Evaluating the Knowledge of and Behavior Toward COVID-19 and the Possibility of Isolating at a City Level: Survey Study.

BACKGROUND: Mass testing campaigns were proposed in France during the first wave of the COVID-19 pandemic to detect and isolate asymptomatic individuals infected by SARS-CoV-2. During mass testing in Saint-Étienne (February 2021), we performed a survey of the general population. OBJECTIVE: We evaluated, on the scale of a city's population, the literacy level about SARS-CoV-2 transmission, barrier gesture respect, and isolation acceptability or possibility in case of SARS-CoV-2 infection. METHODS: We used the validated CovQuest-CC questionnaire. Data were analyzed and correlated with volunteer characteristics and their SARS-CoV-2 screening results using multivariate analysis. RESULTS: In total, 4707 participants completed the CovQuest-CC questionnaire. Multivariate analysis revealed that female sex was a determinant of a higher score of knowledge about SARS-CoV-2 transmission (adjusted ß coefficient=0.14, 95% CI 0.04-0.23; corrected P=.02). Older ages of 50-59 years (adjusted ß coefficient=0.25, 95% CI 0.19-0.31; corrected P<.001) and ≥60 years (adjusted ß coefficient=0.25, 95% CI 0.15-0.34; corrected P<.001) were determinants of a higher score on barrier gesture respect compared to ages 20-49 years considered as reference. Female sex was also a determinant of a higher score on barrier gesture respect (adjusted ß coefficient=0.10, 95% CI 0.02-4.63; corrected P<.001). The knowledge score was correlated with the score on barrier gesture respect measures (adjusted ß coefficient=0.03, 95% CI 0.001-0.004; corrected P=.001). Older ages of 50-59 years (adjusted ß coefficient=0.21, 95% CI 0.13-0.29; corrected P<.001) and ≥60 years (adjusted ß coefficient=0.25, 95% CI 0.1-0.38; corrected P<.001) were determinants of a higher score on isolation acceptability or possibility compared to the age of 20-49 years considered as reference. Finally, the knowledge score regarding SARS-CoV-2 transmission was significantly associated with a lower risk of RT-PCR (reverse transcriptase-polymerase chain reaction) positivity (adjusted odds ratio 0.80, 95% CI 0.69-0.94; corrected P<.03), implying that a 1-point increase in the knowledge score lowers the risk of positivity by 20% on average. CONCLUSIONS: This study identified factors associated with health literacy regarding SARS-CoV-2 infection in asymptomatic individuals in a large French city's population. We can confirm that in the context of the COVID-19 pandemic, the determinants of better health literacy are not the same as those in other contexts. It seems critical to obtain a more detailed understanding of the determinants of individual citizens' behavior, as part of a strategy to combat the large-scale spread of the virus. The harsh experience of this pandemic should teach us how to nurture research to structure customized interventions to encourage the adoption of ad hoc behaviors to engage citizens in adapting behaviors more favorable to their health.

Combining SARS-CoV-2 interferon-gamma release assay with humoral response assessment to define immune memory profiles.

OBJECTIVES: In the post-SARS-CoV-2 pandemic era, "breakthrough infections" are still documented, due to variants of concerns (VoCs) emergence and waning humoral immunity. Despite widespread utilization, the definition of the anti-Spike (S) immunoglobulin-G (IgG) threshold to define protection has unveiled several limitations. Here, we explore the advantages of incorporating T-cell response assessment to enhance the definition of immune memory profile. METHODS: SARS-CoV-2 interferon-gamma release assay test (IGRA) was performed on samples collected longitudinally from immunocompetent healthcare workers throughout their immunization by infection and/or vaccination, anti-receptor-binding domain IgG levels were assessed in parallel. The risk of symptomatic infection according to cellular/humoral immune capacities during Omicron BA.1 wave was then estimated. RESULTS: Close to 40% of our samples were exclusively IGRA-positive, largely due to time elapsed since their last immunization. This suggests that individuals have sustained long-lasting cellular immunity, while they would have been classified as lacking protective immunity based solely on IgG threshold. Moreover, the Cox regression model highlighted that Omicron BA.1 circulation raises the risk of symptomatic infection while increased anti-receptor-binding domain IgG and IGRA levels tended to reduce it. CONCLUSION: The discrepancy between humoral and cellular responses highlights the significance of assessing the overall adaptive immune response. This integrated approach allows the identification of vulnerable subjects and can be of interest to guide antiviral prophylaxis at an individual level.

