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 β coefficient=0.14, 95% CI 0.04-0.23; corrected P=.02). Older ages of 50-59 years (adjusted β coefficient=0.25, 95% CI 0.19-0.31; corrected P<.001) and ≥60 years (adjusted β 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 β 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 β coefficient=0.03, 95% CI 0.001-0.004; corrected P=.001). Older ages of 50-59 years (adjusted β coefficient=0.21, 95% CI 0.13-0.29; corrected P<.001) and ≥60 years (adjusted β 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.

Vaccines for healthcare associated infections without vaccine prevention to date

In spite of the widespread implementation of preventive strategies, the prevalence of healthcare-associated infections (HAIs) remains high. The prevalence of multidrug resistant organisms is high in HAIs. In 2019, the World Health Organization retained antimicrobial resistance as one of the ten issues for global health. The development of vaccines may contribute to the fight against antimicrobial resistance to reduce the burden of HAIs. Staphylococcus aureus, Gram negative bacteria and Clostridium difficile are the most frequent pathogens reported in HAIs. Consequently, the development of vaccines against these pathogens is crucial. At this stage, the goal of obtaining effective vaccines against S.aureus and Gram negative bacteria has not yet been achieved. However, we can expect in the near future availability of a vaccine against C. difficile. In addition, identifying populations who may benefit from these vaccines is complex, as at-risk patients are not great responders to vaccines, or as vaccination may occur too late, when they are already confronted to the risk. Vaccinating healthcare workers (HCWs) against these pathogens may have an impact only if HCWs play a role in the transmission and in the pathogens acquisition in patients, if the vaccine is effective to reduce pathogens carriage and if vaccine coverage is sufficient to protect patients. Acceptance of these potential vaccines should be evaluated and addressed in patients and in HCWs.

Development and Validation of the COVID-19 Knowledges and Behavior Questionnaire in a French Population (CoVQuest-CC)

Background: The SARS-CoV-2 pandemic has led most countries to take restrictive measures affecting social activities and individual freedoms to limit viral transmission. It was shown that practical, motivational and social barriers impact on adherence to the isolation and social distancing measures advocated by the health authorities. The purpose of this study was to develop and validate a COVID-19 Knowledges and Behavior Questionnaire adapted to a teenager and adult French population. Methods: CoVQuest-CC was developed by a multidisciplinary team made of infectious diseases physicians, medical virologist, specialists of infectious control, experts of the questionnaires methodology, experts in public health and prevention, and statisticians. CoVQuest-CC was responded to by a big cohort from the general population during their participation in a massive SARS-CoV-2 screening campaign in 2021 in Saint-Etienne, France. Results: The confirmatory factorial analysis yielded good results (CFI = 0.94, TLI = 0.94, RMSEA = 0.04), and confirmed the five-dimensional structure of the questionnaire. Each dimension had a satisfying internal consistency, with Cronbach alphas of 0.83, 0.71, 0.65, 0.72 and 0.83 for transmission knowledge, barrier gesture respect, tests acceptability, home isolation possibility and test practicability, respectively. Conclusions: According to our knowledge, CoVQuest-CC is the first validated, consistent and reliable self-administrated French-specific questionnaire investigating the general population’s knowledge and attitudes towards COVID-19. It shows acceptable psychometric properties and can be use by Public Health teams or caregivers for public health and research purposes. Trial Registration: The study protocol was approved by the IRB ILE-DE-FRANCE 1 (No. IRB: I ORG0009918). All participants were given written and verbal information about the study and gave informed consent to participate. ClinicalTrials.gov identifier (NCT number): NCT04859023.

COVID-19 in health-care workers: lessons from SARS and MERS epidemics and perspectives for chemoprophylaxis and vaccines

Introduction: The world is now facing the COVID-19 pandemic. Experience with SARS-CoV and MERS-CoV, and early reports about SARS-CoV-2 infection suggest that health-care settings and health-care workers (HCWs) are vulnerable in the context of the emergence of a new coronavirus. Areas covered: To highlight the need for prophylactic strategies particularly for HCWs, we identified SARS-CoV, MERS-CoV, and SARS-CoV-2 outbreaks in health-care settings and the incidence of infections in HCWs by a search on MEDLINE and MEDxRIV (for SARS-Cov-2). To identify prophylactic strategies against, we conducted a search on MEDLINE and clinicaltrials.gov about studies involving SARS-CoV, MERS-CoV, and SARS-CoV-2. Expert opinion: HCWs account for a great part of SARS, MERS, and SARS-CoV-2 infections, they may also contribute to the spread of the disease, particularly in health-care settings, and contribute to nosocomial outbreaks. Some preventive strategies were evaluated in previous emerging coronavirus epidemics, particularly in MERS-CoV. For COVID-19 prevention, different chemoprophylaxis with drug repositioning and new agents are under evaluation, and different vaccine candidates entered clinical development, with clinical trials. HCWs are a crucial target population for pre-exposure and post-exposure prophylaxis.

