Confirmed Coronavirus Disease Research Articles

Prevalence and risk factors associated with multidrug-resistant bacteria in COVID-19 patients.

Bacterial coinfection among patients with confirmed coronavirus disease 2019 (COVID-19) is a critical medical concern that increases the disease severity and mortality rate. The current study is aimed at evaluating the effects of bacterial coinfections among COVID-19 patients, especially in relation to degree of severity and mortality. A retrospective study was conducted for patients with positive COVID-19 test, admitted to a regional COVID-19 hospital in Jeddah, Saudi Arabia, between May and August 2020. A specimen (e.g., blood, urine, or sputum) was collected from patients with confirmed COVID-19, and was cultured to determine bacterial coinfection caused by multidrug resistant (MDR) bacteria. COVID-19 patients were categorized into 2 groups based on the result of bacterial coinfection culture, as COVID-19 patients with coinfection and COVID-19 patients without coinfection. Independent sample t test or Mann-Whitney U test was used to compare age and hospitalization period between these groups. In addition, binominal logistic regression was applied to identify risk factors associated with mortality and bacterial coinfection. The study included 342 patients with laboratory confirmed COVID-19. Eighty (23.3%) patients were diagnosed with bacterial coinfection, while the remaining 262 (76.6%) patients did not test positive for bacterial coinfection. Length of hospital stay was prolonged among COVID-19 patients diagnosed with bacterial coinfection (16.01 ± 11.36 days) when compared with patients without bacterial coinfection (6.5 ± 6.12 days). Likewise, the mortality rate was significantly higher among COVID-19 patients with bacterial coinfection (90%) compared to those without bacterial coinfection (49.2%). Gram-negative bacteria were predominant compared to gram-positive, as Klebsiella pneumoniae (35 [43.8%]) and Acinetobacter baumanni (32 [40%]). On the other hand, Staphylococcus aureus (4 [5%]), Enterococcus faecalis (1 [1.3%]), and Enterococcus faecium (1 [1.3%]) were identified as gram-positive bacterial species from recruited patients. The findings of the current study showed that prolong hospitalization is the main risk factor associated with bacterial coinfection and death. Thus, health care providers should minimize hospitalization as well as following a continuous monitoring for bacterial coinfection among COVID-19 patients, to control the spread of infection and reducing the severity and mortality rate among COVID-19 patients.

Investigating vertical transmission and maternofoetal outcomes in pregnant women with COVID-19: a case-control study from Pakistan.

To estimate the frequency of severe acute respiratory syndrome coronavirus-2 among pregnant women, the impact in terms of obstetrical and clinical outcomes and vertical transmission to the neonates. The prospective, case-control study was conducted at Zainab Panjwani Memorial Hospital, Karachi, from March to December 2021, and comprised pregnant women regardless of gestational age who exhibited symptoms or had a suspicion of exposure to any confirmed coronavirus disease-2019 individual. They were screened for severe acute respiratory syndrome coronavirus-2 infection using polymerase chain reaction or serology. Those who tested negative were designated as control group A, while who had a positive serology result along with a negative polymerase chain reaction were taken as recovered case group B1, and those who tested positive for polymerase chain reaction were called the positive case group B2. Groups B1 and B2 were followed up till delivery. The clinical presentation of coronavirus disease-2019 infection in pregnancy and its obstetrical and neonatal outcomes was assessed. Products of conception were tested for the detection of the severe acute respiratory syndrome coronavirus-2 genome. The viral genome from group B2 cases was sequenced to confirm vertical transmission. Data was analysed using GraphPad Prism V8. Of the 139 pregnant women, 74(53.2%) were in group A with mean age 25.87±6.90 years, 49(35.3%) were in group B1 with mean age 25.53±7.02 years, and 16(11.5%) were in group B2 with mean age 27.12±5.03 years. The gestational age at which termination of pregnancy occurred was 38.3±1.26 weeks in group B1 and 38.3±1.85 weeks for group B2. There were 96 neonates across the 3 groups. Of the 11(11.45%) neonates in group B2, 1(9.09%) had postnatal transmission of severe acute respiratory syndrome coronavirus-2 and this mother-neonate case was taken as the Indexed case. The severe acute respiratory syndrome coronavirus-2 genome isolated from the neonate showed similar mutations as the viral strain infecting the mother. The risk of vertical transmission was found to be low. The severe acute respiratory syndrome coronavirus-2 genome was the same for both the mother and the neonate.

