Polymerase Chain Reaction Test Research Articles

Utilizing novel Escherichia coli-specific conserved signature proteins for enhanced monitoring of recreational water quality.

Escherichia coli serves as a proxy indicator of fecal contamination in aquatic ecosystems. However, its identification using traditional culturing methods can take up to 24h. The application of DNA markers, such as conserved signature proteins (CSPs) genes (unique to all species/strains of a specific taxon), can form the foundation for novel polymerase chain reaction (PCR) tests that unambiguously identify and detect targeted bacterial taxa of interest. This paper reports the identification of three new highly-conserved CSPs (genes), namely YahL, YdjO, and YjfZ, which are exclusive to E. coli/Shigella. Using PCR primers based on highly conserved regions within these CSPs, we have developedquantitative PCR (qPCR) assays for the evaluation of E. coli/Shigella species in water ecosystems. Both in-silico and experimental PCR testing confirmed the absence of sequence match when tested against other bacteria, thereby confirming 100% specificity of the tested CSPs for E. coli/Shigella. The qPCR assays for each of the three CSPs provided reliable quantification for all tested enterohaemorrhagic and environmental E. coli strains, a requirement for water testing. For recreational water samples, CSP-based quantification showed a high correlation (r > 7, p < 0.01) with conventional viable E. coli enumeration. This indicates that novel CSP-based qPCR assays for E. coli can serve as robust tools for monitoring water ecosystems and other critical areas, including food monitoring.

Surveillance for highly pathogenic avian influenza A (H5N1) in a raptor rehabilitation center-2022.

An ongoing, severe outbreak of highly pathogenic avian influenza virus (HPAI) A H5N1 clade 2.3.4.4b has been circulating in wild and domestic bird populations throughout the world, reaching North America in 2021. This HPAI outbreak has exhibited unique characteristics when compared to previous outbreaks. The global distribution of disease, prolonged duration, extensive number of species and individual wild birds affected, and the large impact on the global poultry industry have all exceeded historical impacts of previous outbreaks in North America. In this study, we describe the results of HPAI surveillance conducted at The Raptor Center, a wildlife rehabilitation hospital at University of Minnesota (Saint Paul, MN, U.S.A.), from March 28th-December 31, 2022. All wild raptors admitted to the facility were tested for avian influenza viruses using polymerase chain reaction (PCR) testing. All non-negative samples were submitted to the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) National Veterinary Services Laboratories for confirmatory HPAI testing and genetic sequencing. During the study period, 996 individual birds representing 20 different species were tested for avian influenza, and 213 birds were confirmed HPAI positive. Highly pathogenic avian influenza surveillance conducted at The Raptor Center contributed 75% of the HPAI positive raptor detections within the state of Minnesota, located within the Mississippi flyway, significantly augmenting state wildlife surveillance efforts. The viral genotypes observed in birds sampled at The Raptor Center were representative of what was seen in wild bird surveillance within the Mississippi flyway during the same time frame. Wildlife rehabilitation centers provide an opportune situation to augment disease surveillance at the human, wildlife and domestic animal interface during ongoing infectious disease outbreaks.

Association between SARS-CoV-2 Infection and Adverse Perinatal Outcomes by Race/Ethnicity in a Large Integrated Health Care System.

