Evaluation of a fully automated high-throughput serology assay for detection of Hepatitis D virus antibodies.

BACKGROUND: HDV antibody testing is recommended for universal screening and as the first line in an HDV double reflex testing strategy for effectively identifying patients with active infection for therapeutic treatments. OBJECTIVE: The aim of this study is to evaluate the performance of a newly developed ARCHITECT HDV Total Ig (ARCHITECT HDV Ig) prototype assay. STUDY DESIGN: Performance characteristics were determined for the ARCHITECT HDV Ig and a reference test, LIAISON XL Anti-HDV using a well-characterized specimen panel, comprising HDV RNA positive (n = 62) and negative (n = 70) samples, and healthy US blood donors. RESULTS: Healthy US blood donors (n=200) showed 99.5% (199/200, 95%CI=97.65-99.98) specificity with ARCHITECT HDV Ig and 98.5 % (197/200, 95 %CI = 96.10-99.64) with LIAISON Anti-HDV. Among known HDV RNA positive samples, ARCHITECT HDV Ig detected 59/62 demonstrating 95.2 % sensitivity while LIAISON Anti-HDV sensitivity was 90.3 % (56/62). Among 101 HBV positive samples, 70 were reactive in the ARCHITECT test, 59 of which tested positive for HDV RNA for a positive predictive value (PPV) for the presence of HDV RNA was 84.3 %. For LIAISON Anti-HDV, 79 specimens were reactive and 56 contained HDV RNA: PPV for HDV RNA was 70.9 %. Among 70 HDV RNA negative samples, 39 were HBV positive. ARCHITECT HDV Ig negative predictive value (NPV) was 71.8 % and LIAISON Anti-HDV NPV was 41 % for the HBV positive group, respectively. CONCLUSION: When compared to the LIASON Anti-HDV test, the ARCHITECT HDV Ig assay demonstrated enhanced sensitivity and specificity and better NPV and PPV values for HDV RNA status. The ARCHITECT HDV Ig assay represents a promising tool for universal screening of all HBsAg-positive persons.

Identification of inflammatory clusters in long-COVID through analysis of plasma biomarker levels.

Mechanisms underlying long COVID remain poorly understood. Patterns of immunological responses in individuals with long COVID may provide insight into clinical phenotypes. Here we aimed to identify these immunological patterns and study the inflammatory processes ongoing in individuals with long COVID. We applied an unsupervised hierarchical clustering approach to analyze plasma levels of 42 biomarkers measured in individuals with long COVID. Logistic regression models were used to explore associations between biomarker clusters, clinical variables, and symptom phenotypes. In 101 individuals, we identified three inflammatory clusters: a limited immune activation cluster, an innate immune activation cluster, and a systemic immune activation cluster. Membership in these inflammatory clusters did not correlate with individual symptoms or symptom phenotypes, but was associated with clinical variables including age, BMI, and vaccination status. Differences in serologic responses between clusters were also observed. Our results indicate that clinical variables of individuals with long COVID are associated with their inflammatory profiles and can provide insight into the ongoing immune responses.

Immune-Escape Mutations Are Prevalent among Patients with a Coexistence of HBsAg and Anti-HBs in a Tertiary Liver Center in the United States.

The concurrent seropositivity of HBsAg and anti-HBs has been described among patients with chronic hepatitis B (CHB), but its prevalence is variable. HBV S-gene mutations can affect the antigenicity of HBsAg. Patients with mutations in the 'α' determinant region of the S gene can develop severe HBV reactivation under immunosuppression. In this study at a tertiary liver center in the United States, we evaluated the frequency and virological characteristics of the HBsAg mutations among CHB patients with the presence of both HBsAg and anti-HBs. In this cohort, 45 (2.1%) of 2178 patients were identified to have a coexistence of HBsAg and anti-HBs, and 24 had available sera for the genome analysis of the Pre-S1, Pre-S2, and S regions. The frequency of mutations in the S gene was significantly higher among those older than 50 years (mean 8.5 vs. 5.4 mutations per subject, p = 0.03). Twelve patients (50%) had mutations in the 'α' determinant region of the S gene. Mutations at amino acid position 126 were most common in eight subjects. Three had a mutation at position 133. Only one patient had a mutation at position 145-the classic vaccine-escape mutation. Despite the universal HBV vaccination program, the vaccine-escape mutant is rare in our cohort of predominantly Asian patients.

