Do asymptomatic STEC-long-term carriers need to be isolated or decolonized? New evidence from a community case study and concepts in favor of an individualized strategy.

Asymptomatic long-term carriers of Shigatoxin producing Escherichia coli (STEC) are regarded as potential source of STEC-transmission. The prevention of outbreaks via onward spread of STEC is a public health priority. Accordingly, health authorities are imposing far-reaching restrictions on asymptomatic STEC carriers in many countries. Various STEC strains may cause severe hemorrhagic colitis complicated by life-threatening hemolytic uremic syndrome (HUS), while many endemic strains have never been associated with HUS. Even though antibiotics are generally discouraged in acute diarrheal STEC infection, decolonization with short-course azithromycin appears effective and safe in long-term shedders of various pathogenic strains. However, most endemic STEC-strains have a low pathogenicity and would most likely neither warrant antibiotic decolonization therapy nor justify social exclusion policies. A risk-adapted individualized strategy might strongly attenuate the socio-economic burden and has recently been proposed by national health authorities in some European countries. This, however, mandates clarification of strain-specific pathogenicity, of the risk of human-to-human infection as well as scientific evidence of social restrictions. Moreover, placebo-controlled prospective interventions on efficacy and safety of, e.g., azithromycin for decolonization in asymptomatic long-term STEC-carriers are reasonable. In the present community case study, we report new observations in long-term shedding of various STEC strains and review the current evidence in favor of risk-adjusted concepts.

High Genetic Diversity in Third-Generation Cephalosporin-Resistant Escherichia coli in Wastewater Systems of Schleswig-Holstein.

The spread of multidrug-resistant bacteria from humans or livestock is a critical issue. However, the epidemiology of resistant pathogens across wastewater pathways is poorly understood. Therefore, we performed a detailed comparison of third-generation cephalosporin-resistant Escherichia coli (3GCREC) from wastewater treatment plants (WWTPs) to analyze dissemination pathways. A total of 172 3GCREC isolated from four WWTPs were characterized via whole genome sequencing. Clonal relatedness was determined using multi-locus sequence typing (MLST) and core genome MLST. Resistance genotypes and plasmid replicons were determined. A total of 68 MLST sequence types were observed with 28 closely related clusters. Resistance genes to eight antibiotic classes were detected. In fluoroquinolone-resistant isolates, resistance was associated with three-or-more point mutations in target genes. Typing revealed high genetic diversity with only a few clonal lineages present in all WWTPs. The distribution paths of individual lines could only be traced in exceptional cases with a lack of enrichment of certain lineages. Varying resistance genes and plasmids, as well as fluoroquinolone resistance-associated point mutations in individual isolates, further corroborated the high diversity of 3GCREC in WWTPs. In total, we observed high diversity of 3GCREC inside the tested WWTPs with proof of resistant strains being released into the environment even after treatment processes.

Activity of antimicrobial examination gloves under realistic conditions: challenge not fulfilled.

BACKGROUND: Antimicrobial materials or surfaces are advertised as part of infection prevention bundles. However, the efficacy of such antimicrobial surfaces has not been sufficiently investigated in hospitals. In this study, the antimicrobial activity of examination gloves with light-activated antimicrobial properties against Gram-positive microorganisms was investigated modelling real live conditions. METHOD: In a standardized experimental set-up with dry and realistic contamination, the antimicrobial properties of gloves claiming light dependent antimicrobial activity against Gram-positive organisms were tested in comparison with conventional examination gloves. All gloves were contaminated through a standardized activity of the test persons for construction with contaminated building blocks. For contamination suspensions of Enterococcus faecium ATCC 6057, Acinetobacter baumannii (outbreak strain), methicillin resistant Staphylococcus aureus ATCC 43300 or E. faecium (VRE) patient isolate were dried on the surfaces. After the standardized activity, the gloves were held for 10 min in the light present in the room (bright conditions) and the grade of contamination was determined subsequently by quantitative culture. In one experimental series gloves were held in a dark box after contamination as a control (dark conditions). RESULTS: The light intensity in all experiments under bright conditions was significantly above the limit value specified by the manufacturer for the activation of antimicrobial properties (> 500 lx). The mean values for experiments with antimicrobial active and non-active gloves were 955 and 935 lx, respectively. As claimed by the manufacture, the gloves showed no sufficient efficacy against A. baumannii under bright conditions. Against Gram-positive microorganisms such as E. faecium, E. faecium (VRE) and methicillin resistant S. aureus the gloves showed only very low antimicrobial activity with a reduction factor < 1 log10 even after 10 min in bright conditions. Interestingly, comparable results for experiments with A. baumannii and E. faecium were shown under dark conditions. CONCLUSION: The lack of activity of the active principle against Gram-negative microorganisms could be confirmed. The reduction factors of > 4 log10 within 5 min for Gram-positive microorganisms claimed for the product using a standard test procedure (ASTM D7907) could not be confirmed in a realistic experimental test set-up even after 10 min of light exposure. The effectiveness against Gram-positive microorganisms should be further investigated under realistic (dry) conditions, including patient care. At this stage, the use of supposedly antimicrobial gloves should not be recommended, as the belief in their efficacy may encourage the misuse of gloves.