SARS-CoV-2 infection: advocacy for training and social distancing in healthcare settings

This article reports the observed rate of infection with severe acute respiratory syndrome coronavirus-2 in healthcare workers (HCWs) who worked on wards dedicated to care of patients with coronavirus disease 2019 (COVID-19) compared with HCWs who worked on non-COVID-19 wards. The infection rate was significantly higher among HCWs who worked on non-COVID-19 wards (odds ratio 2.3, P=0.005), illustrating the need to strengthen social distancing measures and training.

Interplay of nasal and rectal carriage of Staphylococcus aureus in intensive care unit patients

The aim of this study was to investigate the relationship between nasal and rectal Staphylococcus aureus carriage in intensive care unit (ICU) patients and the occurrence of ICU-acquired infections related to S. aureus carriage. Three hundred and ninety-five patients admitted in ICU were screened for S. aureus nasal and rectal carriages and followed to record S. aureus infections during their stay. S. aureus strains were genotyped by arbitrarily primed PCR, spa-typing, microarray and whole genome sequencing. At ICU admission, 112 of 363 (30.9%) patients carried S. aureus including 61 (16.8%) exclusive nasal carriers, 40 (11.0%) combined nasal and rectal carriers and 11 (3.0%) exclusive rectal carriers. The 152 S. aureus isolates from nasal and rectal swabs belonged to 19 clonal complexes (CCs). Patients colonized in both nose and rectum harboured different strains in at least 40% of cases according to arbitrarily primed PCR data. Nasal carriers of CC5 S. aureus had an increased risk of rectal carriage (RR = 1.85, P < .05). S. aureus nasal and rectal carriage was a risk factor of S. aureus ICU-acquired infection (RR = 4.04; 95%CI [1.38-11.76]). Incidence rates of endogenous ICU-acquired infections in exclusive nasal carriers, exclusive rectal carriers and in both nasal and rectal carriers were 0.08 (5/61), 0.09 (1/11) and 0.03 (1/40), respectively (p = 0.47). Rectal swabbing increased the detection of S. aureus carriage and revealed an important diversity of S. aureus strains in ICU patients. Further studies are needed to understand how S. aureus rectal carriage increases the risk of endogenous ICU-acquired infections.

Epidemiology and clinical relevance of Staphylococcus aureus intestinal carriage: a systematic review and meta-analysis

INTRODUCTION

Recent data highlight the importance of screening more than one site for improving the detection of S. aureus colonization. Intestinal carriage is frequently under-investigated and its clinical impact ought to be defined a better way. Areas covered: This review and meta-analysis provide an updated overview of prevalence, characteristics and clinical significance of S. aureus intestinal carriage in different populations, both for methicillin-susceptible and -resistant S. aureus strains. Expert commentary: Intestinal S. aureus carriage is documented with higher prevalence in children and in patients with S. aureus skin and soft tissue infections. This site of colonization was shown to be associated with a high risk of dissemination in the environment and with S. aureus infection. Intestinal carriage is frequently retrieved in nasal carriers, reflecting probably an association with a high bacterial load. Exclusive intestinal carriage present in one third of intestinal carriers can be associated with infection. Comparative genotyping analysis of different strains from nasal and extra-nasal sites of carriage, including the intestinal ones, in the same individuals, would allow a better comprehension of the pathophysiology of S. aureus endogenous infection. It could also permit to improve the prevention of these infections by decolonization of sites implicated in infection genesis.

Carbapenemase-producing Acinetobacter baumannii: An outbreak report with special highlights on economic burden

OBJECTIVE

We aimed to describe the management of a carbapenemase-producing Acinetobacter baumannii (CP-AB) outbreak using the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement. We also aimed to evaluate the cost of the outbreak and simulate costs if a dedicated unit to manage such outbreak had been set-up.