Recent studies have reported associations between severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection during pregnancy and adverse perinatal outcomes but the extent to which these associations vary by race/ethnicity remains uncertain. Therefore, we examined how the association between prenatal SARS-CoV-2 infection and adverse perinatal outcomes may be modified by race/ethnicity. A retrospective cohort study was performed using data on 67,986 pregnant women extracted from the Kaiser Permanente Southern California electronic health records between April 6, 2020, and December 31, 2021. Upon admission to labor and delivery, all women were routinely tested for coronavirus disease 2019 (COVID-19) using real-time reverse-transcriptase polymerase chain reaction test. Adjusted odds ratios (aORs) were used to estimate associations. During the study period, COVID-19 was diagnosed in 4,960 (7%) of singleton pregnancies, with the highest rates observed among Hispanics (9.4%) and non-Hispanic Blacks (6.2%). Compared with non-Hispanic Whites, Hispanics (aOR: 1.12, 95% CI: 1.03, 1.21) with SARS-CoV-2 infection had the highest odds of a pregnancy associated with nonreassuring fetal heart rate tracing. Neonates of all races/ethnicities, except for non-Hispanic Blacks, showed significantly increased odds of SARS-CoV-2 infection, with the highest risk observed among Asians/Pacific Islanders (aOR: 10.88, 95% CI: 1.33, 89.04). Non-Hispanic White mothers who tested positive were admitted to intensive care unit (ICU) at a higher rate at delivery and within 7 days of delivery (aOR: 34.77, 95% CI: 11.3, 107.04; aOR: 26.48, 95% CI: 9.55, 73.46, respectively). Hispanics were also at a significantly higher odds of admission to ICU (aOR: 4.62, 95% CI: 2.69, 7.94; aOR: 4.42, 95% CI: 2.58, 7.56, respectively). Non-Hispanic Black, Hispanic, and Asian/Pacific Islander mothers who tested positive for SARS-CoV-2 prenatally, were at increased risk for preeclampsia/eclampsia, and preterm birth as compared to non-Hispanic White mothers. The findings highlight racial/ethnic disparities in the association between SARS-CoV-2 infection and adverse perinatal outcomes. The risk of neonatal SARS-CoV-2 infection was highest for Asian/Pacific Islanders. We also observed a remarkably high risk of ICU admission for non-Hispanic White mothers infected with SARS-CoV-2. · Race/ethnicity influences perinatal outcomes in pregnancies impacted by SARS-CoV-2.. · The risk of neonatal SARS-CoV-2 infection was highest for Asian/Pacific Islanders.. · White mothers had a notably high risk of ICU admission at delivery following SARS-CoV-2 infection..

Whole-Blood PCR Preferred for Timely Diagnosis of Neuroinvasive West Nile Virus Infections: Lessons From the 2021 Arizona Outbreak.

In 2021, the state of Arizona experienced the largest focal outbreak of West Nile virus (WNV) in US history. Timely and accurate diagnostic testing remains a challenge for WNV due to transient viremia and limited immunoassay specificity. Recent studies have identified whole blood (WB) and urine as more sensitive specimen types for the detection of WNV RNA. We evaluated ordering practices, test performance, and patient characteristics of probable and confirmed cases. In total, we identified 190 probable and proven cases, including 127 patients (66.8%) with neuroinvasive disease. Among all cases, only 29.5% had WNV polymerase chain reaction (PCR) testing ordered on WB, of which 80.3% resulted as positive, including 7 cases in which WNV serologic testing was negative and 5 cases for which serologic testing was not ordered. In comparison, only 23.7% of cases that had cerebrospinal fluid (CSF) PCR ordered had a positive result, including 3 cases that were negative by PCR on WB. In contrast, WNV PCR on WB detected 12 neuroinvasive cases that were CSF PCR negative. WNV PCR testing in urine was only ordered on 2 patients, both of whom were positive. Crossing cycle threshold (Ct) values were not significantly different between WB and CSF specimen types, nor was there a correlation between Ct value and days from symptom onset at the time of sample collection; all specimen types and time points had Ct values, with 98% above 30. WB was positive by WNV PCR in several patients for >7 days (range, 7-25 days) after symptom onset, as was the CSF PCR. Taken together, these findings indicate that WNV PCR testing on WB may be the best initial test for timely diagnosis of WNV infection, irrespective of clinical manifestation; however, if negative in patients with suspected neuroinvasive disease, WNV PCR testing on CSF should be ordered.

Concordance between ER, PR, Ki67, and HER2-low expression in breast cancer by MammaTyper RT-qPCR and immunohistochemistry: implications for the practising pathologist.