Human immunodeficiency virus and oral microbiota: mutual influence on the establishment of a viral gingival reservoir in individuals under antiretroviral therapy.

The role of the oral microbiota in the overall health and in systemic diseases has gained more importance in the recent years, mainly due to the systemic effects that are mediated by the chronic inflammation caused by oral diseases, such as periodontitis, through the microbial communities of the mouth. The chronic infection by the human immunodeficiency virus (HIV) interacts at the tissue level (e.g. gut, genital tract, brain) to create reservoirs; the modulation of the gut microbiota by HIV infection is a good example of these interactions. The purpose of the present review is to assess the state of knowledge on the oral microbiota (microbiome, mycobiome and virome) of HIV-infected patients in comparison to that of HIV-negative individuals and to discuss the reciprocal influence of HIV infection and oral microbiota in patients with periodontitis on the potential establishment of a viral gingival reservoir. The influence of different clinical and biological parameters are reviewed including age, immune and viral status, potent antiretroviral therapies, smoking, infection of the airway and viral coinfections, all factors that can modulate the oral microbiota during HIV infection. The analysis of the literature proposed in this review indicates that the comparisons of the available studies are difficult due to their great heterogeneity. However, some important findings emerge: (i) the oral microbiota is less influenced than that of the gut during HIV infection, although some recurrent changes in the microbiome are identified in many studies; (ii) severe immunosuppression is correlated with altered microbiota and potent antiretroviral therapies correct partially these modifications; (iii) periodontitis constitutes a major factor of dysbiosis, which is exacerbated in HIV-infected patients; its pathogenesis can be described as a reciprocal reinforcement of the two conditions, where the local dysbiosis present in the periodontal pocket leads to inflammation, bacterial translocation and destruction of the supporting tissues, which in turn enhances an inflammatory environment that perpetuates the periodontitis cycle. With the objective of curing viral reservoirs of HIV-infected patients in the future years, it appears important to develop further researches aimed at defining whether the inflamed gingiva can serve of viral reservoir in HIV-infected patients with periodontitis.

Factors Contributing to Delayed Return to Work among French Healthcare Professionals Afflicted by COVID-19 at a Hospital in the Rhône-Alpes Region, 2021.

COVID-19 is an emerging disease whose impact on the return to work of hospital staff is not yet known. This study was aimed at evaluating the prevalence of delayed return to work associated with medical, personal, and professional factors in hospital staff who tested positive for COVID-19 during the second epidemic wave. A descriptive, analytical observational study was conducted. The source population consisted of all staff of a French University Hospital Center who had an RT-PCR test or an antigenic test positive for SARS-CoV-2 during the period from 6 September to 30 November 2020. A delayed return to work was defined as a return to work after a period of at least 8 days of eviction, whereas before the eviction period decided by the French government was 14 days. Data collection was carried out through an anonymous online self-questionnaire. The participation rate was 43% (216 participants out of 502 eligible subjects). Moreover, 40% of the staff had a delayed return to work, and 24% of them reported a delayed return to work due to persistent asthenia. Delayed return to work was significantly associated with age, fear of returning to work, and persistent asthenia, but the number of symptoms lasting more than 7 days was the only factor that remained significantly associated after multivariate analysis. From this study, it appears that interest in identifying the number of persistent symptoms as a possible indicator of delayed work emerges. Moreover, persistent asthenia should be given special attention by practitioners to detect a possible long COVID.

Prospective Evaluation of the BD MAX StaphSR Assay for the Screening of Methicillin-Susceptible and -Resistant Staphylococcus aureus from Nasal Swabs Taken in Intensive Care Unit Patients.

