Clinical characteristics of hospitalized mild/moderate COVID-19 patients with a prolonged negative conversion time of SARS-CoV-2 nucleic acid detection

Virus-Induced Pathogenic Antibodies: Lessons from Long COVID and Dengue Hemorrhage Fever

Virus-induced antibodies represent a dual-edged sword in the immune response to viral infections. While antibodies are critical for neutralizing pathogens, some can paradoxically exacerbate disease severity through mechanisms such as antibody-dependent enhancement (ADE), autoantibody, and prolonged inflammation. Long coronavirus disease (COVID) and dengue hemorrhagic fever (DHF) exemplify conditions where pathogenic antibodies play a pivotal role in disease progression. Long COVID is associated with persistent immune dysregulation and autoantibody production, leading to chronic symptoms and tissue damage. In DHF, pre-existing antibodies against dengue virus contribute to ADE, amplifying viral replication, immune activation, and vascular permeability. This review explores the mechanisms underlying these pathogenic antibody responses, highlighting the shared pathways of immune dysregulation and comparing the distinct features of both conditions. By examining these studies, we identify key lessons for therapeutic strategies, vaccine design, and future research aimed at mitigating the severe outcomes of viral infections.

Estimating the association between cigarette and e-cigarette use patterns and SARS-CoV-2 negative conversion time: retrospective online survey in China

BACKGROUND

Cigarette smoking has been reported to be associated with SARS-CoV-2 negative conversion, while little is known about the effect of its dual use with e-cigarettes. This study aimed to investigate whether tobacco product use patterns including e-cigarette use were linked with delayed negative conversion of SARS-CoV-2.

METHODS

An online national survey was conducted from January 28 through February 21, 2023, targeting a community-based population in mainland of China after peak waves of the coronavirus disease 2019 (COVID-19). Participants were followed from the onset of COVID-19 symptoms until the negative conversion day or the day of answering the questionnaire as the endpoint of the study. Multi-variable adjusted Cox proportional hazard models were used to compare the negative conversion time of SARS-CoV-2 across different cigarette and e-cigarette use patterns.

RESULTS

A total of 66,537 participants infected with COVID-19 were enrolled and 13,294 were included in the analyses. During the median duration of 7 days (interquartile range 5 to 10 days), a total of 11,587 (87.2%) had a negative conversion. Compared with never users, current exclusive smokers (multi-variable adjusted HR 0.59, 95% CI 0.48-0.71), current dual users (HR 0.31, 95% CI 0.22-0.44), and previous smokers (HR 0.56, 95% CI 0.37-0.83) took longer to turn negative after 10 days of follow-up.

CONCLUSIONS

Both current exclusive cigarette use and dual use of cigarettes and e-cigarettes were associated with the delayed negative conversion of SARS-CoV-2, which strengthens the importance of smoking and vaping cessation messaging and community-based tobacco control strategies during pandemics like COVID-19 next time.

The severity assessment and nucleic acid turning-negative-time prediction in COVID-19 patients with COPD using a fused deep learning model

BACKGROUND

Previous studies have shown that patients with pre-existing chronic obstructive pulmonary diseases (COPD) were more likely to be infected with coronavirus disease (COVID-19) and lead to more severe lung lesions. However, few studies have explored the severity and prognosis of COVID-19 patients with different phenotypes of COPD.

PURPOSE

The aim of this study is to investigate the value of the deep learning and radiomics features for the severity evaluation and the nucleic acid turning-negative time prediction in COVID-19 patients with COPD including two phenotypes of chronic bronchitis predominant patients and emphysema predominant patients.

METHODS

A total of 281 patients were retrospectively collected from Hohhot First Hospital between October 2022 and January 2023. They were divided to three groups: COVID-19 group of 95 patients, COVID-19 with emphysema group of 94 patients, COVID-19 with chronic bronchitis group of 92 patients. All patients underwent chest computed tomography (CT) scans and recorded clinical data. The U-net model was pretrained to segment the pulmonary involvement area on CT images and the severity of pneumonia were evaluated by the percentage of pulmonary involvement volume to lung volume. The 107 radiomics features were extracted by pyradiomics package. The Spearman method was employed to analyze the correlation of the data and visualize it through a heatmap. Then we establish a deep learning model (model 1) and a fusion model (model 2) combined deep learning with radiomics features to predict nucleic acid turning-negative time.