A novel test and treat program for hepatitis C virus infection utilizing HCV core antigen testing, among police and general population, Islamabad, Pakistan, 2022.

Hepatitis C virus core antigen (HCVcAg) testing can simplify and decrease costs of HCV infection confirmation compared to molecular testing (nucleic acid testing). We piloted HCVcAg testing for the confirmation of active infection. The study was conducted during June through December 2022 among the police and the general population of Islamabad, Pakistan age 18 years and older. Initial screening for HCV antibody was conducted using a rapid diagnostic test (RDT) for all consenting participants. Those who tested positive had venous blood samples tested for HCVcAg, platelets and aspartate aminotransferase (AST). Persons with HCVcAg values ≥3 fmol/L were defined as viremic, and they were offered treatment with direct acting antiviral (DAA) medications, sofosbuvir and daclatasvir. Aspartate aminotransferase to platelet ratio index (APRI) was calculated for each HCV infected person, and those with an APRI score <1.5 received treatment for 12 weeks, while those with APRI ≥ to 1.5 received 24 weeks of treatment. A total of 15,628 persons were screened for anti-HCV using RDT and 643 (4.1%) tested positive. HCVcAg values of ≥3 fmol/L was found in 399/643 (62.1%), and all were offered and accepted treatment. Of those treated, 273/399 (68.4%) returned for a follow-up SVR and HCVcAg was not detected in 261/273, a 95.6% cure rate. The pilot study demonstrated the effectiveness of reaching and treating an urban population using RDT for screening and HCVcAg for confirmation of infection and test of cure.

Quantitative HBeAg is a strong predictor of HBeAg loss among patients receiving pegylated interferon.

BACKGROUND: HBeAg loss is an important endpoint for antiviral therapy in chronic hepatitis B (CHB), however there are no reliable biomarkers to identify patients who will respond to the addition of pegylated interferon to nucleos(t)ide analogue (NA) therapy. AIM: To evaluate the use of serum biomarkers to predict HBeAg loss. METHODS: HBeAg positive CHB participants on NAs who switched-to or added-on 48 weeks pegylated interferon alpha2b (clinicaltrial.gov NCT01928511) were evaluated at week 72 for HBeAg loss. The predictive ability of qHBeAg, qHBsAg, HBV RNA and clinical variables for HBeAg loss were investigated. RESULTS: HBeAg loss occurred in 15/55 (27.3%) participants who completed 48 weeks of pegylated interferon. There was a lower baseline qHBeAg (1.18 IU/mL [2.27] versus 10.04 IU/mL [24.87], P = 0.007) among participants who lost HBeAg. Baseline qHBeAg (OR = 0.15, 95% CI 0.03-0.66, P = 0.01) and detectable HBV DNA at baseline (OR = 25.00, 95% CI 1.67-374.70, P = 0.02) were independent predictors of HBeAg loss. In addition, on-treatment qHBeAg was also a strong predictor of HBeAg loss (OR = 0.39, 95% CI 0.18-0.81, P = 0.012). The models combining detectable baseline HBV DNA with baseline (C-statistic 0.82) and on-treatment (C-statistic 0.83) had good accuracy for predicting HBeAg loss. A rise in qHBeAg ≥ 10 IU/ml was a predictor of flare (ALT ≥ 120 U/ml) on univariable analysis but not after adjustment for treatment arm. CONCLUSIONS: Baseline and on-treatment qHBeAg is a useful biomarker that can identify participants on NA therapy who may benefit from adding or switching to pegylated interferon.

Next-generation sequencing survey of acute febrile illness in Senegal (2020-2022).

