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Background Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen in blood has been described, but the diagnostic and prognostic role of antigenemia is not well understood. This study aimed to determine the frequency, duration, and concentration of nucleocapsid antigen in plasma and its association with coronavirus disease 2019 (COVID-19) severity. Methods We utilized an ultrasensitive electrochemiluminescence immunoassay targeting SARS-CoV-2 nucleocapsid antigen to evaluate 777 plasma samples from 104 individuals with COVID-19. We compared plasma antigen to respiratory nucleic acid amplification testing (NAAT) in 74 individuals with COVID-19 from samples collected ±1 day of diagnostic respiratory NAAT and in 52 SARS-CoV-2–negative individuals. We used Kruskal–Wallis tests, multivariable logistic regression, and mixed-effects modeling to evaluate whether plasma antigen concentration was associated with disease severity. Results Plasma antigen had 91.9% (95% CI 83.2%–97.0%) clinical sensitivity and 94.2% (84.1%–98.8%) clinical specificity. Antigen-negative plasma samples belonged to patients with later respiratory cycle thresholds (Ct) when compared with antigen-positive plasma samples. Median plasma antigen concentration (log10 fg/mL) was 5.4 (interquartile range 3.9–6.0) in outpatients, 6.0 (5.4–6.5) in inpatients, and 6.6 (6.1–7.2) in intensive care unit (ICU) patients. In models adjusted for age, sex, diabetes, and hypertension, plasma antigen concentration at diagnosis was associated with ICU admission [odds ratio 2.8 (95% CI 1.2–6.2), P=.01] but not with non-ICU hospitalization. Rate of antigen decrease was not associated with disease severity. Conclusions SARS-CoV-2 plasma nucleocapsid antigen exhibited comparable diagnostic performance to upper respiratory NAAT, especially among those with late respiratory Ct. In addition to currently available tools, antigenemia may facilitate patient triage to optimize intensive care utilization.

Little is known about the extent and serotypes of dengue viruses circulating in Africa. We evaluated the presence of dengue viremia during 4 years of surveillance (2014–2017) among children with febrile illness in Kenya. Acutely ill febrile children were recruited from 4 clinical sites in western and coastal Kenya, and 1,022 participant samples were tested by using a highly sensitive real-time reverse transcription PCR. A complete case analysis with genomic sequencing and phylogenetic analyses was conducted to characterize the presence of dengue viremia among participants during 2014–2017. Dengue viremia was detected in 41.9% (361/862) of outpatient children who had undifferentiated febrile illness in Kenya. Of children with confirmed dengue viremia, 51.5% (150/291) had malaria parasitemia. All 4 dengue virus serotypes were detected, and phylogenetic analyses showed several viruses from novel lineages. Our results suggests high levels of dengue virus infection among children with undifferentiated febrile illness in Kenya.

Background Numerous nucleic acid amplification assays utilizing different target genes of the SARS-CoV-2 genome have received emergency use authorization (EUA) by the United States Food and Drug Administration (FDA). Limited data are available comparing the test performance characteristics of these assays. Methods A diagnostic comparison study was performed to evaluate the performance of the Cepheid Xpert Xpress SARS-CoV-2 assay compared to the Hologic Panther Fusion SARS-CoV-2 assay using clinical nasopharyngeal specimens. Agreement between the two assays was assessed by overall, positive, and negative percent agreement and Cohen’s kappa coefficient. Results A total of 104 (54 positive and 50 negative) clinical nasopharyngeal samples were tested by both assays. Using the Panther Fusion as a reference standard, the Xpert demonstrated an overall agreement of 99.0% [95% confidence interval (CI): 94.8–100], positive percent agreement of 98.1% (95% CI: 90.1–100), and a negative percent agreement of 100% (95% CI: 94.2–100). The kappa coefficient was 0.98 (95% CI: 0.94–1.0). One sample positive by the Panther Fusion with a cycle threshold (Ct) of 38.6 was found to be reproducibly negative by the Xpert assay. Conclusions The Cepheid Xpert Xpress SARS-CoV-2 assay provides test performance comparable to the Hologic Panther Fusion SARS-CoV-2 assay while offering laboratories rapid, on-demand testing capacity.

O’nyong-nyong virus (ONNV) is a little-known arbovirus causing intermittent, yet explosive, outbreaks in Africa. It is closely related to chikungunya virus, an emerging infectious disease. O’nyong-nyong virus causes a self-limited illness characterized by bilateral polyarthritis, rash, low-grade fever, and lymphadenopathy. In 1959, an extensive outbreak of ONNV occurred in East Africa, and decades later, another large outbreak was documented in Uganda in 1996. Limited evidence for interepidemic transmission is available, although serologic studies indicate a high prevalence of exposure. 1,045 febrile child participants in western and coastal Kenya were tested for the presence of ONNV using a multiplexed real-time reverse transcriptase–PCR assay. More than half of the participants had malaria parasitemia, and there was no evidence of active ONNV viremia in these participants. Further work is required to better understand the interepidemic circulation of ONNV and to reconcile evidence of high serologic exposure to ONNV among individuals in East Africa.

Dengue and COVID-19 co-circulation presents a diagnostic conundrum for physicians evaluating patients with acute febrile illnesses, both in endemic regions and among returning travelers. We present a case of a returning traveler from Pakistan who, following repeated negative SARS-CoV-2 tests, was found to have a Dengue virus serotype 2 infection.

Background Respiratory virus infections are significant causes of morbidity and mortality, and may induce host metabolite alterations by infecting respiratory epithelial cells. We investigated the use of liquid chromatography quadrupole time-of-flight mass spectrometry (LC/Q-TOF) combined with machine learning for the diagnosis of influenza infection. Methods We analyzed nasopharyngeal swab samples by LC/Q-TOF to identify distinct metabolic signatures for diagnosis of acute illness. Machine learning models were performed for classification, followed by Shapley additive explanation (SHAP) analysis to analyze feature importance and for biomarker discovery. Findings A total of 236 samples were tested in the discovery phase by LC/Q-TOF, including 118 positive samples (40 influenza A 2009 H1N1, 39 influenza H3 and 39 influenza B) as well as 118 age and sex-matched negative controls with acute respiratory illness. Analysis showed an area under the receiver operating characteristic curve (AUC) of 1.00 (95% confidence interval [95% CI] 0.99, 1.00), sensitivity of 1.00 (95% CI 0.86, 1.00) and specificity of 0.96 (95% CI 0.81, 0.99). The metabolite most strongly associated with differential classification was pyroglutamic acid. Independent validation of a biomarker signature based on the top 20 differentiating ion features was performed in a prospective cohort of 96 symptomatic individuals including 48 positive samples (24 influenza A 2009 H1N1, 5 influenza H3 and 19 influenza B) and 48 negative samples. Testing performed using a clinically-applicable targeted approach, liquid chromatography triple quadrupole mass spectrometry, showed an AUC of 1.00 (95% CI 0.998, 1.00), sensitivity of 0.94 (95% CI 0.83, 0.98), and specificity of 1.00 (95% CI 0.93, 1.00). Limitations include lack of sample suitability assessment, and need to validate these findings in additional patient populations. Interpretation This metabolomic approach has potential for diagnostic applications in infectious diseases testing, including other respiratory viruses, and may eventually be adapted for point-of-care testing. Funding None.