Screening and Analysis of SARS-CoV-2 Antibody Among Unvaccinated Blood Donors in Chongqing, China.

To investigate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody among unvaccinated voluntary blood donors in Chongqing, and to provide evidence for epidemic surveillance. A total of 10,208 voluntary blood donors from January 5 to January 20, 2021, in the Chongqing area were collected, and the SARS-CoV-2 immunoglobulin (Ig) G and IgM antibodies were detected by chemiluminescence, and the differences of antibody-positive rate in different gender, age, ABO blood group, and different risk areas were analyzed. Among 10208 blood donors, 10 were found to be positive for SARS-COV-2 IgG antibody, giving a positivity rate of SARS-COV-2 IgG at 0.10%, and 29 were positive for SARS-CoV-2 IgM antibody, with a positivity rate of SARS-CoV-2 IgM at 0.28%. There was no statistical difference in the positive rate of antibody among different genders, ages, and ABO blood types, but it was related to the number of confirmed coronavirus disease 2019 (COVID-19) cases in each city. The SARS-CoV-2 seroprevalence rate in Chongqing was low and correlated with the number of confirmed COVID-19 cases.

Mucosal antibody response and SARS-CoV-2 shedding in patients with COVID-19 related olfactory dysfunction.

Olfactory dysfunction (OD) was one of the most common symptom of infection with the Wuhan strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and could persist for several months after symptom onset. The pathogenesis of prolonged OD remains poorly understood but probably involves sustained viral replication associated with limited mucosal immune response to the virus. This prospective study was conducted to investigate the potential relationship between nasal SARS-CoV-2 viral load and antibody levels in patients with loss of smell. One hundred and five patients were recruited 2 weeks after presenting with confirmed coronavirus disease 2019 associated OD. Based on the identification sniffing test performed at enrollment, 52 patients were still anosmic or hyposmic and 53 were normosmic. SARS-CoV-2 was detectable in nasal wash of about 50% of anosmic and normosmic patients. Higher viral load was detected in anosmic patients with lower levels of SARS-CoV-2 specific nasal immunoglobulins (Ig) IgG and IgA. This association was not observed in normosmic patients. No relationship between nasal viral load and antibodies to endemic coronaviruses was observed. SARS-CoV-2 replication in the nasal cavity may be promoted by defective mucosal antibody responses in patients with OD. Boosting mucosal immunity may limit nasal SARS-CoV-2 replication and thereby help in the control of persistent OD.

Impact of COVID-19 in Thalassemia Patients Undergoing Hematopoietic Stem Cell Transplant Recipients

Objective: This article primarily examines the clinical attributes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in transplant recipients with thalassemia, offering significant insights into the treatment and care of this patient population. Method: The present study retrospectively analyzed the data of all thalassemia patients who underwent Hematopoietic stem cell transplantation (HSCT) at the First Affiliated Hospital of Guangxi Medical University between December 2019 and December 2022. A total of 280 patients were included, of which 81 had confirmed coronavirus disease 2019 (COVID-19). The study collected information on patient demographics, transplantation type and timing, graft-versus-host disease (GVHD), use of immunosuppressive agents, onset time and severity of COVID-19, and prognosis. Follow-up was conducted until March 31, 2023.Univariate analysis was performed using SPSS v25.0, and GraphPad Prism was used for the cumulative incidence comparisons. Results: The median age was 3.6(2-19) years.The main type of thalassemia was β type (93.9%). Identical sibling donors accounted for 40%, haploidentical donors accounted for 25.4%, and identical unrelated donors accounted for 34.6% (10/10). The main source of hematopoietic stem cells was bone marrow combined with peripheral blood (85%).There were no significant differences in age, gender, diagnosis, donor type, graft type, use of immunosuppressive agents, GVHD, and pneumonia of pro-COVID-19 between infected patients and non-infected patients with SARS-CoV-2. Most of the patients were mild (74 cases, 91.3%) in terms of the severity of COVID-19 infection, only 8.6% of the moderate cases, and none severe and died. 74 cases were cured without drug treatment. Of the seven patients treated with medications, four were azvudine and three were nematasvir. The median number of days (IQR) of treatment for COVID-19 was 5(5) days. The cumulative incidence in the immunosuppressive group was higher than that in the non-immunosuppressive group over the same time frame. There was no significant difference in the final infection rate of COVID-19 among patients receiving transplantation in different years(2020,2021,2022), which was 24.7 26.8 36.5 ( p=0.368), respectively. Conclusion: The low infection rate and no severe cases may be due to scientific protection and timely medication. There are no special risk factors for COVID-19 infection in thalassemia patients after transplantation.