Introduction: Acute febrile illnesses (AFI) in developing tropical and sub-tropical nations are challenging to diagnose due to the numerous causes and non-specific symptoms. The proliferation of rapid diagnostic testing and successful control campaigns against malaria have revealed that non-Plasmodium pathogens still contribute significantly to AFI burden. Thus, a more complete understanding of local trends and potential causes is important for selecting the correct treatment course, which in turn will reduce morbidity and mortality. Next-generation sequencing (NGS) in a laboratory setting can be used to identify known and novel pathogens in individuals with AFI. Methods: In this study, plasma was collected from 228 febrile patients tested negative for malaria at clinics across Senegal from 2020-2022. Total nucleic acids were extracted and converted to metagenomic NGS libraries. To identify viral pathogens, especially those present at low concentration, an aliquot of each library was processed with a viral enrichment panel and sequenced. Corresponding metagenomic libraries were also sequenced to identify non-viral pathogens. Results and Discussion: Sequencing reads for pathogens with a possible link to febrile illness were identified in 51/228 specimens, including (but not limited to): Borrelia crocidurae (N = 7), West Nile virus (N = 3), Rickettsia felis (N = 2), Bartonella quintana (N = 1), human herpesvirus 8 (N = 1), and Saffold virus (N = 1). Reads corresponding to Plasmodium falciparum were detected in 19 specimens, though their presence in the cohort was likely due to user error of rapid diagnostic testing or incorrect specimen segregation at the clinics. Mosquito-borne pathogens were typically detected just after the conclusion of the rainy season, while tick-borne pathogens were mostly detected before the rainy season. The three West Nile virus strains were phylogenetically characterized and shown to be related to both European and North American clades. Surveys such as this will increase the understanding of the potential causes of non-malarial AFI, which may help inform diagnostic and treatment options for clinicians who provide care to patients in Senegal.

Performance of HCV core antigen and PCR testing in a predominantly genotype 3 population.

Hepatitis C core antigen (HCVcAg) is becoming increasingly recognized as an alternative to molecular testing for the confirmation of chronic hepatitis C. However, there are limited data on the performance of this assay in a genotype 3 (GT3) predominant country like Pakistan. We conducted a study to evaluate the diagnostic performance of HCVcAg against the HCV polymerase chain reaction (PCR) molecular test. HCV antibody-positive patients requiring confirmatory testing were recruited from August to October 2018 at the Pakistan Kidney and Liver Institute and Research Center (PKLI&RC), Lahore, Pakistan. Patients with previously known diagnoses or treatment histories were excluded. The Abbott HCV Ag assay was used for HCVcAg testing. Results ≥3.00 fmol/L were considered positive for HCVcAg. The Abbott RealTime HCV assay was used for PCR testing with a lower detection limit of ≥12 IU/mL. We computed the sensitivity, specificity and correlation of HCVcAg against HCV PCR. A total of 394 patients were recruited. The median age of the patients was 42 years. Most participants were females (51.5%, n = 203), 30.7% (n = 121) had HTN, 10.4% DM (n = 41) and 5% had APRI ≥2. The overall sensitivity was 98.0% and the specificity was 98.6%. The lowest detection limit of cAg was an HCV RNA value of 4657 IU/mL. The levels of cAg were highly correlated with those of HCV RNA by Spearman's rank correlation test (r = 0.935, p < .001). HCVcAg represents a suitable alternative with high sensitivity and specificity compared with HCV PCR in the GT3-predominant population and can be incorporated into algorithms to improve linkage to care.

COVID-19 waves in an urban setting 2020-2022: an electronic medical record analysis.