Long time persistence and evolution of carbapenemase-producing Enterobacterales in the wastewater of a tertiary care hospital in Germany.

BACKGROUND: Worldwide observations revealed increased frequencies of multi-resistant Enterobacterales and resistance genes in hospital wastewater compared to any other type of wastewater. Despite the description of clonal lineages possibly adapted to hospital wastewater, little is known about long term persistence as well as evolution of these lineages. METHODS: In this study, wastewater isolates of different Enterobacterales species from a tertiary care hospital were investigated with 2.5 years distance. Whole Genome Sequencing (WGS) and resistance gene identification were performed for E. coli, C. freundii, S. marcescens, K. pneumoniae, K. oxytoca, and E. cloacae isolates (n = 59), isolated in 2022 and compared with strains isolated from the same wastewater pipeline in 2019 (n = 240). RESULTS: Individual clonal lineages with highly related isolates could be identified in all species identified more than once in 2022 that appear to persist in the wastewater drainage. A common motif of all persistent clonal lineages was the carriage of mobile genetic elements encoding carbapenemase genes with hints for horizontal gene transfer in persistent clones in this environment observed over the 2.5-year period. Multiple plasmid replicons could be detected in both years. In 2022 isolates blaVIM-1 replaced blaOXA-48 as the most common carbapenemase gene compared to 2019. Interestingly, despite a similar abundance of carbapenemase genes (>80% of all isolates) at both time points genes encoding extended spectrum ß-lactamases decreased over time. CONCLUSIONS: This data indicates that hospital wastewater continuously releases genes encoding carbapenemases to the urban wastewater system. The evolution of the resident clones as well as the reasons for the selection advantage in this specific ecological niche needs to be further investigated in the future.

Phenotypic Variation in Clinical S. aureus Isolates Did Not Affect Disinfection Efficacy Using Short-Term UV-C Radiation.

Pigmentation, catalase activity and biofilm formation are virulence factors that cause resistance of Staphylococcus aureus to environmental stress factors including disinfectants. In recent years, automatic UV-C room disinfection gained greater importance in enhanced disinfection procedures to improve disinfection success in hospitals. In this study, we evaluated the effect of naturally occurring variations in the expression of virulence factors in clinical S. aureus isolates on tolerance against UV-C radiation. Quantification of staphyloxanthin expression, catalase activity and biofilm formation for nine genetically different clinical S. aureus isolates as well as reference strain S. aureus ATCC 6538 were performed using methanol extraction, a visual approach assay and a biofilm assay, respectively. Log10 reduction values (LRV) were determined after irradiation of artificially contaminated ceramic tiles with 50 and 22 mJ/cm2 UV-C using a commercial UV-C disinfection robot. A wide variety of virulence factor expression was observed, indicating differential regulation of global regulatory networks. However, no direct correlation with the strength of expression with UV-C tolerance was observed for either staphyloxanthin expression, catalase activity or biofilm formation. All isolates were effectively reduced with LRVs of 4.75 to 5.94. UV-C disinfection seems therefore effective against a wide spectrum of S. aureus strains independent of occurring variations in the expression of the investigated virulence factors. Due to only minor differences, the results of frequently used reference strains seem to be representative also for clinical isolates in S. aureus.

Absence of self-reported neuropsychiatric and somatic symptoms after Omicron variant SARS-CoV-2 breakthrough infections.