We report persistent severe acute respiratory syndrome coronavirus 2 infection in a patient with HIV/AIDS; the virus developed spike N terminal domain and receptor binding domain neutralization resistance mutations. Our findings suggest that immunocompromised patients can harbor emerging variants of severe acute respiratory syndrome coronavirus 2.

Background and AimsPatients with decompensated HBV-related liver cirrhosis (HBV D-LC) showed compromised immune responses, which manifested as a proneness to develop infections and hyporesponsiveness to vaccines, resulting in accelerated disease progression. The alterations in T cell-dependent B cell responses in this pathophysiological process were not well understood. This study aimed to investigate T cell-dependent B cell responses in this process and discuss the mechanism from the perspective of metabolism.MethodsChanges in phenotypes and subsets of peripheral B cells between HBV D-LC patients and healthy controls (HCs) were compared by flow cytometry. Isolated B cells were activated by coculture with circulating T follicular (cTfh) cells. After coculture, the frequencies of plasmablasts and plasma cells and immunoglobin levels were analyzed. Oxidative phosphorylation (OXPHOS) and glycolysis were analyzed by a Seahorse analyzer. Mitochondrial function and the AKT/mTOR pathway were analyzed by flow cytometry.ResultsThe proliferation and differentiation capacities of B cells after T cell stimulation were impaired in D-LC. Furthermore, we found that B cells from D-LC patients showed reductions in OXPHOS and glycolysis after activation, which may result from reduced glucose uptake, mitochondrial dysfunction and attenuated activation of the AKT/mTOR pathway.ConclusionsB cells from HBV D-LC patients showed dysfunctional energy metabolism after T cell-dependent activation. Understanding the regulations of B cell metabolic pathway and their changes may provide a new direction to rescue B cell hyporesponsiveness in patients with HBV D-LC, preventing these patients be infected and improving sensitivity to vaccines.

Snake bite envenoming is a worldwide problem which affects the health and safety of the public. The classical antivenom methods are difficult to be used immediately and accurately. Based on this situation, a new metal-organic framework and hydrogel based first-aid treatment was first set up in this study as a facile, economic, effective, and universal alternative strategy. According to the subsequent in vitro and in vivo experiments, this dual effective (block and absorption) strategy was proven to be useful in dealing with three different representative snake venoms (Bungarus fasciatus, Protobothrops mucrosquamatus, and cobra venom).

BACKGROUND Spontaneous peritonitis is one of the most common infectious complications in cirrhotic patients with ascites. Spontaneous fungal peritonitis (SFP) is a type of spontaneous peritonitis that is a less recognized but devastating complication in end-stage cirrhosis. Although high mortality was previously noted, scant data are available to fully define the factors responsible for the occurrence of SFP and its mortality. AIM To illustrate the differences between SFP and spontaneous bacterial peritonitis (SBP) and discuss the risk factors for the occurrence of SFP and its short-term mortality. METHODS We performed a matched case-control study between January 1, 2007 and December 30, 2018. Patients with SFP were included in a case group. Sex-, age-, and time-matched patients with SBP were included in a control group and were further divided into control-1 group (positive bacterial culture) and control-2 group (negative bacterial culture). The clinical features and laboratory parameters, severity models, and prognosis were compared between the case and control groups. Logistic regression analysis was used to determine the risk factors for occurrence, and the Cox regression model was used to identify the predictive factors for short-term mortality of SFP. RESULTS Patients with SFP exhibited more severe systemic inflammation, higher ascites albumin and polymorphonuclear neutrophils, and a worsened 15-d mortality than patients in the control groups. Antibiotic administration (case vs control-1: OR = 1.063, 95%CI: 1.012-1.115, P = 0.014; case vs control-2: OR = 1.054, 95%CI: 1.014-1.095, P = 0.008) remarkably increased the occurrence of SFP or fungiascites. Hepatorenal syndrome (HR = 5.328, 95%CI: 1.050-18.900) and total bilirubin (μmol/L; HR = 1.005, 95%CI: 1.002-1.008) represented independent predictors of SFP-related early mortality. CONCLUSION Long-term antibiotic administration increases the incidence of SFP, and hepatorenal syndrome and total bilirubin are closely related to short-term mortality.

Background A major challenge in dengue management in resource limited settings is the confirmation of diagnosis. Clinical features of dengue often overlap with other infections and molecular diagnostic tools are not readily accessible to clinicians at hospitals. In addition, the prediction of plasma leakage in dengue is also difficult. Hematocrit level and ultrasound scans (combined with clinical parameters) are helpful to detect plasma leakage once it has happened, not before. Methods Colombo Dengue Study (CDS) is a prospective cohort study of clinically suspected adult dengue patients recruited from the National hospital of Sri Lanka (within the first 3 days of fever) that aimed to a) identify clinical and basic laboratory test parameters to differentiate dengue from non-dengue fever, b) evaluate the comparative efficacy of loop-mediated isothermal amplification (LAMP) for dengue diagnosis (vs. NS1 antigen test and RT-qPCR) and c) identify early associations that are predictive of plasma leakage or severe dengue. The basic laboratory tests considered here included hematological parameters, serum biochemistry and inflammatory markers. Results Only 70% of clinically suspected patients were confirmed as having dengue by either the NS1 antigen test or RT-qPCR. On a Bayesian latent class model which assumes no “gold standard”, LAMP performed equally or better than RT-qPCR and NS1 antigen test respectively. When confirmed dengue patients were compared with others, the earlier group had significantly lower lymphocyte counts and higher aspartate aminotransferase levels (AST) within the first 3 days of fever. Confirmed dengue patients with plasma leakage had a lower mean age and a higher median baseline AST level compared to those without plasma leakage (p

Background BK virus (BKV) is a significant cause of nephropathy in kidney transplantation. The goal of this study was to characterize the course and source of BKV in kidney transplant recipients. Methods We prospectively collected pretransplant plasma and urine samples from living and deceased kidney donors and performed BKV polymerase chain reaction (PCR) and immunoglobulin G (IgG) testing on pretransplant and serially collected posttransplant samples in kidney transplant recipients. Results Among deceased donors, 8.1% (17/208) had detectable BKV DNA in urine prior to organ procurement. BK viruria was observed in 15.4% (6/39) of living donors and 8.5% (4/47) of deceased donors of recipients at our institution (P = .50). BKV VP1 sequencing revealed identical virus between donor–recipient pairs to suggest donor transmission of virus. Recipients of BK viruric donors were more likely to develop BK viruria (66.6% vs 7.8%; P < .001) and viremia (66.6% vs 8.9%; P < .001) with a shorter time to onset (log-rank test, P < .001). Though donor BKV IgG titers were higher in recipients who developed BK viremia, pretransplant donor, recipient, and combined donor/recipient serology status was not associated with BK viremia (P = .31, P = .75, and P = .51, respectively). Conclusions Donor BK viruria is associated with early BK viruria and viremia in kidney transplant recipients. BKV PCR testing of donor urine may be useful in identifying recipients at risk for BKV complications.

SummaryBackgroundThere is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses.MethodsWe describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape.FindingsWe found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape.InterpretationOur results highlight the need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered.FundingThe work was partially funded by The Saban Research Institute at Children’s Hospital Los Angeles intramural support for COVID-19 Directed Research (X.G. and J.D.B.), the Johns Hopkins Center of Excellence in Influenza Research and Surveillance HHSN272201400007C (A.P.), NIH/NIAID R01AI127877 (S.D.B.), NIH/NIAID R01AI130398 (S.D.B.), NIH 1U54CA260517 (S.D.B.), an endowment to S.D.B. from the Crown Family Foundation, an Early Postdoc.Mobility Fellowship Stipend to O.F.W. from the Swiss National Science Foundation (SNSF), and a Coulter COVID-19 Rapid Response Award to S.D.B. L.G. is a SHARE Research Fellow in Pediatric Hematology-Oncology.