RESULTS

COVID-19 patients with emphysema was lowest in the lymphocyte count compared to COVID-19 patients and COVID-19 companied with chronic bronchitis, and they have the most extensive range of pulmonary inflammation. The lymphocyte count was significantly correlated with pulmonary involvement and the time for nucleic acid turning negative (r=-0.145, P < 0.05). Importantly, our results demonstrated that model 2 achieved an accuracy of 80.9% in predicting nucleic acid turning-negative time.

CONCLUSION

The pre-existing emphysema phenotype of COPD severely aggravated the pulmonary involvement of COVID-19 patients. Deep learning and radiomics features may provide more information to accurately predict the nucleic acid turning-negative time, which is expected to play an important role in clinical practice.

Associations between genetic mutations in different SARS-CoV-2 strains and negative conversion time of viral RNA among imported cases in Hangzhou: A cross-sectional study

PURPOSE

Previous studies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have focused on factors that influence the achievement of negative conversion of viral RNA. This study aimed to investigate the effects of the genetic mutations in different SARS-CoV-2 strains on the negative conversion time (NCT) among imported cases in Hangzhou, Zhejiang Province, China, in order to provide valuable insights for developing targeted epidemic prevention guidelines.

METHODS

This retrospective study involved 146 imported SARS-CoV-2 cases in Hangzhou from 8 April 2021 to 11 June 2022. We compared the SARS-CoV-2-specific indicators, clinical indexes, and NCT among the wild-type (WT), Delta, and Omicron groups. Spearman correlation analysis was used to identify the correlations of NCT with mutation types/frequencies.

RESULTS

The mean age of the imported cases was 35.3 (SD: 12.3) years, with 71.92 % males and 28.08 % females. The mean cycle threshold (Ct) values of open reading frame 1ab (ORF1ab) and nucleocapsid (N) RNA were 25.17 (SD: 6.44) and 23.4 (SD: 6.76), respectively. The mutations of SARS-CoV-2 strains were mainly located in N, membrane (M), spike (S), ORF1a, ORF1b, ORF3a, ORF6, and ORF9b genes among the WT, Delta, and Omicron groups. NCT was significantly prolonged in the WT and Delta groups compared to the Omicron group. T lymphocyte, white blood cell, eosinophil, and basophil counts were dramatically higher in the WT group than the Delta group. White blood cell, red blood cell, and basophil counts were significantly lower in the Delta group than the Omicron group. Spearman correlation analysis revealed a significant correlation between the NCT of viral RNA and mutation types of viral genes of WT and Omicron strains. Additionally, NCT was markedly negatively correlated with the frequencies of five mutations in Omicron strains (ORF1b:P1223L, ORF1b:R1315C, ORF1b:T2163I, ORF3a:T223I, and ORF6:D61L).

CONCLUSIONS

This study indicates that five mutations in Omicron strains (ORF1b:P1223L/R1315C/T2163I, ORF3a:T223I and ORF6:D61L) shortened NCT in imported SARS-CoV-2 cases.

The efficacy of herbal medicines on the length of stay and negative conversion time/rate outcomes in patients with COVID-19: a systematic review

Introduction

In recent years, diverse initiatives have been carried out to control the COVID-19 pandemic, ranging from measures restricting social activities to analyzing drugs and vaccines. Studies on herbal medicines are also increasingly conducted in various countries as an adjuvant therapy or supplement. Therefore, this systematic review aimed to investigate the efficacy of herbal medicines analyzed from various countries through clinical trials with the randomized controlled trial method. The outcomes of Length of Stay (LOS), Negative Conversion Time (NCT), and Negative Conversion Rate (NCR) were the main focus.

Methods

An extensive review of literature spanning from 2019 to 2023 was carried out using well-known databases including PubMed, Scopus, and Cochrane. The search included relevant keywords such as "randomized controlled trial," "COVID-19," and "herbal medicine."