There are limited data on the role of multigene tests and their correlation with immunohistochemistry (IHC), especially on core biopsy. MammaTyper is a quantitative conformite Europeeanne (CE) marked, National Institute for Health and Care excellence (NICE) approved, in in vitro diagnostic quantitative real-time polymerase chain reaction (RT-qPCR) test for assessment of mRNA expression of four biomarkers (ESR1, PGR, ERBB2, MKI67). We evaluated the concordance of MammaTyper with oestrogen receptor (ER), progesterone receptor(PR), HER2, and Ki67 by IHC on 133 core needle biopsies of breast cancer. HER2 was positive if IHC 3+ or 2+ and fluorescence in situ hybridization (FISH)-amplified. Global and hotspot Ki67 expression was analysed using a cutoff of ≥20% assessed manually and by digital image analysis. Agreements were expressed as overall percent agreement (OPA), positive percent agreement (PPA), negative percent agreement (NPA), and Cohen's kappa. RT-qPCR results of ESR1 were highly concordant with IHC with OPA of 94.7% using 1% cutoff and 91.7% when the low ER-positive category was included. The PPA and NPA between RT-qPCR and IHC for PR was 91.5% and 88.0%, respectively, when using the 1% cutoff. For ERBB2/HER2, the OPA was 95% and the PPA was 84.6%. 40 of 72 HER2 IHC score 0 tumours were classified as ERBB2 low. Best concordance between MKI67 by MammaTyper and Ki67 IHC was achieved using hotspot digital image analysis (OPA: 87.2%, PPA: 90.6%, NPA: 80%). RT-qPCR-based assessment of the mRNA expression of ESR1, PGR, ERBB2, and MKI67 showed high concordance with IHC, suggesting that the MammaTyper test on core needle biopsies represents a reliable, efficient, and reproducible alternative for breast cancer classification and refining HER2 low categorisation.

OUTCOMES OF INFECTIOUS PANUVEITIS ASSOCIATED WITH SIMULTANEOUS MULTI-POSITIVE OCULAR FLUID POLYMERASE CHAIN REACTION.

To evaluate features of infectious panuveitis associated with multiple pathogens detected by ocular fluid sampling. Single-center, retrospective, consecutive case series of patients with aqueous/vitreous polymerase chain reaction testing with >1 positive result in a single sample from 2001 to 2021. Of 1,588 polymerase chain reaction samples, 28 (1.76%) were positive for two pathogens. Most common pathogens were cytomegalovirus (n = 16, 57.1%) and Epstein-Barr virus (n = 13, 46.4%), followed by varicella zoster virus (n = 8, 28.6%), Toxoplasma gondii (n = 6, 21.4%), herpes simplex virus 2 (n = 6, 21.4%), herpes simplex virus 1 (n = 6, 21.4%), and Toxocara (n = 1, 3.6%). Mean initial and final visual acuity (logarithm of the minimum angle of resolution) were 1.3 ± 0.9 (Snellen ∼20/400) and 1.3 ± 1.1 (Snellen ∼20/400), respectively. Cytomegalovirus-positive eyes (n = 16, 61.5%) had a mean final visual acuity of 0.94 ± 1.1 (Snellen ∼20/175), whereas cytomegalovirus-negative eyes (n = 10, 38%) had a final visual acuity of 1.82 ± 1.0 (Snellen ∼20/1,320) ( P < 0.05). Main clinical features included intraocular inflammation (100%), retinal whitening (84.6%), immunosuppression (65.4%), retinal hemorrhage (38.5%), and retinal detachment (34.6%). Cytomegalovirus or Epstein-Barr virus were common unique pathogens identified in multi-PCR-positive samples. Most patients with co-infection were immunosuppressed with a high rate of retinal detachment and poor final visual acuity. Cytomegalovirus-positive eyes had better visual outcomes compared with cytomegalovirus-negative eyes.

Prevalence, serovars, and risk factors associated with the presence of Salmonella in pork sold in public markets in Quito, Ecuador

Background Salmonella enterica are bacteria that include more than 2,500 serovars. Most of these serovars have been linked to human foodborne illnesses, mainly related to poultry and pigs. Thus, these animals are considered the reservoirs of many Salmonella serovars and strains related to antibiotic resistance. This study aimed to determine the prevalence, serovars, β-lactam resistance genes, and the risk factors associated with Salmonella enterica in pork commercialized in open markets of Quito city. Methods For this, 165 pork meat samples were taken from municipal markets in three areas in the city. These samples were microbiologically processed following the ISO 6579-2014 standardized method. The polymerase chain reaction (PCR) test was used to identify Salmonella serotyping and resistance genes. Strains not identified by PCR were typed by the Kauffman White Le Minor scheme. A multivariate analysis was performed to identify risk factors associated with the presence of the microorganism. Results Salmonella prevalence in pork was 9.1%. Identified serovars were 4, [5], 12: i:- (53.3%), Infantis (33.3%), and Derby (13.4%). Furthermore, the β-lactam resistance genes bla CTX-M-65 could be identified in three S. infantis isolates. Multivariate analysis showed that temperature (above 8°C) and cutting surfaces (wood) presented significant association values. Conclusions In conclusion, pork in traditional markets of Quito is contaminated with Salmonella enterica, whose main serovars pose a public health concern, and shows beta-lactam resistance.

