Virological Characteristics Research Articles

Macrodendritic ulcerative keratitis and conjunctival lymphoid hyperplasia in horses with equine herpesvirus-2 and equine herpesvirus-5 infections.

The aim of this study was to describe the clinical, confocal microscopic, histologic, and virologic features of horses with macrodendritic ulcerative keratitis and conjunctival lymphoid hyperplasia associated with equine herpesvirus-2 and equine herpesvirus-5 infection. Four foals with bilateral ocular disease. Complete ophthalmic examination was performed for each horse, and corneal samples were collected for cytology and microbiologic evaluation, including virus isolation and molecular diagnostics for the equine herpesviruses. Invivo confocal microscopy examination of the cornea was performed in two horses. Conjunctival biopsies for histopathology were collected from two horses with nodular conjunctival thickening. Each horse had bilateral, large, superficial dendritic corneal ulcerations that covered extensive regions of the corneal surface. Corneal invivo confocal microscopy examination in two horses detected inflammatory cells and populations of morphologically abnormal corneal epithelial cells adjacent to the ulcerations. The abnormal epithelial cells included round, relatively small, hyperreflective cells intermixed with elongated, enlarged, hyperreflective cells. Equine herpesvirus-2 was isolated from corneal samples of 2 horses and detected by PCR assay in the other two horses. Equine herpesvirus-5 was also detected by PCR assay in three of the horses. Conjunctival histopathology identified predominantly lymphocytic infiltrates. The macrodendrites and conjunctival masses resolved with topical antiviral therapy (cidofovir or idoxuridine) in all horses and did not recur. The equine gammaherpesviruses may be associated with the development of macrodendritic ulcerative keratitis and conjunctival lymphocytic masses in foals. Invivo confocal microscopy of horses with macrodendrites revealed similar findings to other host species with herpetic dendritic keratitis.

Protocol for the Mpox Prospective Observational Cohort Study (MPOCS) Among Individuals with mpox in Canada

In mid-2022, a global mpox epidemic emerged that was concentrated in gay, bisexual and other men who have sex with men, prompting the WHO to declare a public health emergency of international concern. Shortly after cases were first identified in Canada, we established the Mpox Prospective Observational Cohort Study (MPOCS) to characterize clinical, psychosocial, epidemiologic and virologic characteristics of this re-emerging infection. Community members were engaged in identifying research priorities, creating participant-facing materials, and forming a community advisory board. This article outlines the MPOCS study protocol. Although cases of mpox in Canada have rapidly declined, our research procedures may serve as a template for rapidly studying emerging infectious disease threats in the future, particularly among sexual networks.

The molecular epidemiology of HIV-1 in Sweden 1996 to 2022, and the influence of migration from Ukraine.

BackgroundThe global distribution of HIV-1 subtypes is evolving, which is reflected in the Swedish HIV cohort. The subtype HIV-1A6, which may be prone to developing resistance to cabotegravir, is the most common subtype in Ukraine.AimWe aimed to examine trends in HIV-1 subtype distribution in Sweden, with a special focus on HIV-1A6, and to describe the virology, demography and treatment of Ukrainian people living with HIV (PLWH) who migrated to Sweden in 2022.MethodsData about PLWH in Sweden are included in a national database (InfCareHIV). We used the online tool COMET to establish HIV-1 subtypes and the Stanford database to define drug resistance mutations. We investigated the relation between virological characteristics and demographic data.ResultsThe early epidemic was predominated by HIV-1 subtype B infections in people born in Sweden. After 1990, the majority of new PLWH in Sweden were PLWH migrating to Sweden, resulting in an increasingly diverse epidemic. In 2022, HIV-1A6 had become the sixth most common subtype in Sweden and 98 of the 431 new PLWH that were registered in Sweden came from Ukraine. We detected HIV RNA in plasma of 32 Ukrainian patients (34%), of whom 17 were previously undiagnosed, 10 had interrupted therapy and five were previously diagnosed but not treated. We found HIV-1A6 in 23 of 24 sequenced patients.ConclusionThe molecular HIV epidemiology in Sweden continues to diversify and PLWH unaware of their HIV status and predominance of HIV-1A6 should be considered when arranging care directed at PLWH from Ukraine.

Experimental Infection of Chickens with H5N8 High Pathogenicity Avian Influenza Viruses Isolated in Japan in the Winter of 2020-2021.

