Journal of Medical Virology最新文献

Mice are valuable small animal models for studying SARS-CoV-2 pathogenesis. Ancestral SARS-CoV-2 strains do not efficiently utilize murine Ace2, rendering wild-type mice resistant to infection. Although human ACE2 transgenic models such as K18-hACE2 have provided critical insights, they express multiple copies of both murine and human ACE2, and random transgene insertion can result in non-physiological receptor expression. To overcome these limitations, we employed a human ACE2 knock-in (hACE2-KI) model in which the murine Ace2 coding sequence is replaced with human ACE2 using CRISPR/Cas9 technology, generating an mAce2-null background. This design allows human ACE2 expression under endogenous regulatory control while eliminating murine Ace2 expression, thereby providing a more physiologically relevant platform to investigate SARS-CoV-2 pathogenesis and evaluate therapeutic and preventive strategies. In this study, SARS-CoV-2-associated disease was evaluated and compared among hACE2-KI, K18-hACE2 and C57BL/6J mice. Mice were intranasally inoculated with 10⁵ plaque-forming units of SARS-CoV-2 lineages B.1 or B.1.351. Both hACE2-KI and K18-hACE2 mice developed severe disease after SARS-CoV-2 infection. Following infection with B.1, both K18-hACE2 mice and hACE2-KI mice exhibited significant weight loss and mortality, with high viral loads detected in the lungs and brain. hACE2-KI mice infected with SARS-CoV-2 B.1.351 also showed significant weight loss and viral loads, resulting in high mortality. The pathology and inflammatory response within the lungs and brain of infected hACE2-KI mice revealed robust expression of viral nucleocapsid protein, histopathological changes, and upregulated cytokine and chemokine responses. Together, these findings demonstrate that the hACE2-KI knock-in mouse model supports robust SARS-CoV-2 replication and mimics severe COVID-19 disease.

COVID-19 vaccine uptake remains low in several parts of Ghana. Therefore, this study assessed prior exposure to SARS-CoV-2 by detecting immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies among unvaccinated adults in the Wassa Amenfi East District, and examined socio-demographic determinants of vaccine hesitancy and potential motivators for future vaccine acceptance. This cross-sectional study was conducted at Bethany Memorial Hospital, Wassa Akropong, Ghana, where unvaccinated adults aged ≥ 18 years were randomly selected. Blood samples were tested for SARS-CoV-2 IgG and IgM antibodies, and a structured questionnaire captured demographic characteristics, reasons for vaccine refusal, and factors influencing future acceptance. Data were analysed using descriptive statistics and Chi-square or Fisher's exact tests, with statistical significance set at p < 0.05. Seroprevalence rates for IgG, IgM, and combined IgG/IgM were 85% (142/166), 9.0% (15/166), and 7.8% (13/166), respectively. Antibody prevalence did not differ significantly by age, gender, or pregnancy status. Gender-specific patterns of hesitancy were observed: females more frequently reported fears of side effects, infertility, and pregnancy-related concerns, whereas males more commonly cited reduced productivity, impotence, and a perceived lack of need for vaccination (p < 0.05). Older adults were more likely to doubt vaccine efficacy, while younger adults reported fertility-related fears. Across all groups, credible evidence of vaccine safety and efficacy emerged as the strongest motivators for future acceptance. These findings indicate widespread prior exposure to SARS-CoV-2 among unvaccinated adults and highlight the need for gender-responsive, evidence-based community engagement to address vaccine hesitancy in low-coverage settings.

Human papillomavirus (HPV) assays vary regarding the minimum amount of virus they detect. We investigated analytical thresholds of HPV detection and cervical screening sensitivity and specificity. One hundred cervical intraepithelial neoplasia grade 2 or worse (CIN2+) cases and 200 matched population-based controls were obtained at the Swedish National HPV Reference Laboratory and analyzed by 10 laboratories across 10 countries. Cumulative sensitivity (weighted according to the global HPV type distribution in invasive cervical cancer (ICC)) and specificity were estimated at varying analytical detection thresholds. Consensus results found HPV in 99/100 CIN2+ cases and 52/200 controls. HPV16 prevalence declined in HPV-vaccinated birth cohorts, among both cases and controls. Line plots of 1-specificity and ICC-weighted sensitivity found optimal analytical detection thresholds as 3 International Units (IU)/µl for HPV16/18, 25 IU/µl for HPV31/33/35/45/52/58 and 100 genome equivalents (GE)/µl for HPV 39/51/56/59 resulting in 92.00% cumulative specificity and 90.08% ICC-weighted sensitivity. Thresholds defined using virus amounts per 10⁴ human cells gave similar results. Comparator assay testing using manufacturer-defined thresholds achieved high ICC-weighted sensitivity (96.61%) but low specificity (82.50%). This international collaborative study has identified HPV analytical detection thresholds optimizing the sensitivity and specificity of cervical screening.

