Diagnostic stewardship to limit repeat plasma cytomegalovirus viral load testing.

BACKGROUND: Frequent serial monitoring of plasma cytomegalovirus (CMV) viral load caused unnecessary budgets for laboratory testing without changes in treatment. We aimed to implement diagnostic stewardship to limit CMV viral load testing at appropriate intervals. METHODS: A quasi-experimental study was performed. To avoid unnecessary plasma CMV viral load testing, the inpatient electronic pop-up reminder was launched in 2021. In cases with plasma CMV viral load testing was ordered in intervals of less than five days, telephone interview and feedback were performed. Pre-post intervention data was compared in terms of clinical and monetary outcomes. The rate of plasma CMV viral load testing performed in intervals of less than five days was compared between 2021 and 2019 using the Poisson regression model. RESULTS: After the protocol implementation, there was a significant decrease in the rate of plasma CMV viral load test orders in intervals of less than five days from 17.5% to 8.0% [incidence rate ratio 0.40, p < 0.001]. There was no statistically significant difference in the incidence of CMV DNAemia and CMV disease (p = 0.407 and 0.602, respectively). As a result, the hospital could save the costs of plasma CMV viral load testing per 1,000 patients performed with intervals of less than five days from 2,646,048.11 to 1,360,062.89 Thai Baht. CONCLUSIONS: The diagnostic stewardship program is safe and helpful in reducing unnecessary plasma CMV viral load testing and costs.

Incidence of anti-platelet factor4/polyanionic antibodies, thrombocytopenia, and thrombosis after COVID-19 vaccination with ChAdOx1 nCoV-19 in Thais.

BACKGROUND: The prevalence of anti-platelet factor 4 (PF4)/polyanionic antibodies occurring after vaccination with ChAdOx1 nCoV-19 is low. Most of these antibodies are not associated with vaccine-induced thrombotic thrombocytopenia. It remains unknown whether these antibodies are preexisting or occur as a result of vaccination. In this study, we demonstrated the incidence of anti-PF4/polyanionic antibodies, thrombocytopenia, and thrombosis after vaccination with ChAdOx1 nCoV-19 in a large cohort of Thais. METHODS: We conducted a prospective study in a cohort of health care workers and members of the general population who received COVID-19 vaccination with ChAdOx1 nCoV-19. Blood collection for complete blood count, D-dimer, and anti-PF4/polyanionic antibodies was performed before vaccination (day 0), day 10, and day 28 after vaccination. Anti-PF4/polyanionic antibodies were detected using enzyme-link immunosorbent assay (ELISA). Functional assay was performed for all positive ELISA tests. RESULTS: A total of 720 participants were included in the study. 214 participants received both the first and second doses, 91 participants received only the first, 51 received only the second, and 364 received the third booster dose of ChAdOx1 nCoV-19. Median age was 42 years (IQR, 34-53). 67% of participants were female. Three participants developed seroconversion, yielding an incidence of vaccination-induced anti-PF4/polyanionic antibodies of 0.42% (95% confidence interval 0.08, 1.23). Fourteen (1.9%) participants had preexisting anti-PF4/polyanionic antibodies before the vaccination but their optical density of anti-PF4/polyanionic antibodies did not significantly increase over time. None of the anti-PF4/polyanionic positive sera induced platelet aggregation. Abnormal D-dimer levels following vaccination were not different among the positive and negative anti-PF4/polyanionic groups (11.8% vs. 13.2%, p = 0.86). Thrombocytopenia occurred in one person with negative anti-PF4/polyanionic antibodies. No clinical thrombosis or bleeding occurred. CONCLUSION: We found a low incidence of seroconversion of anti-PF4/polyanionic antibodies after vaccination with ChAdOx1 nCoV-19 in Thais. Most of the anti-PF4/polyanionic antibodies were preexisting and did not significantly increase after vaccination with ChAdOx1 nCoV-19. Following vaccination, some participants with anti-PF4/polyanionic antibodies had elevated D-dimer levels, while only one developed thrombocytopenia and no thrombotic events were observed.

Effects of pitavastatin on atherosclerotic-associated inflammatory biomarkers in people living with HIV with dyslipidemia and receiving ritonavir-boosted atazanavir: a randomized, double-blind, crossover study.