During the winter of 2020-2021, numerous outbreaks of high pathogenicity avian influenza (HPAI) were caused by viruses of the subtype H5N8 in poultry over a wide region in Japan. The virus can be divided into five genotypes-E1, E2, E3, E5, and E7. The major genotype responsible for the outbreaks was E3, followed by E2. To investigate the cause of these outbreaks, we experimentally infected chickens with five representative strains of each genotype. We found that the 50% chicken infectious dose differed by up to 75 times among the five strains, and the titer of the E3 strains (102.75 50% egg infectious dose (EID50)) was the lowest, followed by that of the E2 strains (103.50 EID50). In viral transmission experiments, in addition to the E3 and E2 strains, the E5 strain was transmitted to naïve chickens with high efficiency (>80%), whereas the other strains had low efficiencies (<20%). We observed a clear difference in the virological characteristics among the five strains isolated in the same season. The higher infectivity of the E3 and E2 viruses in chickens may have caused the large number of HPAI outbreaks in Japan during this season.

Pediatric HIV+ Kaposi sarcoma exhibits clinical, virological, and molecular features different from the adult disease.

BACKGROUNDKaposi sarcoma (KS) is among the most common childhood cancers in Eastern and Central Africa. Pediatric KS has a distinctive clinical presentation compared with adult KS, which includes a tendency for primary lymph node involvement, a considerable proportion of patients lacking cutaneous lesions, and a potential for fulminant disease. The molecular mechanisms or correlates for these disease features are unknown.METHODSThis was a cross-sectional study. All cases were confirmed by IHC for KS-associated herpesvirus (KSHV) LANA protein. Baseline blood samples were profiled for HIV and KSHV genome copy numbers by qPCR and secreted cytokines by ELISA. Biopsies were characterized for viral and human transcription, and KSHV genomes were determined when possible.RESULTSSeventy participants with pediatric KS were enrolled between June 2013 and August 2019 in Malawi and compared with adult patients with KS. They exhibited high KSHV genome copy numbers and IL-6/IL-10 levels. Four biopsies (16%) had a viral transcription pattern consistent with lytic viral replication.CONCLUSIONThe unique features of pediatric KS may contribute to the specific clinical manifestations and may direct future treatment options.FUNDINGUS National Institutes of Health U54-CA-254569, PO1-CA019014, U54-CA254564, RO1-CA23958.

NS1-Specific Antibody Response Facilitates the Identification of Children With Dengue and Zika in Hyperendemic Areas.

Infections by dengue virus (DENV) and Zika virus (ZIKV) have some similar symptoms and a cross-reactive immune response, although with different risk populations and outcomes. Here, we evaluated the virologic characteristics and the nonstructural protein 1 (NS1)-specific antibody responses to DENV and ZIKV in children suspected of dengue in different epidemiologic moments in Colombia. Viral RNA, circulating NS1 and IgM/IgG specific for DENV and ZIKV were performed by reverse transcription-quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) in 301 children suspected of dengue enrolled in a hospital setting during the ZIKV epidemic and a primary healthcare setting during a DENV epidemic. For the detection of DENV and ZIKV-specific IgM, an NS1-based ELISA was validated using characterized pediatric samples. Clinical and laboratory parameters were also evaluated. DENV RNA or NS1 antigen was detected in the plasma of 62% of children, and in none, the ZIKV RNA was found. NS1-based ELISA for DENV and ZIKV IgM showed a sensitivity/specificity of 90/84% and 73/98%, respectively. Of 114 children without detectable viremia or antigenemia, 30.7%, 17.5%, 22% and 30% were IgM-DENV + , IgM-ZIKV + , IgM-DENV + ZIKV + and IgM-DENV - ZIKV - , respectively. The ZIKV/DENV IgM-NS1 ratio allows the identification of the infecting orthoflavivirus in 88% of the children with IgM-DENV + ZIKV + , confirming a high predominance of DENV infections in the 2 pediatric settings. Overall, 88% of the children with clinical suspicion of dengue had an identifiable orthoflaviviral infection, with 80% caused by DENV, 7% by ZIKV and 0.7% classified as recent infections or coinfection, demonstrating active viral cocirculation in the pediatric population of southern Colombia. The IgM-NS1 detection improved the identification of orthoflaviviral infections in children without viremia or antigenemia, suggesting it is a helpful complementary tool for medical personnel in tropical regions with high viral cocirculation and different clinical scenes.