Prevalence and predictors of post-acute COVID syndrome among infected healthcare workers at University Malaya Medical Centre.

Post Acute COVID Syndrome (PACS), a complex and poorly understood condition characterised by persistent symptoms following the acute phase of COVID-19 infection, has emerged as a significant global health concern. Healthcare workers who had been at the forefront of the pandemic response are at heightened risk of contracting the virus and subsequently developing PACS. Therefore, we aim to determine the prevalence and risk factors for PACS among healthcare workers infected with COVID-19. A cross-sectional study was conducted between October 2022 and August 2023 using an online REDCap electronic data capture tool questionnaire. PACS was defined as new or persistent symptoms lasting more than 28 days after a positive SARS-CoV-2 polymerase chain reaction or rapid test kit antigen test. Multivariable logistic regression was performed to determine predictors associated with PACS. Among 609 infected healthcare workers, they were predominantly female (71.8%), Malays (84.6%), and aged 18-39 years (70.1%). 50.7% of infected healthcare workers experienced PACS. The most common PACS symptoms experienced were fatigue (27.9%), cough (25.1%), decreased physical strength (20.5%), and musculoskeletal pain (19.2%). Those who are more likely to develop PACS were females, underlying asthma, and COVID-19 severity category 3. On the other hand, those who received booster vaccinations were less likely to develop PACS. PACS is prevalent among healthcare workers with COVID-19 at the University Malaya Medical Centre. These findings emphasise the critical need for those with higher risk to receive regular health monitoring and checkups to detect any early signs of PACS. It underscores the need for continuous support and healthcare interventions to mitigate the impacts of PACS and ensure the physical and mental well-being of healthcare workers.

COVID-19-associated cerebral microbleeds in the general population.

Cerebral microbleeds are frequent incidental findings on brain MRI and have previously been shown to occur in Coronavirus Disease 2019 (COVID-19) cohorts of critically ill patients. We aimed to determine the risk of having microbleeds on medically indicated brain MRI and compare non-hospitalized COVID-19-infected patients with non-infected controls. In this retrospective case-control study, we included patients over 18 years of age, having an MRI with a susceptibility-weighted sequence, between 1 January 2019 and 1 July 2021. Cases were identified based on a positive reverse transcriptase polymerase chain reaction test for SARS-CoV-2 and matched with three non-exposed controls, based on age, sex, body mass index and comorbidities. The number of cerebral microbleeds on each scan was determined using artificial intelligence. We included 73 cases and 219 matched non-exposed controls. COVID-19 was associated with significantly greater odds of having cerebral microbleeds on MRI [odds ratio 2.66 (1.23-5.76, 95% confidence interval)], increasingly so when patients with dementia and hospitalized patients were excluded. Our findings indicate that cerebral microbleeds may be associated with COVID-19 infections. This finding may add to the pathophysiological considerations of cerebral microbleeds and help explain cases of incidental cerebral microbleeds in patients with previous COVID-19.

The risk-based operational safety strategy for Perkin-Elmer/Cetus DNA Thermal Cycler PCR systems

Introduction: this article was conducted in the field of polymerase chain reaction (PCR) test safety, where it is essential to understand the contribution and impact of risk analysis methods to improve test safety medical diagnosis at the institutional level. In this context, the current study focuses on failure modes and effects analysis (FMEA) applied to the Perkin-Elmer/Cetus deoxyribonucleic acid (DNA) thermocycler.Objective: to describe the application of FMEA to improve the operational safety of Perkin-Elmer/Cetus DNA thermal cyclers used in medical diagnostics in ataxic patients. Methods: to carry out this study, a methodology based on an exhaustive review of the scientific literature available in academic databases and relevant sources was used. Previous studies on FMEA analysis of DNA thermocyclers in common and expanded forms were collected and analyzed.Results: the results obtained demonstrated that FMEA is an effective tool to identify and evaluate possible failure modes of Perkin-Elmer/Cetus DNA thermal cyclers. Several defects were identified and their consequences, causes and classification based on their severity and frequency were determined. Likewise, corrective actions are proposed to reduce the identified risks.Conclusions: early identification of possible failure modes and implementation of corrective actions can reduce risk and guarantee the quality of the diagnoses carried out and therefore improve operational safety

Comparison of Polymerase Chain Reaction and Urine Culture in the Evaluation of Patients with Complex Urinary Tract Infections.