Screening patients for S. aureus nasal carriage has proved effective in preventing cross-contamination and endogenous infection with this bacterium. The aim of this study was to assess the performance of the BD MAX StaphSR assay with liquid Amies elution swabs, taken during routine care of intensive care unit patients. Direct and pre-enriched cultures were used as reference methods to screen for S. aureus and methicillin-resistant S. aureus (MRSA). Discrepant results between the BD MAX StaphSR assay and cultures were resolved by using the Xpert SA Nasal Complete assay. A total of 607 nasal swabs taken from 409 patients were included in this study. Compared to culture methods, the sensitivity and specificity of the BD MAX StaphSR assay were 92.5% and 91.7% for S. aureus screening, and 94.7% and 98.3% for MRSA screening, respectively. In 52 (8.6%) specimens, there was a discrepancy between the results of cultures and the BD MAX StaphSR assay, including 13 (25%) where the results of the BD MAX StaphSR assay were confirmed by the Xpert SA Nasal Complete test. This prospective study showed that the BD MAX StaphSR assay is reliable for S. aureus and MRSA detection from nasal samples taken with liquid Amies elution swabs.

Arboviral Risk Associated with Solid Organ and Hematopoietic Stem Cell Grafts: The Prophylactic Answers Proposed by the French High Council of Public Health in a National Context.

Diseases caused by arboviruses are on the increase worldwide. In addition to arthropod bites, most arboviruses can be transmitted via accessory routes. Products of human origin (labile blood products, solid organs, hematopoietic stem cells, tissues) present a risk of contamination for the recipient if the donation is made when the donor is viremic. Mainland France and its overseas territories are exposed to a complex array of imported and endemic arboviruses, which differ according to their respective location. This narrative review describes the risks of acquiring certain arboviral diseases from human products, mainly solid organs and hematopoietic stem cells, in the French context. The main risks considered in this study are infections by West Nile virus, dengue virus, and tick-borne encephalitis virus. The ancillary risks represented by Usutu virus infection, chikungunya, and Zika are also addressed more briefly. For each disease, the guidelines issued by the French High Council of Public Health, which is responsible for mitigating the risks associated with products of human origin and for supporting public health policy decisions, are briefly outlined. This review highlights the need for a "One Health" approach and to standardize recommendations at the international level in areas with the same viral epidemiology.

Ultrafast inactivation of SARS-CoV-2 by 254-nm UV-C irradiation on porous and non-porous media of medical interest using an omnidirectional chamber.

Covid-19 has spurred a renewed interest in decontamination techniques for air, objects and surfaces. Beginning in 2020, urgent effort was done to permit the reuse of UV-C for inactivating SARS-CoV-2. However, those studies diverged widely on the dose necessary to reach this goal; until today, the real value of the sensitivity of the virus to a 254-nm illumination is not known precisely. In this study, decontamination was performed in an original UV-C large decontamination chamber (UVCab, ON-LIGHT, France) delivering an omnidirectional irradiation with an average dose of 50 mJ/cm2 in 60 s. Viral inactivation was checked by both cell culture and PCR test. SARS-CoV-2 was inactivated by UV-C light within 3 s on both porous (disposable gown) and non-porous (stainless steel and apron) surfaces. For the porous surface, an irradiation of 5 min was needed to achieve a completely negative PCR signal. The Z value estimating the sensitivity of SARS-CoV-2 to UV-C in the experimental conditions of our cabinet was shown to be > 0.5820 m2/J. These results illustrate the ability of this apparatus to inactivate rapidly and definitively high loads of SARS-CoV-2 deposited on porous or non-porous supports and opens new perspectives on material decontamination using UV-C.

Extended safety and tolerability of subcutaneous CAP256V2LS and VRC07-523LS in HIV-negative women: study protocol for the randomised, placebo-controlled double-blinded, phase 2 CAPRISA 012C trial.