Persistent somatic and neuropsychiatric symptoms have been frequently described in patients after infection with severe acute respiratory syndrome coronavirus 2 even after a benign clinical course of the acute infection during the early phases of the coronavirus severe acute respiratory syndrome coronavirus 2 pandemic and are part of Long COVID. The Omicron variant emerged in November 2021 and has rapidly become predominant due to its high infectivity and suboptimal vaccine cross-protection. The frequency of neuropsychiatric post-acute sequelae after infection with the severe acute respiratory syndrome coronavirus 2 Omicron and adequate vaccination status is not known. Here, we aimed to characterize post-acute symptoms in individuals with asymptomatic or mildly symptomatic breakthrough infection with severe acute respiratory syndrome coronavirus 2. These individuals had either proven infection with the Omicron variant (n = 157) or their infection occurred in 2022 where Omicron was the predominant variant of severe acute respiratory syndrome coronavirus 2 in Germany (n = 107). This monocentric cross-sectional study was conducted at the University Medical Center Hamburg-Eppendorf between 11 February 2022 and 11 April 2022. We employed questionnaires addressing self-reported somatic symptom burden (Somatic Symptom Scale 8) and neuropsychiatric symptoms including mood (Patient Health Questionnaire 2), anxiety (Generalized Anxiety Disorder 7), attention (Mindful Attention Awareness Scale) and fatigue (Fatigue Assessment Scale) in a cohort of hospital workers. Scores were compared between 175 individuals less than 4 weeks after positive testing for severe acute respiratory syndrome coronavirus 2, 88 individuals more than 4 weeks after positive testing and 87 severe acute respiratory syndrome coronavirus 2 uninfected controls. The majority (n = 313; 89.5%) of included individuals were vaccinated at least three times. After recovery from infection, no significant differences in scores assessing neuropsychiatric and somatic symptoms were detected between the three groups (severe acute respiratory syndrome coronavirus 2 uninfected controls, individuals less and more than 4 weeks after positive testing) independent of age, sex, preconditions and vaccination status. In addition, self-reported symptom burden did not significantly correlate with the number of vaccinations against severe acute respiratory syndrome coronavirus 2, time from recovery or the number of infections. Notably, in all three groups, the mean scores for each item of our questionnaire lay below the pathological threshold. Our data show that persistent neuropsychiatric and somatic symptoms after recovery from severe acute respiratory syndrome coronavirus 2 infection in fully vaccinated hospital workers do not occur more frequently than that in uninfected individuals. This will guide healthcare professionals in the clinical management of patients after recovery from breakthrough infections with severe acute respiratory syndrome coronavirus 2.

Integration of Sequencing and Epidemiologic Data for Surveillance of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infections in a Tertiary-Care Hospital.

BACKGROUND: The ongoing coronavirus disease 2019 pandemic significantly burdens hospitals and other healthcare facilities. Therefore, understanding the entry and transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical for effective prevention and preparedness measures. We performed surveillance and analysis of testing and transmission of SARS-CoV-2 infections in a tertiary-care hospital in Germany during the second and third pandemic waves in fall/winter 2020. METHODS: Between calendar week 41 in 2020 and calendar week 1 in 2021, 40%, of all positive patient and staff samples (284 total) were subjected to full-length viral genome sequencing. Clusters were defined based on similar genotypes indicating common sources of infection. We integrated phylogenetic, spatial, and temporal metadata to detect nosocomial infections and outbreaks, uncover transmission chains, and evaluate containment measures' effectiveness. RESULTS: Epidemiologic data and contact tracing readily recognize most healthcare-associated (HA) patient infections. However, sequencing data reveal that temporally preceding index cases and transmission routes can be missed using epidemiologic methods, resulting in delayed interventions and serially linked outbreaks being counted as independent events. While hospital-associated transmissions were significantly elevated at a moderate rate of community transmission during the second wave, systematic testing and high vaccination rates among staff have led to a substantial decrease in HA infections at the end of the second/beginning of the third wave despite high community transmissions. CONCLUSIONS: While epidemiologic analysis is critical for immediate containment of HA SARS-CoV-2 outbreaks, integration of genomic surveillance revealed weaknesses in identifying staff contacts. Our study underscores the importance of high testing frequency and genomic surveillance to detect, contain and prevent SARS-CoV-2-associated infections in healthcare settings.

Infectivity of SARS-CoV-2 on Inanimate Surfaces: Don't Trust Ct Value.