Functional assessments of SARS-CoV-2 single-round infectious particles with variant-specific spike proteins on infectivity, drug sensitivity, and antibody neutralization

Working with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is restricted to biosafety level III (BSL-3) laboratory. The study used a trans-complementation system consisting of virus-like particles (VLPs) and DNA-launched replicons to generate SARS-CoV-2 single-round infectious particles (SRIPs) with variant-specific spike (S) proteins. S gene of Wuhan-Hu-1 strain (SWH1) or Omicron BA.1 variant (SBA.1), along with the envelope (E) and membrane (M) genes, were cloned into a tricistronic vector, co-expressed in the cells to produce variant-specific S-VLPs. Additionally, the replicon of the WH1-like strain without S, E, M and accessory genes, was engineered under the control by a CMV promoter to produce self-replicating RNAs within VLP-producing cells, led to create SWH1- and SBA.1-based SARS-CoV-2 SRIPs. The SBA.1-based SRIP showed lower virus yield, replication, N protein expression, fusogenicity, and infectivity compared to SWH1-based SRIPs. SBA.1-based SRIP also exhibited intermediate resistance to neutralizing antibodies produced by SWH1-based vaccines, but were effective at infecting cells with low ACE2 expression. Importantly, both S-based SRIPs responded similarly to remdesivir and GC376, with EC50 values ranging from 0.17 to 1.46 μM, respectively. The study demonstrated that this trans-complementation system is a reliable and efficient tool for generating SARS-CoV-2 SRIPs with variant-specific S proteins. SARS-CoV-2 SRIPs, mimicking authentic live viruses, facilitate comprehensive analysis of variant-specific virological characteristics, including antibody neutralization, and drug sensitivity in non-BSL-3 laboratories.

Virological characteristics and the rapid antigen test as deisolation criteria in immunocompromised patients with COVID-19: A prospective cohort study.

There are limited data supporting current Centers for Disease Control and Preventionguidelines for the isolation period in moderate to severely immunocompromised patients with coronavirus disease 2019 (COVID-19).Adult COVID-19 patients who underwent solid organ transplantation (SOT) or received active chemotherapy against hematologic malignancy were enrolled and weekly respiratory samples were collected. Samples with positive genomic real-time polymerase chain reactionresults underwent virus culture and rapid antigen testing (RAT).A total of 65 patients (40 with hematologic malignancy and 25 SOT) were enrolled. The median duration of viable virus shedding was 4 weeks (interquartile range: 3-7). Multivariable analysis revealed that B-cell depletion (hazard ratio [HR]:4.76) was associated with prolonged viral shedding, and COVID-19 vaccination (≥3 doses) was negatively associated with prolonged viral shedding (HR: 0.22). The sensitivity, specificity, positive predictive value, and negative predictive value of RAT for viable virus shedding were 79%, 76%, 74%, and 81%, respectively. The negative predictive value of RAT was only 48% (95% confidence interval [CI]: 33-65) in the samples from those with symptom onset ≤20 days, but it was as high as 92% (95% CI: 85-96) in the samples from those with symptom onset >20 days.About half of immunocompromised COVID-19 patients shed viable virus for ≥4 weeks from the diagnosis, and virus shedding was prolonged especially in unvaccinated patients with B-cell-depleting therapy treatment. RAT beyond 20 days in immunocompromised patients had a relatively high negative predictive value for viable virus shedding.

Resurgence of influenza during COVID-19 in Chongqing, China: A retrospective analysis.

To better understand the trends of influenza and the impact of public health and social measures (PHSMs) implemented during the coronavirus disease 2019 (COVID-19) period in Chongqing, China. Data from the China Influenza Surveillance Information System from January 2017 to June 2022 were extracted. Epidemiological characteristics (influenza-like illness [ILI] and ILI%) and virological characteristics (influenza positive rate and circulating (sub)types) of influenza were described and compared between the pre-COVID-19 period and the COVID-19 period. Our survey showed that the implementation of PHSMs during the COVID-19 period had a positive impact on reducing influenza transmission. However, influenza activity resurged in 2021-2022 as the PHSMs were eased. Children under 5 years old constituted the highest proportion of ILI cases. The overall influenza positive rate was 23.70%, with a higher rate observed during the pre-COVID-19 period (31.55%) compared to the COVID-19 period (13.68%). Influenza virus subtypes co-circulated and the predominant subtype varied each year, with influenza A subtypes predominated in 2018/2019, while influenza B/Victoria lineage dominated in 2020/2021. PHSMs are effective measures to mitigate the spread of influenza. The findings underscore the need for bolstering monitoring systems, advocating influenza vaccination, and implementing practical PHSMs to strengthen prevention and control measures against influenza.