INTRODUCTION: Women-controlled HIV prevention technologies that overcome adherence challenges of available daily oral pre-exposure prophylaxis and give women a choice of options are urgently needed. Broadly neutralising monoclonal antibodies (bnAbs) administered passively may offer a valuable non-antiretroviral biological intervention for HIV prevention. Animal and human studies have demonstrated that bnAbs which neutralise HIV can prevent infection. The optimal plasma antibody concentrations to confer protection against HIV infection in humans is under intense study. The Centre for the AIDS Programme of Research in South Africa (CAPRISA) 012C trial will evaluate extended safety and pharmacokinetics of CAP256V2LS and VRC07-523LS among young HIV-negative South African and Zambian women. The study design also allows for an evaluation of a signal of HIV prevention efficacy. METHODS AND ANALYSIS: CAPRISA 012 is a series of trials with three distinct protocols. The completed CAPRISA 012A and 012B phase 1 trials provided critical data for the CAPRISA 012C trial, which is divided into parts A and B. In part A, 90 participants were randomised to receive both CAP256V2LS and VRC07-523LS at 20 mg/kg or placebo, subcutaneously every 16 or 24 weeks. Part B will enrol 900 participants in South Africa and Zambia who will be randomised in a 1:1 ratio and receive an initial loading dose of 1.2 g of CAP256V2LS and VRC07-523LS or placebo followed by 600 mg of CAP256V2LS and 1.2 g of VRC07-523LS or placebo subcutaneously every 6 months. Safety will be assessed by frequency and severity of reactogenicity and other related adverse events. Pharmacokinetics of both antibodies will be measured in systemic and mucosal compartments over time, while participants will be monitored for breakthrough HIV infections. ETHICS AND DISSEMINATION OF STUDY FINDINGS: The University of KwaZulu-Natal Biomedical Research Ethics Committee and South African Health Products Regulatory Authority have approved the trial (BREC/00002492/2021, SAHPRA20210317). Results will be disseminated through conference presentations, peer-reviewed publications and the clinical trial registry. TRIAL REGISTRATION NUMBER: PACTR202112683307570.

Determinants of protection against SARS-CoV-2 Omicron BA.1 and Delta infections in fully vaccinated outpatients.

We aimed to evaluate the association between the humoral and cellular immune responses and symptomatic SARS-CoV-2 infection with Delta or Omicron BA.1 variants in fully vaccinated outpatients. Anti-receptor binding domain (RBD) IgG levels and interferon-gamma (IFN-γ) release were evaluated at PCR-diagnosis of SARS-CoV-2 in 636 samples from negative and positive patients during Delta and Omicron BA.1 periods. Median levels of anti-RBD IgG in positive patients were significantly lower than in negative patients for both variants (p < 0.05). The frequency of Omicron BA.1 infection in patients with anti-RBD IgG concentrations ≥1000 binding antibody units (BAU)/mL was 51.0% and decreased to 34.4% in patients with concentrations ≥3000 BAU/mL. For Delta infection, the frequency of infection was significantly lower when applying the same anti-RBD IgG thresholds (13.3% and 5.3% respectively, p < 0.05). In addition, individuals in the hybrid immunity group had a 4.5 times lower risk of Delta infection compared to the homologous vaccination group (aOR = 0.22, 95% CI: [0.05-0.64]. No significant decrease in the risk of Omicron BA.1 infection was observed in the hybrid group compared to the homologous group, but the risk decreased within the hybrid group as anti-RBD IgG titers increased (aOR = 0.08, 95% CI: [0.01-0.41], p = 0.008). IFN-γ release post-SARS-CoV-2 peptide stimulation was not different between samples from patients infected (either with Delta or Omicron BA.1 variant) or not (p > 0.05). Our results show that high circulating levels of anti-RBD IgG and hybrid immunity were independently associated with a lower risk of symptomatic SARS-CoV-2 infection in outpatients with differences according to the infecting variant (www.clinicaltrials.gov; ID NCT05060939).

Long-term humoral response following Delta and Omicron BA.1 co-infection.

This study reports the 6-month humoral immune response in vaccinated patients concomitantly infected with Delta and Omicron BA.1 variants of SARS-CoV-2. Interestingly, the simultaneous exposure to the Delta and BA.1 S proteins does not confer an additional immune advantage compared to exposure to the BA.1 S protein alone.

A third vaccine dose equalises the levels of effectiveness and immunogenicity of heterologous or homologous COVID-19 vaccine regimens, Lyon, France, December 2021 to March 2022.