Background: Global and national surveillance efforts have tracked COVID-19 incidence and clinical outcomes, but few studies have compared comorbid conditions and clinical outcomes across each wave of the pandemic. We analyzed data from the COVID-19 registry of a large urban healthcare system to determine the associations between presenting comorbidities and clinical outcomes during the pandemic. Methods: We analyzed registry data for all inpatients and outpatients with COVID-19 from March 2020 through September 2022 (N = 44,499). Clinical outcomes were death, hospitalization, and intensive care unit (ICU) admission. Demographic and clinical outcomes data were analyzed overall and for each wave. Unadjusted and multivariable logistic regressions were performed to explore the associations between age, sex, race, ethnicity, comorbidities, and mortality. Results: Waves 2 and 3 (Alpha and Delta variants) were associated with greater hospitalizations, ICU admissions, and mortality than other variants. Chronic pulmonary disease was the most common comorbid condition across all age groups and waves. Mortality rates were higher in older patients but decreased across all age groups in later waves. In every wave, mortality was associated with renal disease, congestive heart failure, cerebrovascular disease, diabetes, and chronic pulmonary disease. Multivariable analysis found that liver disease and renal disease were significantly associated with mortality, hospitalization, and ICU admission, and diabetes was significantly associated with hospitalization and ICU admission. Conclusion: The COVID-19 registry is a valuable resource to identify risk factors for clinical outcomes. Our findings may inform risk stratification and care planning for patients with COVID-19 based on age and comorbid conditions.

Development and Validation of Three Automated High-Throughput Molecular Tests to Detect Monkeypox Virus Infections.

BACKGROUND: The 2022 outbreak of the clade IIb monkeypox virus and subsequent global spread lead to an urgent need for the development of high-throughput, sensitive, and reproducible diagnostic tests. METHODS: We developed 3 assays to detect monkeypox virus, 2 (MPXV+ and MPXV) for m2000 RealTime and 1 (MPXV) for Alinity m platforms. Dual targets in E9L and B6R (MPXV+) and J2L and B7R (MPXV) increased mutation resistance. In silico prediction indicates MPXV+ cross-reactivity with orthopox viruses and specific monkeypox virus detection with MPXV. RESULTS: m2000 RealTime MPXV+ and MPXV assay sensitivity was determined to be 3.2 plaque-forming units/mL using a reference virus culture diluted into universal transport medium (UTM). Alinity m MPXV lower limit of detection was 200 copies/mL using monkeypox virus plasmids in pooled UTM matrix. m2000 RealTime MPXV+ and MPXV assays were validated with lesion swabs in UTM and 1:1 saliva to UTM mixtures. Commercially available and remnant clinical lesion specimens in UTM were tested with RealTime MPXV+, RealTime MPXV and Alinity m MPXV assays and demonstrated high agreement to known mpox (MPX)-positive specimens. CONCLUSIONS: RealTime MPXV+, RealTime MPXV, and Alinity MPXV are high throughput and sensitive assays used for the detection of monkeypox virus. These assays maybe useful during MPX outbreaks.

Characterization of Dengue Virus Serotype 2 Cosmopolitan Genotype Circulating in Colombia.

Dengue virus (DENV) is the etiological agent of dengue fever (DF), which is among the most prevalent vector-borne diseases in the tropics. In 2022, the Colombian health surveillance system reported more than 69,000 cases of DF. As part of a hospital-based fever surveillance study, acute-phase sera were collected from 4,545 patients with suspected dengue between 2020 and 2023 in three municipalities of Colombia. Combined reverse transcription-polymerase chain reaction and antigen rapid testing confirmed that 376 patients (8.3%) had DF. The virus was isolated in cell culture from 166 of these patients (44.1%), and genome sequencing was performed successfully on 122 (73.5%). Three DENV serotypes (1, 2, and 3) were identified. Phylogenetic analyses of the DENV-2 sequences revealed that 42 of 50 of the isolates (84%) belonged to the DENV-2 cosmopolitan genotype lineage, clustering with sequences from Asia, Peru, and Brazil. We report the detection, isolation, and whole-genome sequencing (11 Kb) of the DENV-2 cosmopolitan genotype and its recent introduction to Colombia.

Parallel evolution of picobirnaviruses from distinct ancestral origins.

