Burden of non-serious infections during biological use for rheumatoid arthritis

INTRODUCTION

Biologicals have become a cornerstone in rheumatoid arthritis (RA) treatment. The increased risk of serious infections associated with their use is well-established. Non-serious infections, however, occur more frequently and are associated with a high socioeconomic burden and impact on quality of life but have not received the same attention in the literature to date. The aim of this study was to gain insight into the various non-serious infections reported in RA patients using biologicals and their experienced burden.

MATERIALS AND METHODS

The Dutch Biologic Monitor was a prospective observational study that included adults with rheumatoid arthritis and biological use who answered bimonthly questionnaires on the adverse drug reactions (ADRs) they experienced from their biological and reported the associated impact score (ranging from 1, no impact, to 5, very high impact). ADRs were assigned a MedDRA code by pharmacovigilance experts and labeled as definite, probable, possible or no infection by infectious disease professionals. Descriptive statistics were performed using medians and interquartile ranges.

RESULTS

A total of 586 patients were included in the final analysis. Eighty-five patients (14.5%) reported a total of 421 ADRs labeled as probable or definite infections by the experts. Patient-assigned burden was ADR-specific. Upper respiratory tract infections were most frequently reported and had a high rate of recurrence or persistence, with a median impact score of 3.0 (IQR 2.0-3.0) which remained stable over time.

DISCUSSION

Non-serious infections significantly outnumbered serious infections in this real-life cohort of RA patients using biologicals (77.1 non-serious infections and 1.3 serious infections per 100 patient years, respectively). Infections in the upper respiratory tract were rated as having an average burden, which remained constant over a long period of time. Awareness of the impact of recurrent and chronic non-serious infections may enable healthcare professionals to timely treat and maybe even prevent them, which would lessen the associated personal and socioeconomic burden.

Cross-Reactivity of Human, Wild Boar, and Farm Animal Sera from Pre- and Post-Pandemic Periods with Alpha- and Βeta-Coronaviruses (CoV), including SARS-CoV-2

Panels of pre- and post-pandemic farm animals, wild boar and human sera, including human sera able to neutralize SARS-CoV-2 in vitro, were tested in serological tests to determine their cross-reactivity with β- and α-CoV originating from farm animals. Sera were tested in neutralization assays with high ascending concentrations (up to 1 × 104 TCID50 units/well) of β-CoV Bovine coronavirus (BCV), SARS-CoV-2, and porcine α-CoV-transmissible gastroenteritis virus (TGEV). In addition, sera were tested for immunostaining of cells infected with β-CoV porcine hemagglutinating encephalomyelitis (PHEV). Testing revealed a significantly higher percentage of BCV neutralization (78%) for sera of humans that had experienced a SARS-CoV-2 infection (SARS-CoV-2 convalescent sera) than was observed for human pre-pandemic sera (37%). Also, 46% of these human SARS-CoV-2 convalescent sera neutralized the highest concentration of BCV (5 × 103 TCID50/well) tested, whereas only 9.6% of the pre-pandemic sera did. Largely similar percentages were observed for staining of PHEV-infected cells by these panels of human sera. Furthermore, post-pandemic sera collected from wild boars living near a densely populated area in The Netherlands also showed a higher percentage (43%) and stronger BCV neutralization than was observed for pre-pandemic sera from this area (21%) and for pre- (28%) and post-pandemic (20%) sera collected from wild boars living in a nature reserve park with limited access for the public. High percentages of BCV neutralization were observed for pre- and post-pandemic sera of cows (100%), pigs (up to 45%), sheep (36%) and rabbits (60%). However, this cross-neutralization was restricted to sera collected from specific herds or farms. TGEV was neutralized only by sera of pigs (68%) and a few wild boar sera (4.6%). None of the BCV and PHEV cross-reacting human pre-pandemic, wild boar and farm animal sera effectively neutralized SARS-CoV-2 in vitro. Preexisting antibodies in human sera effectively neutralized the animal β-CoV BCV in vitro. This cross-neutralization was boosted after humans had experienced a SARS-CoV-2 infection, indicating that SARS-CoV-2 activated a "memory" antibody response against structurally related epitopes expressed on the surface of a broad range of heterologous CoV, including β-CoV isolated from farm animals. Further research is needed to elucidate if a symptomless infection or environmental exposure to SARS-CoV-2 or another β-CoV also triggers such a "memory" antibody response in wild boars and other free-living animals.

A SARS-CoV-2 and influenza rapid antigen test-based hospital isolation policy awaiting RT-PCR, a prospective observational study

OBJECTIVES

This study aimed to evaluate the clinical performance of a combined SARS-CoV-2/influenza rapid antigen test (SIRAT) and to evaluate a SIRAT-based hospital isolation policy awaiting RT-PCR results for patients presenting at the emergency department (ED).

METHODS

We performed a prospective observational study including all adult patients presenting with influenza-like symptoms at the ED of two hospitals from 31 October 2022 to 31 March 2023. A SIRAT and SARS-CoV-2 and influenza RT-PCR were performed on upper respiratory samples. SIRAT results were compared with RT-PCR. Droplet and contact isolation measures (DCIM) were imposed based on SIRAT results awaiting RT-PCR. We monitored symptomatic nosocomial SARS-CoV-2 and influenza infections potentially caused by delayed isolation of patients with false negative SIRAT and the hours of unnecessary DCIM saved.

RESULTS

We included 1740 patients of whom 1296 were hospitalized. SARS-CoV-2 and influenza A/B prevalence were 12.7% (221/1740) and 9.9% (171/1740). Sensitivity and specificity of the SIRAT were 67.7% (95% CI 61.1-73.9%) (149/220) and 99.4% (95% CI 99.0-99.8%) (1510/1518) for SARS-CoV-2 and 52.7% (95% CI 44.9-60.4%) (89/169) and 99.1% (95% CI 98.5-99.5%) (1530/1544) for influenza A/B. We found a 0% nosocomial transmission risk for SARS-CoV-2 (95% CI 0-8.8%) and influenza (95% CI 0-10%). In all, 8712 hours in total or a median up to 6 hours 59 minutes (IQR (interquartile range) 11h03) per patient of unnecessary DCIM were saved.

DISCUSSION

A SIRAT-guided hospital isolation policy awaiting RT-PCR results for patients who present at the ED can save unnecessary isolation hours without having to lead to significant symptomatic nosocomial transmission of SARS-CoV-2 or influenza viruses.