To compare organism identification using polymerase chain reaction (PCR) and urine culture (UC) in patients with complex urinary tract infections (cUTIs), we reviewed the results of 3395 patients seen during 2022 with cUTI who underwent concomitant PCR and UC testing. We compared the overall positivity rates as well as the ability of each test to identify fastidious organisms (FOs) and the presence of polymicrobial infections (PMOs) and conducted concordance analysis between the tests. PCR detected 36.4% more organisms than UC and was 20 and nearly 36 times more likely to detect PMOs and FOs, respectively. PCR identified 90.6% of organisms found in UC, whereas UC identified 40.7% of organisms found in PCR testing. We found that 62.4% of organisms found in PCR were not found in urine culture, while UC found 9.4% of organisms not identified in polymerase chain reaction. All these differences were statistically significant (p < 0.05). Although we found that PCR was superior to UC in overall pathogen detection, and detection of both PMOs and FOs, both identified potentially pathogenic organisms not found in the corresponding test. Our data strongly suggest that the evaluation of patients with cUTI is best accomplished using PCR in conjunction with UC.

Quality assurance of SARS-CoV-2 testing laboratories during the pandemic period in India – An experience from a designated provider laboratory

PurposeIndian Council of Medical Research (ICMR) initiated an Inter-Laboratory Quality Control testing (ILQC) program for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) testing. Under this program, SARS-CoV-2 testing laboratories across the country submit specimens to the assigned State Quality Control (SQCs) laboratories for ILQC testing. This study aimed to investigate the performance of public and private SARS-CoV-2 testing laboratories in Delhi and highlights the country’s effort in ramping up testing facility with close monitoring of the quality of Covid-19 testing results. MethodsIn the present study, two-years of SARS-CoV-2 testing data is included. During July 2020 through February 2022, a total of 1791 anonymised specimens were received from 56 public and private laboratories. These specimens were processed by reverse transcriptase – polymerase chain reaction (RT-PCR) tests as per National Institute of Virology (NIV) protocol and the results were uploaded on the ICMR quality control/quality assurance (QC/QA) portal without directly conveying the results to respective participating laboratories. This portal generated a final report stating concordance and intimate results to individual laboratories. ResultsAmong the 1791 specimens, 25 were rejected and the remaining 1766 were tested. Among these specimens 1691 (95.75%) revealed concordance, and 75 (4.24%) were discordant. A total of 29 laboratories had 100% concordance, 21 laboratories had over 90% concordance and six laboratories had over 80% concordance. ConclusionsThe study demonstrates that the establishment of an inter-laboratory comparison program for SARS-CoV-2 testing helped in monitoring quality of SARS-CoV-2 testing in the country.

COVID-19 and Asthma Onset in Children.

Respiratory viral infections increase risk of asthma in infants and children. Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus can cause severe lung inflammation and prolonged respiratory symptoms. We sought to determine whether SARS-CoV-2 infection modified pediatric incident asthma risk. This retrospective cohort study examined children ages 1 to 16 within the Children's Hospital of Philadelphia Care Network who received polymerase chain reaction (PCR) testing for SARS-CoV-2 between March 1, 2020 and February 28, 2021. Multivariable Cox regression models assessed the hazard ratio of new asthma diagnosis between SARS-CoV-2 PCR positive and SARS-CoV-2 PCR negative groups within an 18-month observation window. Models were adjusted for demographic characteristics, socioeconomic variables, and atopic comorbidities. There were 27 423 subjects included in the study. In adjusted analyses, SARS-CoV-2 PCR positivity had no significant effect on the hazard of new asthma diagnosis (hazard ratio [HR]: 0.96; P = .79). Black race (HR: 1.49; P = .004), food allergies (HR: 1.26; P = .025), and allergic rhinitis (HR: 2.30; P < .001) significantly increased the hazard of new asthma diagnosis. Preterm birth (HR: 1.48; P = .005) and BMI (HR: 1.13; P < .001) significantly increased the hazard of new asthma diagnosis for children <5 years old. SARS-CoV-2 PCR positivity was not associated with new asthma diagnosis in children within the observation period, although known risk factors for pediatric asthma were confirmed. This study informs the prognosis and care of children with a history of SARS-CoV-2 infection.