Pathological and virological insights from an outbreak of European brown hare syndrome in the Italian hare (Lepus corsicanus).

European brown hare syndrome (EBHS) is a highly contagious and fatal viral disease, mainly affecting European brown hares (Lepus europaeus). The etiological agent, EBHS virus (EBHSV), belongs to the Lagovirus genus within the Caliciviridae family. The Italian hare (Lepus corsicanus) is endemic to Central-Southern Italy and Sicily and is classified as a vulnerable species. L. corsicanus is known to be susceptible to EBHS, but virological data available is scarce due to the few cases detected so far. In this study, we describe the occurrence of EBHS in two free-ranging L. corsicanus, found dead in a protected area of Central Italy. The two hares were identified as L. corsicanus using phenotypic criteria and confirmed through mitochondrial DNA analysis. Distinctive EBHS gross lesions were observed at necropsy and confirmed by subsequent histological examination. EBHSV was detected in the livers of the two animals initially using an antigen detection ELISA, followed by an EBHSV-specific reverse transcription-PCR, thus confirming the viral infection as the probable cause of death. The EBHS viruses detected in the two hares were identical, as based on blast analysis performed for the VP60 sequences and showed 98.86% nucleotide identity and 100% amino acid identity with strain EBHSV/GER-BY/EI97.L03477/2019, isolated in Germany in 2019. Phylogenetic analysis places our virus in group B, which includes strains that emerged after the mid-1980s. This study supports previous reports of EBHS in L. corsicanus and further expands the knowledge of the pathological and virological characteristics of the etiological agent. The ability of EBHSV to cause a fatal disease in the Italian hare represents a serious threat to the conservation of this vulnerable species, especially in populations kept in enclosed protected areas.

Virological and clinical features of acute respiratory failure associated with COVID-19 in pregnancy: a case-control study

Objective: Pregnancy is a risk factor for acute respiratory failure (ARF) following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We hypothesised that SARS-CoV-2 viral load in the respiratory tract might be higher in pregnant intensive care unit (ICU) patients with ARF than in non-pregnant ICU patients with ARF as a consequence of immunological adaptation during pregnancy. Design: Single-centre, retrospective observational case-control study. Setting: Adult level 3 ICU in a French university hospital. Participants: Eligible participants were adults with ARF associated with coronavirus disease 2019 (COVID-19) pneumonia. Main outcome measure: The primary endpoint of the study was viral load in pregnant and non-pregnant patients. Results: 251 patients were included in the study, including 17 pregnant patients. Median gestational age at ICU admission amounted to 28 + 3/7 weeks (interquartile range [IQR], 26 + 1/7 to 31 + 5/7 weeks). Twelve patients (71%) had an emergency caesarean delivery due to maternal respiratory failure. Pregnancy was independently associated with higher viral load (-4.6 ± 1.9 cycle threshold; P < 0.05). No clustering or over-represented mutations were noted regarding SARS-CoV-2 sequences of pregnant women. Emergency caesarean delivery was independently associated with a modest but significant improvement in arterial oxygenation, amounting to 32 ± 12 mmHg in patients needing invasive mechanical ventilation. ICU mortality was significantly lower in pregnant patients (0 v 35%; P < 0.05). Age, Simplified Acute Physiology Score (SAPS) II score, and acute respiratory distress syndrome were independent risk factors for ICU mortality, while pregnancy status and virological variables were not. Conclusions: Viral load was substantially higher in pregnant ICU patients with COVID-19 and ARF compared with non-pregnant ICU patients with COVID-19 and ARF. Pregnancy was not independently associated with ICU mortality after adjustment for age and disease severity.

Raman Fingerprints of SARS-CoV-2 Omicron Subvariants: Molecular Roots of Virological Characteristics and Evolutionary Directions.