IMPORTANCE: Picobirnaviruses (PBVs) are highly heterogeneous viruses encoding a capsid and RdRp. Detected in a wide variety of animals with and without disease, their association with gastrointestinal and respiratory infections, and consequently their public health importance, has rightly been questioned. Determining the "true" host of Picobirnavirus lies at the center of this debate, as evidence exists for them having both vertebrate and prokaryotic origins. Using integrated and time-stamped phylogenetic approaches, we show they are contemporaneous viruses descending from two different ancestors: avian Reovirus and fungal Partitivirus. The fungal PBV-R2 species emerged with a single segment (RdRp) until it acquired a capsid from vertebrate PBV-R1 and PBV-R3 species. Protein and RNA folding analyses revealed how the former came to resemble the latter over time. Thus, parallel evolution from disparate hosts has driven the adaptation and genetic diversification of the Picobirnaviridae family.

Seroprevalence of Human T-Cell Lymphotropic Virus-1 in a Jamaican Antenatal Population and Assessment of Pooled Testing as a Cost Reduction Strategy for Implementation of Routine Antenatal Screening.

Mother to child transmission (MTCT) of human T-cell lymphotropic virus (HTLV)-1 is associated with increased risk of adult T-cell leukemia and can be unrecognized without routine antenatal screening. We assessed the seroprevalence of HTLV-1/2 among pregnant women attending The University Hospital of the West Indies Antenatal Clinic, 2019, and validated a cost-effective strategy to screen antenatal clinic attendees for HTLV-1/2. Residual antenatal samples from 370 women were tested for HTLV-1/2 by chemiluminescence microparticle immunoassay (CMIA). Six samples were confirmed HTLV-1 positive by Western blot (none for HTLV-2) for a prevalence of 1.62%. Four mother-child pairs were able to be recruited for HTLV testing of children, with two children testing HTLV-1/2 positive. Medical records of HTLV-1-infected women revealed that all women breastfed, indicating an unrecognized risk for HTLV MTCT. To assess whether pooling of samples as a cost-reduction strategy could be introduced, we pooled all antenatal samples received between November and December 2021 into 12 pools of eight samples/pool. Two pools were CMIA positive, and de-pooling of samples identified two CMIA-positive samples (one per pool), both confirmed as HTLV-1 by Western blot. These results indicate that HTLV-1 remains prevalent in pregnant Jamaican women and that sample pooling can be a cost-effective strategy to limit MTCT in Jamaica.

The diversification of SARS-CoV-2 Omicron variants and evaluation of their detection with molecular and rapid antigen assays.

BACKGROUND: The SARS-CoV-2 pandemic saw the rapid rise, global spread, and diversification of the omicron variant in 2022. Given the overwhelming dominance of this variant globally and its diverse lineages, there is an urgent need to ensure that diagnostic assays are capable of detecting widely circulating omicron sub-lineages. STUDY DESIGN: Remnant clinical VTM samples from SARS-CoV-2 PCR confirmed infections (n = 733) collected in Wisconsin (n = 94), New York (n = 267), and South Carolina (n = 372) throughout 2022 were sequenced, classified, and tested with m2000 RealTime SARS-CoV-2, Alinity m SARS-CoV-2, ID NOW COVID-19 v2.0, BinaxNOW COVID-19 Ag Card, and Panbio COVID-19 Rapid Test Device assays. RESULTS: Sequences and lineage classifications were obtained for n = 641/733 (87.4%) samples and included delta (n = 6) and representatives from all major SARS-CoV-2 omicron variants circulating in 2022 (BA.1, BA.2, BA.3, BA.4, BA.5, BE, BF, BQ.1, and XBB). Panels of diverse omicron lineages were tested by molecular assays RealTime (n = 624), Alinity m (n = 80), and ID NOW v2.0 (n = 88) with results showing 100% detection for all samples. BinaxNOW and Panbio had sensitivities of 494/533 (92.7%) and 416/469 (88.7%), respectively for specimens with >4 log10 copies/test, consistent with expected performance for frozen specimens. Furthermore, BinaxNOW demonstrated SARS-CoV-2 detection in clinical samples 1-4 days, and up to 18 days post-symptom onset in BA.1 infected patients with >4 log10 copies/test. CONCLUSIONS: This data highlights the rise and diversification of SARS-CoV-2 omicron variants over the course of 2022 and demonstrate that each of the 5 tested assays can detect the breadth of omicron variants circulating globally.