Results

A total of 8 articles were part of the inclusion criteria with outcomes of LOS, NCT, and NCR. In terms of LOS outcomes, all types of herbal medicines showed significant results, such as Persian Medicine Herbal (PM Herbal), Persian Barley Water (PBW), Jingyin Granules (JY granules), Reduning Injection, and Phyllanthus emblica (Amla). However, only JY granules showed significant results in NCR outcome, while JY granules and Reduning Injection showed significant results in reducing NCT.

Conclusion

These findings enrich our understanding of the potential benefits of herbal medicines in influencing LOS, NCR and NCT parameters in COVID-19 patients. Herbal medicines worked to treat COVID-19 through antiviral, anti-inflammatory, and immunomodulatory mechanisms.

Comparison of time to negative conversion of SARS-CoV-2 between young and elderly among asymptomatic and mild COVID-19 patients: a cohort study from a national containment center

Objective

We aimed to study the relationship between age and time to negative conversion of SARS-CoV-2 in patients with asymptomatic and mild forms of COVID-19.

Methods

We conducted a cohort study including all patients diagnosed with COVID-19 from the national COVID-19 containment center of Tunisia. Patients were subdivided into two cohorts: (under 60 years) and (over 60 years) and were followed up until PCR negativization. Log rank test and Cox regression were applied to compare time to negative conversion between the old group and the young group.

Results

The study included 289 patients with non-severe forms of COVID-19. Age over 60 was significantly associated with delayed negative conversion in male sex (Hazard ratio (HR): 1.9; 95% CI: 1.2-3.07) and among patients with morbid conditions (HR:1.68; 95% CI: 1.02-2.75) especially diabetics (HR: 2.06; 95% CI: 1.01-4.21). This association increased to (HR:2.3; 95% CI: 1.13-4.66) when male sex and comorbidities were concomitantly present and rose to (HR: 2.63; 95% CI: 1.02-6.80) for men with diabetes. Cox regression analysis revealed a significantly delayed negative conversion in symptomatic patients. Significant interaction was observed between gender and age and between age and chronic conditions.

Conclusion

Age is associated with delayed negative conversion of viral RNA in certain subgroups. Identifying these subgroups is crucial to know how prioritize preventive strategies in elderly.

Prolonged Viral Shedding in Cancer Patients with Asymptomatic or Mild Omicron Infection: A Retrospective Study

Background

This study aimed to investigate the risk factors for persistent viral shedding in cancer patients after Omicron infection.

Methods

Patients with asymptomatic or mild Omicron infection (≥18 years) who were treated in a makeshift hospital in Shanghai were enrolled from 9 Apr to 11 May, 2022. Deidentified information of all patients were collected retrospectively. Logistic regression model was used to identify risk factors associated with prolonged duration of viral shedding (defined as the time from the day of first positive SARS-CoV-2 RNA test to the first day of two consecutive negative SARS-CoV-2 RNA tests).

Results

A total of 1442 Omicron-infected patients were enrolled, including 129 cancer patients and 1313 non-cancer patients. The baseline clinical characteristics of cancer and non-cancer patients were balanced by propensity score matching (1:4). Compared with non-cancer patients, a higher odds ratio ([OR] 1.84, 95% CI 1.24-2.76, P = 0.003) of lasting viral shedding for ≥7 days was found in cancer patients. Further subgroup analyses found that cancer patients were at higher risk for prolonged viral shedding in a subgroup of patients without hypertension (OR 1.89), diabetes (OR 1.80), or other chronic disease (OR 2.13), unvaccinated (OR 1.97), and asymptomatic (OR 2.36). In addition, 29 patients with active cancer and 19 patients with inactive cancer were identified. The median duration of viral shedding in the active cancer group was longer than that in the inactive cancer group (10 vs 6 days, P = 0.002). The risk of persistent viral shedding ≥7 days was also increased in the active cancer group (OR 5.33, 95% CI 1.49-21.51, P = 0.013).

Conclusion

Cancer disease is an independent risk factor for prolonged viral shedding in Omicron infected patients, especially in patients with active cancer.

Increased nutrition risk is associated with a prolonged negative conversion of viral RNA in children and adolescents with COVID-19

BACKGROUND

This study aimed to determine the factors affecting the time to negative conversion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in children and adolescents, with particular reference to nutrition risk assessment on admission.