BACKGROUND: Chronic inflammation has been described in people living with HIV (PLHIV) receiving antiretroviral therapy (ART) despite viral suppression. Inflammation associated non-communicable diseases, including atherosclerosis, are becoming recognized complication of HIV infection. We studied the effect of pitavastatin on atherosclerotic-associated inflammatory biomarkers in PLHIV receiving ART. METHODS: A randomized, double-blind, crossover study was conducted in HIV-infected persons with dyslipidemia and receiving atazanavir/ritonavir (ATV/r) to evaluate the effect of 2 mg/day pitavastatin treatment versus placebo. High-sensitivity CRP (hs-CRP), cytokines, and cellular markers in PLHIV receiving 12 weeks of pitavastatin or placebo were investigated. RESULTS: A total of 24 HIV-infected individuals with a median (interquartile range) age of 46 (41-54) years were recruited, and the median CD4 T cell count was 662 (559-827) cells/mm3. The median duration of ATV/r use was 36 (24-48) months. Significant change in levels of basic fibroblast growth factor (FGF) between pitavastatin treatment and placebo at week 12 from baseline was observed (27.1 vs. 20.5 pg/mL; p=0.023). However, there were no significant changes from baseline of hs-CRP and other plasma cytokine levels at week 12 of pitavastatin or placebo. Regarding cellular markers, percentages of HLA-DR+CD38-CD4+ T cells and PD1+CD4+ T cells significantly decreased from baseline in PLHIV receiving pitavastatin for 12 weeks, as compared to placebo (- 0.27 vs. 0.02%; p=0.049 and - 0.23 vs. 0.23%; p=0.022, respectively). CONCLUSIONS: Pitavastatin treatment increases basic FGF levels, and lowers HLA-DR+CD38-CD4+ T cells, and PD1+CD4+ T cells. Further study on the effects of pitavastatin on preventing cardiovascular diseases in PLHIV should be pursued.

SARS-CoV-2-specific humoral and cell-mediated immune responses after immunization with inactivated COVID-19 vaccine in kidney transplant recipients (CVIM 1 study).

Immunogenicity following inactivated SARS-CoV-2 vaccination among solid organ transplant recipients has not been assessed. Seventy-five patients (37 kidney transplant [KT] recipients and 38 healthy controls) received two doses, at 4-week intervals, of an inactivated whole-virus SARS-CoV-2 vaccine. SARS-CoV-2-specific humoral (HMI) and cell-mediated immunity (CMI) were measured before, 4 weeks post-first dose, and 2 weeks post-second dose. The median (IQR) age of KT recipients was 50 (42-54) years and 89% were receiving calcineurin inhibitors/mycophenolate/corticosteroid regimens. The median (IQR) time since transplant was 4.5 (2-9.5) years. Among 35 KT patients, the median (IQR) of anti-RBD IgG level measured by CLIA after vaccination was not different from baseline, but was significantly lower than in controls (2.4 [1.1-3.7] vs. 1742.0 [747.7-3783.0] AU/ml, p < .01) as well as percentages of neutralizing antibody inhibition measured by surrogate viral neutralization test (0 [0-0] vs. 71.2 [56.8-92.2]%, p < .01). However, the median (IQR) of SARS-CoV-2 mixed peptides-specific T cell responses measured by ELISpot was significantly increased compared with baseline (30 [4-120] vs. 12 [0-56] T cells/106  PBMCs, p = .02) and not different from the controls. Our findings revealed weak HMI but comparable CMI responses in fully vaccinated KT recipients receiving inactivated SARS-CoV-2 vaccination compared to immunocompetent individuals (Thai Clinical Trials Registry, TCTR20210226002).

An additional dose of viral vector COVID-19 vaccine and mRNA COVID-19 vaccine in kidney transplant recipients: A randomized controlled trial (CVIM 4 study).