SARS-CoV-2 RNA is frequently identified in patient rooms and it was speculated that the viral load quantified by PCR might correlate with infectivity of surfaces. To evaluate Ct values for the prediction of infectivity, we investigated contaminated surfaces and Ct-value changes after disinfection. Viral RNA was detected on 37 of 143 investigated surfaces of an ICU. However, virus isolation failed for surfaces with a high viral RNA load. Also, SARS-CoV-2 could not be cultivated from surfaces artificially contaminated with patient specimens. In order to evaluate the significance of Ct values more precisely, we used surrogate enveloped bacteriophage Φ6. A strong reduction in Φ6 was achieved by three different disinfection methods. Despite a strong reduction in viability almost no change in the Ct values was observed for UV-C and alcoholic surface disinfectant. Disinfection using ozone resulted in a lack of Φ6 recovery as well as a detectable shift in Ct values indicating strong degradation of the viral RNA. The observed lack of significant effects on the detectable viral RNA after effective disinfection suggest that quantitative PCR is not suitable for predicting the infectivity of SARS-CoV-2 on inanimate surfaces. Ct values should therefore not be considered as markers for infectivity in this context.

Reading the Score of the Air-Change in Airborne Microbial Load in Contrast to Particulate Matter during Music Making.

The potential impact of music-making on air quality around musicians was inferred at the outset of the SARS-CoV-2 pandemic from measurements on individual musical instruments and from theoretical considerations. However, it is unclear to what extent playing together in an orchestra under optimal ventilation conditions really increases infection risks for individual musicians. In this study, changes in indoor air quality were assessed by measuring common parameters, i.e., temperature, relative humidity, and carbon dioxide, along with particle counting and determining the presence of airborne pharyngeal bacteria under different seating arrangements. The study was conducted in cooperation with a professional orchestra on a stage ventilated by high volume displacement ventilation. Even with a full line-up, the particle load was only slightly influenced by the presence of the musicians on stage. At the same time, however, a clear increase in pharyngeal flora could be measured in front of individual instrument groups, but independent of seat spacing. Simultaneous measurement of various air parameters and, above all, the determination of relevant indicator bacteria in the air, enables site-specific risk assessment and safe music-making even during a pandemic.

Evidence of surface contamination in hospital rooms occupied by patients infected with monkeypox, Germany, June 2022.

The extent of monkeypox virus environmental contamination of surfaces is unclear. We examined surfaces in rooms occupied by two monkeypox patients on their fourth hospitalisation day. Contamination with up to 105 viral copies/cm2 on inanimate surfaces was estimated by PCR and the virus was successfully isolated from surfaces with more than 106 copies. These data highlight the importance of strict adherence of hospital staff to recommended protective measures. If appropriate, pre-exposure or early post-exposure vaccination should be considered for individuals at risk.

Therapeutic Management of COVID-19 in a Pediatric Patient with Neurodegenerative CLN2 Disease and ICV-Enzyme Replacement Therapy: A Case Report.

The 12 years old male patient presented here suffers from neuronal ceroid lipofuscinoses 2 (CLN2) (MIM# 204500) and receives intracerebroventricular enzyme replacement therapy (ICV-ERT) every 14 days. After the emergence of the coronavirus disease 2019 (COVID-19) pandemic, routine care of children and adolescents with rare chronic diseases has become challenging. Although, in general, children do not develop severe COVID-19, when severe acute respiratory syndrome coronavirus 2 infection was detected by polymerase chain reaction-screening examination in our CLN2 patient before hospital admission for ICV-ERT, he was regarded to be at risk. Upon diagnosis, the patient developed respiratory deterioration symptoms and was admitted to our pediatric intensive care unit to receive oxygen, remdesivir, and steroids. As far as we know, this is the first CLN2 patient receiving intraventricular enzyme therapy with COVID-19 who required intensive care treatment and specific therapy.

Three Separate Spike Antigen Exposures by COVID-19 Vaccination or SARS-CoV-2 Infection Elicit Strong Humoral Immune Responses in Healthcare Workers.

