Journal of Infectious Diseases最新文献

Background: Bacterial vaginosis (BV) is a condition marked by high vaginal bacterial diversity. Gardnerella vaginalis has been implicated in BV but is also detected in healthy women. The Gardnerella genus has been expanded to encompass 6 validly named species and several genomospecies. We hypothesized that particular Gardnerella species may be more associated with BV.

Methods: Quantitative polymerase chain reaction (PCR) assays were developed targeting the cpn60 gene of species groups including G. vaginalis, G. piotii/pickettii, G. swidsinskii/greenwoodii, and G. leopoldii. These assays were applied to vaginal swabs from individuals with (n = 101) and without BV (n = 150) attending a sexual health clinic in Seattle, Washington. Weekly swabs were collected from 42 participants for up to 12 weeks.

Results: Concentrations and prevalence of each Gardnerella species group were significantly higher in participants with BV; 91.1% of BV-positive participants had 3 or more Gardnerella species groups detected compared to 32.0% of BV-negative participants (P < .0001). BV-negative participants with 3 or more species groups detected were more likely to develop BV within 100 days versus those with fewer (60.5% vs 3.7%, P < .0001).

Conclusions: These results suggest that BV reflects a state of high Gardnerella species diversity. No Gardnerella species group was a specific marker for BV.

Background: "Zero-dose" children are those who are without any routine vaccination or are lacking the first dose of the diphtheria, tetanus, and pertussis-containing vaccine. Based on global estimates from the World Health Organization/United Nations Children's Fund in 2022, Nigeria has the highest number of zero-dose children, with >2.3 million unvaccinated.

Methods: We used data from the 2021 Nigeria Multiple Indicator Cluster Survey/National Immunization Coverage Survey to identify zero-dose and underimmunized children. Geospatial modeling techniques were employed to determine the prevalence of zero-dose children and predict risk areas with underimmunized children at a high resolution (1 × 1 km).

Results: Zero-dose and underimmunized children are more prevalent in socially deprived groups. Univariate and multivariate bayesian analyses showed positive correlations between the prevalence of zero-dose and underimmunized children and factors such as stunting, contraceptive prevalence, and literacy. The prevalence of zero-dose and underimmunized children varies significantly by region and ethnicity, with higher rates observed in the country's northern parts. Significant heterogeneity in the distribution of undervaccinated children was observed.

Conclusions: Nigeria needs to enhance its immunization system and coverage. Geospatial modeling can help deliver vaccines effectively to underserved communities. By adopting this approach, countries can ensure equitable vaccine access and contribute to global vaccination objectives.

Dysbiosis of the vaginal microbiome poses a serious risk for sexual human immunodeficiency virus type 1 (HIV-1) transmission. Prevotella spp are abundant during vaginal dysbiosis and associated with enhanced HIV-1 susceptibility; however, underlying mechanisms remain unclear. Here, we investigated the direct effect of vaginal bacteria on HIV-1 susceptibility of vaginal CD4+ T cells. Notably, pre-exposure to Prevotella timonensis enhanced HIV-1 uptake by vaginal T cells, leading to increased viral fusion and enhanced virus production. Pre-exposure to antiretroviral inhibitors abolished P timonensis-enhanced infection. Our study shows that the vaginal microbiome directly affects mucosal CD4+ T-cell susceptibility, emphasizing importance of vaginal dysbiosis diagnosis and treatment.

Background: Atypical/Nor98 scrapie (AS) is an idiopathic infectious prion disease affecting sheep and goats. Recent findings suggest that zoonotic prions from classical bovine spongiform encephalopathy (C-BSE) may copropagate with atypical/Nor98 prions in AS sheep brains. Investigating the risk AS poses to humans is crucial.

Methods: To assess the risk of sheep/goat-to-human transmission of AS, we serially inoculated brain tissue from field and laboratory isolates into transgenic mice overexpressing human prion protein (Met129 allele). We studied clinical outcomes as well as presence of prions in brains and spleens.

Results: No transmission occurred on the primary passage, with no clinical disease or pathological prion protein in brains and spleens. On subsequent passages, 1 isolate gradually adapted, manifesting as prions with a phenotype resembling those causing MM1-type sporadic Creutzfeldt-Jakob disease in humans. However, further characterization using in vivo and in vitro techniques confirmed both prion agents as different strains, revealing a case of phenotypic convergence. Importantly, no C-BSE prions emerged in these mice, especially in the spleen, which is more permissive than the brain for C-BSE cross-species transmission.

Conclusions: The results obtained suggest a low zoonotic potential for AS. Rare adaptation may allow the emergence of prions phenotypically resembling those spontaneously forming in humans.

Background: We aimed to analyze the clinical characteristics of peripheral Epstein-Barr virus (EBV)-infected lymphocyte subtypes in children with chronic active EBV infection (CAEBV).

Methods: The levels of peripheral EBV infection of CD4+ T cells, CD8+ T cells, and CD56+ natural killer (NK) cells were determined by flow cytometry and quantitative polymerase chain reaction (qPCR) in patients with CAEBV from July 2017 to July 2022.

Results: In total, 112 children with CAEBV were evaluated. Of these, CD4+ type, CD8+ type, and CD56+ type were defined in 44, 21, and 47 patients, respectively. Patients with CD8+ T-cell type had a significantly higher frequency of rash, while hepatomegaly was more common in patients with CD4+ T-cell type. Generally, patients with CD8+ T-cell type had the lowest overall survival rate (P = .017). Patients treated with chemotherapy and hematopoietic stem cell transplantation (HSCT) had a better prognosis (P = .001). In multivariate analysis, rash, hemophagocytic lymphohistiocytosis, CD8+ T-cell type, and no decrease of plasma EBV-DNA after treatment were independent indicators of poor prognosis (P = .002, .024, .022, and .012, respectively).