BackgroundTo cope with the persistence of the COVID-19 epidemic and the decrease in antibody levels following vaccination, a third dose of vaccine has been recommended in the general population. However, several vaccine regimens had been used initially for the primary vaccination course, and the heterologous Vaxzevria/Comirnaty regimen had shown better efficacy and immunogenicity than the homologous Comirnaty/Comirnaty regimen.AimWe wanted to determine if this benefit was retained after a third dose of an mRNA vaccine.MethodsWe combined an observational epidemiological study of SARS-CoV-2 infections among vaccinated healthcare workers at the University Hospital of Lyon, France, with a prospective cohort study to analyse immunological parameters before and after the third mRNA vaccine dose.ResultsFollowing the second vaccine dose, heterologous vaccination regimens were more protective against infection than homologous regimens (adjusted hazard ratio (HR) = 1.88; 95% confidence interval (CI): 1.18-3.00; p = 0.008), but this was no longer the case after the third dose (adjusted HR = 0.86; 95% CI: 0.72-1.02; p = 0.082). Receptor-binding domain-specific IgG levels and serum neutralisation capacity against different SARS-CoV-2 variants were higher after the third dose than after the second dose in the homologous regimen group, but not in the heterologous group.ConclusionThe advantage conferred by heterologous vaccination was lost after the third dose in terms of both protection and immunogenicity. Immunological measurements 1 month after vaccination suggest that heterologous vaccination induces maximal immunity after the second dose, whereas the third dose is required to reach the same level in individuals with a homologous regimen.

[Viruses present in the environment: virological considerations and examples of their impact on human health]. / Les virus dans l'environnement, considérations virologiques et exemples de leur impact en santé humaine.

Animal viruses are present in most human environments. Their viability in these media is very variable and the most important element that conditions this viability is the existence or not of a phospholipid envelope surrounding the nucleocapsid. After some general considerations on the structure of viruses, their multiplication cycle and their resistance to different physico-chemical agents, some examples of the impact of animal viruses present in the environment on human health will be presented. The situations that are related concern recent epidemiological events: circulation of type 2 polioviruses derived from the Sabin vaccine strain in the wastewater of New York, London and Jerusalem; risk of transmission of Sars-CoV-2 during the spreading of sludge from wastewater treatment plants on agricultural land in the era of the Covid-19 pandemic; « new ¼ forms of food-borne poisoning of viral origin (hepatitis E, tick-borne encephalitis, Nipah virus infection); contamination by epidemic viruses of mobile phones used by pediatricians; role of fomites in the spread of orthopoxvirus infections (smallpox, cowpox, monkeypox). The risk attached to animal viruses present in the environment must be assessed in a measured way without overestimating or underestimating their potential consequences for human health.

Staphylococcus aureus nasal colonization level and intracellular reservoir: a prospective cohort study.

Staphylococcus aureus is a major pathogen in humans. The nasal vestibule is considered as the main reservoir of S. aureus. However, even though the nasal cavity may also be colonized by S. aureus, the relationships between the two sites are still unclear. We conducted a prospective study in humans to assess the S. aureus colonization profiles in the vestibule and nasal cavity, and to investigate the presence of intracellular S. aureus in the two sites. Patients undergoing ear, nose, and throat surgery were swabbed during endoscopy to determine S. aureus nasal load, genotype, and presence of intracellular S. aureus. Among per-operative samples from 90 patients, the prevalence of S. aureus carriage was 32.2% and 33.3% in the vestibule and the nasal cavity, respectively. The mean S. aureus load was 4.10 and 4.25 log10 CFU/swab for the nasal vestibule and nasal cavity, respectively (P > 0.05). Genotyping of S. aureus revealed that all nasal strains isolated from a given individual belong to the same clonal complex and spa-type. An intracellular carriage was observed in 5.6% of the patients, all of whom exhibited a S. aureus vestibule load higher than 3 log10 CFU/swab. An intracellular niche was observed in the vestibule as well as in the nasal cavity. In conclusion, the nasal cavity was also found to be a major site of S. aureus carriage in humans and should draw attention when studying host-pathogen interactions related to the risk of infection associated with colonization.