METHODS

We performed a prospective epidemiological study. Multiple interventions were implemented including cohorting measures and limitation of admissions. Cost estimation was performed using administrative local data.

RESULTS

Five patients were colonized with CP-AB and hospitalized in the neurosurgery ward. The index case was a patient who had been previously hospitalized in Portugal. Four secondary colonized patients were further observed within the unit. The strains of A. baumannii were shown to belong to the same clone and all of them produced an OXA-23 carbapenemase. The closure of the ward associated with the discharge of the five patients in a cohorting area of the Infectious Diseases Unit with dedicated staff put a stop to the outbreak. The estimated cost of this 17-week outbreak was $474,474. If patients had been managed in a dedicated unit - including specific area for cohorting of patients and dedicated staff - at the beginning of the outbreak, the estimated cost would have been $189,046.

CONCLUSION

Controlling hospital outbreaks involving multidrug-resistant bacteria requires a rapid cohorting of patients. Using simulation, we highlighted cost gain when using a dedicated cohorting unit strategy for such an outbreak.

Decolonization of Staphylococcus aureus carriage

Staphylococcus aureus nasal colonization is a well-known independent risk factor for infection caused by this bacterium. Screening and decolonization of carriers have been proven effective in reducing S. aureus infections in some populations. However, a gap remains between what has been proven effective and what is currently done. We aimed to summarize recommendations and current knowledge of S. aureus decolonization to answer the following questions: Why? For whom? How? When? And what are the perspectives?

Identifying Hemodialysis Patients With the Highest Risk of Staphylococcus aureus Endogenous Infection Through a Simple Nasal Sampling Algorithm

In contrast to Staphylococcus aureus intermittent nasal carriers, persistent ones have the highest risk of infection. This study reports the usefulness of a simple nasal sampling algorithm to identify the S. aureus nasal carriage state of hemodialysis patients (HPs) and their subsequent risk of infection.From a cohort of 85 HPs, 76 were screened for S. aureus nasal carriage once a week during a 10-week period. The S. aureus nasal load was quantified by using either culture on chromogenic medium or fully automated real-time polymerase chain reaction assay. Molecular typing was used to compare strains from carriage and infection.The algorithm based on quantitative cultures was able to determine the status of S. aureus nasal carriage with a sensitivity of 95.8%, a specificity of 94.2%, a positive predictive value of 88.5%, and a negative predictive value of 98.0%. Of note, the determination of the S. aureus carriage state was obtained on the first nasal sample for all the 76 HPs, but 1 (98.7%). The algorithm based on quantitative polymerase chain reaction assay directly from the specimen yielded similar performances. During the 1-year follow-up after the last sampling episode, HPs classified as persistent nasal carriers with the algorithm were found to have a higher risk of S. aureus infection than those classified as nonpersistent carriers (P < 0.05), especially for infections of endogenous origin (P < 0.001).This simple algorithm is reliable for determining the S. aureus nasal carriage status in clinical practice and could contribute to characterize at an early stage of take-up patients with the highest risk of S. aureus infection.

Molecular dynamics of Staphylococcus aureus nasal carriage in Hajj pilgrims

During the 2012 Hajj season, the risk of acquisition of Staphylococcus aureus nasal carriage in a cohort of French pilgrims was 22.8%, and was statistically associated with the acquisition of viral respiratory pathogens (p 0.03). The carriage of S. aureus belonging to the emerging clonal complex 398 significantly increased following the pilgrimage (p < 0.05).

Delta-toxin production deficiency in Staphylococcus aureus: a diagnostic marker of bone and joint infection chronicity linked with osteoblast invasion and biofilm formation