Immunogenicity following an additional dose of Coronavirus disease 2019 (COVID-19) vaccine was investigated in an extended primary series among kidney transplant (KT) recipients. Eighty-five KT participants were randomized to receive either an mRNA (M group; n = 43) or viral vector (V group; n = 42) vaccine. Among them, 62% were male, with a median (IQR) age of 50 (43-59) years and post-transplantation duration of 46 (26-82) months. At 2 weeks post-additional dose, there was no difference in the seroconversion rate between the M and V groups (70% vs. 65%, p = .63). A median (IQR) of anti-RBD antibody level was not statistically different between the M group compared with the V group (51.8 [5.1-591] vs. 28.5 [2.9-119.3] BAU/ml, p = .18). Furthermore, the percentage of participants with positive SARS-CoV-2 surrogate virus neutralization test results was not statistically different between groups (20% vs. 15%, p = .40). S1-specific T cell and RBD-specific B cell responses were also comparable between the M and V groups (230 [41-420] vs. 268 [118-510], p = .65 and 2 [0-10] vs. 2 [0-13] spot-forming units/106 peripheral blood mononuclear cells, p = .60). In conclusion, compared with an additional dose of viral vector COVID-19 vaccine, a dose of mRNA COVID-19 vaccine did not elicit significantly different responses in KT recipients, regarding either humoral or cell-mediated immunity. (TCTR20211102003).

Comparison of the immunogenicity of ChAdOx1 nCoV-19 vaccine against the wild-type and delta variants in kidney transplant recipients and healthy volunteers.

Little is known about immunogenicity after ChAdOx1 nCov-19 vaccination after transplantation. We assessed the vaccine response by antibody testing, surrogate neutralization test (sVNT) against wild-type (WT) and delta variant (DT), and T cell assay in 83 kidney transplant recipients (KTRs) and 52 healthy volunteers (HVs). For KTRs, a positive anti-RBD antibody was seen in 2.8% after one dose and 15.7% after two doses of the vaccine. After two doses, the positivity rate by sVNT was equal (4.9% each, for WT and DT) and was 13.4% by T cell response. Post two doses, KTRs had significantly lower geometric mean titer than HVs (1.93 [95% CI: 1.39-2.69] vs. 248.3 [95% CI: 203.7-302.6] BAU/ml, respectively, p < .001). Daily mycophenolate dose of ≥1000 mg significantly associated with negative seroconversion [risk ratio (RR) of 0.33, 95% CI: 0.15-0.72, p = .005]. Compared with cyclosporine, daily tacrolimus dose of ≤3 mg and >3 mg of tacrolimus significantly associated with negative seroconversion [RR = 0.38 (95% CI, 0.17-0.85, p = .018) and RR = 0.16 (95% CI, 0.37-0.73, p = .018)], respectively. The vaccine was safe and well-tolerated but the immune response after the two doses of ChAdOx1 nCov-19 vaccine in KTRs was very low.

Saliva sample pooling for the detection of SARS-CoV-2.

As the battle against coronavirus disease 2019 pandemic continues, an increase in workload and medical expenses have been a concern to the health care system worldwide. Developing a measure that helps to conserve the health care resource is, therefore, highly desirable, and the pooling of the specimens for testing is one of the attractive strategies. Recently, we showed that saliva could be a potential alternative specimen for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time polymerase chain reaction (RT-PCR). In the present study, we performed the pooling of saliva specimens for testing by SARS-CoV-2 RT-PCR. We showed that the saliva pool of either 5 or 10 samples, by allowing the detection of either gene in the pool at an increased cycle threshold cutoff value, further performing individual sample testing in the positive pools did not compromise the detection of SARS-CoV-2.

Incidence of thromboembolism in patients with COVID-19: a systematic review and meta-analysis.

BACKGROUND: Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, the incidence of thromboembolism has been increasingly reported. The aim of this systematic review was to explore the incidence of venous and arterial thromboembolism among COVID-19 patients requiring hospitalization. METHODS: Medline, Embase, Scopus, and grey literature were searched until June 2020. Observational studies reported on the incidence of venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT) or arterial thromboembolism (ATE) were included. The pool incidences and their 95% confidence intervals (CI) were calculated using the random-effects model. RESULTS: A total of 36 studies were included. In the intensive care unit (ICU) setting, the pooled incidence of VTE was 28% (95% CI, 22-34%). Subgroups based on compression ultrasound (CUS) screening revealed a higher incidence of DVT in the CUS screening group than in the no CUS screening group (32% [95% CI, 18-45%] vs. 6% [95% CI, 4-9%]). The pooled incidence of ATE in ICU was 3% (95% CI, 2-5%). In the non-ICU setting, the pooled incidence of VTE was 10% (95% CI, 6-14%,). CONCLUSIONS: The incidence of VTE in COVID-19 patients was higher in the ICU setting than in the non-ICU setting, and also significantly higher in studies that incorporated the CUS screening protocol. The incidence of ATE in the ICU setting was low. VTE prophylactic measures should be given to all hospitalized patients diagnosed with COVID-19.