METHODS

This retrospective observational study was conducted in a sentinel hospital for novel coronavirus in Quanzhou, China. The study population comprised children and adolescents with COVID-19 admitted to the isolation wards between March 25 and April 12, 2022. Based on the Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP), nutrition risk screening was performed within 24 h of admission. Univariate and multivariate analyses were used to identify independent factors for the time to negative viral RNA conversion.

RESULTS

A total of 185 patients with confirmed COVID-19 were included in this study. The median time to viral RNA conversion (from the first day of a positive nucleic acid test to the first day of consecutive negative results) was 15 days (IQR 12-18 days), ranging from 4 to 25 days. High nutrition risk (hazard ratio [HR]: 0.543, 95% CI: 0.334-0.881) and fever (HR: 0.663; 95% CI: 0.483-0.910) were independent factors influencing the negative conversion of SARS-CoV-2 RNA.

CONCLUSION

High nutrition risk and fever were independently associated with delayed viral clearance in children and adolescents with SARS-CoV-2 infection, so these factors should be considered during the treatment plans for infected children and adolescents.

Prognostic Value of Neutrophil-to-Lymphocyte Ratio and Vaccination for Negative Conversion Time of Nucleic Acid in Nonsevere COVID-19 Patients Infected by SARS-CoV-2 Omicron Variant

SARS-CoV-2 Omicron variant is significantly different from all the previous variants and has rapidly replaced other variants as the dominant variant across the globe. An easily obtained, inexpensive, and rapid marker is needed to predict the negative conversion time (NCT) of nucleic acid in nonsevere COVID-19 patients infected by the Omicron variant. This retrospective study enrolled 226 patients infected by the Omicron variant between April 23, 2022, and May 16, 2022. The median age of the patients was 61 (interquartile range (IQR), 48-70) years, and 56.2% were male. 84 patients (37.2%) had at least one comorbidity, and 49 patients (21.7%) were classified into the moderate illness group. 145 patients (64.2%) received at least one dose of vaccine, in which 67 patients (29.6%) received a booster dose of vaccine. The median duration of NCT was 8 (IQR, 7-11) days. Univariate Cox analyses found that high NLR (>2.22), aged ≥65 years, vaccination, and moderate illness were significantly related to the NCT of nucleic acid. Multivariate Cox regression analysis showed that high NLR (NLR > 2.22, hazard ratio (HR):0.718, 95% CI: 0.534-0.964, p = 0.028) and vaccination (vaccinated ≥1 dose, HR: 1.536, 95% CI: 1.147-2.058, p = 0.004) were independently associated with NCT of nucleic acid. NLR is a rapid, simple, and useful prognostic factor for predicting NCT of nucleic acid in nonsevere COVID-19 patients with the Omicron variant. In addition, vaccination may also play a valuable role in predicting the NCT of nucleic acid.

Clinical and virological features of asymptomatic and mild symptomatic patients with SARS-CoV-2 Omicron infection at Shanghai Fangcang shelter hospital

OBJECTIVE

The objective of this study is to evaluate and compare clinical and virological characteristics of asymptomatic and mild symptomatic patients of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.2.2 variant infection and identify risk factors associated with the prolonged viral negative conversion duration.

METHODS

We conducted a retrospective observational study in a Shanghai (China) Fangcang shelter hospital from April 9 to May 17, 2022. The patient-related demographic or clinical data were retrospectively recorded. Comparisons of demographic and clinical characteristics between asymptomatic and mild-symptomatic patients were performed. Cox regression was performed to identify the risk factors of prolonged viral negative conversion duration.

RESULTS

A total of 551 patients confirmed with SARS-CoV-2 Omicron variant infection were enrolled in the study. Of these, 297 patients (53.9%) were asymptomatic and 254 patients (46.1%) had mild symptoms. When comparing the clinical and virological characteristics between the asymptomatic and mild symptomatic groups, several clinical parameters, including age, gender, time to viral clearance from the first positive swab, chronic comorbidities, and vaccination dose did not show statistically significant differences. In mild symptomatic patients, the median viral negative conversion duration (NCD) was 7 days (interquartile range [IQR]: 5-9), which was comparable to the median of 7 days (IQR: 5-10) in asymptomatic patients (p = .943). Multivariate Cox analysis revealed that patients age ≥ 60 years had a significantly higher hazard ratio (HR) for prolonged viral NCD (HR: 1.313; 95% confidence interval: 1.014-1.701, p = .039).