Phytochemicals for mitigating the COVID-19 crisis: evidence from pre-clinical and clinical studies

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in December 2019 quickly escalated to pandemic levels and had a severe impact on public health. There are 761 million confirmed coronavirus disease 2019 (COVID-19) cases, with over 6.88 million deaths worldwide till March 2023. Severe cases of the disease caused critical respiratory failure followed by multiorgan involvement. Clinical escalation of COVID-19 has been correlated with markedly increased plasma inflammatory markers [e.g., C-reactive protein (CRP)] and pro-inflammatory cytokine levels [e.g., interleukin (IL)-6, tumor necrosis factor-α (TNF-α)]. Therapeutic options have mostly utilized corticosteroids, antivirals (e.g., remdesivir), and monoclonal antibody-based immunomodulation (e.g., tocilizumab). These existing treatments have adverse side effects, inadequate efficacy, and limitations in administering to patients with comorbidities and other underlying diseases. Monoclonal antibody-based therapies and some of the antivirals are very costly. Many phytochemicals have previously reported anti-inflammatory, antiviral, and antioxidant properties. Studying the effectiveness of such phytochemicals against COVID-19 and identifying new plant-derived molecules with antiviral properties have been a focus since the SARS-CoV-2 outbreak. This review article has documented in vitro, in vivo, and clinical studies encompassing 28 different phytochemicals belonging to various chemical groups (e.g., polyphenols, alkaloids, terpenes) that show anti-COVID-19 activity. These findings suggest that multiple phytochemicals can interfere with virus entry and replication inside the host cell. Many of them can protect from cytokine storm by acting on intracellular signalling pathways in addition to inhibiting virus multiplication. Phytochemicals may prove useful in alleviating post-COVID complications associated with kidney injury, and central nervous system complications, as well. Plant-derived compounds are usually cheaper and have fewer side effects. But, developing new formulations with better absorption and bioavailability remains a priority. This review informs the readers of the current status and indicates the ongoing research in this highly relevant field.

Functional magnetic resonance imaging in coronavirus disease 2019 induced olfactory dysfunction.

To evaluate the functional magnetic resonance imaging changes in the olfactory structures of coronavirus disease 2019 patients experiencing olfactory dysfunction. This study included patients aged 25-65 years who presented with a sudden loss of smell, confirmed coronavirus disease 2019 infection, and persistent olfactory dysfunction for a minimum of 2 months without any treatment. Irrespective of the side of brain activation, the analysis of the cumulative maximum diameter of the activation zones revealed significantly lower activation in the upper frontal lobe (p = 0.037) and basal ganglia (p = 0.023) in olfactory dysfunction patients. Irrespective of the side of activation, the analysis of the number of activation points demonstrated significantly lower activation in the upper frontal lobe (p = 0.036) and basal ganglia (p = 0.009) in olfactory dysfunction patients. Patients with coronavirus-triggered olfactory dysfunction exhibited lower activity in their basal ganglia and upper frontal lobe.