Sexually transmitted infections (STIs) remain a major global health threat. A comprehensive assessment of their epidemiological features and future trajectories is essential for informing targeted public health policies and achieving international control targets. Using data from the Global Burden of Disease (GBD) Study 2021, we evaluated the incidence of five common STIs (trichomoniasis, chlamydial infection, gonococcal infection, genital herpes, and syphilis). We applied hierarchical clustering to evaluate regional temporal trends, decomposition analysis to identify drivers of burden variations, and frontier analysis to assess burden reduction potential relative to development levels. A Bayesian age-period-cohort model with integrated nested Laplace approximation was employed to project future age-standardized incidence rates (ASIR) through 2035. In 2021, ~723 million new STIs cases were reported globally. Trichomoniasis accounted for the highest proportion of cases (46.60%), followed by chlamydial (32.70%) and gonococcal infections (12.40%). From 1990 to 2021, the global ASIR remained statistically stable (EAPC -0.02, 95% CI -0.07 to 0.03). Unsafe sex was the leading risk factor, accounting for 16.25% of global STIs-related DALYs in 2021, with the highest attribution observed in high Socio-Demographic Index (SDI) regions. Population growth drove 84.84% of the absolute burden increase. Notably, high STIs burdens persisted in regions like South Africa despite its relatively high SDI. While overall ASIR is projected to decline through 2035, a significant demographic shift is expected: the steepest decline is projected in the 20-24 age group, while increasing trends are predicted for the 40-44 age group and children aged < 5 and 10-14 years. Despite stable global incidence, the shifting age profile and persistent regional disparities indicate that "one-size-fits-all" strategies are insufficient. Public health interventions must be recalibrated to address the rising burden in middle-aged populations and the specific needs of high-burden regions to meet the WHO 2030 targets.

The Crimean-Congo Hemorrhagic Fever Virus (Orthonairovirus haemorrhagiae) causes a hemorrhagic fever with mortality rates reaching up to 40%. For years, this virus has maintained its position among the top priority pathogens identified by the World Health Organization (WHO). This is due to its endemic presence across a vast region-from Africa and Spain to the Balkans, the Middle East, and throughout Asia-its potential for human-to-human transmission, and the lack of an effective and approved vaccine or treatment. Therefore, the development of an effective vaccine against CCHFV is of critical importance. Building on the success of mRNA-based vaccines during the Coronavirus Disease 2019 (COVID-19) pandemic, this study reports the development of a messenger ribonucleic acid (mRNA) vaccine candidate expressing the nucleocapsid protein (NP) of CCHFV. The CCHFV NP in vitro transcript (IVT) was designed with pseudouridine (Ψ) nucleoside modification. As part of the preclinical characterization of the IVT vaccine candidate, the biochemical and immunological properties of NP were confirmed in Huh-7 cells transfected with IVT NP-ΨmRNA. Afterwards, the efficacy of IVT NP-ΨmRNA immunization was evaluated in immunocompetent BALB/c and transiently immunosuppressed (IS) C57BL/6 mice. In CCHFV challenge studies, IS C57BL/6 mice were used. IS C57BL/6 mice were immunized intramuscularly with 2 doses of IVT NP- ΨmRNA, either naked or encapsulated in Poly(lactic-co-glycolic acid) (PLGA) nanoparticles, administered 14 days apart. High levels of CCHFV NP-specific humoral (IgM and IgG) and cellular (cytokine and lymphoproliferative) responses were demonstrated in BALB/c mice immunized with IVT NP- ΨmRNA. In challenge experiments, 100% survival was observed with both the naked and PLGA-encapsulated IVT NP-ΨmRNA immunizations. These findings demonstrate 100% survival following lethal CCHFV challenge under the experimental conditions tested in this mouse model and support the potential of NP-encoding pseudouridine-modified mRNA vaccines. Additionally, 100% survival was observed in mice immunized with inactivated CCHFV, whereas only 20% survival was detected in the unmodified IVT NP-mRNA vaccinated animals. In the protected mice, viral clearance was observed in the spleen, liver tissues, and blood on day 14 post-challenge. This study demonstrates that NP, the most abundant protein of the virus, is capable of providing significant survival benefits in the tested mouse model. Furthermore, our report represents a significant step in identifying a potential vaccine candidate and provides a solid foundation for further preclinical studies necessary to support future clinical development.