Prior SARS-CoV-2 infection enhances and reshapes spike protein-specific memory induced by vaccination.

The diversity of vaccination modalities and infection history are both variables that have an impact on the immune memory of individuals vaccinated against SARS-CoV-2. To gain more accurate knowledge of how these parameters imprint on immune memory, we conducted a long-term follow-up of SARS-CoV-2 spike protein-specific immune memory in unvaccinated and vaccinated COVID-19 convalescent individuals as well as in infection-naïve vaccinated individuals. Here, we report that individuals from the convalescent vaccinated (hybrid immunity) group have the highest concentrations of spike protein-specific antibodies at 6 months after vaccination. As compared with infection-naïve vaccinated individuals, they also display increased frequencies of an atypical mucosa-targeted memory B cell subset. These individuals also exhibited enhanced TH1 polarization of their SARS-CoV-2 spike protein-specific follicular T helper cell pool. Together, our data suggest that prior SARS-CoV-2 infection increases the titers of SARS-CoV-2 spike protein-specific antibody responses elicited by subsequent vaccination and induces modifications in the composition of the spike protein-specific memory B cell pool that are compatible with enhanced functional protection at mucosal sites.

Effect of Non-Surgical Periodontal Therapy on Clinical Parameters of Periodontitis, Oral Candida spp. Count and Lactoferrin and Histatin Expression in Saliva and Gingival Crevicular Fluid of HIV-Infected Patients.

BACKGROUND: Periodontitis (PDT) has gained attention in the literature with the increase in life expectancy of people living with HIV on combined antiretroviral therapy (cART). Thus, the search for inflammatory biomarkers could be useful to understand the pathophysiology of chronic oral diseases in the cART era. OBJECTIVE: The aim of this study was to evaluate the impact of non-surgical periodontal therapy (NSPT) on clinical parameters of PDT, Candida spp. count and expression of lactoferrin (LF) and histatin (HST) in saliva and gingival crevicular fluid (GCF) of HIV-infected patients. METHODS: Bleeding index (BI), probing depth (PD), clinical attachment level (CAL), colonyforming units (CFUs) of Candida spp, and LF and HST levels were measured in saliva and GCF of both groups at three different times: baseline (before treatment), and 30 and 90 days after the NSPT. Clinical, mycological and immunoenzymatic analyses were also performed. RESULTS: Twenty-two HIV-infected patients and 25 non-HIV-infected patients with PDT participated in the study. NSPT was effective in improving periodontal clinical parameters, including ≤ 4 sites with PD ≤ 5mm and BI ≤ 10%. Significant change in oral Candida spp. count occurred neither between the two groups nor after NSPT. And the salivary and GCF levels of LF and HST were not influenced by the NSPT; by contrast, except for salivary LF, HST and LF were shown to exhibit significantly higher levels in HIV-infected than in non-HIV-infected patients. CONCLUSION: NSPT was effective in improving periodontal disease parameters in HIV-infected patients, but did not affect LF and HST expression in saliva and GCF of HIV-infected patients.

Monitoring of Both Humoral and Cellular Immunities Could Early Predict COVID-19 Vaccine Efficacy Against the Different SARS-CoV2 Variants.

Reliable immunoassays are essential to early predict and monitor vaccine efficacy against SARS-CoV-2. The performance of an Interferon Gamma Release Assay (IGRA, QuantiFERON® SARS-CoV-2), and a current anti-spike serological test, compared to a plaque reduction neutralization test (PRNT) taken as gold standard were compared. Eighty vaccinated individuals, whose 16% had a previous history of COVID-19, were included in a longitudinal prospective study and sampled before and two to four weeks after each dose of vaccine. In non-infected patients, 2 doses were required for obtaining both positive IGRA and PRNT assays, while serology was positive after one dose. Each dose of vaccine significantly increased the humoral and cellular response. By contrast, convalescent subjects needed a single dose of vaccine to be positive on all 3 tests. Both IGRA and current serology assay were found predictive of a positive titer of neutralizing antibodies that is correlated with vaccine protection. Patients over 65 or 80 years old had a significantly reduced response. The response tended to be better with the heterologous scheme (vs. homologous) and with the mRNA-1273 vaccine (vs. BNT162b2) in the homologous group, in patients under 55 and under 65 years old, respectively. Finally, decrease intensity or absence of IGRA response and to a less extent of anti-spike serology were also correlated to reinfection which has occurred during the follow up. In conclusion, both IGRA and current anti-spike serology assays could be used at defined thresholds to monitor the vaccine response against SARS-CoV-2 and to simply identify non-responding individuals after a complete vaccination scheme. Two available specific tests (IGRA and anti-spike antibodies) could early assess the vaccine-induced immunity against SARS-CoV-2 at the individual scale, to potentially adapt the vaccination scheme in non-responder patients.