Inhaled Fluticasone Furoate for Outpatient Treatment of Covid-19

BackgroundThe effectiveness of inhaled glucocorticoids in shortening the time to symptom resolution or preventing hospitalization or death among outpatients with mild-to-moderate coronavirus disease 2019 (Covid-19) is unclear.MethodsWe conducted a decentralized, double-blind, randomized, placebo-controlled platform trial in the United States to assess the use of repurposed medications in outpatients with confirmed coronavirus disease 2019 (Covid-19). Nonhospitalized adults 30 years of age or older who had at least two symptoms of acute infection that had been present for no more than 7 days before enrollment were randomly assigned to receive inhaled fluticasone furoate at a dose of 200 μg once daily for 14 days or placebo. The primary outcome was the time to sustained recovery, defined as the third of 3 consecutive days without symptoms. Key secondary outcomes included hospitalization or death by day 28 and a composite outcome of the need for an urgent-care or emergency department visit or hospitalization or death through day 28.ResultsOf the 1407 enrolled participants who underwent randomization, 715 were assigned to receive inhaled fluticasone furoate and 692 to receive placebo, and 656 and 621, respectively, were included in the analysis. There was no evidence that the use of fluticasone furoate resulted in a shorter time to recovery than placebo (hazard ratio, 1.01; 95% credible interval, 0.91 to 1.12; posterior probability of benefit [defined as a hazard ratio >1], 0.56). A total of 24 participants (3.7%) in the fluticasone furoate group had urgent-care or emergency department visits or were hospitalized, as compared with 13 participants (2.1%) in the placebo group (hazard ratio, 1.9; 95% credible interval, 0.8 to 3.5). Three participants in each group were hospitalized, and no deaths occurred. Adverse events were uncommon in both groups.ConclusionsTreatment with inhaled fluticasone furoate for 14 days did not result in a shorter time to recovery than placebo among outpatients with Covid-19 in the United States. (Funded by the National Center for Advancing Translational Sciences and others; ACTIV-6 ClinicalTrials.gov number, NCT04885530.)

Association of IL-17F Gene Polymorphism and Its Serum Level with SARS-CoV-2 Infection.

Although multiple studies have addressed the clinical outcomes of coronavirus disease, little data exist regarding the defi- nition of immune and inflammatory profiles associated with this infection. Its clinical manifestations often worsen in association with hypercytokinemia (elevated interleukin 8 and interleukin 17). We conducted this research to elucidate the effect of interleukin 17 levels and interleukin 17F gene polymorphism on the severity and outcomes of coronavirus disease. Ninety patients with confirmed coronavirus disease and 30 healthy controls were enrolled. Coronavirus disease cases were classified into nonsevere, severe, and critical according to the World Health Organization definition. Approximately 10 mL peripheral blood sample was collected from all patients and controls by venipuncture in-plane and ethylenediaminetetraacetic acid tube. Enzyme-linked immunosorbent assay kits were used for calculating serum interleukin 17 levels, whereas real-time polymerase chain reaction was used for genotyping using the 5'-nuclease allelic discrimination assay for single nucleotide polymorphisms genotyping. As regards interleukin 17 levels, there was a significant elevation of interleukin 17 in coronavirus disease cases compared to control healthy persons (P < .001). Moreover, serum interleukin 17 levels tended to be significantly higher with increased disease sever- ity (P = .004). Patients with critical diseases expressed a significant rise of interleukin 17 compared to severe (P = .03) and nonsevere cases (P = .02). We noted no significant difference between the critical, severe, and nonsevere cases regarding different interleukin 17F genotypes. Coronavirus disease is associated with elevated levels of interleukin 17, which tended to be considerably higher with disease severity. However, different interleukin 17F genotypes do not affect either the predisposition or the severity of coronavirus disease.

A retrospective analysis of factors associated with the length of hospital stay in COVID-19 patients treated with Nirmatrelvir / Ritonavir.