Toward reaching hepatitis B goals: hepatitis B epidemiology and the impact of two decades of vaccination, Georgia, 2021.

BackgroundGeorgia has adopted the World Health Organization European Region's and global goals to eliminate viral hepatitis. A nationwide serosurvey among adults in 2015 showed 2.9% prevalence for hepatitis B virus (HBV) surface antigen (HBsAg) and 25.9% for antibodies against HBV core antigen (anti-HBc). HBV infection prevalence among children had previously not been assessed.AimWe aimed to assess HBV infection prevalence among children and update estimates for adults in Georgia.MethodsThis nationwide cross-sectional serosurvey conducted in 2021 among persons aged ≥ 5 years used multi-stage stratified cluster design. Participants aged 5-20 years were eligible for hepatitis B vaccination as infants. Blood samples were tested for anti-HBc and, if positive, for HBsAg. Weighted proportions and 95% confidence intervals (CI) were calculated for both markers.ResultsAmong 5-17 year-olds (n = 1,473), 0.03% (95% CI: 0-0.19) were HBsAg-positive and 0.7% (95% CI: 0.3-1.6) were anti-HBc-positive. Among adults (n = 7,237), 2.7% (95% CI: 2.3-3.4) were HBsAg-positive and 21.7% (95% CI: 20.4-23.2) anti-HBc-positive; HBsAg prevalence was lowest (0.2%; 95% CI: 0.0-1.5) among 18-23-year-olds and highest (8.6%; 95% CI: 6.1-12.1) among 35-39-year-olds.ConclusionsHepatitis B vaccination in Georgia had remarkable impact. In 2021, HBsAg prevalence among children was well below the 0.5% hepatitis B control target of the European Region and met the ≤ 0.1% HBsAg seroprevalence target for elimination of mother-to-child transmission of HBV. Chronic HBV infection remains a problem among adults born before vaccine introduction. Screening, treatment and preventive interventions among adults, and sustained high immunisation coverage among children, can help eliminate hepatitis B in Georgia by 2030.

Novel fully automated prototype assays for specific detection of phosphorylated and non-phosphorylated Hepatitis B core antigens.

BACKGROUND: Hepatitis B core antigen (HBcAg) has been proposed as a surrogate marker to reflect transcriptional activity of HBV covalently closed circular DNA (cccDNA) during active infections and may be a valuable tool to monitor the efficacy of antiviral therapies. However, HBcAg-specific immunoassays are unavailable, and current assays that measure hepatitis B core-related antigen (HBcrAg) cannot distinguish between HBcAg, HBeAg, and precore (PreC) proteins. OBJECTIVE: Two fully automated assays were developed to specifically detect phosphorylated HBcAg (P-HBcAg, representing non-HBV DNA-containing particles) and non-phosphorylated HBcAg (representing HBV DNA-containing particles) circulating in HBV infected patients. STUDY DESIGN: P-HBcAg and HBcAg levels were analyzed in 124 single timepoint patients with active infections, in three longitudinal specimens from patients with acute HBV infections, and in four chronic hepatitis B (CHB) patients on-therapy (TDF - tenofovir disoproxil fumarate, pegIFN - pegylated interferon, NAPs - nucleic acids polymers). RESULTS: Analyzing acute infections revealed that P-HBcAg and HBcAg levels correlate more closely than HBcrAg to HBV DNA. During antiviral treatment of CHB patients, HBcAg correlates well with HBV DNA and indicates a therapeutic response to the treatment at the beginning of the therapy. In contrast, P-HBcAg tracks more closely to HBV RNA. Importantly, P-HBcAg is detectable several months after HBcAg became undetectable indicating that cccDNA is still transcriptionally active in hepatocytes. CONCLUSIONS: Overall, the ability to specifically distinguish between the various states of HBcAg (phosphorylated and non-phosphorylated) can provide additional insights for disease staging, drug development, and management of HBV therapies.