The latest RNA genomic mutation of SARS-CoV-2 virus, termed the Omicron variant, has generated a stream of highly contagious and antibody-resistant strains, which in turn led to classifying Omicron as a variant of concern. We systematically collected Raman spectra from six Omicron subvariants available in Japan (i.e., BA.1.18, BA.2, BA.4, BA.5, XE, and BA.2.75) and applied machine-learning algorithms to decrypt their structural characteristics at the molecular scale. Unique Raman fingerprints of sulfur-containing amino acid rotamers, RNA purines and pyrimidines, tyrosine phenol ring configurations, and secondary protein structures clearly differentiated the six Omicron subvariants. These spectral characteristics, which were linked to infectiousness, transmissibility, and propensity for immune evasion, revealed evolutionary motifs to be compared with the outputs of genomic studies. The availability of a Raman "metabolomic snapshot", which was then translated into a barcode to enable a prompt subvariant identification, opened the way to rationalize in real-time SARS-CoV-2 activity and variability. As a proof of concept, we applied the Raman barcode procedure to a nasal swab sample retrieved from a SARS-CoV-2 patient and identified its Omicron subvariant by coupling a commercially available magnetic bead technology with our newly developed Raman analyses.

Evolving antibody evasion and receptor affinity of the Omicron BA.2.75 sublineage of SARS-CoV-2

SARS-CoV-2 Omicron BA.2.75 has diversified into multiple subvariants with additional spike mutations and several are expanding in prevalence, particularly CH.1.1 and BN.1. Here, we investigated the viral receptor affinities and neutralization evasion properties of major BA.2.75 subvariants actively circulating in different regions worldwide. We found two distinct evolutionary pathways and three newly identified mutations that shaped the virological features of these subvariants. One phenotypic group exhibited a discernible decrease in viral receptor affinities, but a noteworthy increase in resistance to antibody neutralization, as exemplified by CH.1.1, which is apparently as resistant as XBB.1.5. In contrast, a second group demonstrated a substantial increase in viral receptor affinity but only a moderate increase in antibody evasion, as exemplified by BN.1. We also observed that all prevalent SARS-CoV-2 variants in the circulation presently, except for BN.1, exhibit profound levels of antibody evasion, suggesting this is the dominant determinant of virus transmissibility today.

Multiple mutations of SARS-CoV-2 Omicron BA.2 variant orchestrate its virological characteristics.

Most studies investigating the characteristics of emerging SARS-CoV-2 variants have been focusing on mutations in the spike proteins that affect viral infectivity, fusogenicity, and pathogenicity. However, few studies have addressed how naturally occurring mutations in the non-spike regions of the SARS-CoV-2 genome impact virological properties. In this study, we proved that multiple SARS-CoV-2 Omicron BA.2 mutations, one in the spike protein and another downstream of the spike gene, orchestrally characterize this variant, shedding light on the importance of Omicron BA.2 mutations out of the spike protein.

Clinical, Virological, and Immunological Features in Cosmopolitan Genotype DENV-2-Infected Patients during a Large Dengue Outbreak in Sri Lanka in 2017.

In 2017, Sri Lanka experienced its largest dengue epidemic and reported severe and unusual presentations of dengue with high morbidity. This outbreak was associated with the reemergence of dengue virus-2 (DENV-2), with the responsible strain identified as a variant of the previously circulating DENV-2 cosmopolitan genotype. In this study, we characterized the DENV-2 cosmopolitan genotype from patients during this epidemic. Also, we identified host factors that contributed to the severity of dengue infection in patients infected with this particular virus. Ninety-one acute serum samples from patients at the National Hospital in Kandy were randomly selected. Of these, 40.2% and 48.9% were positive for dengue IgM and IgG, respectively. NS1 antigen levels were significantly higher in primary infections. The severe dengue (SD) and dengue with warning signs (DWWS) groups exhibited significantly higher viral genome and infectivity titers than the dengue without warning signs (DWoWS) group. The highest viremia level was observed in SD patients. As for host cytokine response, interferon α (IFN-α) levels were significantly higher in the DWoWS group than in the DWWS and SD groups, whereas interleukin (IL)-12p40 and tumor necrosis factor α (TNF-α) levels in SD patients were significantly higher than in the other two groups. The TNF-α, IL-4, and monocyte chemoattractant protein-1 concentrations were positively correlated with NS1 antigen levels. From whole-genome analysis, NS4 had the highest frequency of amino acid variants, followed by the E gene. Our study suggests that viremia levels and immune responses contributed to SD outcomes, and these findings may help in identifying an effective therapeutic strategy against SD infection.

