relatively safe profile.

Performance evaluation of SARS-CoV-2 antigen detection in the post-pandemic era: multi-laboratory assessment

OBJECTIVES

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen detection is an indispensable tool for epidemic surveillance in the post-pandemic era. Faced with irregular performance, a comprehensive external quality assessment (EQA) scheme was conducted by the National Center for Clinical Laboratories (NCCL) to evaluate the analytical performance and status of SARS-CoV-2 antigen tests.

METHODS

The EQA panel included ten lyophilized samples containing serial 5-fold dilutions of inactivated SARS-CoV-2-positive supernatants of the Omicron BA.1 and BA.5 strains and negative samples, which were classified into "validating" samples and "educational" samples. Data were analyzed according to qualitative results for each sample.

RESULTS

A total of 339 laboratories in China participated in this EQA scheme, and 378 effective results were collected. All validating samples were correctly reported by 90.56 % (307/339) of the participants and 90.21 % (341/378) of the datasets. The positive percent agreement (PPA) was >99 % for samples with concentrations of 2 × 107 copies/mL but was 92.20 % (697/756) for 4 × 106 copies/mL and 25.26 % (382/1,512) for 8 × 105 copies/mL samples. Colloidal gold was the most frequently used (84.66 %, 320/378) but showed the lowest PPAs (57.11 %, 1,462/2,560) for positive samples compared with fluorescence immunochromatography (90 %, 36/40) and latex chromatography (79.01 %, 335/424). Among 11 assays used in more than 10 clinical laboratories, ACON showed a higher sensitivity than other assays.

CONCLUSIONS

The EQA study can help to validate whether it's necessary to update antigen detection assays for manufacturers and provide participants with information about the performance of assays to take the first step toward routine post-market surveillance.

Epidemiological and clinical characteristics of COVID-19 reinfection during the epidemic period in Yangzhou city, Jiangsu province

Background

With the continuous progress of the epidemic of coronavirus disease 2019 (COVID-19) infection and the constant mutation of the virus strain, reinfection occurred in previously infected individuals and caused waves of the epidemic in many countries. Therefore, we aimed to explore the characteristics of COVID-19 reinfection during the epidemic period in Yangzhou and provide a scientific basis for assessing the COVID-19 situation and optimizing the allocation of medical resources.

Methods

We chose previously infected individuals of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reported locally in Yangzhou city from January 2020 to November 30, 2022. A telephone follow-up of cases was conducted from February to March 2023 to collect the COVID-19 reinfection information. We conducted a face-to-face survey on that who met the definition of reinfection to collect information on clinical symptoms, vaccination status of COVID-19, and so on. Data were analyzed using SPSS 19.0.

Results

Among the 999 eligible respondents (92.24% of all the participants), consisting of 42.28% males and 57.72% females, the reinfection incidence of females was significantly higher than that of male cases (χ2 = 5.197, P < 0.05); the ages of the respondents ranged from 1 to 91 years, with the mean age of 42.28 (standard deviation 22.73) years; the most of the sufferers were infected initially with Delta variant (56.88%), followed by the Omicron subvariants BA.1/BA.2 (39.52%). Among all the eligible respondents, 126 (12.61%) reported COVID-19 reinfection appearing during the epidemic period, and the intervals between infections were from 73 to 1,082 days. The earlier the initial infection occurred, the higher the reinfection incidence and the reinfection incidence was significantly increased when the interval was beyond 1 year (P < 0.01) .119 reinfection cases (94.4%) were symptomatic when the most common symptoms included fever (65.54%) and cough (61.34%); compared with the initial infection cases, the proportion of clinical symptoms in the reinfected cases was significantly higher (P < 0.01). The reinfection incidence of COVID-19 vaccination groups with different doses was statistically significant (P < 0.01). Fewer reinfections were observed among the respondents with three doses of COVID-19 vaccination compared to the respondents with two doses (χ2 = 14.595, P < 0.001) or without COVID-19 vaccination (χ2 =4.263, P = 0.039).

Conclusion

After the epidemic period of COVID-19, the reinfection incidence varied with different types of SARS-CoV-2 strains. The reinfection incidence was influenced by various factors such as virus characteristics, vaccination, epidemic prevention policies, and individual variations. As the SARS-CoV-2 continues to mutate, vaccination and appropriate personal protection have practical significance in reducing the risk of reinfection.