Conclusions: In children with CAEBV, rash was more frequent in patients with CD8+ T-cell type, whereas patients with CD4+ T-cell type were more likely to develop hepatomegaly. Patients with CD8+ T-cell type had a poor prognosis despite receiving chemotherapy or further HSCT.

Background: The association between low-frequency human immunodeficiency virus type 1 (HIV-1) drug resistance mutations (DRMs) and treatment failure (TF) is controversial. We explore this association using next-generation sequencing (NGS) methods that accurately sample low-frequency DRMs.

Methods: We enrolled women with HIV-1 in Malawi who were either antiretroviral therapy (ART) naive (cohort A), had ART failure (cohort B), or had discontinued ART (cohort C). At entry, cohorts A and C began a nonnucleoside reverse transcriptase inhibitor-based regimen and cohort B started a protease inhibitor-based regimen. We used Primer ID MiSeq to identify regimen-relevant DRMs in entry and TF plasma samples, and a Cox proportional hazards model to calculate hazard ratios (HRs) for entry DRMs. Low-frequency DRMs were defined as ≤20%.

Results: We sequenced 360 participants. Cohort B and C participants were more likely to have TF than cohort A participants. The presence of K103N at entry significantly increased TF risk among A and C participants at both high and low frequency, with HRs of 3.12 (95% confidence interval [CI], 1.58-6.18) and 2.38 (95% CI, 1.00-5.67), respectively. At TF, 45% of participants showed selection of DRMs while in the remaining participants there was an apparent lack of selective pressure from ART.

Conclusions: Using accurate NGS for DRM detection may benefit an additional 10% of patients by identifying low-frequency K103N mutations.

The coronavirus disease 2019 (COVID-19) pandemic has been called the deadliest disease event in history. In this study, we compared the cause-specific mortality rate of the Spanish flu (1918-1920) with that of COVID-19 (2020-2022) in the Netherlands. During the periods of exposure, about 50 000 people died of COVID-19 and 32 000 people of the Spanish flu. In absolute numbers, COVID-19 seems to be deadlier than Spanish flu. However, the crude mortality rates for COVID-19 and Spanish flu were 287 and 486 per 100 000 inhabitants, respectively. Comparing age-standardized mortality rates, there would have been 28 COVID-19- and 194 Spanish flu-related deaths in 1918-1920, or 214 Spanish flu- and 98 COVID-19-related deaths in 2020-2022 per 100 000 inhabitants per year. Thus, taking the population differences into account, the Spanish flu would have been deadlier than COVID-19.

Regulatory T (Treg) cells are involved in the antiviral immune response in patients with coronavirus disease 2019 (COVID-19); however, whether Treg cells are involved in the neutralizing antibody (nAb) response remains unclear. Here, we found that individuals who recovered from mild but not severe COVID-19 had significantly greater frequencies of Treg cells and lower frequencies of CXCR3+ circulating T follicular helper (cTfh) cells than healthy controls. Furthermore, the frequencies of Treg and CXCR3+ cTfh cells were negatively and positively correlated with the nAb responses, respectively, and Treg cells was inversely associated with CXCR3+ cTfh cells in individuals who recovered from mild COVID-19 but not in those with severe disease. Mechanistically, Treg cells inhibited memory B-cell differentiation and antibody production by limiting the activation and proliferation of cTfh cells, especially CXCR3+ cTfh cells, and functional molecule expression. This study provides novel insight showing that mild COVID-19 elicits concerted nAb responses, which are shaped by both Treg and Tfh cells.

The subtilisin-like protease-1 (SspA-1) plays an important role in the pathogenesis of a highly virulent strain of Streptococcus suis 2. However, the mechanism of SspA-1-triggered excessive inflammatory response is still unknown. In this study, we demonstrated that activation of type I IFN signaling is required for SspA-1-induced excessive proinflammatory cytokine production. Further experiments showed that the TLR2 endosomal pathway mediates SspA-1-induced type I IFN signaling and the inflammatory response. Finally, we mapped the major signaling components of the related pathway and found that the TIR adaptor proteins Mal, TRAM, and MyD88 and the downstream activation of IRF1 and IRF7 were involved in this pathway. These results explain the molecular mechanism by which SspA-1 triggers an excessive inflammatory response and reveal a novel effect of type I IFN in S. suis 2 infection, possibly providing further insights into the pathogenesis of this highly virulent S. suis 2 strain.

Background: A human immunodeficiency virus (HIV) outbreak was identified among people who inject drugs (PWID) in Glasgow in 2015, with >150 diagnoses by the end of 2019. The outbreak response involved scaling up HIV testing and improving HIV treatment initiation and retention.

Methods: We parameterized and calibrated a dynamic, deterministic model of HIV transmission among PWID in Glasgow to epidemiological data. We use this model to evaluate HIV testing and treatment interventions. We present results in terms of relative changes in HIV prevalence, incidence, and cases averted.

Results: If the improvements in both testing and treatment had not occurred, we predict that HIV prevalence would have reached 17.8% (95% credible interval [CrI], 14.1%-22.6%) by the beginning of 2020, compared to 5.9% (95% CrI, 4.7%-7.4%) with the improvements. If the improvements had been made on detection of the outbreak in 2015, we predict that peak incidence would have been 26.2% (95% CrI, 8.8%-49.3%) lower and 62.7% (95% CrI, 43.6%-76.6%) of the outbreak cases could have been averted. The outbreak could have been avoided if the improvements had already been in place.

Conclusions: Our modeling suggests that the HIV testing and treatment interventions successfully brought the HIV outbreak in Glasgow under control by the beginning of 2020.