Objectives: This study reviewed factors influencing the length of hospital stay in adult inpatients with confirmed Coronavirus disease (COVID-19) who were treated with Nirmatrelvir/Ritonavir. Methods: We did a retrospective analysis of data from a cohort of inpatients with confirmed diagnosis of Omicron variant of SARS-CoV-2 infection who were treated with Nirmatrelvir/Ritonavir. We included patients who were treated from 13th March 2022 to 6th May 2022 in various in-patient treatment units in Quanzhou, Fujian Province, China. The primary study outcome was the length of hospital stay. Secondary study outcome was viral elimination defined as negative for ORF1ab and N genes [cycle threshold (Ct) value ≥35 in real-time PCR], according to local guidelines. Hazard ratios (HR) of event outcomes were analyzed using Multivariate Cox regression models. Results: We studied 31 inpatients with high risk for severe COVID-19 who were treated with Nirmatrelvir/Ritonavir. We found that inpatients with shorter length of hospital stay (≤17days) were mostly females with lower body mass index (BMI) and Charlson Comorbidity Index (CCI) index. Their treatment regimen with Nirmatrelvir/Ritonavir was started within 5days of diagnosis (p < 0.05). Multivariate Cox regression indicated that inpatients starting treatment of Nirmatrelvir/Ritonavir within 5days had a shorter length of hospital stay (HR 3.573, p = 0.004) and had a faster clearance of viral load (HR 2.755, p = 0.043). Conclusion: This study assumes relevance during the Omicron BA.2 epidemic as our findings suggest that early treatment with Nirmatrelvir/Ritonavir within 5days of diagnosis (≤5days) was highly effective in shortening the length of hospital stay and faster viral load clearance.

COVID-19, post-acute COVID-19 syndrome (PACS, "long COVID") and post-COVID-19 vaccination syndrome (PCVS, "post-COVIDvac-syndrome"): Similarities and differences.

Worldwide there have been over 760 million confirmed coronavirus disease 2019 (COVID-19) cases, and over 13 billion COVID-19 vaccine doses have been administered as of April 2023, according to the World Health Organization. An infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to an acute disease, i.e. COVID-19, but also to a post-acute COVID-19 syndrome (PACS, "long COVID"). Currently, the side effects of COVID-19 vaccines are increasingly being noted and studied. Here, we summarise the currently available indications and discuss our conclusions that (i) these side effects have specific similarities and differences to acute COVID-19 and PACS, that (ii) a new term should be used to refer to these side effects (post-COVID-19 vaccination syndrome, PCVS, colloquially "post-COVIDvac-syndrome"), and that (iii) there is a need to distinguish between acute COVID-19 vaccination syndrome (ACVS) and post-acute COVID-19 vaccination syndrome (PACVS) - in analogy to acute COVID-19 and PACS ("long COVID"). Moreover, we address mixed forms of disease caused by natural SARS-CoV-2 infection and COVID-19 vaccination. We explain why it is important for medical diagnosis, care and research to use the new terms (PCVS, ACVS and PACVS) in order to avoid confusion and misinterpretation of the underlying causes of disease and to enable optimal medical therapy. We do not recommend to use the term "Post-Vac-Syndrome" as it is imprecise. The article also serves to address the current problem of "medical gaslighting" in relation to PACS and PCVS by raising awareness among the medical professionals and supplying appropriate terminology for disease.

Using Machine Learning Models To Investigate The Relationship Between Corporeal Workload And Clinical And Epidemiological Features Of Patients Infected With COVID-19 In Egypt.

To explore if clinical and epidemiological features of patients positive for coronavirus disease-2019 are affected by somatic work stress. The retrospective study was conducted at Kafrelsheik University Hospital, Egypt, and comprised data of patients admitted between April 1, to June 6, 2020, with confirmed coronavirus disease-2019 infection. Health records of healthy subjects who had come to the hospital as part of their routine check-up were also included for comparison, and the researchers were blinded during the gathering and analysis phase. Demographic features, vitalsigns, infection severity,somatic workload of the patients'jobs at admission, and detailed discharge profile was noted. The relationship between clinical features and somatic work stress was evaluated. Data was analysed using SPSS 26. Of the 1072 cases, 602(56.2%) were men and 470(43.8%) were women. The overall median age was 43 years (interquartile range: 29 years). The healthy group had 500 random subjects. There were significant differences in all vital signs between the patients and healthy controls (p<0.05). Among the patients, infection severity was higher in men, but it was notsignificant (p>0.05). The overall mortality was 69(6.4%); 46(4.3%) men and 23(2.2%) women. There was no significant association between gender and outcome (p>0.05). There were 816(76.11%) patients with low intensity physical workload pre-infection, 136(12.68%) moderate and 120(11.19%) high. Infection severity was significantly high in the low-intensity group (p<0.05). However, the fate of the patients was notsignificantly associated with their pre-infection work profile (p>0.05). Coronavirus disease-2019 significantly affected patients'vitalsigns, and infection severity wassignificantly associated with physical work stress. However, mortality and pre-infection somatic workload were not associated.

