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A two-step strategy combining assisted benchmark testing (entry controls) and External Quality Assessments (EQAs) with blinded simulated clinical specimens to enhance and maintain the quality of nucleic acid amplification testing was developed. This strategy was successfully applied to 71 diagnostic laboratories in The Netherlands when upscaling the national diagnostic capacity during the SARS-CoV-2 pandemic. The availability of benchmark testing in combination with advice for improvement substantially enhanced the quality of the laboratory testing procedures for SARS-CoV-2 detection. The three subsequent EQA rounds demonstrated high quality testing with regard to specificity (99.6% correctly identified) and sensitivity (93.3% correctly identified). Even with the implementation of novel assays, changing workflows using diverse equipment and a high degree of assay heterogeneity, the overall high quality was maintained using this two-step strategy. We show that in contrast to the limited value of Cq value for absolute proxies of viral load, these Cq values can, in combination with metadata on strategies and techniques, provide valuable information for laboratories to improve their procedures. In conclusion, our two-step strategy (preparation phase followed by a series of EQAs) is a rapid and flexible system capable of scaling, improving, and maintaining high quality diagnostics even in a rapidly evolving (e.g. pandemic) situation. [ABSTRACT FROM AUTHOR]

Our study aim was to determine how a new clinical pathway, including PCR‐based influenza point‐of‐care test (POCT), influences the hospitalisation costs of patients suspected of influenza presenting at the emergency department of a Dutch hospital during two consecutive influenza epidemics (2016‐2017 and 2017‐2018). Compared to mean costs per patient of €3661 in 2016‐2017, the implementation of this new clinical pathway with influenza POCT in 2017 was associated with mean costs per influenza‐positive patient of €2495 in 2017‐2018 (P =.3). Our study suggests favourable economic results regarding a new clinical pathway with influenza POCT, reflecting a more efficient care of patients suspected of influenza presenting at the emergency department. [ABSTRACT FROM AUTHOR]

Objectives and design: Non-Hodgkin lymphoma has been linked to infection with Coxiella burnetii, potentially through overproduction of IL-10 during infection with C. burnetii.Materials and methods: Description of a case report.Results: We describe a patient with retroperitoneal non-Hodgkin lymphoma and vascular infection with C. burnetii. Immunofluorescence staining and fluorescence in situ hybridization targeting specific C. burnetii 16S rRNA were performed on the retroperitoneal lymphoma tissue sample obtained at diagnosis of NHL. Both were strongly positive for the presence of C. burnetii.Conclusions: This case provokes questions regarding a potential association between C. burnetii and NHL, and underlines the importance of further exploration of this association. [ABSTRACT FROM AUTHOR]

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Background After the largest outbreaks of Q fever ever recorded in history occurred in the Netherlands, concern arose that Coxiella may be transmitted via donated tissues of latent or chronically infected donors. The Dutch Health Council recently advised to screen tissue donors, donating high risk tissues, for Coxiella infection. Methods After validation of an enzyme immunoassay (EIA) test for IgG antibodies against phase 2 of C. burnetii for use on post-mortem samples, serum samples of 1033 consecutive Dutch post-mortem tissue donors were tested for IgG antibodies against phase 2 of C. burnetii. Confirmation of reactive results was done by immunofluorescence assay (IFA). All available tissues (corneas, heart valves, skin and bone marrow) from donors with IgG reactivity were tested for presence of Coxiella DNA by PCR. Risk factors for IgG reactivity were investigated. Results After validation of the tests for use on post-mortem samples, 50/1033 donors (4.8%) screened positive for phase 2 anti-Coxiella IgG by EIA, and 31 were confirmed by IFA (3.0%). One donor showed a serological profile compatible with chronic infection. All tested tissues (25 corneas, 6 heart valves, 4 skin and 3 bone marrow) from donors with IgG reactivity tested negative for the presence of Coxiella DNA. Except for living in a postal code area with a high number of Q fever notifications, no risk factors for IgG reactivity were found. Conclusions The strong correlation between notifications and seroprevalence confirms that the used assays are sufficiently specific for use on post-mortem samples, although one has to be aware of differences between batches. Thus, this study provides a validated method for screening tissue donors for infection with Coxiella burnetii that can be used in future outbreaks. [ABSTRACT FROM AUTHOR]

The article discusses a case-control study that was performed to identify and quantify the risk factors for development of chronic Q fever after Coxiella burnetii infection in the Netherlands. A comparison was made of comorbidity, cardiovascular risk factors, medications, and demographic characteristics from patients with proven, probable or possible chronic Q fever and patients who had acute Q fever but who did not develop chronic Q fever. It was found that valvular surgery, vascular prosthesis, aneurysm, renal insufficiency, and older age were independent risk factors associated with the development of chronic Q fever.