BACKGROUND: The immunogenicity of different COVID-19 vaccine regimens and combinations in naïve and convalescent individuals has not been formally tested in controlled studies, and real-life observational studies are scarce. METHODS: We assessed the SARS-CoV-2 infection and COVID-19 vaccination-induced immunity of 697 hospital workers at the University Medical Center Hamburg-Eppendorf between 17 and 31 January 2022. RESULTS: The overall prevalence of anti-NC-SARS-CoV-2 antibodies indicating prior infection was 9.8% (n = 68) and thus lower than the seroprevalence in the general population. All vaccinated individuals had detectable anti-S1-RBD-SARS-CoV-2 antibodies (median AU/mL [IQR]: 13,891 [8505-23,543]), indicating strong protection against severe COVID-19. Individuals who received three COVID-19 vaccine doses (median AU/mL [IQR]: 13,856 [8635-22,705]) and those who resolved a prior SARS-CoV-2 infection and had received two COVID-19 vaccine doses (median AU/mL [IQR] 13,409 [6934-25,000]) exhibited the strongest humoral immune responses. CONCLUSIONS: The current study indicates that three exposures to the viral spike protein by either SARS-CoV-2 infection or COVID-19 vaccination are necessary to elicit particularly strong humoral immune responses, which supports current vaccination recommendations.

Impact of Oral Rinsing with Octenidine Based Solution on SARS-CoV-2 Loads in Saliva of Infected Patients an Exploratory Study.

OBJECTIVE: In this study, the in-vivo effect of an antiseptic mouth rinse with Octenisept plus phenoxyethanol (OCT + PE) on the oral SARS-CoV-2 load was investigated. MATERIAL AND METHODS: In eight COVID-19 patients, saliva samples were obtained before mouth rinsing and at five time points post rinsing with OCT + PE (n = 47 saliva samples in total). SARS-CoV-2 RNA was detected and quantified by RT-qPCR and virus isolation in cell culture was performed to assess for infectivity. RESULTS: Immediately after mouth rinsing (1 min), a significant reduction of the SARS-CoV-2 RNA loads in saliva was achieved (p = 0.03) with 7/8 participants having SARS-CoV-2 RNA levels undetectable by RT-qPCR. At later time points, RNA levels returned to baseline levels in all study participants. Infectivity of saliva samples was demonstrated by successful virus isolation from saliva samples collected at later time points. CONCLUSIONS: This study highlights that saliva samples from COVID-19 patients are infectious and demonstrates that mouth rinsing with OCT + PE temporarily leads to a significant reduction of the SARS-CoV-2 load in saliva. CLINICAL RELEVANCE: Mouth rinsing with OCT + PE could provide a simple, rapid, and efficient method for SARS-CoV-2 infection prevention, particularly in the field of dental and respiratory medicine.

High burden and diversity of carbapenemase-producing Enterobacterales observed in wastewater of a tertiary care hospital in Germany.

Hospitals are one of the main reservoirs of multi-resistant Enterobacterales (MRE). As MRE are resistant to the most frequently used antibiotics, therapy for patients with MRE infections is challenging. It has been previously described that MRE from hospital wastewater can pass into municipal wastewater and even surface water. In this study, we investigated the diversity and epidemiology of MRE in the wastewater of a large tertiary care hospital. Wastewater samples were collected for a four-day period and tested for the presence of Enterobacterales resistant to 3rd gen. cephalosporins. Representative isolates were further characterized by whole genome sequencing. In 120 ß-glucuronidase-producing isolates, 68 Escherichia coli and, interestingly, also 52 Citrobacter freundii were identified. In 120 ß-glucosidase-producing isolates 45 Serratia marcescens, 34 Klebsiella oxytoca, 32 Enterobacter cloacae and 9 Klebsiella pneumoniae were observed. For all species various MLST sequence types and different clusters of resistance genes were determined, showing a great diversity within the different Enterobacterales, further corroborated by clonal analysis performed by cgMLST. The most prominent clone was wastewater associated E. coli ST635, which accounted for 47.1% of all E. coli isolates. Interestingly, 45.6% of E. coli, 88.5% of C. freundii, 95.6% of S. marcescens, 91.2% of K. oxytoca, 96.9% of E. cloacae and 88.9% of K. pneumoniae isolates carried a carbapenemase gene, indicating a high burden with carbapenemase-producing Enterobacterales. Comparison with clinical isolates from the same hospital displayed few clonal matches. One wastewater isolate of K. pneumoniae was identified to be closely related compared to a clone that had been introduced into the hospital during an outbreak four years earlier. One E. coli isolate was identified as identical to an isolate from a patient, with inpatient stay during the sampling period. The data obtained in this study highlight the problem of antibiotic resistance of Enterobacterales in hospital wastewater. In particular, the clustered occurrence of carbapenemase genes is of great concern and underscores the problem of increasingly scarce antibiotic options against these bacteria.