Early oral nutritional supplement improves COVID-19 outcomes among hospitalized older patients during the Omicron wave

ObjectivesThe effect of and optimal timing for initiating an oral nutritional supplement(ONS) in hospitalized older patients with the Omicron variant infection remain unclear. The aim of this study was to explore the associations between the ONS and clinical outcomes. MethodsThis study used a retrospective cohort design as primary analysis and a case–control design as sensitivity analysis. We collected data from patients with confirmed coronavirus disease 2019 (COVID-19) between April 2022 and June 2022 at Shanghai Fourth People's Hospital, one of the designated medical centers for COVID-19 in Shanghai, China. Patients were identified as ONS users or non-ONS users, with the former defined as early ONS (ONS initiated within 48 h from hospital admission), and late ONS (ONS initiated after 48 h) users. ResultsThe study included 1181 hospitalized patients ≥60 y of age. The mean age of the cohort was 78 y, and most patients were women (57.7%). Mortalities after propensity-score matching were 1.2% and 4.3% in the ONS group and non-ONS groups, respectively (P = 0.032). Subgroup analysis results showed that median (IQR) hospital length of stay and the median (IQR) length from symptom onset to viral clearance were shorter for the early ONS than for the late ONS group (9 [6-13] d versus 14 [11 -18] d; P < 0.001, and 11 [8-17] d versus 17 [13-22] d; P < 0.001, respectively). The findings from the case–control analysis supported those from the primary analysis. ConclusionsEarly ONS might have significantly lowered risk for in-hospital death, as well as reduce hospital length of stay and days of viral clearance in older patients with COVID-19 during the Omicron wave.

Characteristics of Critically Ill COVID-19 Patients in Busan, Republic of Korea.

This study aimed to improve the clinical course of patients through rapid response by analyzing the characteristics of critically ill patients with confirmed coronavirus disease 2019 (COVID-19) in Busan between December 1, 2020, and December 31, 2021. We divided patients diagnosed with COVID-19 into mild-to-moderate and critical groups based on their clinical severity. The critically ill patients were further sub-divided into delta and delta variant non-epidemic group. The following factors were significantly more frequent in critically ill patients than in patients with mild-tomoderate symptoms: male sex, age ≥60 years, symptoms at the time of diagnosis, and those with underlying diseases. The following factors were significantly more common in the non-delta variant epidemic group than in the delta variant epidemic group in critically ill patients: male sex, age ≥60 years, underlying diseases, and not being vaccinated. In the delta variant epidemic group, the duration between confirmation of disease and its progression to critically ill status was significantly shorter than that in the non-delta variant epidemic group. COVID-19 is characterized by the emergence of new variants and repeated epidemics. Therefore, it is necessary to analyze the characteristics of critically ill patients to efficiently distribute and manage medical resources.

Investigation on the relationship between the number of coronavirus disease 2019 cases at the beginning of the epidemic and the decrease of PM2.5 in Hubei, China: The role of temperature changes