CONCLUSION

Asymptomatic and symptomatic patients with non-severe SARS-CoV-2 Omicron BA.2.2 variant infection have similar clinical features and virological courses. Old age was an independent risk factor for prolonged SARS-CoV-2 conversion time.

Pre-existing Immunocompromised Status as a Preventer of Mortality in COVID-19 Patients: Friend or Foe?

Objective COVID-19 has been negatively impacted by a number of comorbidities. Aside from that, some conditions or treatments that cause immunosuppression can alter the course of the disease, leading to worse outcomes. The primary goal of this study is to compare the clinical presentation, laboratory analysis, radiological findings, and outcomes of patients with COVID-19 with and without immunosuppression. Materials and methods The study includes patients with pre-existing immunosuppression and COVID-19 infection who were admitted and received inpatient treatment at Marmara University Hospital, Istanbul, Pulmonary Medicine ward between April 2020 and June 2020. Data on demographics, epidemiology, clinical course, laboratory analysis, radiological findings, length of hospital stay, morbidity, and mortality were collected from all patients. Results The study group consisted of 23 patients who had pre-existing immunosuppression, and the control group consisted of 207 immunocompetent patients, making a total of 230 patients. Significant differences in lymphocyte count, ROX (respiratory-rate oxygenation) index on Day 0, and fibrinogen levels were discovered between the two groups. SARI (severe acute respiratory infection) was more common in the control group than in the study group (p<0.022), but there was no difference in mortality. Conclusion The mean number and percentage of lymphocytes were lower in immunocompromised COVID-19 patients at the time of diagnosis. Higher ROX index values and a lower risk of developing SARI could explain the hypothesis that these patients may be benefiting from a pre-existing corticosteroid regimen. Additional research with larger numbers of patients may be beneficial in drawing a more definitive conclusion.

Clinical and psychological status analysis of children and parents infected with familial aggregation omicron variant in Shanghai in parent-child ward

Aims

To analyze the clinical characteristics, treatment outcomes and sleep psychological problems of children and parents infected with familial aggregation Omicron variants under a parent-child ward treatment mode to provide a theoretical reference for the diagnosis and comprehensive treatment of Omicron variant strains.

Methods

The clinical data of 225 children and 230 adult family members admitted were retrospectively collected and analyzed to investigate their clinical characteristics and response to treatments.

Results

The proportion of infected adults and children was the same, and the proportion of children with mild disease was higher than that of adults, but the clinical symptoms were milder. The clinical symptoms of fever, nausea, vomiting and wheezing in children were significantly higher than in adults (P < 0.05). In addition, dry pharynx, pharynx itching and pharyngeal pain were lower than in adults (P < 0.05). The time of turning negative in the moderate group was longer than in the mild group, and the time of turning negative in the unvaccinated group was higher than in the vaccinated group (P < 0.05). The Cycle Threshold Value (Ct value) of Open Reading Frame 1ab (ORF1ab) and Nucleocapsid protein (N) gene of children were higher adults. The increase in the rate of Ct value of ORF1ab and N gene in adults treated with Traditional Chinese Medicine (TCM) was significantly higher than in those who underwent symptomatic treatment (P < 0.01). Based on the Children's Sleep Habits Questionnaire (CSHQ)score, we found varying levels of sleep problems in sleeping habits, latency and anxiety, night awakenings and abnormal sleep at all ages (P < 0.05). In the adult group, those with Self-Rating Scale of Sleep (SRSS) scores ≥3 accounted for more than 50% of adults with insomnia, sleep deprivation, sleep instability and early awakening. The proportion of adults with anxiety and depression was 21.3% and 16.4%.