We present the case of an inpatient with pneumonia and repeatedly negative nasopharyngeal SARS-CoV-2 testing. In such challenging cases, alternative diagnostic options include lower respiratory tract and plasma SARS-CoV-2 RNA testing, of which the latter may be particularly useful where bronchoscopy is deferred due to clinical factors or transmission risk.

Background Molecular diagnostics such as pathogen-directed PCRs have transformed testing for ocular infections since the late 1990s. Although these assays remain important diagnostic tools for samples with low biomass, the lack of diagnostic range motivates alternative molecular approaches for ocular infections. The aim of this study was to determine the performance of a high-throughput RNA sequencing approach, RNA-seq, to detect infectious agents in ocular samples from patients with presumed ocular infections. Methods We compared the performance of RNA-seq to pathogen-directed PCRs using remnant nucleic acids from 41 aqueous or vitreous samples of patients with presumed ocular infections. Pathogen-directed PCRs were performed at the CLIA-certified Stanford Clinical Virology Laboratory. RNA-seq was performed in a masked manner at the Proctor Foundation at the University of California San Francisco. Percent positive and negative agreement between the two testing approaches were calculated. Discordant results were subjected to orthogonal testing. Results The positive percent agreement between RNA-seq and pathogen-directed PCRs was 100% (95% confidence interval (CI): 78.5%–100%). The negative percent agreement was 92.6% (95% CI: 76.6%–97.9%). RNA-seq identified pathogens not on the differential diagnosis for 9.7% (4/41) of the samples. Two pathogens solely identified with RNA-seq were confirmed with orthogonal testing. Conclusions RNA-seq can accurately identify common and rare pathogens in aqueous and vitreous samples of patients with presumed ocular infections. Such an unbiased approach to testing has the potential to improve diagnostics although practical clinical utility warrants additional studies.

We developed an assay that detects minus-strand RNA as a surrogate for actively replicating severe acute respiratory syndrome coronavirus 2. We detected minus-strand RNA in 41 persons with coronavirus disease up to 30 days after symptom onset. This assay might inform clinical decision-making about patient infectiousness.

Interferon-alpha (IFN-α) and nucleot(s)ide analogs (NAs) are first-line drugs for the treatment of chronic hepatitis B virus (HBV) infections. Generally, NAs target the reverse transcription of HBV pregenomic RNA, but they cannot eliminate covalently-closed-circular DNA (cccDNA). Although effective treatment with NAs can dramatically decrease HBV proteins and DNA loads, and even promote serological conversion, cccDNA persists in the nucleus of hepatocytes due to the lack of effective anti-cccDNA drugs. Of the medications currently available, only IFN-α can potentially target cccDNA. However, the clinical effects of eradicating cccDNA using IFN-α in the hepatocytes of patients with HBV are not proficient as well as expected and are not well understood. Herein, we review the anti-HBV mechanisms of IFN-α involving cccDNA modification as the most promising approaches to cure HBV infection. We expect to find indications of promising areas of research that require further study to eliminate cccDNA of HBV in patients.

Background Although the tumour immune microenvironment is known to significantly influence immunotherapy outcomes, its association with changes in gene expression patterns in hepatocellular carcinoma (HCC) during immunotherapy and its effect on prognosis have not been clarified. Methods A total of 365 HCC samples from The Cancer Genome Atlas liver hepatocellular carcinoma (TCGA-LIHC) dataset were stratified into training datasets and verification datasets. In the training datasets, immune-related genes were analysed through univariate Cox regression analyses and least absolute shrinkage and selection operator (LASSO)-Cox analyses to build a prognostic model. The TCGA-LIHC, GSE14520, and Imvigor210 cohorts were subjected to time-dependent receiver operating characteristic (ROC) and Kaplan–Meier survival curve analyses to verify the reliability of the developed model. Finally, single-sample gene set enrichment analysis (ssGSEA) was used to study the underlying molecular mechanisms. Results Five immune-related genes (LDHA, PPAT, BFSP1, NR0B1, and PFKFB4) were identified and used to establish the prognostic model for patient response to HCC treatment. ROC curve analysis of the TCGA (training and validation sets) and GSE14520 cohorts confirmed the predictive ability of the five-gene-based model (AUC > 0.6). In addition, ROC and Kaplan–Meier analyses indicated that the model could stratify patients into a low-risk and a high-risk group, wherein the high-risk group exhibited worse prognosis and was less sensitive to immunotherapy than the low-risk group. Functional enrichment analysis predicted potential associations of the five genes with several metabolic processes and oncological signatures. Conclusions We established a novel five-gene-based prognostic model based on the tumour immune microenvironment that can predict immunotherapy efficacy in HCC patients.

An ultra-sensitive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid antigen assay (S-PLEX, MesoScale Diagnostics) was evaluated in 250 retrospective and 200 prospective upper respiratory specimens. In samples with cycle threshold

Background Acute-on-chronic liver failure (ACLF) is a comprehensive syndrome characterized by an acute deterioration of liver function and high short-term mortality rates in patients with chronic liver disease. Whether plasma soluble urokinase plasminogen activator receptor (suPAR) is a suitable biomarker for the prognosis of patients with ACLF remains unknown. Method A prospective cohort of 282 patients with ACLF from three hospitals in China was included. 88.4% of the group was hepatitis B virus-related ACLF (HBV-related ACLF). Cox regression was used to assess the impact of plasma suPAR and other factors on 30- and 90-day mortality. Reactive oxygen species (ROS) production were detected to explore the role of suPAR in regulating neutrophil function in HBV-related ACLF. Result There was no difference in plasma suPAR levels between HBV-related and non-HBV-related ACLF. Patients with clinical complications had higher suPAR levels than those without these complications. A significant correlation was also found between suPAR and prognostic scores, infection indicators and inflammatory cytokines. Cox’s regression multivariate analysis identified suPAR ≥ 14.7 ng/mL as a predictor for both day 30 and 90 mortality (Area under the ROC curve: 0.751 and 0.742 respectively), independent of the MELD and SOFA scores in patients with ACLF. Moreover, we firstly discovered suPAR enhanced neutrophil ROS production under E.coli stimulation in patients with HBV-related ACLF. Conclusions suPAR was a useful independent biomarker of short-term outcomes in patients with ACLF and might play a key role in the pathogenesis. Trial registration CNT, NCT02965560.

Illness severity in COVID-19 correlates with specificity of serological responses, but antibody levels decrease in most patients., SARS-CoV-2-specific antibodies, particularly those preventing viral spike receptor binding domain (RBD) interaction with host angiotensin-converting enzyme 2 (ACE2) receptor, can neutralize the virus. It is, however, unknown which features of the serological response may affect clinical outcomes of COVID-19 patients. We analyzed 983 longitudinal plasma samples from 79 hospitalized COVID-19 patients and 175 SARS-CoV-2-infected outpatients and asymptomatic individuals. Within this cohort, 25 patients died of their illness. Higher ratios of IgG antibodies targeting S1 or RBD domains of spike compared to nucleocapsid antigen were seen in outpatients who had mild illness versus severely ill patients. Plasma antibody increases correlated with decreases in viral RNAemia, but antibody responses in acute illness were insufficient to predict inpatient outcomes. Pseudovirus neutralization assays and a scalable ELISA measuring antibodies blocking RBD-ACE2 interaction were well correlated with patient IgG titers to RBD. Outpatient and asymptomatic individuals’ SARS-CoV-2 antibodies, including IgG, progressively decreased during observation up to five months post-infection.