Hepatitis C Exposure Diagnosis and Testing in Infants Born to Hepatitis C Virus-infected Mothers.

There has been a 5-fold increase in the number of cases of hepatitis C virus (HCV) infection among pregnant women, which is potentially associated with the increase in opioid use. This study was a retrospective review of infants born at a tertiary urban hospital in New Jersey, from January 1, 2011 to January 1, 2021, who were born to mothers with a prenatal diagnosis of HCV. Of the 142 mothers with a prenatal diagnosis of HCV, 114 (80%) infants had a diagnosis of HCV exposure in the electronic health records. Of the HCV-exposed infants with follow-up data at 24 months of age, 52 (46%) were tested, with 34 of 52 (65%) receiving adequate testing. Infants documented as HCV exposed were more likely to be born to a mother with nonopioid drug use in pregnancy ( P = 0.01) and have a higher birth weight ( P = 0.03). Of tested infants, those with a higher number of well-child pediatrician visits ( P = 0.01) were more likely to receive adequate testing. Trends showed more polymerase chain reaction testing than antibody testing for those who were inadequately tested. A significant proportion of infants born to HCV-infected mothers were either not identified at birth (20%) or did not receive adequate testing on follow-up (35%). Further work needs to be done to improve documentation of HCV exposure at birth and follow-up testing to avoid missing congenitally acquired HCV.

Detection of Clarithromycin Resistance in Helicobacter pylori Using MmaxSure™ H. pylori & ClaR Assay

Introduction: Clarithromycin resistance is a crucial factor in the eradication of Helicobacter pylori. This study aimed to evaluate the performance of MmaxSure™ H. pylori & ClaR Assay (MmaxSure™) in the diagnosis and detection of clarithromycin resistance in H. pylori. Methods: Subjects who underwent esophagogastroduodenoscopy between April 2020 and October 2022 were enrolled. The diagnostic performances of MmaxSure™ and dual priming oligonucleotide (DPO)-based multiplex polymerase chain reaction (PCR) were compared with the rapid urease test and culture. Secondary gene sequencing analysis was performed in discordant cases of PCR tests. Results: A total of 156 gastric biopsy samples were analyzed. In H. pylori detection, MmaxSure™ showed a 95.9% sensitivity (95% CI: 90.6–98.6), a 42.7% specificity (95% CI: 26.3–60.7), and a kappa value of 0.457. For the detection of A2143G mutation samples, MmaxSure™ showed a 91.2% sensitivity (95% CI: 76.3–98.1), a 93.4% specificity (95% CI: 87.5–97.1), and a kappa value of 0.804. There were a total of 10 discordant cases compared to gene sequencing in A2143G mutation detection for MmaxSure™. Conclusion: In this study, MmaxSure™ showed comparable diagnostic performance to DPO-PCR in the detection of the H. pylori and A2143G mutation. Further research is needed to confirm the clinical effectiveness of the MmaxSure™ assay in H. pylori eradication.

Prevalence, Molecular Detection, and Antimicrobial Resistance of Salmonella Isolates from Poultry Farms across Central Ethiopia: A Cross-Sectional Study in Urban and Peri-Urban Areas.

A cross-sectional study was conducted to assess the prevalence, molecular detection, and antimicrobial resistance of Salmonella isolates within 162 poultry farms in selected urban and peri-urban areas of central Ethiopia. A total of 1515 samples, including cloacal swabs (n = 763), fresh fecal droppings (n = 188), litter (n = 188), feed (n = 188), and water (n = 188), were bacteriologically tested. The molecular detection of some culture-positive isolates was performed via polymerase chain reaction (PCR) by targeting spy and sdfl genes for Salmonella Typhimurium and Salmonella Enteritidis, respectively. Risk factors for the occurrence of the bacterial isolates were assessed. Antimicrobial susceptibility testing of PCR-confirmed Salmonella isolates was conducted using 12 antibiotics. In this study, it was observed that 50.6% of the farms were positive for Salmonella. The overall sample-level prevalence of Salmonella was 14.4%. Among the analyzed risk factors, the type of production, breed, and sample type demonstrated a statistically significant association (p < 0.05) with the bacteriological prevalence of Salmonella. The PCR test disclosed that 45.5% (15/33) and 23.3% (10/43) of the isolates were positive for genes of Salmonella Typhimurium and Salmonella Enteritidis, respectively. The antimicrobial susceptibility test disclosed multi-drug resistance to ten of the tested antibiotics that belong to different classes. Substantial isolation of Salmonella Typhimurium and Salmonella Enteritidis in poultry and on poultry farms, along with the existence of multi-drug resistant isolates, poses an alarming risk of zoonotic and food safety issues. Hence, routine flock testing, farm surveillance, biosecurity intervention, stringent antimicrobial use regulations, and policy support for the sector are highly needed.