Human immunodeficiency virus coinfection differentially impacts hepatitis B virus viral markers based on hepatitis Be antigen status in patients with suppressed viremia.

Hepatitis B virus (HBV) RNA and hepatitis B core-related antigen (HBcrAg), reflecting transcriptional activity of covalently closed circular DNA, are gaining traction as important markers to assess viral activity. Whether their expression differs under viral suppression by HIV co-infection status is unknown. Among adults with chronic HBV on antiviral therapy, we sought to determine if the expression of HBV markers (specialized and well-established) differs between HBV-HIV co-infection vs. HBV mono-infection. We compared HBV marker levels among 105 participants in the Hepatitis B Research Network (HBRN) HBV-HIV Ancillary Study and 105 participants in the HBRN mono-infected Cohort Study, matched for HBeAg status and HBV DNA suppression on therapy. Among HBeAg+ participants (N = 58 per group), after adjusting for age, sex, race, ALT and HBV DNA, viral markers were higher (p < .05) in the HBV-HIV versus the HBV-only sample (HBeAg: 1.05 vs. 0.51 log10 IU/mL; HBsAg: 3.85 vs. 3.17 log10 IU/mL; HBV RNA: 5.60 vs. 3.70 log10 U/mL; HBcrAg: 6.59 vs. 5.51 log10 U/mL). Conversely, among HBeAg(-) participants (N = 47 per group), HBsAg (2.00 vs. 3.04 log10 IU/mL) and HBV RNA (1.87 vs. 2.66 log10 U/mL) were lower (p < .05) in HBV-HIV vs. HBV-only; HBcrAg levels were similar (4.14 vs. 3.64 log10 U/mL; p = .27). Among adults with chronic HBV with suppressed viremia on antiviral therapy, viral markers tracked with HIV co-infection status and associations differed inversely by HBeAg status. The greater sensitivity and specificity of HBV RNA compared to HBcrAg allows for better discrimination of transcriptional activity regardless of HBeAg status.

Detection of SARS-CoV-2 antibodies after confirmed Omicron BA.1 and presumed BA.4/5 infections using Abbott ARCHITECT and Panbio assays.

Background: Commercial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests were developed before variants with spike protein mutations emerged, leading to concerns that these tests have reduced sensitivity for detecting antibody responses in individuals infected with Omicron subvariants. This study was performed to evaluate Abbott ARCHITECT serologic assays, AdviseDx SARS-CoV-2 IgG II, and SARS-CoV-2 IgG for the detection of spike (S) and nucleocapsid (N) IgG antibody increases in vaccinated healthcare workers infected with Omicron subvariants. Methods: During the BA.1/2 and BA.4/5 waves, 171 SARS-CoV-2-infected individuals (122 in the BA.1/2 wave, 49 in the BA.4/5 wave) were tested for S and N IgG post infection. Sequencing and SARS-CoV-2 variant confirmation were performed on nasal swab samples from individuals infected during the BA.1/2 wave. Results: Twenty-seven Omicron sequence confirmed individuals in the BA.1/2 wave and all 49 in the BA.4/5 wave had pre-infection antibody data. Compared to pre-infection levels, post-infection S IgG increased 6.6-fold from 1294 ± 302 BAU/ml (mean ± standard error measurement) to 9796 ± 1252 BAU/ml (P < 0.001) during the BA.1/2 wave, and 3.6-fold from 1771 ± 351 BAU/ml to 8224 ± 943 BAU/ml (P < 0.001) during the BA.4/5 wave. N IgG increased post infection 19.1-fold from 0.2 ± 0.1 to 3.7 ± 0.5 (P < 0.001) during the BA.1/2 wave and 13.5-fold from 0.22 ± 0.1 to 3.2 ± 0.3 (P < 0.001) during the BA.4/5 wave. Among 159 infection-naïve individuals, positive N IgG levels were detected with a sensitivity of 88% in the 87 individuals who were tested between 14 days and 60 days post infection. Conclusions: The large increases in post-infection S IgG along with the N IgG sensitivity that was comparable to previously reported N IgG sensitivity data in unvaccinated individuals after Omicron infection, support the use of Abbott SARS-CoV-2 assays for detecting increased S IgG and seroconversion of N IgG in vaccinated individuals post Omicron infection. Given that 68% of the United States population is fully vaccinated, these results are of current relevance.