Prediabetes among HIV-infected individuals receiving antiretroviral therapy: prevalence, diagnostic tests, and associated factors.

BACKGROUND: Metabolic complications in human immunodeficiency virus (HIV)-infected individuals are common. Prediabetes represents a high risk for future diabetes development. This study aimed to determine the prevalence, diagnostic methods, and associated factors of prediabetes among HIV-infected individuals receiving antiretroviral therapy (ART). METHODS: A cross-sectional study was conducted among HIV-infected adults without a history of diabetes who were receiving ART. Fasting plasma glucose (FPG), 2-hour plasma glucose (2-h PG) after a 75-g oral glucose tolerance test, and hemoglobin A1c (HbA1c) were assessed. RESULTS: A total of 397 patients with a mean age of 47.0 ± 9.8 years and 55.7% male, were studied. All received ART with undetectable plasma viral load. The mean duration of ART was 9.6 ± 5.2 years, and the mean CD4 cell count was 554 ± 235 cells/mm3. Among the patients, 28 (7.1%) had first-diagnosed diabetes, and 133 (33.5%) patients had prediabetes. Glycemia estimation by FPG, 2-h PG, and HbA1c showed a prediabetes prevalence of 17.4%, 14.7%, and 12.5%, respectively. The kappa statistics for the agreement of FPG and 2-h PG, HbA1c and 2-h PG, and HbA1c and FPG were 0.317, 0.429, and 0.396, respectively. In multivariate analysis, hypertension [odds ratio (OR) 3.38; 95% confidence interval (CI), 1.16-9.91; p = 0.026), and triglycerides > 150 mg/dL (OR 2.11; 95% CI, 1.01-4.44; p = 0.047) were factors significantly associated with prediabetes. CONCLUSIONS: Prediabetes among HIV-infected individuals receiving ART is common. The agreements of glycemia estimation methods are minimal to weak. HbA1c may underestimate prediabetes prevalence. Using FPG together with HbA1c increases the detection rate to approximately three-quarters of prediabetes patients. HIV-infected individuals who had hypertension and hypertriglyceridemia should be regularly assessed for prediabetes. Trial registration ClinicalTrial.gov, NCT03545217. Registered 1 June 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03545217.

A randomized controlled trial of sitafloxacin vs. ertapenem as a switch therapy after treatment for acute pyelonephritis caused by extended-spectrum ß-lactamase-producing Escherichia coli: A pilot study.

BACKGROUND: The overuse and misuse of carbapenems have contributed to the antibiotic resistance crisis. The role of oral fluoroquinolones as a switch therapy for the treatment of urinary tract infection from Escherichia coli (ESBL-EC) is limited. OBJECTIVE: To compare the clinical and bacteriological efficacy of sitafloxacin and ertapenem for non-bacteremic acute pyelonephritis caused by ESBL-EC. METHODS: A prospective randomized controlled trial of patients with acute pyelonephritis caused by ESBL-EC was performed as a pilot study. One of the carbapenems was initially given to the patients. After day 3, patients were randomized to receive either sitafloxacin or ertapenem. RESULTS: Thirty-six patients were enrolled: 19 (52.8%) in the sitafloxacin group and 17 (47.2%) in the ertapenem group. There was no statistically significant difference in baseline characteristics between the two groups except a lower proportion of previous urinary catheter insertion in the sitafloxacin group (15.8% vs. 52.9%, p = 0.018). Signs and symptoms at presentation were similar between the two groups except a higher proportion of patients with chills in the sitafloxacin group (68.4% vs. 29.4%, p = 0.019). At day 10, all but one patient in the ertapenem group had clinical cure. Microbiological eradication was comparable between the sitafloxacin and ertapenem groups (84.2% vs. 75%, p = 0.677). There were no significant adverse effects. CONCLUSIONS: Treatment of non-bacteremic acute pyelonephritis caused by ESBL-EC with carbapenem followed by oral sitafloxacin is effective and well-tolerated. Sitafloxacin may be considered as an alternative choice of switch therapy in this clinical setting.