Background Measles virus (MeV) is an important cause of acute febrile illness and pediatric mortality globally, with recent U.S. outbreaks associated with under-vaccination. MeV is highly contagious and timely diagnosis is critical to limit spread. RNA detection is the most sensitive method for acute measles diagnosis; however, MeV nucleic acid amplification assays are not widely available. Methods We performed a diagnostic accuracy study of a triple-target, real-time RT-PCR (rRT-PCR) assay for simultaneous detection of MeV N, H, and L genes. Results The MeV triple-target rRT-PCR was tested against serial dilutions (7.0−2.0 log10 copies/mL) of five MeV isolates representing circulating genotypes, and detected 98.7% (74/75) of nasopharyngeal (NP) swab dilutions, 100% (75/75) of plasma dilutions, and 85.3% (64/75) of urine dilutions. MeV RNA detection in urine was markedly improved with the addition of a nucleic acid stabilizing agent. A 95% lower limit of detection (LLOD) of Conclusions The MeV triple-target rRT-PCR assay showed high analytic sensitivity across circulating MeV genotypes in three clinically-relevant matrices. Implementation of this assay in the clinical laboratory may facilitate timely diagnosis of acute measles infection and implementation of appropriate infection control interventions.

Pooled nucleic acid amplification tests for severe acute respiratory syndrome coronavirus 2 could increase availability of testing at decreased cost. However, the effect of dilution on analytical sensitivity through sample pooling has not been well characterized. We tested 1,648 prospectively pooled specimens by using 3 nucleic acid amplification tests for severe acute respiratory syndrome coronavirus 2: a laboratory-developed real-time reverse transcription PCR targeting the envelope gene, and 2 commercially available Panther System assays targeting open reading frame 1ab. Positive percent agreement (PPA) of pooled versus individual testing ranged from 71.7% to 82.6% for pools of 8 and from 82.9% to 100.0% for pools of 4. We developed and validated an independent stochastic simulation model to estimate effects of dilution on PPA and efficiency of a 2-stage pooled real-time reverse transcription PCR testing algorithm. PPA was dependent on the proportion of tests with positive results, cycle threshold distribution, and assay limit of detection.

Background Significant overlap exists between the symptoms of SARS-CoV-2 and other respiratory viruses. This poses a serious challenge to clinical diagnosis, laboratory testing, and infection control programs. Objectives To evaluate the performance of the Hologic Panther Fusion Respiratory Assays (RA) compared to the GenMark ePlex Respiratory Pathogen Panel (RPP) and to assess the ability of the Panther Fusion to perform parallel testing of SARS-CoV-2 and other respiratory viruses from a single sample. Study design A diagnostic comparison study was carried out using 375 clinical nasopharyngeal specimens. Assay performance was assessed by overall, positive, and negative percent agreement and Cohen’s kappa coefficient. Results Overall agreement between the Fusion RA and ePlex RPP was 97.3 % (95 % CI 96.3−98.0), positive percent agreement was 97.2 % (95 % CI 93.0−99.2), negative percent agreement was 97.3 % (95 % CI 96.3−98.0), and the kappa coefficient was 0.85 (95 % CI 0.81−0.89). Forty additional viruses in 30 specimens were detected by Fusion that were not detected by ePlex. The maximum specimen throughput for parallel testing of the Fusion Respiratory Assays with SARS-CoV-2 was 275 samples in 20.7 h for Fusion SARS-CoV-2 and 350 samples in 20.0 h for Aptima Transcription Mediated Amplification SARS-CoV-2. Conclusion Fusion RA demonstrated substantial agreement compared to the ePlex RPP. However, the Fusion detected respiratory viruses not identified by ePlex, consistent with higher clinical sensitivity. Workflows for parallel testing of respiratory pathogens and SARS-CoV-2 demonstrate that the Panther Fusion instrument provides a flexible, moderate to high throughput testing option for pandemic and seasonal respiratory viruses.

SARS-CoV-2-specific antibodies, particularly those preventing viral spike receptor binding domain (RBD) interaction with host angiotensin-converting enzyme 2 (ACE2) receptor, could offer protective immunity, and may affect clinical outcomes of COVID-19 patients. We analyzed 625 serial plasma samples from 40 hospitalized COVID-19 patients and 170 SARS-CoV-2-infected outpatients and asymptomatic individuals. Severely ill patients developed significantly higher SARS-CoV-2-specific antibody responses than outpatients and asymptomatic individuals. The development of plasma antibodies was correlated with decreases in viral RNAemia, consistent with potential humoral immune clearance of virus. Using a novel competition ELISA, we detected antibodies blocking RBD-ACE2 interactions in 68% of inpatients and 40% of outpatients tested. Cross-reactive antibodies recognizing SARS-CoV RBD were found almost exclusively in hospitalized patients. Outpatient and asymptomatic individuals’ serological responses to SARS-CoV-2 decreased within 2 months, suggesting that humoral protection may be short-lived.

Highlights • Four nucleic acid amplification tests for SARS-CoV-2 RNA demonstrated comparable performance using clinical specimens. • A limited number of discrepancies were observed in specimens with low viral loads. • The isothermal amplification assay was slightly less sensitive but was one hour faster than the other methods. • Assay selection requires consideration of test performance, instrument/reagent availability, turnaround and throughput., Background Numerous nucleic acid amplification tests, including real-time, reverse transcription PCR (rRT-PCR) and isothermal amplification methods, have been developed to detect SARS-CoV-2 RNA, including many that have received emergency use authorization (EUA). There is a need to assess their test performance relative to one another. Objectives The aim of this study was to compare the test performance of a high complexity laboratory-developed rRT-PCR EUA from Stanford Health Care (SHC) targeting the SARS-CoV-2 envelope (E) gene with other tests: the Atila isothermal amplification assay targeting the nucleocapsid (N) gene and open reading frame 1ab (ORF1ab), the Altona E and spike (S) multiplex, real-time RT-PCR, and the US Centers for Disease Control and Prevention (CDC) N1 and N2 rRT-PCRs. Study Design A diagnostic comparison study was performed by testing nasopharyngeal samples from persons under investigation for coronavirus disease 2019 (COVID-19). Assay performance was assessed by percent agreement and Cohen’s kappa coefficient. Results Positive percent agreement with the SHC EUA reference assay was 82.8% (95% confidence interval (CI) 65.0 to 92.9) for Atila, 86.7% (95% CI 69.7 to 95.3) for the Altona E and S targets, and 86.7% (95% CI 69.7 to 95.3) and 90.0% (95% CI 73.6 to 97.3), for the CDC N1 and N2 targets, respectively. All assays demonstrated 100% negative percent agreement. Kappa coefficients ranged from 0.86 to 0.92, indicating excellent agreement. Conclusions Performance was comparable among the SARS-CoV-2 nucleic acid amplification methods tested, with a limited number of discrepancies observed in specimens with low viral loads.