Prevalence, risk and severity of SARS-CoV-2 infections in psoriasis patients receiving conventional systemic, biologic or topical treatment during the COVID-19 pandemic: a cross-sectional cohort study (PsoCOVID)

BACKGROUND

The risk of SARS-CoV-2 infection does not appear to be increased for psoriasis patients using biologics compared to those on other treatments, but evidence is still limited.

OBJECTIVES

(1) to estimate the prevalence of SARS-CoV-2 infection in patients with psoriasis, (2) to compare SARS-CoV-2 infection rates for different psoriasis treatments groups (biologic vs. systemic conventional vs. topical therapy) corrected for confounders and (3) to describe patients with severe COVID-19 for all treatment groups.

METHODS

In this cross-sectional cohort study all patients received a questionnaire to gather data on psoriasis treatment, SARS-CoV-2 infections and related risk factors. Simultaneously, they underwent a blood test to screen for antibodies to SARS-CoV-2 N-antigen. Prevalence of SARS-CoV-2 infections was calculated and logistic regression and Cox proportional-hazards models were performed to determine the association between treatment group and SARS-CoV-2 infection risk, corrected for confounders. Patients with severe COVID-19 disease were described and the mortality rate per treatment group was calculated for the target population.

RESULTS

Patients were included between April 12 2021 and October 31 2021. Of 551 patients, 59 (10.7% (CI95% 8.3-13.6)) had experienced a SARS-CoV-2 infection, based on questionnaire data combined with serological data. In our study cohort, corrected for confounders, biologic or non-biologic systemic therapy users did not appear to have increased SARS-CoV-2 infection risk compared to patients using other treatment. Only 4 hospitalizations (0.7% (CI95% 0.2-1.0) were reported in our study population and no ICU admissions were reported. The rough mortality rate in the target cohort was 0.32% (CI95% 0.13-0.66) in all treatment groups.

CONCLUSIONS

Corrected for risk-mitigating behavior and vaccination status, a higher SARS-CoV-2 incidence for biologics or non-biologics systemics compared to other treatments could not be proven. Severe cases were infrequent in all treatment groups. This finding further strengthens treatment recommendations that systemic therapies for patients with psoriasis do not require preventive cessation for reduction of SARS-CoV-2 infection risk.

Infections in Biological and Targeted Synthetic Drug Use in Rheumatoid Arthritis: Where do We Stand? A Scoping Review and Meta-analysis

INTRODUCTION

The advent of biological and targeted synthetic therapies has revolutionized rheumatoid arthritis (RA) treatment. However, this has come at the price of an increased risk of infections. The aim of this study was to present an integrated overview of both serious and non-serious infections, and to identify potential predictors of infection risk in RA patients using biological or targeted synthetic drugs.

METHODS

We systematically reviewed available literature from PubMed and Cochrane and performed multivariate meta-analysis with meta-regression on the reported infections. Randomized controlled trials and prospective and retrospective observational studies including patient registry studies were analyzed, combined as well as separately. We excluded studies focusing on viral infections only.

RESULTS

Infections were not reported in a standardized manner. Meta-analysis showed significant heterogeneity that persisted after forming subgroups by study design and follow-up duration. Overall, the pooled proportions of patients experiencing an infection during a study were 0.30 (95% CI, 0.28-0.33) and 0.03 (95% CI, 0.028-0.035) for any kind of infections or serious infections only, respectively. We found no potential predictors that were consistent across all study subgroups.

CONCLUSIONS

The high heterogeneity and the inconsistency of potential predictors between studies show that we do not yet have a complete picture of infection risk in RA patients using biological or targeted synthetic drugs. Besides, we found non-serious infections outnumbered serious infections by a factor 10:1, but only a few studies have focused on their occurrence. Future studies should apply a uniform method of infectious adverse event reporting and also focus on non-serious infections and their impact on treatment decisions and quality of life.

First description and phylogenetic analysis of coxsackie virus A non-polio enteroviruses and parechoviruses A in South Sudanese children

Enteroviruses (EV) and parechoviruses A (PeV-A) are commonly circulating viruses able to cause severe disease. Surveillance studies from sub-Saharan Africa are limited and show high but variable infection rates and a high variation in genotypes. This is the first study to describe EV and PeV-A circulation in children in South Sudan. Of the fecal samples collected, 35% and 10% were positive for EV and PeV-A, respectively. A wide range of genotypes were found, including several rarely described EV and PeV-A types. Coxsackie virus A (CVA) EV-C types, particularly CVA13, were the most dominant EV types. The CVA13 types had a high diversity with the majority belonging to four different previously described clusters. PeV-A1 and -A14 were the most common PeV-A genotypes. A lack of representative data from our and other studies from sub-Saharan Africa demonstrates the need for more systematic surveillance of non-polio EV and PeV-A types in this region.

The Impact of SARS-CoV-2 Immune Status and Societal Restrictions in Controlling COVID-19 across the World

To control the COVID-19 pandemic, many countries implemented vaccination and imposed societal restrictions both at the national level and for international travel. As a check of corona status, COVID passes have been issued. A COVID pass could be obtained when either fully vaccinated against COVID-19, or after recovering from a documented COVID-19 episode, or after a recent (24-48 h) negative SARS-CoV-2 antigen test. A global analysis of SARS-CoV-2 immune status determined by past infection and/or vaccination, vaccination rates, as well as societal restrictions in controlling the COVID-19 pandemic is presented. The data show that across the world, vaccination was more effective in reducing SARS-CoV-2 infections with the delta variant than the omicron variant. Strict societal restrictions could control spread of the virus, but relief of the restrictions was associated with an increase in omicron infections. No significant difference in SARS-CoV-2 infections were found when comparing countries or territories which did or did not implement a COVID pass.

External quality assessment of SARS-CoV-2 serology in European expert laboratories, April 2021

Background

Countries worldwide are focusing to mitigate the ongoing SARS-CoV-2 pandemic by employing public health measures. Laboratories have a key role in the control of SARS-CoV-2 transmission. Serology for SARS-CoV-2 is of critical importance to support diagnosis, define the epidemiological framework and evaluate immune responses to natural infection and vaccine administration.

Aim

The aim of this study was the assessment of the actual capability among laboratories involved in sero-epidemiological studies on COVID-19 in EU/EEA and EU enlargement countries to detect SARS-CoV-2 antibodies through an external quality assessment (EQA) based on proficiency testing.