CLINICAL OUTCOMES OF CRYPTOCOCCAL MENINGITIS AMONG HIV-INFECTED PATIENTS IN THE ERA OF ANTIRETROVIRAL THERAPY.

Cryptococcal meningitis (CM) is a common opportunistic infection in HIV-infected patients and the clinical outcome can be severe. This study aimed to determine the survival rate and prognostic factors among HIV-infected patients with CM in the era of antiretroviral therapy (ART). Understanding of these facts may help clinicians to manage CM patients efficiently and patients with poor prognostic factors could be closely monitored. We conducted a retrospective cohort study among new cases of HIV-associated CM who were treated at Ramathibodi Hospital, Mahidol University, Thailand, during 2002-2013. Of 195 patients, 119 (61%) were male; the median (interquartile range, IQR) age was 33 (29-39) years. The median (IQR) CD4 cell count was 20 (9-44) cells/mm3. The median survival time was >12 years and the 75% survival time was 5 years. Using the Cox proportional hazard model, the factors associated with mortality were impaired consciousness [hazard ratio (HR)=2.38; 95% confidence interval (CI): 1.03-5.50], low initial cerebrospinal fluid (CSF) protein (≤60 mg/dl) (HR=2.88; 95%CI: 1.13-7.35), low initial CSF glucose (≤30 mg/dl) (HR=2.36; 95%CI: 1.01-5.51), high opening pressure during induction therapy (>25 cmH2O) (HR=2.90, 95%CI: 1.21-6.94), no ART (HR=14.8; 95%CI: 5.39-40.7) and relapse of CM (HR=4.31; 95%CI: 1.42-13.1). The HIV-associated CM survival rate in the ART era is higher than it was during the pre-ART era.

Disseminated cryptococcosis in an HIV-seronegative pregnant woman with transient T-lymphocytopenia: a case report and review of the literature.

We report a case of an HIV-seronegative pregnant woman with disseminated cryptococcosis, poorly controlled during gestation. Immunological studies showed T-lymphocytopenia during gestation, but rapid recovery postpartum. T-lymphocytopenia may play a role in increased susceptibility to and severity of cryptococcal infection during pregnancy.

CRISPR/Cas9 genome editing of CCR5 combined with C46 HIV-1 fusion inhibitor for cellular resistant to R5 and X4 tropic HIV-1.

Hematopoietic stem-cell (HSC) transplantation using a donor with a homozygous mutation in the HIV co-receptor CCR5 (CCR5Δ32/Δ32) holds great promise as a cure for HIV-1. Previously, there were three patients that had been reported to be completely cured from HIV infection by this approach. However, finding a naturally suitable Human Leukocyte Antigen (HLA)-matched homozygous CCR5Δ32 donor is very difficult. The prevalence of this allele is only 1% in the Caucasian population. Therefore, additional sources of CCR5Δ32/Δ32 HSCs are required. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas) system is one method to mediate CCR5 knockout in HSCs that has been successfully employed as a gene editing tool in clinical trials. Additional anti-HIV-1 strategies are still required for broad-spectrum inhibition of HIV-1 replication. Here in this study, we combined an additional anti-HIV-1 therapy, which is C46, a cell membrane-anchored HIV-1 fusion inhibitor with the CRISPR/Cas9 mediated knockout CCR5. The combined HIV-1 therapeutic genes were investigated for the potential prevention of both CCR5 (R5)- and CXCR4 (X4)-tropic HIV-1 infections in the MT4CCR5 cell line. The combinatorial CRISPR/Cas9 therapies were superior compared to single method therapy for achieving the HIV-1 cure strategy and shows potential for future applications.

HIV-1 proviral DNA in purified peripheral blood CD34+ stem and progenitor cells in individuals with long-term HAART; paving the way to HIV gene therapy.