Several point-of-care (POC) molecular tests have received emergency use authorization (EUA) from the Food and Drug Administration (FDA) for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The test performance characteristics of the Accula (Mesa Biotech) SARS-CoV-2 POC test need to be evaluated to inform its optimal use. The aim of this study was to assess the test performance of the Accula SARS-CoV-2 test. The performance of the Accula test was assessed by comparing results of 100 nasopharyngeal swab samples previously characterized by the Stanford Health Care EUA laboratory-developed test (SHC-LDT), targeting the envelope (E) gene., Several point-of-care (POC) molecular tests have received emergency use authorization (EUA) from the Food and Drug Administration (FDA) for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The test performance characteristics of the Accula (Mesa Biotech) SARS-CoV-2 POC test need to be evaluated to inform its optimal use. The aim of this study was to assess the test performance of the Accula SARS-CoV-2 test. The performance of the Accula test was assessed by comparing results of 100 nasopharyngeal swab samples previously characterized by the Stanford Health Care EUA laboratory-developed test (SHC-LDT), targeting the envelope (E) gene. Assay concordance was assessed by overall percent agreement, positive percent agreement (PPA), negative percent agreement (NPA), and Cohen’s kappa coefficient. Overall percent agreement between the assays was 84.0% (95% confidence interval [CI], 75.3 to 90.6%), PPA was 68.0% (95% CI, 53.3 to 80.5%), and the kappa coefficient was 0.68 (95% CI, 0.54 to 0.82). Sixteen specimens detected by the SHC-LDT were not detected by the Accula test and showed low viral load burden, with a median cycle threshold value of 37.7. NPA was 100% (95% CI, 94.2 to 100%). Compared to the SHC-LDT, the Accula SARS-CoV-2 test showed excellent negative agreement. However, positive agreement was low for samples with low viral load. The false-negative rate of the Accula POC test calls for a more thorough evaluation of POC test performance characteristics in clinical settings and for confirmatory testing in individuals with moderate to high pretest probability of SARS-CoV-2 who test negative on Accula.

Background Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in blood, also known as RNAemia, has been reported, but its prognostic implications are poorly understood. This study aimed to determine the frequency of SARS-CoV-2 RNA in plasma and its association with coronavirus disease 2019 (COVID-19) clinical severity. Methods An analytical cross-sectional study was performed in a single-center tertiary care institution and included consecutive inpatients and outpatients with confirmed COVID-19. The prevalence of SARS CoV-2 RNAemia and the strength of its association with clinical severity variables were examined and included intensive care unit (ICU) admission, invasive mechanical ventilation, and 30-day all-cause mortality. Results Paired nasopharyngeal and plasma samples were included from 85 patients. The median age was 55 years, and individuals with RNAemia were older than those with undetectable SARS-CoV-2 RNA in plasma (63 vs 50 years; P = .04). Comorbidities were frequent including obesity (37.6%), hypertension (30.6%), and diabetes mellitus (22.4%). RNAemia was detected in 28/85 (32.9%) of patients, including 22/28 (78.6%) who required hospitalization. In models adjusted for age, RNAemia was detected more frequently in individuals who developed severe disease including ICU admission (32.1 vs 14.0%; P = .04) and invasive mechanical ventilation (21.4% vs 3.5%; P = .02). All 4 deaths occurred in individuals with detectable RNAemia. An additional 121 plasma samples from 28 individuals with RNAemia were assessed longitudinally, and RNA was detected for a maximum duration of 10 days. Conclusions This study demonstrated a high proportion of SARS-CoV-2 RNAemia, and an association between RNAemia and clinical severity suggesting the potential utility of plasma viral testing as a prognostic indicator for COVID-19., This cross-sectional study assessed the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNAemia in 85 individuals, and association with clinical severity. Results demonstrate a high frequency of SARS-CoV-2 RNAemia, and an association between RNAemia and clinical severity variables including intensive care unit admission and mortality.

Highlights • The Stanford EUA rRT-PCR and Panther Fusion SARS-CoV-2 assay demonstrated similar performance using clinical specimens. • High agreement allowed increased testing capacity and limited the impact of supply disruption and instrument down-time. • These assays are suitable for the routine diagnosis of active SARS-CoV-2 infection., Background Numerous nucleic acid amplification assays have recently received emergency use authorization (EUA) for the diagnosis of SARS-CoV-2 infection, and there is a need to assess their test performance relative to one another. Objectives The aim of this study was to compare the test performance of the Hologic Panther Fusion SARS-CoV-2 assay targeting two regions of open reading frame 1ab (ORF1ab) to a high complexity molecular-based, laboratory-developed EUA from Stanford Health Care (SHC) targeting the SARS-CoV-2 envelope (E) gene. Study design We performed a diagnostic comparison study by testing nasopharyngeal samples on the two assays. Assay agreement was assessed by overall percent agreement and Cohen’s kappa coefficient. Results A total of 184 nasopharyngeal samples were tested using the two assays, of which 180 showed valid results and were included for the comparative analysis. Overall percent agreement between the assays was 98.3 % (95 % confidence interval (CI) 95.2–99.7) and kappa coefficient was 0.97 (95 % CI 0.93–1.0). One sample was detected on the SHC laboratory developed test (LDT) and not on the Panther Fusion, and had a Ct of 35.9. Conversely, 2 samples were detected on the Panther Fusion and not on the LDT, and had Ct values of 37.2 and 36.6. Conclusion The Panther Fusion SARS-CoV-2 assay and the SHC LDT perform similarly on clinical nasopharyngeal swab specimens. Other considerations, including reagent availability, turnaround time, labor requirements, cost and instrument throughput should guide the decision of which assay to perform.

Background Currently, the primary mechanism for poliovirus detection is acute flaccid paralysis (AFP) surveillance, with environmental sampling serving as a complement. However, as AFP cases drop, environmental surveillance will become increasingly critical for poliovirus detection. Mexico provides a natural environment to study oral polio vaccine (OPV) transmission, as it provides routine injected polio vaccine immunization and biannual OPV campaigns in February and May. Methods As part of a study of OPV transmission in which 155 children were vaccinated with OPV, monthly sewage samples were collected from rivers leading from 3 indigenous Mexican villages (Capoluca, Campo Grande, and Tuxpanguillo) from February to May 2015. Samples were also collected from October 2015 to October 2017, during which time there were standard OPV campaigns. Samples were analyzed for the presence of OPV serotypes, using a real-time qualitative polymerase chain reaction assay capable of detecting as few as 9, 12, and 10 copies/100 µL of viral ribonucleic acid for OPV serotypes 1, 2, and 3 (OPV-1, -2, and -3), respectively. Included here are 54 samples, taken up to November 2016. Results Of the 54 samples, 13 (24%) were positive for OPV. After the vaccination of 155 children in February 2015, OPV was found 2 months after vaccination. After unrestricted OPV administration in February 2016, OPV was detected in sewage up to 8 months after vaccination. OPV-3 was found in 11 of the 13 positive samples (85%), OPV-2 was found in 3 positive samples (23%), and OPV-1 was found in 1 sample (8%). Conclusions OPV can be detected even when small amounts of the vaccine are introduced into a community, as shown by OPV-positive sewage samples even when only 155 children were vaccinated. When OPV vaccination was unrestricted, sewage samples were positive up to 8 months after vaccination, implying community OPV circulation for at least 8 months. OPV-3 was the serotype most found in these samples, indicating prolonged transmission of OPV-3 when compared to the other serotypes. Future work could compare the phylogenetic variance of OPV isolates from sewage after OPV vaccinations.