Impact of Dextran-Sodium-Sulfate-Induced Enteritis on Murine Cytomegalovirus Reactivation.

(1) Background: Ulcerative colitis (UC) is an inflammatory bowel disease that causes inflammation of the intestines, which participates in human cytomegalovirus (HCMV) reactivation from its latent reservoir. CMV-associated colitis plays a pejorative role in the clinical course of UC. We took advantage of a model of chemically induced enteritis to study the viral reactivation of murine CMV (MCMV) in the context of gut inflammation. (2) Methods: Seven-week-old BALB/c mice were infected by 3 × 103 plaque-forming units (PFU) of MCMV; 2.5% (w/v) DSS was administered in the drinking water from day (D) 30 to D37 post-infection to induce enteritis. (3) Results: MCMV DNA levels in the circulation decreased from D21 after infection until resolution of the acute infection. DSS administration resulted in weight loss, high disease activity index, elevated Nancy index shortening of the colon length and increase in fecal lipocalin. However, chemically induced enteritis had no impact on MCMV reactivation as determined by qPCR and immunohistochemistry of intestinal tissues. (4) Conclusions: Despite the persistence of MCMV in the digestive tissues after the acute phase of infection, the gut inflammation induced by DSS did not induce MCMV reactivation in intestinal tissues, thus failing to recapitulate inflammation-driven HCMV reactivation in human UC.

Evaluation of Rapid Lateral-Flow Tests Directed against the SARS-CoV-2 Nucleoprotein Using Viral Suspensions Belonging to Different Lineages of SARS-CoV-2.

Within the successive waves that occurred during the SARS-CoV-2 pandemic, recommendations arose to test symptomatic and contact subjects by using rapid antigen devices directed against the viral nucleocapsid protein with the aim to isolate contagious patients without delay. The objective of this study was to evaluate the ability of four rapid lateral-flow tests (RLFT) that were commercially available on the French market in 2022 to recognize various strains of SARS-CoV-2. Series of five-fold dilutions of seven viral suspensions belonging to different lineages of SARS-CoV-2 (19A, 20A, Alpha, Beta, Gamma, Delta and Omicron) were used to evaluate the analytical sensitivity of four commercially available RLFTs (manufacturers: Abbott, AAZ, Becton-Dickinson and Biospeedia). Cell culture and quantitative RT-PCR were used as references. Excellent correlations were observed for each lineage strain between the viral titer obtained via cell culture and the number of RNA copies measured by quantitative RT-PCR. Although the four tests were able to recognize all the tested variants, significant differences in terms of sensitivity were observed between the four RLFTs. Despite the limitation represented by the small number of devices and clinical isolates that were tested, this study contributed by rapidly comparing the sensitivity of SARS-CoV-2 RLFTs in the Omicron era.

Evaluation of the BL-RED (Beta-Lactamase Rapid Electrochemical Detection) test for the rapid detection of resistance to third-generation cephalosporins in Enterobacteriaceae.

The sensitivity of NG-test CTX-M Multi assay and BL-RED test incubated 10 min for the detection of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae was 80.6% and 90.3% respectively. Using an extended 60 min incubation with the BL-RED test, its sensitivity was increased to 100% and 60.9% for ESBL-producing and cephalosporinase-overexpressing Enterobacteriaceae respectively.