Human immunodeficiency virus (HIV)-1 infection is an important public health problem worldwide. After primary HIV-1 infection, transcribed HIV-1 DNA is integrated into the host genome, serving as a reservoir of the virus and hindering a definite cure. Although highly active antiretroviral therapy suppresses active viral replication, resulting in undetectable levels of HIV RNA in the blood, a viral rebound can be detected after a few weeks of treatment interruption. This supports the concept that there is a stable HIV-1 reservoir in people living with HIV-1. Recently, a few individuals with HIV infection were reported to be probably cured by hematopoietic stem transplantation (HSCT). The underlying mechanism for this success involved transfusion of uninfected hematopoietic stem and progenitor cells (HSPCs) from CCR5-mutated donors who were naturally resistant to HIV infection. Thus, gene editing technology to provide HIV-resistant HSPC has promise in the treatment of HIV infections by HSCT. In this study, we aimed to find HIV-infected individuals likely to achieve a definite cure via gene editing HSCT. We screened for total HIV proviral DNA by Alu PCR in peripheral blood mononuclear cells (PBMCs) of 20 HIV-infected individuals with prolonged viral suppression. We assessed the amount of intact proviral DNA via a modified intact proviral DNA assay (IPDA) in purified peripheral CD34+ HSPCs. PBMCs from all 20 individuals were positive for the gag gene in Alu PCR, and peripheral CD34+ HSPCs were IPDA-negative for six individuals. Our results suggested that these six HIV-infected individuals could be candidates for further studies into the ability of gene editing HSCT to lead to a definite HIV cure.

Factors determining the appropriateness of ceftriaxone usage at the emergency room of a university hospital in Thailand.

BACKGROUND: Ceftriaxone is one of the most common empirical antibiotics prescribed at emergency rooms in Thailand. Inappropriate prescriptions of antibiotics have been frequently reported. The authors aimed to study factors that determine the appropriateness ofceftriaxone usage at an emergency room ofa university hospital in Thailand. MATERIAL AND METHOD: A cross-sectional study was conducted among patients with age of> 15 years old who received ceftriaxone as empirical treatment at the emergency room between April 1 and May 31, 2010. Appropriateness ofceftriaxone usage was considered according to local recommendations and current published guidelines. RESULTS: During the 2-months period, 278 patients for whom ceftriaxone was prescribed were included in the analysis. Of these, 109 (39.2%) were men and a median (interquartile range; IQR) age of 62.2 (45.2-75.7) years. Ceftriaxone usage was considered appropriate in 162 (58.3%) cases. By multiple logistic regression, female gender [odds ratio (OR) 1.96, 95% confidence interval (CI) 1.03-3. 70], fever (OR 3.12, 95% CI 1.3-6.11), had signs and symptoms of infections (OR 2.92, 95% CI 1.37-6.28), and suspicion of sepsis (OR 7.90, 95% CI 3.67-17.07), were associated with appropriateness of ceftriaxone usage, while diagnosis of gastrointestinal tract infection was associated with inappropriate ceftriaxone usage (OR 0.20, 95% CI 0.05-0.77). CONCLUSION: Proportion of appropriate use of ceftriaxone is fair. As assessed by established criteria, clinical suspicion of infection was associated with appropriateness of ceftriaxone usage for empirical treatment in an emergency room setting. Interventions to improve appropriateness of ceftriaxone prescription should focus on these factors.

Saliva and wastewater surveillance for SARS-CoV-2 during school reopening amid COVID-19 pandemic in Thailand.