Genetic Sequence and Pathogenicity of Infectious Bursal Disease Virus in Chickens in Egypt During 2017-2021.

The continued circulation of infectious bursal disease virus (IBDV) in Egypt, despite the use of various vaccines, is a serious problem that requires continuous detection of IBDV. In the current study, real-time reverse transcriptase polymerase chain reaction testing of 100 diseased chicken flocks during 2017-2021 revealed the presence of very virulent IBDV (vvIBDV) in 67% of the flocks, non-vvIBDV in 11%, and a mixture of both vvIBDV and non-vvIBDV in 4%. Twenty-nine IBDV isolates were submitted for partial sequencing of the viral protein 2 hypervariable region (VP2-HVR), and 27 isolates were confirmed to be genogroup A3 (vvIBDV) with 96.3%-98.5% similarity to the global A3 (vvIBDV) and 88.9%-97% similarity to genogroup A1 vaccine strains. The remaining two isolates were non-vvIBDV and showed 91.1% and 100% identity with classical genogroup A1 strains, respectively. Furthermore, the sequence and phylogenetic analysis of VP1 (amino acids 33-254) of two selected isolates of A3, 5/2017 and 98/2021, clustered them as B2, vvIBDV-like, strains with high similarity (99.5%) to four Egyptian, 99% to Chinese and European, and 97.7% to Chinese and Polish vvIBDV isolates. Experimental infection of commercial broiler chickens with two vvIBDV-A3B2 isolates (5/2017 and 98/2021) showed no mortality despite typical tissue lesions, clear histopathological changes, and strong ELISA antibody response. Isolate 98/2021 was more pathogenic, as confirmed by histopathology, whereas isolate 5/2017 induced a stronger serological response. In conclusion, vvIBDV (A3B2) strains with two amino acid (aa) substitutions in VP1 as V141I and V234I as well as VP2 as Y220F and G254S are still circulating in Egypt.

Race, Ethnicity, and Delayed Time to COVID-19 Testing Among US Health Care Workers

Access to COVID-19 testing is critical to reducing transmission and supporting early treatment decisions; when made accessible, the timeliness of testing may also be an important metric in mitigating community spread of the infection. While disparities in transmission and outcomes of COVID-19 have been well documented, the extent of timeliness of testing and the association with demographic factors is unclear. To evaluate demographic factors associated with delayed COVID-19 testing among health care personnel (HCP) during the COVID-19 pandemic. This cross-sectional study used data from the Preventing Emerging Infections Through Vaccine Effectiveness Testing study, a multicenter, test-negative, case-control vaccine effectiveness study that enrolled HCP who had COVID-19 symptoms and testing between December 2020 and April 2022. Data analysis was conducted from March 2022 to Junne 2023. Displaying COVID-19-like symptoms and polymerase chain reaction testing occurring from the first day symptoms occurred up to 14 days after symptoms occurred. Variables of interest included patient demographics (sex, age, and clinical comorbidities) and COVID-19 characteristics (vaccination status and COVID-19 wave). The primary outcome was time from symptom onset to COVID-19 testing, which was defined as early testing (≤2 days) or delayed testing (≥3 days). Associations of demographic characteristics with delayed testing were measured while adjusting for clinical comorbidities, COVID-19 characteristics, and test site using multivariable modeling to estimate relative risks and 95% CIs. A total of 5551 HCP (4859 female [82.9%]; 1954 aged 25-34 years [35.2%]; 4233 non-Hispanic White [76.3%], 370 non-Hispanic Black [6.7%], and 324 non-Hispanic Asian [5.8%]) were included in the final analysis. Overall, 2060 participants (37.1%) reported delayed testing and 3491 (62.9%) reported early testing. Compared with non-Hispanic White HCP, delayed testing was higher among non-Hispanic Black HCP (adjusted risk ratio, 1.18; 95%CI, 1.10-1.27) and for non-Hispanic HCP of other races (adjusted risk ratio, 1.17; 95% CI, 1.03-1.33). Sex and age were not associated with delayed testing. Compared with clinical HCP with graduate degrees, all other professional and educational groups had significantly delayed testing. In this cross-sectional study of HCP, compared with non-Hispanic White HCP and clinical HCP with graduate degrees, non-Hispanic Black HCP, non-Hispanic HCP of other races, and HCP all other professional and education backgrounds were more likely to have delayed COVID-19 testing. These findings suggest that time to testing may serve as a valuable metric in evaluating sociodemographic disparities in the response to COVID-19 and future health mitigation strategies.