In response to the coronavirus disease 2019 pandemic, the Chinese government implemented blockade measures in Hubei, which largely affected the emission of pollutants. This work is aimed to explore the effects of epidemics on pollutants at different temperatures in Hubei, China. We applied for a panel nonlinear model with autonomous search thresholds to explore this, using daily average temperature as a threshold variable, and PM2.5 set as the explained variable, and the cumulative number of confirmed coronavirus disease 2019 cases set as the explanatory variable. An empirical analysis was conducted by running the proposed model and using nine cities in China most impacted by the pandemic. The results show that there was a non-linear negative relationship between the cumulative number of confirmed coronavirus disease 2019 cases and PM2.5. A more detailed non-linear relationship between the two was uncovered by the proposed panel threshold regression model. When the temperature crosses the threshold value (12.5 °C and 20.5 °C) in sequence, the estimated value was −0.0688, −0.0934, and −0.1520 in that order. This means that this negative non-linear relationship increased with increasing temperature. This work helps to explore the effect of coronavirus disease 2019 on pollutions at different temperatures and provides a methodological reference to study their nonlinear relationship.

Use of saliva as an alternative diagnostic method for diagnosis of COVID-19

Mass population testing has been recommended to contain the spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. However, the use of nasopharyngeal swab specimens has caused many logistic challenges. This study investigated the sensitivity and specificity of saliva as a non-invasively-obtained specimen for molecular detection of SARS-CoV-2 RNA. In total, 153 patients with confirmed coronavirus disease 2019 (COVID-19) who had been admitted to the regional referral hospital or who self-isolated at home were included in this study. Nasopharyngeal swab specimens and saliva samples were collected on the same day, and were tested for SARS-CoV-2 infection using reverse transcriptase polymerase chain reaction. The sensitivity and specificity of saliva samples were 81.5% and 76.4%, respectively, in cases that had been confirmed as COVID-19 using nasopharyngeal swab samples. Positive predictive values and negative predictive values were 92.3% and 54.1%, respectively. The highest detection rates were found among samples collected 4-7 days since symptom onset. Saliva samples showed comparable performance to nasopharyngeal swab specimens for the diagnosis of COVID-19 in adults. The performance of saliva as a diagnostic specimen for COVID-19 testing is particularly significant during the first week of symptoms.

Early response to COVID-19 in Brazil: The impact of a targeted approach to suspected cases and on epidemiological surveillance efforts

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entered Brazil before travel restrictions and border closures were imposed. This study reports the characteristics of suspected and confirmed coronavirus disease 2019 (COVID-19) cases among symptomatic international travelers in Brazil and their contacts. MethodsThe REDCap platform developed by the Brazilian Ministry of Health was analyzed to identify and investigate suspected cases of COVID-19 recorded during the period January 1 to March 20, 2020. The impact of Brazil's targeted approach to suspected cases from specific countries on epidemiological surveillance efforts during the early stages of the COVID-19 pandemic were analyzed. ResultsBased on molecular RT-PCR tests, there were 217 (4.2%) confirmed, 1030 (20.1%) unconfirmed, 722 (14.1%) suspected, and 3157 (61.6%) non-investigated cases among travelers returning from countries included on the alert list for surveillance, as defined by the Ministry of Health. Among the 3372 travelers who went to countries not included on the alert list, there were 66 (2.0%) confirmed, 845 (25.3%) unconfirmed, 521 (15.6%) suspected, and 1914 (57.2%) non-investigated cases. A comparison of the characteristics of confirmed cases returning from alert and non-alert countries did not reveal a statistically significant difference in symptoms. Almost half of the hospitalized travelers with known travel dates and hospitalization status (53.6%) were inbound from countries not included on the alert list, and RT-PCR tests were reported for only 30.5%. ConclusionsPolicies adopted at entry points to contain the introduction of SARS-CoV-2 in Brazil were not ideal. An analysis of the early response shows that surveillance of travelers, including testing strategies, data standards, and reporting systems, was insufficient.