Methods

The EQA panels were composed of eight different, pooled human serum samples (all collected in 2020 before the vaccine roll-out), addressing sensitivity and specificity of detection. The panels and two EU human SARS-CoV-2 serological standards were sent to 56 laboratories in 30 countries.

Results

The overall performance of laboratories within this EQA indicated a robust ability to establish past SARS-CoV-2 infections via detection of anti-SARS-CoV-2 antibodies, with 53 of 55 laboratories using at least one test that characterised all EQA samples correctly. IgM-specific test methods provided most incorrect sample characterisations (24/208), while test methods detecting total immunoglobulin (0/119) and neutralising antibodies (2/230) performed the best. The semiquantitative assays used by the EQA participants also showed a robust performance in relation to the standards.

Conclusion

Our EQA showed a high capability across European reference laboratories for reliable diagnostics for SARS-CoV-2 antibody responses. Serological tests that provide robust and reliable detection of anti-SARS-CoV-2 antibodies are available.

A comprehensive comparison between ISAC and ALEX2 multiplex test systems

OBJECTIVES

Diagnosis of type I hypersensitivity is based on anamnesis, provocation as well as blood- and skin testing. Multiplex specific IgE (sIgE) testing enables determination of sIgE antibodies against multiple recombinant or purified natural allergen components. The aim of this study was to evaluate the performance of the novel ALEX^2® (Allergy Explorer, ALEX² test introduced on the market November 2019) multiplex platform and to compare it with the ImmunoCAP ISAC^® test system.

METHODS

Serum samples of 49 patients, routinely determined with ISAC, were selected based on positive results covering in total most of the 112 ISAC components. Cohen's kappa, negative percent agreement (NPA), and positive percent agreement (PPA) of ALEX² data compared to ISAC data (as a non-reference standard) were computed for those allergen components present on both platforms (n=103). Furthermore, in some samples sIgE results against allergen extracts and/or -components tested with either ImmunoCAP^® (ThermoFisher) or IMMULITE^® (Siemens) were available and compared to ALEX² results.

RESULTS

The overall agreement between ISAC and ALEX² common allergen components was 94%. NPA and PPA were respectively 95 and 90%. Kappa values differed for specific allergen groups and varied between 0.60 and 0.92 showing moderate to almost perfect agreement. Of the qualitative discrepancies between ALEX² and ISAC, 59% were related to weak positive results i.e. results under 1 kUA/L or 1 ISU, respectively.

CONCLUSIONS

The method comparison between ISAC and ALEX² multiplex tests showed a high concordance for those allergen components present on both platforms.

Re-emergence of enterovirus D68 in Europe after easing the COVID-19 lockdown, September 2021

We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe.

Increasing the Efficiency of a National Laboratory Response to COVID-19: a Nationwide Multicenter Evaluation of 47 Commercial SARS-CoV-2 Immunoassays by 41 Laboratories

In response to the worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the subsequent antibody tests that flooded the market, a nationwide collaborative approach in the Netherlands was employed. Forty-one Dutch laboratories joined forces and shared their evaluation data to allow for the evaluation of a quantity of serological assays for SARS-CoV-2 that exceeds the capacity of each individual laboratory. As of April 2020, these performance data had been aggregated and shared in regularly updated reports with other laboratories, Dutch government, public health organizations, and the public. This frequently updated overview of assay performance increased the efficiency of our national laboratory response, supporting laboratories in their choice and implementation of assays. Aggregated performance data for 47 immunoassays for SARS-CoV-2 showed that none of the evaluated immunoassays that detect only IgM or IgA met the diagnostic criteria, indicating that they are not suitable for diagnosing acute infections. For the detection of IgG, only the Biozek Corona virus COVID rapid test, Euroimmun SARS-CoV-2 IgG, and Wantai SARS-CoV-2 antibody (Ab) ELISA met predefined performance criteria in hospitalized patients where samples were collected 14 days post-onset of symptoms (DPO), while for patients with mild or asymptomatic infections, only the Wantai SARS-CoV-2 Ab ELISA met the predefined performance criteria if samples were collected 14 days postonset. Here, we describe this unique nationwide collaboration during the onset of the COVID-19 pandemic; the collected data and their results are an example of what can be accomplished when forces are joined during a public health crisis.

Self-testing for the detection of SARS-CoV-2 infection with rapid antigen tests for people with suspected COVID-19 in the community

Objectives

To evaluate the performance of nasal mid-turbinate self-testing using rapid antigen detection tests (RDT) for persons with suspected coronavirus disease 2019 (COVID-19) in the community. Self-testing for COVID-19 infection with lateral flow assay severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RDT, provides rapid results and could enable frequent and extensive testing in the community, thereby improving the control of SARS-CoV-2.

Methods

Participants visiting a municipal SARS-CoV-2 testing centre, received self-testing kits containing either the BD Veritor System (BD-RDT) or Roche SARS-CoV-2 antigen detection test (Roche-RDT). Oro-nasopharyngeal swabs were collected from the participants for quantitative RT-PCR (qRT-PCR) testing. As a proxy for contagiousness, viral culture was performed on a selection of qRT-PCR positive samples to determine the Ct-value at which the chance of a positive culture dropped below 0.5 (Ct-value cut-off). Sensitivity and specificity of self-testing were compared to qRT-PCR with a Ct-value below the Ct value cut-off. Determinants independently associated with a false-negative self-test result were determined.

Results

A total of 3201 participants were included (BD-RDT n = 1595; Roche-RDT n = 1606). Sensitivity and specificity of self-testing compared with the qRT-PCR results with a Ct-value below the Ct-value cut-off were 78.4% (95% CI 73.2%–83.5%) and 99.4% (95% CI 99.1%–99.7%), respectively. A higher age was independently associated with a false-negative self-testing result with an odds ratio of 1.024 (95% CI 1.003–1.044).

Conclusions

Self-testing using currently available RDT has a high specificity and relatively high sensitivity to identify individuals with a high probability of contagiousness.