Biofilm formation, intra-osteoblastic persistence, small-colony variants (SCVs) and the dysregulation of agr, the major virulence regulon, are possibly involved in staphylococcal bone and joint infection (BJI) pathogenesis. We aimed to investigate the contributions of these mechanisms among a collection of 95 Staphylococcus aureus clinical isolates from 64 acute (67.4%) and 31 chronic (32.6%) first episodes of BJI. The included isolates were compared for internalization rate, cell damage and SCV intracellular emergence using an ex vivo model of human osteoblast infection. Biofilm formation was assessed in a microbead immobilization assay (BioFilm Ring test). Virulence gene profiles were assessed by DNA microarray. Seventeen different clonal complexes were identified among the screened collection. The staphylococcal internalization rate in osteoblasts was significantly higher for chronic than acute BJI isolates, regardless of the genetic background. Conversely, no differences regarding cytotoxicity, SCV emergence, biofilm formation and virulence gene distribution were observed. Additionally, agr dysfunction, detected by the lack of delta-toxin production using whole-cell matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analysis (n = 15; 15.8%), was significantly associated with BJI chronicity, osteoblast invasion and biofilm formation. These findings provide new insights into MSSA BJI pathogenesis, suggesting the correlation between chronicity and staphylococcal osteoblast invasion. This adaptive mechanism, along with biofilm formation, is associated with agr dysfunction, which can be routinely assessed by delta-toxin detection using MALDI-TOF spectrum analysis, possibly providing clinicians with a diagnostic marker of BJI chronicity at the time of diagnosis.

Detection and clinical relevance of Staphylococcus aureus nasal carriage: an update

Staphylococcus aureus nasal carriage is a well-defined risk factor of infection with this bacterium. The increased risk of S. aureus infection in nasal carriers is supported by the fact that the strains isolated from both colonization and infection sites are indistinguishable in most of the cases. Persistent nasal carriage seems to be associated with an increased risk of infection and this status could be defined now in clinical routine by using one or two quantitative nasal samples. There is evidence for supporting the detection of nasal carriage of S. aureus in patients undergoing cardiac surgery and in those undergoing hemodialysis in order to implement decolonization measures. More studies are needed to determine which carriers have the highest risk of infection and why decolonization strategies failed to reduce S. aureus infection in some other groups of patients.

Detection of Staphylococcus aureus delta-toxin production by whole-cell MALDI-TOF mass spectrometry

The aim of the present study was to detect the Staphylococcus aureus delta-toxin using Whole-Cell (WC) Matrix Assisted Laser Desorption Ionization-Time-of-Flight (MALDI-TOF) mass spectrometry (MS), correlate delta-toxin expression with accessory gene regulator (agr) status, and assess the prevalence of agr deficiency in clinical isolates with and without resistance to methicillin and glycopeptides. The position of the delta-toxin peak in the mass spectrum was identified using purified delta-toxin and isogenic wild type and mutant strains for agr-rnaIII, which encodes delta-toxin. Correlation between delta-toxin production and agr RNAIII expression was assessed by northern blotting. A series of 168 consecutive clinical isolates and 23 unrelated glycopeptide-intermediate S. aureus strains (GISA/heterogeneous GISA) were then tested by WC-MALDI-TOF MS. The delta-toxin peak was detected at 3005±5 Thomson, as expected for the naturally formylated delta toxin, or at 3035±5 Thomson for its G10S variant. Multivariate analysis showed that chronicity of S. aureus infection and glycopeptide resistance were significantly associated with delta-toxin deficiency (p = 0.048; CI 95%: 1.01-10.24; p = 0.023; CI 95%: 1.20-12.76, respectively). In conclusion, the S. aureus delta-toxin was identified in the WC-MALDI-TOF MS spectrum generated during routine identification procedures. Consequently, agr status can potentially predict infectious complications and rationalise application of novel virulence factor-based therapies.

Kinetic study of compost liquor nitrification

This study is a first kinetic approach about the compost liquor treatment by activated sludge. This industrial wastewater is highly loaded in organic and nitrogen compounds (COD≈12,000 mg L(-1) and NH(4)(+)-N≈4,000 mg L(-1)). The possibility of its treatment in an urban WWTP is studied measuring ammonia oxidation rate with non-acclimated sludge to the industrial effluent. Compost liquor appears as an inhibitor substrate. The ammonia oxidation rate can be modelled by the Haldane model: U(MAX)=0.180 d(-1), K(S)=12.0 mgN.L(-1) and K(I)=26.0 mgN.L(-1). The ammonia oxidation rate also follows for a synthetic substrate which has the same pollutant load as the real substrate. In this case, the ammonia oxidation rate can be modelled by the Monod model: U(MAX)=0.073 d(-1) and K(S)=4.3 mgN.L(-1). This result confirms that the ammonia oxidising bacteria are inhibited by the real wastewater. The following-up of nitrate production shows also the inhibition of nitrite oxidising bacteria. The compost liquor treatment seems not possible in an urban WWTP (<50,000 p.e.). That's why a specific WWTP is recommended and an acclimation step of activated sludge is essential.