Zika virus disease: an alarming situation resurfacing on the radar - a short communication.

On the 13th of December 2022, a 5-year-old girl from Karnataka, India, tested positive for Zika virus. The first Zika virus was isolated from the serum of a rhesus monkey in the Zika Forest of Uganda in 1947. Zika virus was largely dormant for about 70 years before suddenly resurfacing across all of America, from Brazil to the Pacific Islands and is connected to a grouping of microcephaly phenotypes based on a complete virus genome analysis. All of the aforementioned research provides an overview of the migration of this virus from the Americas to continental Africa via mosquitoes. The current study, therefore, aims to evaluate the virologic characteristics, prophylaxis, transmitting mechanisms, diagnosis, clinical manifestations, and treatment of ZIKV infection in light of the virus's widespread dissemination and deadly nature. The investigation's findings aim to demonstrate that in order to prevent further outbreaks, there is a national requirement for active epidemiological and entomological observation of Zika. Data were extracted from academic journals of medicine published in MEDLINE, PubMed, ScienceDirect, Ovid, and Embase inventory databases with a predetermined search strategy. Articles considering the Zika virus and its clinical manifestations, especially neurological, were included. The Zika virus has been declared a public health emergency of global significance by the World Health Organization (WHO). It is of alarming concern that it is now one of the most prevalent infectious diseases associated with birth abnormalities discovered in the past five decades. The onset and accelerated spread of disease to other parts of the world is attributed to the migration of infected hosts and climate change. Rapid laboratory diagnosis, evaluation of serological techniques, and virus isolation are urgently needed, along with newer modalities such as mathematical modeling as prediction devices to curb this issue. Due to its grave neurological manifestations, it is mandated to engineer peptide therapies and a virus-specific vaccination to treat this neurotropic virus. There is currently no vaccination against Zika virus infection. If societies are not adequately prepared, the epidemiological wave will have an impact on the workforce and could pose a serious threat. To alleviate the significant cost on health systems and manage its promotion globally, improved investigation and response activities are needed.

Prevalence of occult hepatitis B virus infection and characterisation of hepatitis B surface antigen mutants among adults in western Croatia

Introduction and ObjectivesOccult hepatitis B virus (HBV) infection (OBI) is characterised by low levels of hepatitis B virus (HBV) DNA in the blood/liver of patients with negative hepatitis B surface antigen (HBsAg). This study aimed to determine the OBI prevalence and virological characteristics (viral genotypes and HBsAg mutants) in patients with an “anti-HBc only” serological profile. Materials and MethodsA total of 24 900 serum samples were routinely screened for hepatitis B markers over a five-year period. All anti-HBc-positive/HBsAg-negative/anti-HBs-negative sera were selected and analysed for the presence of HBV DNA. Mutational analyses of the HBs gene and polymerase gene sequences were performed. Results1749 (7.02%) sera were anti-HBc positive, and 113 (0.45%) sera had an “anti-HBc only” serological profile (HBsAg/anti-HBs negative). HBV DNA was detected in 12/113 (10.61%) “anti-HBc only” positive sera, representing 0.048% of all routinely tested samples. Due to extremely low viremia, HBV genome was successfully sequenced in only two sera where subgenotype D3 was confirmed. Mutational analyses of the S gene revealed multiple missense mutations. In addition to the M133I, Y134F, and G145R mutations, already associated with diagnostic escape, we also found nine novel OBI-related S-gene mutations - S136Y, F158L, K160N, E164G, S167L, A168V, L175S, S210I and F212C. ConclusionsWe detected multiple known and novel S gene mutations in 2/12 (16.6%) OBI cases, nevertheless, further studies are required to determine their role in the pathogenesis of OBI. Understanding the frequencies of clinically relevant HBV mutations may contribute to improvement of diagnostic protocols.

The re-emergence of influenza following the COVID-19 pandemic in Victoria, Australia, 2021 to 2022.