Molecular Epidemiology and Evolutionary Trajectory of Emerging Echovirus 30, Europe

In 2018, an upsurge in echovirus 30 (E30) infections was reported in Europe. We conducted a large-scale epidemiologic and evolutionary study of 1,329 E30 strains collected in 22 countries in Europe during 2016-2018. Most E30 cases affected persons 0-4 years of age (29%) and 25-34 years of age (27%). Sequences were divided into 6 genetic clades (G1-G6). Most (53%) sequences belonged to G1, followed by G6 (23%), G2 (17%), G4 (4%), G3 (0.3%), and G5 (0.2%). Each clade encompassed unique individual recombinant forms; G1 and G4 displayed >2 unique recombinant forms. Rapid turnover of new clades and recombinant forms occurred over time. Clades G1 and G6 dominated in 2018, suggesting the E30 upsurge was caused by emergence of 2 distinct clades circulating in Europe. Investigation into the mechanisms behind the rapid turnover of E30 is crucial for clarifying the epidemiology and evolution of these enterovirus infections.

The clinical relevance of IgM and IgA anti-pneumococcal polysaccharide ELISA assays in patients with suspected antibody deficiency

Unlike immunoglobulin (Ig)G pneumococcal polysaccharide (PnPS)‐antibodies, PnPS IgA and IgM‐antibodies are not routinely determined for the assessment of immunocompetence. It is not yet known whether an isolated inability to mount a normal IgM or IgA‐PnPS response should be considered a relevant primary antibody deficiency (PAD). We studied the clinical relevance of anti‐PnPS IgM and IgA‐assays in patients with suspected primary immunodeficiency in a large teaching hospital in ’s‐Hertogenbosch, the Netherlands. Serotype‐specific‐PnPS IgG assays were performed; subsequently, 23‐valent‐PnPS IgG assays (anti‐PnPS IgG assays), and later anti‐PnPS IgA and IgM assays, were performed in archived material (240 patients; 304 samples). Eleven of 65 pre‐ and six of 10 post‐immunization samples from good responders to PnPS serotype‐specific IgG testing had decreased anti‐PnPS IgA and/or IgM titres. Of these, three pre‐ and no post‐immunization samples were from patients previously classified as ‘no PAD’. Determination of anti‐PnPS IgA and IgM in addition to anti‐PnPS IgG did not reduce the need for serotype‐specific PnPS IgG testing to assess immunocompetence [receiver operating characteristic (ROC) analysis of post‐immunization samples: anti‐PnPS IgA + IgG area under the curve (AUC) = 0.80, 95% confidence interval (CI) = 0.63–0.97; anti‐PnPS IgM + IgG AUC 0.80, 95% CI = 0.62–0.98; anti‐PnPS IgA + IgG + IgM AUC = 0.71, 95% CI = 0.51–0.91; anti‐PnPS IgG AUC = 0.93, 95% CI = 0.85–1.00]. Our data show that patients classified as having an intact antibody response based on measurement of serotype‐specific PnPS IgG can still display impaired anti‐PnPS IgM and IgA responses, and that the additional measurement of anti‐PnPS IgA and IgM could not reduce the need for serotype‐specific IgG testing. Future studies are needed to investigate the clinical relevance of potential ‘specific IgA or IgM antibody deficiency’ in patients with recurrent airway infections in whom no PAD could be diagnosed according to the current definitions.

Test, trace, isolate: evidence for declining SARS-CoV-2 PCR sensitivity in a clinical cohort

Real-time reverse transcription-polymerase chain reaction (RT-PCR) on upper respiratory tract (URT) samples is the primary method to diagnose SARS-CoV-2 infections and guide public health measures, with a supportive role for serology. We reinforce previous findings on limited sensitivity of PCR testing, and solidify this fact by statistically utilizing a firm basis of multiple tests per individual. We integrate stratifications with respect to several patient characteristics such as severity of disease and time since onset of symptoms. Bayesian statistical modelling was used to retrospectively determine the sensitivity of RT-PCR using SARS-CoV-2 serology in 644 COVID-19-suspected patients with varying degrees of disease severity and duration. The sensitivity of RT-PCR ranged between 80% - 95%; increasing with disease severity, it decreased rapidly over time in mild COVID-19 cases. Negative URT RT-PCR results should be interpreted in the context of clinical characteristics, especially with regard to containment of viral transmission based on 'test, trace and isolate'. Keywords: SARS-CoV-2, RT-PCR, serology, sensitivity, public health.

Successful containment of two vancomycin-resistant Enterococcus faecium (VRE) outbreaks in a Dutch teaching hospital using environmental sampling and whole-genome sequencing

BACKGROUND

Vancomycin-resistant enterococci (VRE) may cause nosocomial outbreaks. This article describes all VRE carriers that were identified in 2018 at Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands.

AIM

To investigate the genetic relatedness of VRE isolates and the possibility of a common environmental reservoir using environmental sampling and whole-genome sequencing (WGS).

METHODS

Infection control measures consisted of contact isolation, contact surveys, point prevalence screening, environmental sampling, cleaning and disinfection. VRE isolates were sequenced using a MiSeq sequencer (Illumina, San Diego, CA, USA), and assembled using SPAdes v.3.10.1. A minimal spanning tree and a neighbour joining tree based on allelic diversity of core-genome multi-locus sequence typing and accessory genes were created using Ridom SeqSphere+ software (Ridom GmbH, Münster, Germany).

FINDINGS

Over a 1-year period, 19 VRE carriers were identified; of these, 17 were part of two outbreaks. Before environmental cleaning and disinfection, 55 (14%) environmental samples were VRE-positive. Fifty-one isolates (23 patient samples and 28 environmental samples) were available for WGS analysis. Forty-four isolates were assigned to ST117-vanB, five were assigned to ST17-vanB, and two were assigned to ST80-vanB. Isolates from Outbreak 1 (N=22) and Outbreak 2 (N=22) belonged to ST117-vanB; however, WGS showed a different cluster type with 257 allelic differences.

CONCLUSION

WGS of two outbreak strains provided discriminatory information regarding genetic relatedness, and rejected the hypothesis of a common environmental reservoir. A high degree of environmental contamination was associated with higher VRE transmission. Quantification of environmental contamination may reflect the potential for VRE transmission and could therefore support the infection control measures.