Efficacy of Health Surveillance and Polymerase Chain Reaction Testing in Judo During the COVID-19 Pandemic.

Background The COVID-19 pandemic necessitated infection control for all sporting activities. More careful infection control measures are required in judo, where close contact with opponents cannot be avoided. The Medical Science Committee of the All Japan Judo Federation (AJJF) established infection control guidelines for daily practice and competitions. Infection control measures were also implemented at the national tournament organized by the AJJF. Objective and methods This study aimed to examine the effectiveness of pre-tournament health surveys and PCR testing in guidelines for judo tournaments. Participants had to complete a health survey one to two weeks before the tournament. Initially, PCR testing was performed on all athletes; however, the final policy was to conduct PCR testing only on athletes with an infected person (risk team testing method). The effectiveness of these methods was also examined. Results In 16 competitions between October 2020 and March 2023, 6980 contestants were registered, and PCR testing was performed on 3672 athletes; 29 (0.79%) had a positive PCR test. Only two contestants were unable to attend the tournament because of the health survey. No competition-related cluster outbreaks were observed. From May 2022, the competition was held under the guideline that only teams at risk of infection were tested and could only compete when they tested negative. No teams were tested according to this guideline. In the competitions organized within this guideline, only one person could not compete because of the information provided in the health survey. No clusters were observed in any of the competitions. The incidence of COVID-19 infection in the first week after the convention was 20 (0.60%) in testing only at-risk teams and 21 (0.57%) in testing all competitors, which was not significantly different.(p=0.62) Conclusion During the COVID-19 epidemic, health surveillance was necessary to prevent the registration of competitors at risk of infection prior to tournaments. If teams at risk of infection could be identified, PCR testing of all athletes might not be mandatory, and competitions could be organized safely. The Judoinfectious disease control guidelines we have developed might be used for other contact sports in the future when other infectious diseases are prevalent.

SARS-CoV-2 immunoassays in a predominantly vaccinated population: Performances and qualitative agreements obtained with two analytical approaches and four immunoassays.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serosurveys are typically analysed by applying a fixed threshold for seropositivity ('conventional approach'). However, this approach underestimates the seroprevalence of anti-nucleocapsid (N) in vaccinated individuals-who often exhibit a difficult-to-detect anti-N response. This limitation is compounded by delays between the onset of infection and sample collection. To address this issue, we compared the performance of four immunoassays using a new analytical approach ('ratio-based approach'), which determines seropositivity based on an increase in anti-N levels. Two groups of plasma donors and four immunoassays (Elecsys total anti-N, VITROS total anti-N, Architect anti-N Immunoglobulin G (IgG) and in-house total anti-N) were evaluated. First-group donors (N = 145) had one positive SARS-CoV-2 polymerase chain reaction (PCR) test result and had made two plasma donations, including one before and one after the PCR test (median = 27 days post-PCR). Second-group donors (N = 100) had made two plasma donations early in the Omicron wave. Among first-group donors (97.9% vaccinated), sensitivity estimates ranged from 60.0% to 89.0% with the conventional approach, compared with 94.5% to 98.6% with the ratio-based approach. Among second-group donors, Fleiss's κ ranged from 0.56 to 0.83 with the conventional approach, compared with 0.90 to 1.00 with the ratio-based approach. With the conventional approach, the sensitivity of four immunoassays-measured in a predominantly vaccinated population based on samples collected ~1 month after a positive test result-fell below regulatory agencies requirement of ≥95%. The ratio-based approach significantly improved the sensitivities and qualitative agreement among immunoassays, to the point where all would meet this requirement.