BackgroundCOVID-19 pandemic mitigation measures, including travel restrictions, limited global circulation of influenza viruses. In Australia, travel bans for non-residents and quarantine requirements for returned travellers were eased in November 2021, providing pathways for influenza viruses to be re-introduced.AimWe aimed to describe the epidemiological and virological characteristics of the re-emergence of influenza in Victoria, Australia to inform public health interventions.MethodsFrom 1 November 2021 to 30 April 2022, we conducted an epidemiological study analysing case notification data from the Victorian Department of Health to describe case demographics, interviewed the first 200 cases to establish probable routes of virus reintroduction and examined phylogenetic and antigenic data to understand virus diversity and susceptibility to current vaccines.ResultsOverall, 1,598 notifications and 1,064 positive specimens were analysed. The majority of cases (61.4%) occurred in the 15-34 years age group. Interviews revealed a higher incidence of international travel exposure during the first month of case detections, and high levels of transmission in university residential colleges were associated with return to campus. Influenza A(H3N2) was the predominant subtype, with a single lineage predominating despite multiple importations.ConclusionEnhanced testing for respiratory viruses during the COVID-19 pandemic provided a more complete picture of influenza virus transmission compared with previous seasons. Returned international travellers were important drivers of influenza reemergence, as were young adults, a group whose role has previously been under-recognised in the establishment of seasonal influenza epidemics. Targeting interventions, including vaccination, to these groups could reduce future influenza transmission.

Clinical, epidemiological, and virological features of Mpox in Beijing, China – May 31–June 21, 2023

ABSTRACT The first locally acquired case in the Chinese mainland was reported on May 31, 2023, lagging behind other countries. In this study, we aimed to examine the early clinical and epidemiological characteristics of the earliest cases of Mpox in Beijing, China. Additionally, we investigated the sequence and transmission patterns of the Mpox virus (MPXV). We analyzed 37 reported cases of Mpox in Beijing from May 31, 2023 to June 21, 2023. The age range of the subjects was 24–51 years. Thirty-six cases (97.3%) were identified in men who have sex with men (MSM), and 19 cases (51.4%) tested positive for the human immunodeficiency virus. Thirty-three cases were symptomatic, while four were asymptomatic. Skin lesions were observed in 32 cases (97.0%), fever in 26 (78.8%), and swollen lymph nodes in 17 (51.5%). Rash typically appeared in the genital or perianal area 1–3 days before fever onset, with a minimum incubation period of 2 days. For individuals with skin rashes, the skin lesion samples showed 100% positivity and low Ct values. There were high oropharyngeal swab (75.8%) and blood (84.6%) positivity rates. All MPXV strains belonged to the B.1.3 branch of the West African lineage. These strains carried 76–86 nucleotide substitutions compared with the reference human MPXV genome, and genetic diversity was observed. Our findings provide the first insights into the landscape of early transmission of Mpox in Beijing and help inform policy formulation in the Chinese mainland.

Hepatitis B virus-related cryoglobulinemia: Clinical characteristics, virological features, and treatment

BackgroundHepatitis B virus (HBV) infection is a rare etiology of cryoglobulinemia, and its clinical characteristics, virological features and treatment are poorly understood. MethodsThis retrospective study enrolled 23 patients with HBV-related cryoglobulinemia from 497 cryoglobulinemia patients at Peking Union Medical College Hospital between January 2015 and February 2023. We analyzed the clinical characteristics, virological features and management of patients with HBV-related cryoglobulinemia. ResultsThe 23 patients (13 males; median age 48 years) were all mixed cryoglobulinemia and serological HBsAg positive, while 15 patients exhibited HBV-DNA replication. The presence of HBsAg in cryoglobulins was evaluated in 7 patients, all of whom were positive. The most commonly involved organs were kidneys (69.6%), skin (65.2%), peripheral nerves (21.7%), joints (8.7%), gastrointestinal tract (4.3%), and cardiac (4.3%). Eight patients received antiviral therapy with nucleot (s)ide analogues (NAs) alone, 12 patients received NA- and corticosteroid-based regimens, and 3 patients received NA- and rituximab-based regimens based on the severity of clinical symptoms. After a median follow-up of 44 months, four patients died, and one patient was lost to follow-up. All remaining patients (n = 18) achieved clinical remission, and HBV-DNA replication was not detected in 16 out of 18 patients. There was no HBV reactivation in patients treated with rituximab. The three-year overall survival and progression-free survival were 87.0% and 80.3%, respectively. ConclusionsHBV-related cryoglobulinemia patients should be treated with antiviral therapy. Corticosteroids and rituximab are effective for severe cases, but patients need to be closely monitored for therapy-related infection.