Background Global polio eradication efforts rely in part on molecular methods of detecting polioviruses, both wild and vaccine strains, from human and environmental samples. Previous assays used for detection of Sabin oral polio vaccine (OPV) in fecal samples have been labor and time intensive and vary in their sensitivity and specificity. Methods We developed a high-throughput, multiplex reverse-transcription quantitative polymerase chain reaction assay able to detect all 3 OPV strains in fecal samples. The assay used a KingFisher Duo Prime system for viral RNA isolation and extraction. Positive samples were retested and Sanger sequenced for verification of Sabin serotype identity. Results The 95% lower limit of detection was determined to be 3 copies per reaction for Sabin 1 and 3 and 4 copies per reaction for Sabin 2, with no cross-reactivity between the 3 serotypes and their primers. A total of 554 samples (3.6%) were positive, with 304 positive samples (54.9%) containing >1 serotype. Of the positive samples, 476 (85.9%) contained enough RNA to be sequenced, and of these all sequences were Sabin serotypes. The previous assay we used could process 48 samples in a 10-hour period, whereas the new assay processed >100 samples in 6 hours. Conclusions The new high-throughput, multiplex reverse-transcription quantitative polymerase chain reaction assay allowed for sensitive and specific detection of OPV serotypes while greatly decreasing sample handling and processing time. We were able to sequence 72.4% of the 210 positive samples in the cycle threshold range of 35–37.

Background The World Health Assembly 2012 Polio Eradication and Endgame Strategic Plan calls for the eventual cessation of all oral polio vaccines (OPVs), to be replaced with inactivated polio vaccine (IPV); however, IPV induces less robust mucosal immunity than OPV. This study characterized household and community OPV shedding and transmission after OPV vaccination within primarily IPV-vaccinated communities. Methods Households in 3 IPV-vaccinated Mexican communities were randomized to receive 3 levels of OPV vaccination coverage (70%, 30%, or 10%). Ten stool samples were collected from all household members over 71 days. Analysis compared vaccinated subjects, household contacts of vaccinated subjects, and subjects in unvaccinated households. Logistic and Cox regression models were fitted to characterize transmission of OPV by coverage and household vaccination status. Results Among 148 vaccinated children, 380 household contacts, and 1124 unvaccinated community contacts, 78%, 18%, and 7%, respectively, shed OPV. Community and household contacts showed no differences in transmission (odds ratio [OR], 0.67; 95% confidence interval [CI], .37–1.20), in shedding trajectory (OR, 0.61; 95% CI, .35–1.07), or in time to shedding (hazard ratio, 0.68; 95% CI, .39–1.19). Transmission began as quickly as 1 day after vaccination and persisted as long as 71 days after vaccination. Transmission within unvaccinated households differed significantly across vaccination coverage communities, with the 70% community experiencing the most transmissions (15%), and the 10% community experiencing the least (4%). These trends persisted over time and in the time to first shedding analyses. Conclusions Transmission did not differ between household contacts of vaccinees and unvaccinated households. Understanding poliovirus transmission dynamics is important for postcertification control.

The rapid development and popularization of smart phones and mobile internet has created a new social lifestyle, and correspondingly prompts the transformation of network teaching from desktop computer to mobile teaching. This article has compared the pros and cons of Tsinghua Education Online and WeChat official account (WOA) in fulfilling teaching functions. We also described the construction of WOA platform with the example of WOA-based teaching in biochemistry and molecular biology. The platform can establish nearly 75 menu catalogs and 2,250 items, which is capable for the publication of any types of teaching materials and information. The WOA teaching is well accepted and becomes popular in China due to the free, interactive, attractive, adaptable, portable, sustainable, and more participatory teaching styles. © 2018 International Union of Biochemistry and Molecular Biology, 46(5):555-560, 2018.

Snakebite envenomation is a neglected global health problem, causing substantial mortality, disability, and psychological morbidity, especially in rural tropical and subtropical zones. Antivenin is currently the only specific medicine for envenomation. However, it is restricted by cold storage, snakebite diagnosis, and high price. Snake venom phospholipase A2s (svPLA2s) are found in all kinds of venomous snake families (e.g., Viperidae, Elapidae, and Colubridae). Along with their catalytic activity, svPLA2s elicit a wide variety of pharmacological effects that play a pivotal role in envenomation damage. Hence, neutralization of the svPLA2s could weaken or inhibit toxic damage. Here we overviewed the latest knowledge on the distribution, pathophysiological effects, and inhibitors of svPLA2s to elucidate the potential for a novel, wide spectrum antivenom drug targeting svPLA2s.

To investigate the possibility of earlier cases of severe acute respiratory syndrome coronavirus 2 infection than previously recognized, we retrospectively tested pooled samples from 1,700 persons with respiratory signs/symptoms seen at Stanford Health Care, Palo Alto, California, USA, during the last 2 months of 2019. We found no evidence of earlier infection.

Supplemental Digital Content is available in the text, Single nuclear polymorphism (SNP) of programmed cell death 1 (PD-1) was reported associated with hepatitis B virus (HBV) infection, but the SNP sites studied were limited. Whether the combination of 2 or more SNP sites could better represent the relationship between PD-1 SNP and HBV infection was not studied. Eight hundred ninety-eight HBV-infected patients (222 asymptomatic carriers [AsC], 276 chronic hepatitis B, 105 acute-on-chronic liver failure, and 295 liver cirrhosis) and 364 health controls of South China were enrolled in this study. Four PD-1 SNPs (rs10204525, rs2227982, rs41386349, and rs36084323) were selected and detected by TaqMan probe. The frequency of allele, genotype, and combination of different SNPs were compared between different groups. For allele frequency analysis, G allele of rs10204525 was protective factor (odds ratio (OR) = 0.823, 95% confidence interval (CI) = 0.679–0.997, P = .046) and T allele of rs2227982 was predisposing factor (OR = 1.231, 95% CI = 1.036–1.463, P = .018) in HBV infection. When analyzed in genotype frequency, the genotype GG of rs10204525 and CC of rs2227982 were protective factor of HBV infection. Combination of rs10204525 GG and rs2227982 CC was potent protective factor of HBV infection (OR = 0.552, 95% CI = 0.356–0.857, P = .007) and was also associated with lower HBV load (OR = 0.201, 95% CI = 0.056–0.728, P = .008) in AsC. The 4 SNP sites were not associated with progression of HBV-related liver disease. Rs10204525 and rs2227982 of PD-1 associate with HBV infection and combination of the 2 SNP sites can better predict host susceptibility in HBV infection.

Summary Background There is increasing concern that persistent infection of SARS-CoV-2 within immunocompromised hosts could serve as a reservoir for mutation accumulation and subsequent emergence of novel strains with the potential to evade immune responses. Methods We describe three patients with acute lymphoblastic leukemia who were persistently positive for SARS-CoV-2 by real-time polymerase chain reaction. Viral viability from longitudinally-collected specimens was assessed. Whole-genome sequencing and serological studies were performed to measure viral evolution and evidence of immune escape. Findings We found compelling evidence of ongoing replication and infectivity for up to 162 days from initial positive by subgenomic RNA, single-stranded RNA, and viral culture analysis. Our results reveal a broad spectrum of infectivity, host immune responses, and accumulation of mutations, some with the potential for immune escape. Interpretation Our results highlight the need to reassess infection control precautions in the management and care of immunocompromised patients. Routine surveillance of mutations and evaluation of their potential impact on viral transmission and immune escape should be considered. Funding The work was partially funded by The Saban Research Institute at Children’s Hospital Los Angeles intramural support for COVID-19 Directed Research (X.G. and J.D.B.), the Johns Hopkins Center of Excellence in Influenza Research and Surveillance HHSN272201400007C (A.P.), NIH/NIAID R01AI127877 (S.D.B.), NIH/NIAID R01AI130398 (S.D.B.), NIH 1U54CA260517 (S.D.B.), an endowment to S.D.B. from the Crown Family Foundation, an Early Postdoc.Mobility Fellowship Stipend to O.F.W. from the Swiss National Science Foundation (SNSF), and a Coulter COVID-19 Rapid Response Award to S.D.B. L.G. is a SHARE Research Fellow in Pediatric Hematology-Oncology.