Accurate serology for SARS-CoV-2 and common human coronaviruses using a multiplex approach

Serology is a crucial part of the public health response to the ongoing SARS-CoV-2 pandemic. Here, we describe the development, validation and clinical evaluation of a protein micro-array as a quantitative multiplex immunoassay that can identify S and N-directed SARS-CoV-2 IgG antibodies with high specificity and sensitivity and distinguish them from all currently circulating human coronaviruses. The method specificity was 100% for SARS-CoV-2 S1 and 96% for N antigen based on extensive syndromic (n=230 cases) and population panel (n=94) testing that also confirmed the high prevalence of seasonal human coronaviruses. To assess its potential role for both SARS-CoV-2 patient diagnostics and population studies, we evaluated a large heterogeneous COVID-19 cohort (n=330) and found an overall sensitivity of 89% (≥ 21 days post onset symptoms (dps)), ranging from 86% to 96% depending on severity of disease. For a subset of these patients longitudinal samples were provided up to 56 dps. Mild cases showed absent or delayed, and lower SARS-CoV-2 antibody responses. Overall, we present the development and extensive clinical validation of a multiplex coronavirus serological assay for syndromic testing, to answer research questions regarding to antibody responses, to support SARS-CoV-2 diagnostics and to evaluate epidemiological developments efficiently and with high-throughput.

Development of a SARS-CoV-2 Total Antibody Assay and the Dynamics of Antibody Response over Time in Hospitalized and Nonhospitalized Patients with COVID-19

Severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infections often cause only mild disease that may evoke relatively low Ab titers compared with patients admitted to hospitals. Generally, total Ab bridging assays combine good sensitivity with high specificity. Therefore, we developed sensitive total Ab bridging assays for detection of SARS-CoV-2 Abs to the receptor-binding domain (RBD) and nucleocapsid protein in addition to conventional isotype-specific assays. Ab kinetics was assessed in PCR-confirmed, hospitalized coronavirus disease 2019 (COVID-19) patients (n = 41) and three populations of patients with COVID-19 symptoms not requiring hospital admission: PCR-confirmed convalescent plasmapheresis donors (n = 182), PCR-confirmed hospital care workers (n = 47), and a group of longitudinally sampled symptomatic individuals highly suspect of COVID-19 (n = 14). In nonhospitalized patients, the Ab response to RBD is weaker but follows similar kinetics, as has been observed in hospitalized patients. Across populations, the RBD bridging assay identified most patients correctly as seropositive. In 11/14 of the COVID-19-suspect cases, seroconversion in the RBD bridging assay could be demonstrated before day 12; nucleocapsid protein Abs emerged less consistently. Furthermore, we demonstrated the feasibility of finger-prick sampling for Ab detection against SARS-CoV-2 using these assays. In conclusion, the developed bridging assays reliably detect SARS-CoV-2 Abs in hospitalized and nonhospitalized patients and are therefore well suited to conduct seroprevalence studies.

Differences in Antibody Kinetics and Functionality Between Severe and Mild Severe Acute Respiratory Syndrome Coronavirus 2 Infections

We determined and compared the humoral immune response in patients with severe (hospitalized) and mild (nonhospitalized) coronavirus disease 2019 (COVID-19). Patients with severe disease (n = 38) develop a robust antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including immunoglobulin G and immunoglobulin A antibodies. The geometric mean 50% virus neutralization titer is 1:240. SARS-CoV-2 infection was found in hospital personnel (n = 24), who developed mild symptoms necessitating leave of absence and self-isolation, but not hospitalization; 75% developed antibodies, but with low/absent virus neutralization (60% with titers <1:20). While severe COVID-19 patients develop a strong antibody response, mild SARS-CoV-2 infections induce a modest antibody response. Long-term monitoring will show whether these responses predict protection against future infections.

Using eHealth to Support COVID-19 Education, Self-Assessment, and Symptom Monitoring in the Netherlands: Observational Study

BACKGROUND

The coronavirus disease (COVID-19) situation demands a lot from citizens, health care providers, and governmental institutions. Citizens need to cope with guidelines on social interaction, work, home isolation, and symptom recognition. Additionally, health care providers and policy makers have to cope with unprecedented and unpredictable pressure on the health care system they need to manage. By providing citizens with an app, they always have access to the latest information and can assess their own health. This data could be used to support policy makers and health care providers to get valuable insights in the regional distribution of infection load and health care consumption.

OBJECTIVE

The aim of this observational study is to assess people's use of an app to support them with COVID-19 education, self-assessment, and monitoring of their own health for a 7-day period. In addition, we aim to assess the usability of this data for health care providers and policy makers by applying it to an interactive map and combining it with hospital data. The secondary outcomes of the study were user's satisfaction with the information provided in the app, perceived usefulness of the app, health care providers they contacted, and the follow-up actions from this contact.

METHODS

This observational cohort study was carried out at the nonacademic teaching hospital "Elisabeth Twee Steden" (ETZ) in Tilburg, Netherlands. From April 1, 2020, onwards ETZ offered the COVID-19 education, self-assessment, and symptom tracking diary to their already existing app for patient education and monitoring.

RESULTS

Between April 1 and April 20, 2020, a total of 6194 people downloaded the app. The self-assessment functionality was used abundantly to check one's health status. In total, 5104 people responded to the question about severe symptoms, from which 242 indicated to suffer from severe symptoms. A total of 4929 people responded to the question about mild symptoms, from which 3248 indicated to suffer from these. The data was successfully applied to an interactive map, displaying user demographics and health status. Furthermore, the data was linked to clinical data. App users were satisfied with the information in the app and appreciated the symptom diary functionality. In total, 102 users reached out to a health care provider, leading to 91 contacts.

CONCLUSIONS

Our study demonstrated the successful implementation and use of an app with COVID-19 education, self-assessment, and a 7-day symptom diary. Data collected with the app were successfully applied to an interactive map. In addition, we were able to link the data to COVID-19 screening results from the hospital's microbiology laboratory. This data could be used to support policy makers and health care providers to get valuable insights in the regional distribution of infection load and health care consumption.

TRIAL REGISTRATION

Netherlands Trial Register NL8501; https://www.trialregister.nl/trial/8501.

[The first 100 COVID-19 patients admitted to the Elisabeth-Tweesteden Hospital, Tilburg, The Netherlands]

Here we describe the characteristics of the first 100 laboratory confirmed COVID-19 patients admitted to the Elisabeth-Tweesteden Hospital (Tilburg, The Netherlands). The median age was 72 years, 67% was male, approximately 80% had co-morbidity, approximately 50% of which consisted of hypertension, cardiac and or pulmonary conditions and 25% diabetes. At admission 61% of patients had fever and about 50% presented at day 6 or more after onset of symptoms. At the time of writing 38 patients were discharged, 19 admitted to the intensive care unit (ICU) and 20 patients had died. The median age of ICU patients was 67 years and 63% had co-morbidity. The median time to discharge or to death was 6 and 5.5 days, respectively.