To assess the preparedness and diagnostic capacity of Spanish clinical microbiology laboratories to detect the emerging monkeypox virus (MPXV) Clade Ib through a nationwide external quality assessment. A blinded 16-sample panel (serum and DNA eluates) containing MPXV Clade Ib, Clade II, vaccinia, and negatives was distributed. Of 36 laboratories submitting results, 25 with clade-level capability were included. Performance versus reference was adjudicated as full, partial, or discordant concordance; species-level and clade-specific metrics were estimated, and inter-laboratory agreement summarized with simple and weighted kappa (Wilson 95% CIs; bootstrap for kappa CIs). Species-level MPXV detection was consistently strong (mean sensitivity 85%, specificity 95%). Agreement was substantial (simple kappa 0.70; weighted 0.81). For Clade Ib, mean sensitivity was 50% (range: 0%-100%) with high but variable specificity (100%). For clade II, mean sensitivity averaged 70% (25%-100%) and specificity 98% (66.7%-100%). Methodologies varied across centers: 68% used independent extraction plus commercial PCR, 20% mixed commercial extraction with in-house PCR, and 12% integrated extraction-PCR platforms. In conclusion, Spanish laboratories maintain good capacity for MPXV species-level detection, but clade discrimination-particularly for emerging Clade Ib-remains heterogeneous and suboptimal across participating centers. Expanding QC panels to include new clades and updating/validating assays should enhance national readiness for future transmission events.

The Coronavirus Disease 2019 (COVID-19) pandemic has raised concerns regarding its potential to induce autoimmune responses. Antinuclear antibodies (ANA) are hallmarks of systemic autoimmunity, and emerging evidence suggests their increased prevalence post-infection. This study aimed to assess ANA positivity rates and patterns of distribution before and after the onset of the pandemic in Lombardy, Italy. We conducted a historical analysis of 1879 matched Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) – Reverse Transcription Polymerase Chain Reaction (RT-PCR) and ANA records performed between March 2020 and December 2023. ANA positivity was assessed using indirect immunofluorescence (IIF) on Human Epithelial type 2 (HEp-2) cells and classified according to the International Consensus on ANA Patterns (ICAP). The extracted data were compared to the pre-pandemic period (2019). Cumulative risk analysis and Cox regression were used to evaluate associations among ANA and SARS-CoV-2 exposure, hospitalization, sex, and age. ANA positivity increased during the pandemic (42.4%) compared to 2019 (29.9%, p < 0.00001). Among SARS-CoV-2 positive individuals, ANA positivity was more frequent (12.9% vs 6%, OR: 2.31, p < 0.001). Cox regression confirmed that SARS-CoV-2 infection (HR:1.397), female sex (HR:1.458), hospitalization (HR 5.369) and age (HR:1.003) were independently associated with the risk of ANA positivity. Time-to-event analysis revealed that ANA positivity risk was higher in the first pandemic phases, following original and alfa variants of SARS-CoV-2 infections compared to delta and omicron variants. Nuclear anti-topo I-like [anti-cell (AC)−29] pattern was more prevalent in SARS-CoV-2 positive individuals. SARS-CoV-2 infection is associated with an increased cumulative risk of ANA positivity in the Lombardy population, especially in the earlier phases of the pandemic.

The Epstein-Barr virus (EBV) is associated with a range of diseases, including malignancies and autoimmune disorders. Driven by advances in deep sequencing technologies, recent studies have systematically characterized EBV genomic landscapes in diverse clinical specimens, uncovering distinct geographic patterns in strain distribution. However, a comprehensive understanding of how EBV genomic variation contributes to disease pathogenesis remains incomplete. This review aims to consolidate current knowledge on EBV genomic variation and its role in disease development. First, we delineate the evolutionary origins of EBV genetic variations, focusing on key factors such as replication errors, recombination, and immune-driven selection. Next, we summarize the association between EBV subtypes and diseases, with evidence linking specific genetic variations to malignancies, infectious mononucleosis, and multiple sclerosis. At the mechanistic level, EBV genomic variation may influence pathogenesis through three interconnected mechanisms: viral functional changes, viral–host interactions, and molecular mimicry. Finally, this review explores how genomic insights into EBV can inform clinical applications, including early diagnostic biomarkers and next-generation therapies targeting lineage-specific variations, such as mRNA vaccines and small molecules that disrupt latency. These advances highlight the critical role of EBV genomics in understanding disease mechanisms and developing precision interventions to address the global burden of EBV-related diseases.