Objectives: School closure during the coronavirus disease 2019 (COVID-19) pandemic resulted in a negative impact on children. Serial testing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proposed as a measure for safety school reopening. We aimed to study the usefulness of SARS-CoV-2 surveillance by saliva testing and performing wastewater surveillance for SARS-CoV-2 in a day school in a resource-limited setting. Methods: We conducted a cluster randomized study to investigate the potential use of saliva antigen testing compared to saliva pooling for nucleic acid detection in a primary school in Thailand from December 2021 to March 2022. Wastewater surveillance in the school was also performed. Results: A total of 484 participants attended the study. SARS-CoV-2 was detected in two participants from the tests provided by the study (one in the pool nucleic acid test arm, and another in the quantitative antigen test arm). Additional ten participants reported positive results on an additional rapid antigen test (RAT) performed by nasal swab when they had symptoms or household contact. There was no difference among arms in viral detection by intention-to-treat and per protocol analysis (p = 0.304 and 0.894, respectively). We also investigated the feasibility of wastewater surveillance to detect the virus in this setting. However, wastewater surveillance could not detect the virus. Conclusions: In a low COVID-19 prevalence, serial saliva testing and wastewater surveillance for SARS-CoV-2 rarely detected the virus in a day school setting. Performing RAT on nasal swabs when students, teachers or staff have symptoms or household contact might be more reasonable.

Label free electrochemical DNA biosensor for COVID-19 diagnosis.

The COVID-19 pandemic has significantly increased the development of the development of point-of-care (POC) diagnostic tools because they can serve as useful tools for detecting and controlling spread of the disease. Most current methods require sophisticated laboratory instruments and specialists to provide reliable, cost-effective, specific, and sensitive POC testing for COVID-19 diagnosis. Here, a smartphone-assisted Sensit Smart potentiostat (PalmSens) was integrated with a paper-based electrochemical sensor to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A disposable paper-based device was fabricated, and the working electrode directly modified with a pyrrolidinyl peptide nucleic acid (acpcPNA) as the biological recognition element to capture the target complementary DNA (cDNA). In the presence of the target cDNA, hybridization with acpcPNA probe blocks the redox conversion of a redox reporter, leading to a decrease in electrochemical response correlating to SARS-CoV-2 concentration. Under optimal conditions, a linear range from 0.1 to 200 nM and a detection limit of 1.0 pM were obtained. The PNA-based electrochemical paper-based analytical device (PNA-based ePAD) offers high specificity toward SARS-CoV-2 N gene because of the highly selective PNA-DNA binding. The developed sensor was used for amplification-free SARS-CoV-2 detection in 10 nasopharyngeal swab samples (7 SARS-CoV-2 positive and 3 SARS-CoV-2 negative), giving a 100% agreement result with RT-PCR.

Diagnostic Yield and Impact on Antimicrobial Management of 16S rRNA Testing of Clinical Specimens.

16S rRNA gene sequencing is increasingly used in clinical practice for bacterial identification of clinical specimens. However, studies on its applicability to direct clinical specimens are limited. Here, we studied the diagnostic yield and impact of 16S rRNA gene sequencing from direct clinical specimens on antimicrobial management. Adult inpatients whose attending physician requested 16S rRNA gene sequencing and corresponding bacterial culture from a direct clinical specimen between January and December 2021 in a university hospital were prospectively included in this study. A total of 434 specimens from 374 patients were requested. Of these, 253 (58.3%) specimens were collected from patients whose final diagnosis indicated a bacterial infection, whereas 181 (41.7%) specimens were from nonbacterial infections. Using the final diagnosis as a "gold standard," the sensitivity and specificity of 16S rRNA gene sequencing were 38.3% and 93.9%, respectively. Among the bacterial infection cases, the proportion of 16S rRNA gene sequencing-positive and culture-positive cases was 32.4%, and the proportion of sequencing-positive and culture-negative cases was 5.9%. The impact on antimicrobial management was evident in 10 (2.3%) specimens, which all resulted in the continuation of antibiotics. The impact on antimicrobial management was highest in skin and soft tissue infections, followed by bone and joint infections. In this study, the long turnaround time of 16S rRNA gene sequencing of clinical specimens was a limiting factor. In conclusion, the overall diagnostic yield of 16S rRNA gene sequencing in bacterial infection cases was fair, being useful in selected cases. Restrictions on test requests may improve test utilization in this setting. IMPORTANCE 16S rRNA gene sequencing has been increasingly used in clinical practice. Using the final diagnosis as a gold standard, the sensitivity of 16S rRNA gene sequencing was fair. In the setting with no 16S rRNA gene sequencing test ordering restrictions, only small percentages of the test results had an impact on antimicrobial management. Restrictions on test requests should be developed to maximize the benefit of the test.