Rapid assessment of regional SARS-CoV-2 community transmission through a convenience sample of healthcare workers, the Netherlands, March 2020

To rapidly assess possible community transmission in Noord-Brabant, the Netherlands, healthcare workers (HCW) with mild respiratory complaints and without epidemiological link (contact with confirmed case or visited areas with active circulation) were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Within 2 days, 1,097 HCW in nine hospitals were tested; 45 (4.1%) were positive. Of six hospitals with positive HCW, two accounted for 38 positive HCW. The results informed local and national risk management.

Focusing on Good Responders to Pneumococcal Polysaccharide Vaccination in General Hospital Patients Suspected for Immunodeficiency. A Decision Tree Based on the 23-Valent Pneumococcal IgG Assay

Background and Aim: Recently, the 23-valent IgG-assay was suggested as screening assay to identify poor responders to pneumococcal polysaccharide (PnPS)-vaccination with the serotype-specific assay as a second-line test. However, in a low pre-test probability general hospital setting predicting good responders could be more valuable to reduce the number of samples needing serotyping. Methods: Serotype-specific PnPS antibody-assays were performed for suspected immunodeficiency in two Dutch general hospitals (Jeroen Bosch Hospital, 's-Hertogenbosch; Elisabeth Tweesteden Hospital, Tilburg). 23-Valent PnPS antibody-assays were subsequently performed in archived material. Data were analyzed using receiver operating characteristic curves (AUC) and agreement indices (ICC). Results: Sera of 284 patients (348 samples) were included; 23-valent IgG-titres and the corresponding sum of PnPS-serotype specific antibodies showed moderate correlation (ICC = 0.63). In 232 conjugated-pneumococcal-vaccine-naïve patients (270 samples), a random 23-valent IgG-titer could discriminate between samples with and without ≥7/11, ≥7/13, or ≥6/9 pneumococcal serotypes when both cut-off values 0.35 and 1.0 μg/ml were used (AUC 0.86 and 0.92, respectively). All patients with a pre-immunization-titer ≥38.2 μg/ml and/or post-immunization-titer ≥96.1 μg/ml and none with a post-immunization-titer ≤38.5 μg/ml exhibited a good response to PnPS vaccination. Using these breakpoints as screening test to predict good responders, only 24% of patients would require further serotyping, as opposed to 68% if breakpoints to predict poor responders would have been used. Conclusion: In a low pre-test probability setting, the 23-valent IgG-assay proved to be a reliable screening test for good responders in conjugated-pneumococcal-vaccine-naïve patients, reducing the overall number of patient samples needing further serotyping, thus reducing overall costs of pneumococcal vaccination response assessment.

Pharmacokinetics of favipiravir during continuous venovenous haemofiltration in a critically ill patient with influenza

Favipiravir is a novel antiviral drug approved for influenza treatment in Japan. Little is known about favipiravir pharmacokinetics in critically ill patients. Here, we report a patient with influenza treated with favipiravir and undergoing continuous venovenous haemofiltration (CVVH) on the Intensive Care Unit of a tertiary hospital in the Netherlands. Pharmacokinetic analyses showed increased clearance and decreased plasma levels compared to healthy volunteers. CVVH has no clinically relevant contribution to total clearance. Despite susceptibility to favipiravir, the influenza virus was not cleared. A multi-disciplinary approach is needed to ensure optimal favipiravir treatment in critically ill patients.

Added diagnostic value of broad-range 16S PCR on periprosthetic tissue and clinical specimens from other normally sterile body sites

AIMS

Evaluation of 16S PCR in addition to the standard culture to improve the pathogen detection rate in clinical specimens.

METHODS AND RESULTS

Microbiological culture and direct 16S PCR was performed on specimens from suspected prosthetic joint infection patients (cohort-1) and on tissues and fluids from other normally sterile body sites (cohort-2). Based on clinical and microbiological data, the detection rate for both methods was assessed, assuming no superiority of either 16S PCR or culture. In cohort-1, 469 specimens were obtained. Culture was positive in 170 (36·2%) specimens, 16S PCR detected 70 (41·2%) of those pathogens. Additionally, 16S PCR detected pathogens in 13 of 299 (4·3%) culture-negative specimens. In cohort-2, pathogens were cultured in 52 of 430 (12·1%) specimens and 16S PCR revealed those pathogens in 32 (61·5%) specimens. 16S PCR detected pathogens in 31 of 378 (8·2%) culture-negative specimens.

CONCLUSIONS

Overall, the yield with 16S PCR was low. For cohort-1 16S PCR detected pathogens in 4·3% of culture-negative specimens, where this was 8·2% for cohort-2.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although direct 16S PCR cannot replace culture, it may offer a valuable additional diagnostic option for detection of difficult to culture micro-organisms in culture-negative clinical specimens.

Progressive multifocal leukoencephalopathy in patients treated with fumaric acid esters: a review of 19 cases

Progressive multifocal leukoencephalopathy (PML) is a rare and potentially fatal condition caused by a brain infection with JC polyomavirus (JCV). PML develops almost exclusively in immunocompromised patients and has recently been associated with use of fumaric acid esters (FAEs), or fumarates. We reviewed the literature and the Dutch and European pharmacovigilance databases in order to identify all available FAE-associated PML cases and distinguish possible common features among these patients. A total of 19 PML cases associated with FAE use were identified. Five cases were associated with FAE use for multiple sclerosis and 14 for psoriasis. Ten patients were male and nine were female. The median age at PML diagnosis was 59 years. The median duration of FAE therapy to PML symptom onset or appearance of first PML lesion on brain imaging was 31 months (range 6-110). In all cases a certain degree of lymphocytopenia was reported. The median duration of lymphocytopenia to PML symptom onset was 23 months (range 6-72). The median lymphocyte count at PML diagnosis was 414 cells/µL. CD4 and CD8 counts were reported in ten cases, with median cell count of 137 and 39 cells/µL, respectively. Three patients died (16% mortality). The association between occurrence of PML in patients with low CD4 and CD8 counts is reminiscent of PML cases in the HIV population and suggests that loss of T cells is the most important risk factor.