Background: A large portion of tissues stored worldwide for diagnostic purposes is formalin-fixed and paraffin embedded (FFPE). These FFPE-archived tissues are an extremely valuable source for retrospective (genetic) studies. These include mutation screening in cancer-critical genes as well as pathogen detection. In this study we evaluated the impact of several widely used DNA extraction methods on the quality of molecular diagnostics on FFPE tissues. Findings: We compared 4 DNA extraction methods from 4 identically processed FFPE mammary-, prostate-, colonand lung tissues with regard to PCR inhibition, real time SNP detection and amplifiable fragment size. The extraction methods, with and without proteinase K pre-treatment, tested were: 1) heat-treatment, 2) QIAamp DNAblood- mini-kit, 3) EasyMAG NucliSens and 4) Gentra Capture-Column-kit. Amplifiable DNA fragment size was assessed by multiplexed 200-400-600 bp PCR and appeared highly influenced by the extraction method used. Proteinase K pre-treatment was a prerequisite for proper purification of DNA from FFPE. Extractions with QIAamp, EasyMAG and heat-treatment were found suitable for amplification of fragments up to 400 bp from all tissues, 600 bp amplification was marginally successful (best was QIAamp). QIAamp and Easy- MAG extracts were found suitable for downstream real time SNP detection. Gentra extraction was unsuitable. Hands-on time was lowest for heat-treatment, followed by EasyMAG. Conclusions: We conclude that the extraction method plays an important role with regard to performance in downstream molecular applications. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas aeruginosa is an important bacterial pathogen, particularly as a cause of nosocomial infections in hospitalized patients. Only few reports exist in which cystoscopes were implicated as an outbreak source. We describe an investigation into the cause of a sudden increase in the number of urinary tract infections (UTI) with P . aeruginosa in patients after cystoscopy. In addition, we share the lessons learned and measures taken to reduce the risk of similar infections in the future., Presentation of Case: Over a period of two weeks the urology outpatient department noticed a UTI in four patients following cystoscopy. An investigation was started for a common source of the outbreak in the urological treatment room. Additional screening of patients revealed a total of eleven males with P. aeruginosa UTI following cystoscopy. The infections were found to be due to a defective drying cabinet, which lacked an alarm signaling in case of loss of airflow. Amplified fragment length polymorphism (AFLP) analysis revealed that P. aeruginosa isolates from three patients and six isolates from environmental cultures (including cystoscopes from the drying cabinet) genotypically belonged to one strain., Discussion: The AFLP results suggest that contaminated cystoscopes caused P. aeruginosa UTI in 11 patients, with the drying cabinet as site of transfer of the infective strain. To our knowledge, this is the first report describing a malfunctioning drying cabinet as source of an outbreak following cystoscopy., Conclusion: In case of concomitant P. aeruginosa infections, cystoscopes and drying cabinets should be suspected as a potential source. Molecular techniques are helpful in investigating the epidemiology of an outbreak., (© 2024 The Authors.)

Introduction: Coxiella burnetii, the causative pathogen of Q fever, is regularly detected in throat swabs from patients without serological evidence of Q fever infection. C. burnetii is also frequently found in bulk tank milk from dairy cows. We evaluated the false positivity rate of polymerase chain reaction (PCR) for C. burnetii DNA on throat swabs and investigated whether recent consumption of C. burnetii DNA-positive cow milk could contribute to this phenomenon., Methods: C. burnetii PCR was performed on throat swabs obtained from patients in whom a throat swab was ordered for other diagnostic purposes; patients with community-acquired pneumonia (CAP); and healthy volunteers after consumption of commercial C. burnetii-containing cow milk products., Results: C. burnetii DNA was found in 5.0% of throat swabs ordered for other diagnostic purposes and in 15.3% of throat swabs from CAP patients without serological evidence of Q fever pneumonia. The positive and negative predictive value of C. burnetii PCR on throat swabs for Q fever pneumonia were 66.7% (95% CI, 38.0-88.2) and 48.9% (95% CI, 41.3-54.6), respectively. After consumption of commercial C. burnetii-containing cow milk products, C. burnetii DNA could be detected in throat swabs for as long as 30 min after ingestion., Conclusion: C. burnetii PCR on throat swabs is of low diagnostic value for Q fever pneumonia and was false positive in 15.3% of CAP patients without Q fever pneumonia. Recent consumption of C. burnetii-containing products can influence the outcome of C. burnetii PCR on throat swabs. Therefore, diagnosis of C. burnetii infection should be made in combination with serology or PCR performed on blood., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Purpose: Coxiella burnetii has been suggested as a potential cause of B-cell non-Hodgkin lymphoma (B-NHL), as C. burnetii was detected in B-NHL tissues. To further investigate this potential relationship, we hypothesized that among subjects previously exposed to C. burnetii, the bacterium is more frequently detectable in tissues of patients with B-NHL (cases) compared to patients without B-NHL (controls)., Methods: We aimed to evaluate this hypothesis by assessing the presence of C. burnetii with polymerase chain reaction (PCR), immunofluorescence staining (IF) and fluorescent in-situ hybridization (FISH). Eligible patients were those previously exposed to C. burnetii., Results: Samples were available for 13 cases and 16 controls. C. burnetii was demonstrated in tissues of 8/29 patients in total (28%), with either PCR, IF or FISH: in 5/13 cases (38%) and 3/16 controls (19%), p = 0.41. Negative and positive control samples were all negative and positive appropriately for all three diagnostic methods., Conclusions: In patients previously exposed to C. burnetii the bacterium was detected in tissue samples from subjects with and without B-NHL, without significant differences in the proportion positive samples. Therefore, we conclude that detection of C. burnetii in tissues of patients previously exposed to C. burnetii is a non-specific finding., (Copyright © 2018 Elsevier GmbH. All rights reserved.)