Once regarded as a rare complication, the potentially fatal bone cement implantation syndrome (BCIS) has been increasingly reported. BCIS can present as transient desaturation, hypotension, cardiac dysrhythmias, and cardiovascular collapse. Diagnosis of BCIS is often clinical and confirmed with computed tomography (CT) imaging postoperatively. However, point of care ultrasound (POCUS) examination could be a helpful and timely tool to clinch the diagnosis in a sudden cardiovascular collapse. We present a case of Grade 3 BCIS where POCUS examination revealed a massive clot in the right atrium, which supports the diagnosis.

Phospholipase A2s (PLA2) is a major component of snake venom with diverse pathologic toxicities and, therefore, a potential target for antivenom therapy. Varespladib was initially designed as an inhibitor of mammal PLA2s, and was recently repurposed to a broad-spectrum inhibitor of PLA2 in snake venom. To evaluate the protective abilities of varespladib to hemorrhage, myonecrosis, and systemic toxicities that are inflicted by different crude snake venoms, subcutaneous ecchymosis, muscle damage, and biochemical variation in serum enzymes derived from the envenomed mice were determined, respectively. Varespladib treatment showed a significant inhibitory effect to snake venom PLA2, which was estimated by IC50 in vitro and ED50 in vivo. In animal models, the severely hemorrhagic toxicity of D. acutus and A. halys venom was almost fully inhibited after administration of varespladib. Moreover, signs of edema in gastrocnemius muscle were remarkably attenuated by administration of varespladib, with a reduced loss of myonecrosis and desmin. Serum levels of creatine kinase, lactate dehydrogenase isoenzyme 1, aspartate transaminase, and alanine transaminase were down-regulated after treatment with varespladib, which indicated the protection to viscera injury. In conclusion, varespladib may be a potential first-line drug candidate in snakebite envenomation first aid or clinical therapy.

Background BK virus (BKV) is a major cause of nephropathy in kidney transplantation. Pre-transplant BKV shedding in the donor or recipient may increase the risk for developing BKV viremia in kidney transplant recipients. Methods From August 2016 to December 2017, we prospectively performed pre-transplant BKV DNA PCR testing on plasma and urine samples from deceased kidney donors procured through Donor Network West, our local organ procurement organization and third largest in the country. We also simultaneously performed pre-transplant BKV DNA PCR testing of plasma and urine from living kidney donors and adult kidney transplant recipients as well as post-transplant surveillance testing of recipients at Stanford University Medical Center. Results BKV DNA PCR testing of plasma and urine samples from 212 deceased kidney donors revealed 17 donors that were positive (16 in urine, 1 in plasma; 8.02% BKV DNA detection). Fifty of these specimens went to Stanford kidney transplant recipients, including four donors with BKV viruria (8.00%). During the study period, we obtained complete pre-transplant donor and recipient pairings for 47 deceased and 39 living adult kidney transplant recipients. Of these 86 kidney recipients, none had detectable BKV DNA in pre-transplant donor or recipient plasma specimens, while 10 (four deceased, six living) had BKV DNA detected in the urine. The majority (9/10) were positive in the donor urine, with one positive in the recipient and one in both the recipient and donor. After a minimum follow-up of 5 months, three (30%) had developed BKV viremia, compared with three of the 76 (3.9%, P = 0.009) with negative pre-transplant BKV DNA. The rate of BKV viruria was not significantly different between deceased and living kidney donors (4/47 (8.5%) vs. 6/39 (15.4%), P = 0.32). Conclusion In one of the largest cohorts in the United States that also includes deceased donor testing, we demonstrate that pre-transplant BKV viruria, particularly of the donor, is associated with development of BKV viremia in kidney transplant recipients. Pre-transplant BKV DNA screening in the urine of kidney donors (deceased and living) may be useful in predicting risk for BKV viremia. Disclosures All authors: No reported disclosures.

Background Mexico introduced inactivated polio vaccine (IPV) into its routine immunization (RI) schedule in 2007 but continued to give trivalent oral polio vaccine (tOPV) twice a year during national health weeks (NHW) through 2015. Objectives To evaluate individual variables associated with poliovirus (PV) shedding among children with IPV-induced immunity after vaccination with tOPV and their household contacts. Materials and methods We recruited 72 children (both genders, ≤30 months, vaccinated with at least two doses of IPV) and 144 household contacts (both genders, 2 per household, children and adults) between 08/2010 and 09/2010 in Orizaba, Veracruz. Three NHW took place (one before and two after enrollment). We collected fecal samples monthly for 12 months, and tested 2500 samples for polioviruses types 1, 2 and 3 with three serotype-specific singleplex real-time RT-PCR (rRT-PCR) assays. In order to increase the specificity for OPV virus, all positive and 112 negative samples were also processed with a two-step, OPV serotype-specific multiplex rRT-PCR. Analysis We estimated adjusted hazard ratios (HR) and 95% CI using Cox proportional hazards regression for recurrent events models accounting for individual clustering to assess the association of individual variables with the shedding of any poliovirus for all participants and stratifying according to whether the participant had received tOPV in the month of sample collection. Results 216 participants were included. Of the 2500 collected samples, using the singleplex rRT-PCR assay, PV was detected in 5.7% (n = 142); PV1 in 1.2% (n = 29), PV2 in 4.1% (n = 103), and PV3 in 1.9% (n = 48). Of the 256 samples processed by multiplex rRT-PCR, PV was detected in 106 (PV1 in 16.41% (n = 42), PV2 in 21.09% (n = 54), and PV3 in 23.05% (n = 59). Both using singleplex and multiplex assays, shedding of OPV among non-vaccinated children and subjects older than 5 years of age living in the same household was associated with shedding of PV2 by a household contact. All models were adjusted by sex, age, IPV vaccination and OPV shedding by the same individual during the previous month of sample collection. Conclusion Our results provide important evidence regarding the circulation of poliovirus in a mixed vaccination context (IPV+OPV) which mimics the “transitional phase” that occurs when countries use both vaccines simultaneously. Shedding of OPV2 by household contacts was most likely the source of infection of non-vaccinated children and subjects older than 5 years of age living in the same household.