Congenital Cytomegalovirus Infection in the Absence of Maternal Cytomegalovirus-IgM Antibodies

BACKGROUND

Congenital cytomegalovirus (cCMV) infections are the most prevalent intrauterine infections worldwide and are the result of maternal primary or non-primary infections. Early maternal primary infections are thought to carry the highest risk of fetal developmental abnormalities as seen by ultrasound; however, non-primary infections may prove equally detrimental.

METHODS/RESULTS

This case series presents 5 cases with fetal abnormalities detected in the second and third trimester, in which cCMV infection was ruled out due to negative maternal CMV-IgM.

DISCUSSION

This series highlights the possible pitfalls in serology interpretation and fetal diagnosis necessary for appropriate parental counseling. Once fetal abnormalities have been confirmed and cCMV is suspected, maternal CMV serostatus and fetal infection should be determined. Maternal CMV serology may be ambiguous; therefore, caution should be exercised when interpreting the results.

Acute influenza virus-associated encephalitis and encephalopathy in adults: a challenging diagnosis

Background: Acute influenza-associated encephalopathy/encephalitis (IAE) in adults is a rare but well-known complication of influenza virus infection. The diagnosis is difficult to make due to the absence of distinctive clinical symptoms and validated diagnostic criteria. We present an illustrative case and a case review on acute IAE in adults. Methods: We performed a Medline search of the English literature using the terms influenz*, encephal* and adult, and constructed a database of detailed descriptions of patients with influenza virus infection with influenza-like symptoms at the onset of neurological symptoms. Results: A total of 44 patients were included. Confusion and seizures were the most prevalent neurological symptoms, present in 12 (27 %) and 10 (23 %) patients, respectively. Magnetic resonance imaging (MRI) was performed in 21 patients and anomalies were found in 13 (62 %), with lesions located throughout the brain. Influenza virus RNA was detected in cerebrospinal fluid (CSF) in 5 (16 %) of 32 patients. Eight (18 %) of the forty-four patients died. The benefits of antiviral and immunomodulatory therapy have not been well studied. Discussion: Our results show that many different neurological symptoms can be present in patients with acute onset IAE. Therefore, the diagnosis should be considered in patients with fever and neurological symptoms, especially during the influenza season. Laboratory diagnosis consists of demonstration of influenza virus RNA in brain tissue, CSF or respiratory samples, and demonstration of intrathecal antibody production against influenza virus. The presence of brain lesions in MRI and influenza virus in CSF appear to be of prognostic value.

Progressive multifocal leukoencephalopathy and black fungus in a patient with rheumatoid arthritis without severe lymphocytopenia

Introduction:

Progressive multifocal leukoencephalopathy (PML) is a rare demyelinating brain infection caused by JC polyomavirus (JCV), primarily seen in patients with severely compromised cellular immunity. Clinical presentation varies depending on the affected white matter. PML prognosis is variable and effective treatments are lacking.

Case presentation:

A 75-year-old Chinese woman with type 2 diabetes mellitus, chronic kidney disease and rheumatoid arthritis, treated with low-dose methotrexate and prednisolone for 2.5 years, developed a Pleurostomophora richardsiae infection of her left arm. After 6 months of treating this rare black fungus infection with voriconazole, surgery and immunosuppression discontinuation, she presented with progressive afebrile encephalopathy with right-sided hemiparesis. There were no signs of inflammation or metabolic abnormalities. Brain magnetic resonance imaging revealed diffuse frontal white matter lesions and a cerebrospinal fluid PCR confirmed PML due to JC virus. Severe lymphopenia was never present, and at PML diagnosis, CD4 and CD8 T-cell counts were 454 mm⁻³ and 277 mm⁻³. CD8 T-cells were able to respond to JCV VP1 peptide stimulation with TNFα secretion. Peripheral B-cell count was only 8 mm⁻³. Mirtazapine and Maraviroc were started, but unfortunately, she rapidly deteriorated and died 5 weeks after PML diagnosis.

Conclusion:

Although peripheral lymphocyte counts were never low and CD4 T-cell count was close to normal, the persistent black fungus infection was a hallmark of severely compromised cellular immunity. The unexpected extremely low absolute B-cell count might suggest a protective role for B-cells. The paradoxical, clinical PML onset months after immunosuppressive discontinuation suggests that it was only discovered in the context of an immune reconstitution inflammatory syndrome.

Epidemiology of Guillain-Barré Syndrome in Aruba

The epidemiology of Guillain-Barré syndrome (GBS) in tropical areas is different compared with developed countries. We investigated the epidemiology of GBS on the Caribbean island of Aruba. Data were collected retrospectively from all 36 patients hospitalized with GBS between 2003 and 2011 in Aruba. We observed a seasonal distribution of GBS cases with a peak in February. The incidence rate (IR) fluctuated heavily between individual years. The overall IR was 3.93/100,000, which is higher than that observed in developed countries. Serological studies indicated a possible relation of GBS cases with dengue virus infections. We also observed a relation between the annual number of dengue cases in Aruba and the number of GBS cases in the same year. We conclude that the epidemiology of GBS in tropical areas can be different from temperate climate regions and that dengue may be a trigger for developing GBS.

Inactivation of Influenza A virus, Adenovirus, and Cytomegalovirus with PAXgene tissue fixative and formalin

Formalin fixation is known to inactivate most viruses in a vaccine production context, but nothing is published about virus activity in tissues treated with alternative, non-crosslinking fixatives. We used a model assay based on cell culture to test formalin and PAXgene Tissue fixative for their virus-inactivating abilities. MDCK, A549, and MRC-5 cells were infected with Influenza A virus, Adenovirus, and Cytomegalovirus, respectively. When 75% of the cells showed a cytopathic effect (CPE), the cells were harvested and incubated for 15 min, or 1, 3, 6, or 24 hours, with PBS (positive control), 4% formalin, or PAXgene Tissue Fix. The cells were disrupted and the released virus was used to infect fresh MDCK, A549, and MRC-5 cells cultured on cover slips in 24-well plates. The viral cultures were monitored for CPE and by immunocytochemistry (ICC) to record viral replication and infectivity. Inactivation of Adenovirus by formalin occurred after 3 h, while Influenza A virus as well as Cytomegalovirus were inactivated by formalin after 15 min. All three virus strains were inactivated by PAXgene Tissue fixative after 15 min. We conclude that PAXgene Tissue fixative is at least as effective as formalin in inactivating infectivity of Influenza A virus, Adenovirus, and Cytomegalovirus.