The Transcription Factor SpoVG Is of Major Importance for Biofilm Formation of Staphylococcus epidermidis under In Vitro Conditions, but Dispensable for In Vivo Biofilm Formation.

Staphylococcus epidermidis is a common cause of device related infections on which pathogens form biofilms (i.e., multilayered cell populations embedded in an extracellular matrix). Here, we report that the transcription factor SpoVG is essential for the capacity of S. epidermidis to form such biofilms on artificial surfaces under in vitro conditions. Inactivation of spoVG in the polysaccharide intercellular adhesin (PIA) producing S. epidermidis strain 1457 yielded a mutant that, unlike its parental strain, failed to produce a clear biofilm in a microtiter plate-based static biofilm assay. A decreased biofilm formation capacity was also observed when 1457 ΔspoVG cells were co-cultured with polyurethane-based peripheral venous catheter fragments under dynamic conditions, while the cis-complemented 1457 ΔspoVG::spoVG derivative formed biofilms comparable to the levels seen with the wild-type. Transcriptional studies demonstrated that the deletion of spoVG significantly altered the expression of the intercellular adhesion (ica) locus by upregulating the transcription of the ica operon repressor icaR and down-regulating the transcription of icaADBC. Electrophoretic mobility shift assays (EMSA) revealed an interaction between SpoVG and the icaA-icaR intergenic region, suggesting SpoVG to promote biofilm formation of S. epidermidis by modulating ica expression. However, when mice were challenged with the 1457 ΔspoVG mutant in a foreign body infection model, only marginal differences in biomasses produced on the infected catheter fragments between the mutant and the parental strain were observed. These findings suggest that SpoVG is critical for the PIA-dependent biofilm formation of S. epidermis under in vitro conditions, but is largely dispensable for biofilm formation of this skin commensal under in vivo conditions.

Multi-organ assessment in mainly non-hospitalized individuals after SARS-CoV-2 infection: The Hamburg City Health Study COVID programme.

AIMS: Long-term sequelae may occur after SARS-CoV-2 infection. We comprehensively assessed organ-specific functions in individuals after mild to moderate SARS-CoV-2 infection compared with controls from the general population. METHODS AND RESULTS: Four hundred and forty-three mainly non-hospitalized individuals were examined in median 9.6 months after the first positive SARS-CoV-2 test and matched for age, sex, and education with 1328 controls from a population-based German cohort. We assessed pulmonary, cardiac, vascular, renal, and neurological status, as well as patient-related outcomes. Bodyplethysmography documented mildly lower total lung volume (regression coefficient -3.24, adjusted P = 0.014) and higher specific airway resistance (regression coefficient 8.11, adjusted P = 0.001) after SARS-CoV-2 infection. Cardiac assessment revealed slightly lower measures of left (regression coefficient for left ventricular ejection fraction on transthoracic echocardiography -0.93, adjusted P = 0.015) and right ventricular function and higher concentrations of cardiac biomarkers (factor 1.14 for high-sensitivity troponin, 1.41 for N-terminal pro-B-type natriuretic peptide, adjusted P ≤ 0.01) in post-SARS-CoV-2 patients compared with matched controls, but no significant differences in cardiac magnetic resonance imaging findings. Sonographically non-compressible femoral veins, suggesting deep vein thrombosis, were substantially more frequent after SARS-CoV-2 infection (odds ratio 2.68, adjusted P < 0.001). Glomerular filtration rate (regression coefficient -2.35, adjusted P = 0.019) was lower in post-SARS-CoV-2 cases. Relative brain volume, prevalence of cerebral microbleeds, and infarct residuals were similar, while the mean cortical thickness was higher in post-SARS-CoV-2 cases. Cognitive function was not impaired. Similarly, patient-related outcomes did not differ. CONCLUSION: Subjects who apparently recovered from mild to moderate SARS-CoV-2 infection show signs of subclinical multi-organ affection related to pulmonary, cardiac, thrombotic, and renal function without signs of structural brain damage, neurocognitive, or quality-of-life impairment. Respective screening may guide further patient management.

Contamination of multi dose eyedrops in the intra and perioperative context.