Background Acute kidney injury (AKI) is rare in women during pregnancy and puerperium, however, it is related to increased morbidity and mortality rates. Objective The aim of this study was to investigate the incidence, characteristics, and outcomes of AKI during pregnancy and puerperium in a Chinese population. Methods In this study, pregnant women discharged from hospital between January 2008 and June 2015 were screened. AKI was defined if the level of serum creatitine >70.72umol/l in pregnant women without chronic kidney disease (CKD). Acute-on-CKD was defined as a 50% increase in the level of serum creatinine vs baseline in patients with pre-existed CKD. Results We reported a high incidence (0.81%) of AKI during pregnancy and puerperium. Three hundred and forty-three cases of AKI during pregnancy and puerperium included 21 severe AKI cases and 21 cases with acute-on-CKD. Pre-eclampsia/eclampsia, and postpartum hemorrhage were the most frequent causes of AKI during pregnancy and puerperium. About 17% women with pre-eclampsia/eclampsia and 60% women with HELLP syndrome complicated with AKI. The maternal outcome was good except in the setting of amniotic fluid embolism or hemorrhagic shock, whereas the prenatal outcome was relatively poor. Among the 14 death cases, 7 cases received renal replacement therapy. Amniotic fluid embolism and postpartum hemorrhage were the major causes of death in pregnant women with AKI. Conclusion AKI during pregnancy and puerperium is not as rare as we thought. Pre-eclampsia/eclampsia is the most common cause of AKI during pregnancy and puerperium, however, the outcome of pre-eclampsia-related AKI is good. Amniotic fluid embolism and postpartum hemorrhage are the leading causes of maternal mortality. Severe AKI may predict poor outcome. Electronic supplementary material The online version of this article (doi:10.1186/s12882-017-0551-4) contains supplementary material, which is available to authorized users.

Background. With prolonged replication, attenuated polioviruses used in oral polio vaccine (OPV) can mutate into vaccine-derived poliovirus (VDPV) and cause poliomyelitis outbreaks. Individuals with primary humoral immunodeficiencies can become chronically infected with vaccine poliovirus, allowing it to mutate into immunodeficiency-associated VDPV (iVDPV). It is unclear if children perinatally infected with the human immunodeficiency virus (HIV), who have humoral as well as cellular immunodeficiencies, might be sources of iVDPV. Methods. We conducted a prospective study collecting stool and blood samples at multiple time points from Zimbabwean infants receiving OPV according to the national schedule. Nucleic acid extracted from stool was analyzed by real-time polymerase chain reaction for OPV serotypes. Results. We analyzed 825 stool samples: 285 samples from 92 HIV-infected children and 540 from 251 HIV-uninfected children. Poliovirus shedding was similar after 0–2 OPV doses but significantly higher in the HIVinfected versus uninfected children after ≥3 OPV doses, particularly within 42 days of an OPV dose, independent of seroconversion status. HIV infection was not associated with prolonged or persistent poliovirus shedding. HIV infection was associated with significantly lower polio seroconversion rates. Conclusions. HIV infection is associated with decreased mucosal and humoral immune responses to OPV but not the prolonged viral shedding required to form iVDPV.

OBJECTIVE We aimed to compare the cumulative efficacy and resistance of ADV monotherapy, ADV add-on LAM (ADV + LAM), ADV and ETV (ADV + ETV) combination therapy in LAM-resistant patients. METHODS Ninety-one adult CHB patients with LAM-resistance mutations (YMDD) were identified. Of these 91, 29 patients were treated with ADV monotherapy, 30 were treated with ADV + LAM and 32 were treated with ADV + ETV combination therapy, for at least 24 months. RESULTS The mean serum HBV-DNA decreases from baseline at 3, 6, 12, and 24 months were -3.23, -4.41, -5.32, and -5.58 log(10) IU/mL in the ADV + ETV combination therapy groups, respectively; the most significant among the three treatment groups (p

Community circulation of oral poliovirus vaccine (OPV) likely begins with household transmission. We analyzed stool collected from Zimbabwean mothers who were infected with human immunodeficiency virus (HIV) and those who were uninfected with HIV 1 to 24 weeks after infant oral poliovirus vaccination. Overall, only 5% of the mothers had detectable OPV (16 of 304) despite high infant shedding rates. OPV shedding was similar between HIV-infected mothers and those who were uninfected (11 [6.4%] of 171 vs 5 [3.8%] of 133, respectively) and between mothers of HIV-infected infants and those of uninfected infants (2 [3.5%] of 57 vs 9 [6.3%] of 144, respectively). Mothers of vaccinated infants are unlikely to shed OPV, even when they are infected with HIV.

Adulteration of meat products and costly animal-derived commodities with their inferior/cheaper counterparts is a grievous global problem. Species authentication is still technical challenging, especially to those deep processed products. The present study described the design of seven sets of species-specific primer based on a high heterozygous region of mitochondrial cytochrome c oxidase subunit I (COI) gene. These primers were proven to have high species specificity and no cross-reactions and unexpected products to different DNA source. Multiplex PCR assay was achieved for rapid and economical identification of four commonly consumed meats (pork, beef, chicken, and mutton). The conventional PCR assay was sensitive down to 0.001 ng of DNA template in the reactant. The developed method was also powerful in detecting as low as 0.1-mg adulterated pork (0.05 % in wt/wt) in an artificial counterfeited mutton. Validation test showed that the assay is specific, reproducible, and robust in commercial deep processed meats, leatherware, and feather commodities. This proposed method will be greatly beneficial to the consumers, food industry, leather, and feather commodity manufacture.

Global wild poliovirus eradication may soon be achieved. Since 1988, when the World Health Organization proposed a plan to eradicate poliomyelitis, the number of reported annual global cases has dropped from 350 000 to 223 in 2012 [1]. Only 3 countries remain endemic with uninterrupted transmission, and wild poliovirus serotype 2 has been eradicated for over a decade. The primary tool in the global eradication campaign has been oral polio vaccine (OPV), an inexpensive live attenuated vaccine that is easy to administer and promotes community immunity by spread from vaccinated children to community contacts through the fecal-oral route. However, despite its efficacy, OPV carries risks that will complicate the eradication effort. OPV consists of RNA viruses that can mutate during replication into forms capable of causing paralytic disease. Because about one out of 500 000 vaccinees develop vaccine-associated paralytic poliomyelitis (VAPP) from their first OPV dose, the United States has only used the more expensive inactivated polio vaccine (IPV), a killed virus vaccine that cannot cause poliomyelitis, since 2000 [2, 3]. Of more concern, with prolonged replication of typically more than one year, the viruses in OPV can mutate into vaccine-derived polioviruses (VDPV), which are 1%–15% divergent from parent OPV strains (0.6%–15% for serotype 2) [4]. VDPV can develop after persistent OPV virus replication in the intestinal tracts of individuals with primary humoral immunodeficiencies (iVDPV; 65 cases identified to date) or from continued person-to-person circulation in undervaccinated communities (cVDPV) [4]. From 2000 until September 2013, 23 separate cVDPV outbreaks in 20 different countries have been identified [5]. The one study, conducted in Nigeria, which compared outbreaks of cVDPV and wild poliovirus, suggests that cVDPV outbreaks have an attack rate and disease severity similar to outbreaks from wild poliovirus [6]. Because of the risks of poliomyelitis due to OPV, one of the components of the new “Polio Eradication and Endgame Strategic Plan 2013–2018” includes initiating at least 1 dose of IPV for children in countries that currently only use OPV and then phasing out OPV, starting by transitioning from trivalent OPV to bivalent OPV, which contains only serotypes 1 and 3 [7]. Unknown factors that could affect this new plan include the duration and pattern of OPV-derived virus circulation in a community vaccinated with IPV. To help fill those knowledge gaps, we conducted a study looking at the circulation patterns of OPV and OPV-derived strains in Mexico, a country that introduced IPV into its regular childhood vaccination schedule in 2007 but continues to give OPV twice a year during national immunization weeks (NIW).