Persistent spiking fever in a child with acute myeloid leukemia and disseminated infection with enterovirus

We here report a 7 year old acute myeloid leukemia patient with persistent spiking fever likely caused by chronic echovirus 20 infection. After immunoglobulin substitution fevers subsided and the virus was cleared. Enterovirus infection should be considered in immunocompromised patients with unexplained persistent fever.

Urine is superior to saliva when screening for postnatal CMV infections in preterm infants

BACKGROUND

Cytomegalovirus (CMV) is the most frequently contracted virus in preterm infants. Postnatal infection is mostly asymptomatic but is sometimes associated with severe disease. To diagnose an infection, urine or saliva samples can be tested for CMV-DNA by real-time polymerase chain reaction (rtPCR). Although the diagnostic accuracy of testing saliva samples has not been determined in preterm infants, saliva is widely used because it is easier to obtain than urine.

OBJECTIVES

To determine whether screening of saliva is equivalent to urine to detect a postnatal CMV infection in preterm infants.

STUDY DESIGN

Between 2010 and 2013 saliva and urine samples were collected from infants admitted to the Neonatal Intensive Care Unit of the University Medical Center Utrecht and born with a gestational age (GA) below 32 weeks. Urine samples were obtained within three weeks after birth and urine and saliva samples at term equivalent age (40 weeks GA) and tested for CMV-DNA by rtPCR. Infants with a congenital CMV infection were excluded.

RESULTS

Of 261 preterm infants included in the study, CMV-DNA was detected in urine of 47 and in saliva of 43 children. Of 47 infants with postnatal CMV infection, CMV was detected in 42 saliva samples (sensitivity 89.4%; CI 76.9-96.5). Of 214 children without postnatal CMV infection, one saliva sample tested positive for CMV (specificity 99.5%; CI 97.4-99.9).

CONCLUSIONS

Screening saliva for CMV-DNA by rtPCR is inferior to urine to diagnose postnatal CMV infections in preterm infants.

[The embarrassing lessons of Ebola: scientific knowledge comes too late]

The current Ebola epidemic in Western Africa painfully illustrates both the devastating power of a deadly virus once introduced into a severely compromised health care system, and the unpreparedness of Western countries to respond appropriately. After at least 3857 casualties there has still been hardly any scientific evaluation of therapeutic or preventive treatments. The first uncontrolled observations of a new cocktail of monoclonal antibodies look promising, but given the size of the epidemic, only large-scale vaccination might be sufficient for effective control.

Five-minute Giemsa stain for rapid detection of malaria parasites in blood smears

The Giemsa stain is used as the gold standard for the diagnosis of malaria on blood smears. The classical staining procedure requires between 30 and 45 min. We modified the Giemsa stain and reduced the staining time to 5 min without any loss of quality.

The plasticity of multivesicular bodies and the regulation of antigen presentation

Multivesicular bodies (MVBs) are ubiquitous endocytic organelles containing numerous 50-80 nm vesicles. MVBs are very dynamic in shape and function. In antigen presenting cells (APCs), MVBs play a central role in the loading of major histocompatibility complex class II (MHC II) with antigenic peptides. How MHC II is transported from MVBs to the cell surface is only partly understood. One way involves direct fusion of MVBs with the plasma membrane. As a consequence, their internal vesicles are secreted as so-called exosomes. An alternative has been illustrated in maturing dendritic cells (DCs). Here, MVBs are reshaped into long tubules by back fusion of the internal vesicles with the MVB limiting membrane. Vesicles derived from the tips of these tubules then carry MHC II to the cell surface.

Interleukin-1 receptor type I gene-deficient mice are less susceptible to Staphylococcus epidermidis biomaterial-associated infection than are wild-type mice

Elevated concentrations of interleukin-1 (IL-1) were found in tissue surrounding biomaterials infected with Staphylococcus epidermidis. To determine the role of IL-1 in biomaterial-associated infection (BAI), IL-1 receptor type I-deficient (IL-1R(-/-)) and wild-type mice received subcutaneous implants of silicon elastomer (SE) or polyvinylpyrrolidone-grafted SE (SEpvp), combined with an injection of 10(6) CFU of S. epidermidis or sterile saline. Neither mouse strain was susceptible to BAI around SE. IL-1R(-/-) mice with SEpvp implants had a no abscess formation and a reduced susceptibility to persistent S. epidermidis infection. The normal foreign body response, characterized by giant-cell formation and encapsulation, was delayed around SEpvp in wild-type mice but not in IL-1R(-/-) mice. This coincided with enhanced local IL-4 production in IL-1R(-/-) mice. These data suggest that inhibition of local IL-1 activity may be beneficial for the outcome of BAI.

Biomaterial-associated persistence of Staphylococcus epidermidis in pericatheter macrophages

Biomaterial surfaces may be modified to reduce bacterial adhesion. The susceptibility in mice to Staphylococcus epidermidis infection in tissue surrounding the commonly used catheter materials-silicon elastomer (SE), polyamide (PA), and their surface-modified polyvinylpyrrolidone (PVP)-grafted derivatives, SE-PVP and PA-PVP, respectively-was assessed. Abscesses developed around SE-PVP. Around SE, PA, and PA-PVP catheters, no signs of infection were observed, although mice carrying PA-PVP developed septicemia after 14-21 days. S. epidermidis was cultured from the tissue surrounding PA-PVP segments. Cells around PA-PVP segments containing large numbers of bacteria were identified as macrophages by use of immunohistochemistry and electron microscopy. This persistence of intracellular bacteria was also observed around SE-PVP, SE, and PA catheters, although to a lesser extent. The cytokine profiles around the 4 materials were different. Implanted biomaterial induces an inflammatory response favorable to the persistence of S. epidermidis. Intracellular persistence of bacteria inside macrophages may be a pivotal process in the pathogenesis of biomaterial-associated infection.

Enhanced susceptibility to subcutaneous abscess formation and persistent infection around catheters is associated with sustained interleukin-1beta levels

A persistent Staphylococcus epidermidis infection in mice around a subcutaneous polyvinylpyrrolidone-grafted silicon elastomer catheter (SEpvp) but not around a conventional silicon elastomer catheter was observed. With SEpvp pericatheter tissue, protracted and exaggerated interleukin-1beta (IL-1beta) production was found. Apparently, sustained levels of IL-1beta are associated with enhanced susceptibility to biomaterial-associated S. epidermidis infection.