In this study, we examined the rate of contamination of multi-dose ophthalmic solutions in the operating theatre and the underlying risk for infection by examining the microbiological load on the tips of the dispenser bottles. A total of 245 samples of eye drop bottles were collected and analysed between June 2018 and January 2019. All were collected in the operating theatre of the University Eye Hospital Hamburg-Eppendorf. Contamination of the dropper tip occurred in 2% of the samples. Although the prevalence of contamination was low, the results of this study reveal the possibility of contamination of multi-dose eyedrops even when used by health care professionals in the controlled environment of an operating theatre. Following these results, we recommend the use of single-dose eyedrops in the pre- and intraoperative context.

Low SARS-CoV-2 infection rates and high vaccine-induced immunity among German healthcare workers at the end of the third wave of the COVID-19 pandemic.

In this longitudinal cohort study, we assessed the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) seroconversion rates and analyzed the coronavirus disease 2019 (COVID-19) vaccine-induced immunity of 872 hospital workers at the University Medical Center Hamburg-Eppendorf between May 11 and May 31, 2021. The overall seroprevalence of anti-NC-SARS-CoV-2 antibodies was 4.7% (n = 41), indicating low SARS-CoV-2 infection rates and persistent effectiveness of hospital-wide infection control interventions during the second and third wave of the pandemic. In total, 92.7% (n = 808) out of the entire study cohort, 98.2% (n = 325) of those who had been vaccinated once and all 393 individuals who had been vaccinated twice had detectable anti-S1-RBD-SARS-CoV-2 antibody titers and no significant differences in vaccine-induced immune response were detected between male and female individuals and between different age groups. Vaccinated study participants with detectable anti-NC-SARS-CoV-2 antibody titers (n = 30) developed generally higher anti-S1-RBD-SARS-CoV-2 antibody titers compared to anti-NC-SARS-CoV-2 negative individuals (n = 694) (median titer: 7812 vs. 345 BAU/ml, p < 0.0001). Furthermore, study participants who received heterologous vaccination with AZD1222 followed by an mRNA vaccine showed markedly higher anti-S1-RBD-SARS-CoV-2 antibody titers than individuals who received two doses of an mRNA vaccine or two doses of AZD1222 (median titer: AZD1222/AZD1222: 1069 BAU/ml, mRNA/mRNA: 1388 BAU/ml, AZD1222/mRNA: 9450 BAU/ml; p < 0.0001). Our results indicate that infection control interventions were generally effective in preventing nosocomial transmission of SARS-CoV-2 and that COVID-19 vaccines can elicit strong humoral responses in the majority of a real-world cohort of hospital workers.

Clinical performance and accuracy of a qPCR-based SARS-CoV-2 mass-screening workflow for healthcare-worker surveillance using pooled self-sampled gargling solutions: A cross-sectional study.

INTRODUCTION: The large number of asymptomatic SARS-CoV-2 infections necessitates general screening of employees. We evaluate the performance of a SARS-CoV-2 screening program in asymptomatic healthcare-workers (HCW), utilizing self-sampled gargling-solution and sample pooling for RT-qPCR. METHODS: We conducted a cross-sectional retrospective study to collect real-life data on the performance of a screening-workflow based on automated-pooling and high-throughput qPCR testing over a 3-month-period at the University Hospital Hamburg. RESULTS: Matrix validation reveals that lower limit of detection for SARS-CoV-2 RNA in gargling-solution was 180 copies/mL (5-sample-pool). A total of 55,122 self-collected gargle samples (= 7513 HCWs) was analyzed. The median time to result was 8.5 hours (IQR 7.2-10.8). Of 11,192 pools analyzed, 11,041 (98.7%) were negative, 69 (0.6%) were positive and 82 (0.7%) were invalid. Individual testing of pool participants revealed 57 SARS-CoV-2 previously unrecognized infections. All 57 HCWs were either pre-symptomatic or asymptomatic (prevalence 0.76%,CI95%0.58-0.98%). Accuracy based on HCWs with gargle-solution and NP-swab available within 3-day-interval (N = 521) was 99.5% (CI95%98.3-99.9%), sensitivity 88.9% (CI95%65.3-98.6%) while specificity 99.8% (CI95%98.9-99.9). CONCLUSION: This workflow was highly effective in identifying SARS-CoV-2 positive HCWs, thereby lowering the potential of inter-HCW and HCW-patient transmissions. Automated-sample-pooling helped to conserve qPCR reagents and represents a promising alternative strategy to antigen testing in mass-screening programs.