Temporal and coevolutionary analyses reveal the events driving the emergence and circulation of human mamastroviruses.

Characterized by high genetic diversity, broad host range, and resistance to adverse conditions, coupled with recent reports of neurotropic astroviruses circulating in humans, mamastroviruses pose a threat to public health. The current astrovirus classification system based on host source prevents determining whether strains with distinct tropism or virulence are emerging. By using integrated phylogeny, we propose a standardized demarcation of species and genotypes, with reproducible cut-off values that reconcile the pairwise sequence distribution, genetic distances between lineages, and the topological reconstruction of the Mamastrovirus genus. We further define the various links established by co-evolution and resolve the dynamics of transmission chains to identify host-jump events and the sources from which different mamastrovirus species circulating in humans have emerged. We observed that recombination is relatively infrequent and restricted to within genotypes. The well-known "human" astrovirus, defined here as mamastrovirus species 7, has co-speciated with humans, while there have been two additional host-jumps into humans from distinct hosts. Newly defined species 6 genotype 2, linked to severe gastroenteritis in children, resulted from a marmot to human jump taking place ∼200 years ago while species 6 genotype 7 (MastV-Sp6Gt7), linked to neurological disease in immunocompromised patients, jumped from bovines only ∼50 years ago. Through demographic reconstruction, we determined that the latter reached coalescent viral population growth only 20 years ago and is evolving at a much higher evolutionary rate than other genotypes infecting humans. This study constitutes mounting evidence of MastV-Sp6Gt7 active circulation and highlights the need for diagnostics capable of detecting it.

The Principles of SARS-CoV-2 Intervariant Competition Are Exemplified in the Pre-Omicron Era of the Colombian Epidemic.

The first 18 months of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Colombia were characterized by three epidemic waves. During the third wave, from March through August 2021, intervariant competition resulted in Mu replacing Alpha and Gamma. We employed Bayesian phylodynamic inference and epidemiological modeling to characterize the variants in the country during this period of competition. Phylogeographic analysis indicated that Mu did not emerge in Colombia but acquired increased fitness there through local transmission and diversification, contributing to its export to North America and Europe. Despite not having the highest transmissibility, Mu's genetic composition and ability to evade preexisting immunity facilitated its domination of the Colombian epidemic landscape. Our results support previous modeling studies demonstrating that both intrinsic factors (transmissibility and genetic diversity) and extrinsic factors (time of introduction and acquired immunity) influence the outcome of intervariant competition. This analysis will help set practical expectations about the inevitable emergences of new variants and their trajectories. IMPORTANCE Before the appearance of the Omicron variant in late 2021, numerous SARS-CoV-2 variants emerged, were established, and declined, often with different outcomes in different geographic areas. In this study, we considered the trajectory of the Mu variant, which only successfully dominated the epidemic landscape of a single country: Colombia. We demonstrate that Mu competed successfully there due to its early and opportune introduction time in late 2020, combined with its ability to evade immunity granted by prior infection or the first generation of vaccines. Mu likely did not effectively spread outside of Colombia because other immune-evading variants, such as Delta, had arrived in those locales and established themselves first. On the other hand, Mu's early spread within Colombia may have prevented the successful establishment of Delta there. Our analysis highlights the geographic heterogeneity of early SARS-CoV-2 variant spread and helps to reframe the expectations for the competition behaviors of future variants.