Conclusion

Infections in children and adults during this pandemic were mainly associated with familial aggregation infections, and their clinical symptoms were mainly located in the upper respiratory tract. With comprehensive treatment, children became negative faster, vaccination led to faster recovery, and although some patients experienced sleeping and psychological issues, all patients had good prognoses following comprehensive diagnosis under a parent-child ward treatment mode.

Clinical Characteristics and Treatment Outcomes of Mild to Moderate Covid-19 Patients in Saudi Arabia: A Single Centre Study

Objective

Since the severity of symptoms affects the treatment option for Coronavirus Disease 2019 (COVID-19) patients, the treatment pattern for mild to moderate non-ICU cases must be evaluated, particularly in the current scenario of mutation and variant strain for effective decision making.

Methods

The objective of retrospective analysis was to assess clinical and treatment outcomes in mild to moderate symptoms in non-ICU patients with COVID-19 who were admitted to major tertiary care hospitals in Al Baha, Saudi Arabia, between April and August 2020.

Results

A total of 811 people were admitted for COVID-19 treatment, age ranging from 14 to 66, diabetes mellitus (31%, n = 248) and hypertension (24%, n = 198) were the most common comorbid conditions. The hydroxychloroquine (HCQ) treated group (G1 n = 466) had an MD of 8 and an IQR of 5–13 for time in hospital with a 4.3% mortality rate, while the non-HCQ group (G2 n = 345) had an MD of 6 and an IQR of 3–11 for time in hospital with a 3.2% mortality rate. A combination of antiviral and antibiotic treatment was found to be effective, other most frequent intervention was analgesics 85.7%, anticoagulant 75%, minerals (Zinc 83% and Vit D3 82%).

Conclusions

The therapy and clinical outcomes from the past will be the guiding factor to treat the COVID variants infection in the future. Patients treated with HCQ had a higher mortality rate, whereas those who were given a non-HCQ combination had a greater clinical outcome profile.

Data Availability

Data available on request due to ethical restrictions. The anonymized data presented in this study are available on request from the corresponding author. The data are not publicly available to maintain privacy and adhere to guidelines of the ethics protocol.

Dynamic changes of IgM and IgG antibodies in asymptomatic patients as an effective way to detect SARS-CoV-2 infection

Background

COVID‐19 has become a global pandemic, and close contacts and asymptomatic patients are worthy of attention.

Methods

A total of 1844 people in close contacts with 76 COVID‐19 patients were investigated, and nasopharyngeal swabs and venous blood were collected for centralized medical quarantine observation. Real‐time fluorescence was used to detect SARS‐CoV‐2 nucleic acid in nasopharyngeal swabs of all close contacts, and the colloidal gold method was used to detect serum‐specific antibodies. Levels of IgM‐ and IgG‐specific antibodies were detected quantitatively through chemiluminescence from the first nucleic acid turned negative date (0 week) and on weekly intervals of ≤1 week, 1–2 weeks, 2–3 weeks, 3–4 weeks, 4–5 weeks, 5–6 weeks, and 6–7 weeks.

Results

The total positive rate of the colloidal gold method (88.5%, 23/26) was significantly higher (χ² = 59.182, p < 0.001) than that of the healthy control group (2.0%, 1/50). There was significant difference in IgG concentration at different time points (0–7 weeks) after negative nucleic acid conversion (χ² = 14.034, p = 0.029). Serum IgG levels were significantly higher at weekly time points of 4–5 weeks (Z = −2.399, p = 0.016), 5–6 weeks (Z = −2.049, p = 0.040), and 6–7 weeks (Z = −2.197, p = 0.028) compared with 1–2 weeks after negative nucleic acid conversion. However, there was no significant difference (χ² = 4.936, p = 0.552) in IgM concentration between time points tested (0–7 weeks) after negative nucleic acid conversion. The positive rates of IgM and IgG in asymptomatic patients (χ² = 84.660, p < 0.001) were significantly higher than those in the healthy control group (χ² = 9.201, p = 0.002) within 7 weeks of negative nucleic acid conversion.

Conclusions

The IgG concentration in asymptomatic cases remained at a high level after nucleic acid turned negative. Nucleic acid detection combined with IgM and IgG antibody detection is an effective way to screen asymptomatic infections.