High-throughput screening of spike variants uncovers the key residues that alter the affinity and antigenicity of SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has elicited a worldwide pandemic since late 2019. There has been ~675 million confirmed coronavirus disease 2019 (COVID-19) cases, leading to more than 6.8 million deaths as of March 1, 2023. Five SARS-CoV-2 variants of concern (VOCs) were tracked as they emerged and were subsequently characterized. However, it is still difficult to predict the next dominant variant due to the rapid evolution of its spike (S) glycoprotein, which affects the binding activity between cellular receptor angiotensin-converting enzyme 2 (ACE2) and blocks the presenting epitope from humoral monoclonal antibody (mAb) recognition. Here, we established a robust mammalian cell-surface-display platform to study the interactions of S-ACE2 and S-mAb on a large scale. A lentivirus library of S variants was generated via in silico chip synthesis followed by site-directed saturation mutagenesis, after which the enriched candidates were acquired through single-cell fluorescence sorting and analyzed by third-generation DNA sequencing technologies. The mutational landscape provides a blueprint for understanding the key residues of the S protein binding affinity to ACE2 and mAb evasion. It was found that S205F, Y453F, Q493A, Q493M, Q498H, Q498Y, N501F, and N501T showed a 3–12-fold increase in infectivity, of which Y453F, Q493A, and Q498Y exhibited at least a 10-fold resistance to mAbs REGN10933, LY-CoV555, and REGN10987, respectively. These methods for mammalian cells may assist in the precise control of SARS-CoV-2 in the future.

Early symptoms preceding post-infectious irritable bowel syndrome following COVID-19: a retrospective observational study incorporating daily gastrointestinal symptoms

BackgroundIntestinal microinflammation with immune dysfunction due to severe acute respiratory syndrome coronavirus 2 reportedly precipitates post-infectious irritable bowel syndrome. This study aimed to elucidate potential risk factors for subsequent development of irritable bowel syndrome, hypothesizing that it is associated with specific symptoms or patient backgrounds.MethodsThis single-center retrospective observational study (2020–2021) included adults with confirmed coronavirus disease requiring hospital admission and was conducted using real-world data retrieved from a hospital information system. Patient characteristics and detailed gastrointestinal symptoms were obtained and compared between patients with and without coronavirus disease-induced irritable bowel syndrome. Multivariate logistic models were used to validate the risk of developing irritable bowel syndrome. Moreover, daily gastrointestinal symptoms during hospitalization were examined in patients with irritable bowel syndrome.ResultsAmong the 571 eligible patients, 12 (2.1%) were diagnosed with irritable bowel syndrome following coronavirus disease. While nausea and diarrhea during hospitalization, elevated white blood cell count on admission, and intensive care unit admission were associated with the development of irritable bowel syndrome, nausea and diarrhea were identified as risk factors for its development following coronavirus disease, as revealed by the adjusted analyses (odds ratio, 4.00 [1.01–15.84] and 5.64 [1.21–26.31], respectively). Half of the patients with irritable bowel syndrome had both diarrhea and constipation until discharge, and constipation was frequently followed by diarrhea.ConclusionsWhile irritable bowel syndrome was rarely diagnosed following coronavirus disease, nausea and diarrhea during hospitalization precede the early signs of irritable bowel syndrome following coronavirus disease.

The impact of meteorological factors on the spread of COVID-19.

Clinical studies suggest that warmer climates slow the spread of viral infections. In addition, exposure to cold weakens human immunity. This study describes the relationship between meteorological indicators, the number of cases, and mortality in patients with confirmed coronavirus disease 2019 (COVID-19). This was a retrospective observational study. Adult patients who presented to the emergency department with confirmed COVID-19 were included in the study. Meteorological data [mean temperature, minimum (min) temperature, maximum (max) temperature, relative humidity, and wind speed] for the city of Istanbul were collected from the Istanbul Meteorology 1st Regional Directorate. The study population consisted of 169,058 patients. The highest number of patients were admitted in December (n = 21,610) and the highest number of deaths (n = 46) occurred in November. In a correlation analysis, a statistically significant, negative correlation was found between the number of COVID-19 patients and mean temperature (rho = -0.734, P < 0.001), max temperature (rho = -0.696, P < 0.001) or min temperature (rho = -0.748, P < 0.001). Besides, the total number of patients correlated significantly and positively with the mean relative humidity (rho = 0.399 and P = 0.012). The correlation analysis also showed a significant negative relationship between the mean, maximum, and min temperatures and the number of deaths and mortality. Our results indicate an increased number of COVID-19 cases during the 39-week study period when the mean, max, and min temperatures were consistently low and the mean relative humidity was consistently high.