Background Antigen rapid diagnostic tests (RDT) for SARS-CoV-2 are fast, broadly available, and inexpensive. Despite this, reliable clinical performance data is sparse. Methods In a prospective performance evaluation study, RDT from three manufacturers (NADAL, Panbio, MEDsan) were compared to quantitative reverse transcription polymerase chain reaction (RT-qPCR) in 5 068 oropharyngeal swabs for detection of SARS-CoV-2 in a hospital setting. Viral load was derived from standardized RT-qPCR Cycle threshold (Ct) values. The data collection period ranged from November 12, 2020 to February 28, 2021. Findings Overall, sensitivity of RDT compared to RT-qPCR was 42.57% (95% CI 33.38%-52.31%), and specificity 99.68% (95% CI 99.48%-99.80%). Sensitivity declined with decreasing viral load from 100% in samples with a deduced viral load of 10^8 SARS-CoV-2 RNA copies per ml to 8.82% in samples with a viral load lower than 104 SARS-CoV-2 RNA copies per ml. No significant differences in sensitivity or specificity could be observed between the three manufacturers, or between samples with and without spike protein variant B.1.1.7. The NPV in the study cohort was 98.84%; the PPV in persons with typical COVID-19 symptoms was 97.37%, and 28.57% in persons without or with atypical symptoms. Interpretation RDT are a reliable method to diagnose SARS-CoV-2 infection in persons with high viral load. RDT are a valuable addition to RT-qPCR testing, as they reliably detect infectious persons with high viral loads before RT-qPCR results are available. Funding German Federal Ministry for Education and Science (BMBF), Free State of Bavaria

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BackgroundPublished models predicting nasal colonization with Methicillin-resistant Staphylococcus aureus among hospital admissions predominantly focus on separation of carriers from non-carriers and are frequently evaluated using measures of discrimination. In contrast, accurate estimation of carriage probability, which may inform decisions regarding treatment and infection control, is rarely assessed. Furthermore, no published models adjust for MRSA prevalence.MethodsUsing logistic regression, a scoring system (values from 0 to 200) predicting nasal carriage of MRSA was created using a derivation cohort of 3091 individuals admitted to a European tertiary referral center between July 2007 and March 2008. The expected positive predictive value of a rapid diagnostic test (GeneOhm, Becton & Dickinson Co.) was modeled using non-linear regression according to score. Models were validated on a second cohort from the same hospital consisting of 2043 patients admitted between August 2008 and January 2012. Our suggested correction score for prevalence was proportional to the log-transformed odds ratio between cohorts. Calibration before and after correction, i.e. accurate classification into arbitrary strata, was assessed with the Hosmer-Lemeshow-Test.ResultsTreating culture as reference, the rapid diagnostic test had positive predictive values of 64.8% and 54.0% in derivation and internal validation corhorts with prevalences of 2.3% and 1.7%, respectively. In addition to low prevalence, low positive predictive values were due to high proportion (> 66%) of mecA-negative Staphylococcus aureus among false positive results. Age, nursing home residence, admission through the medical emergency department, and ICD-10-GM admission diagnoses starting with “A” or “J” were associated with MRSA carriage and were thus included in the scoring system, which showed good calibration in predicting probability of carriage and the rapid diagnostic test’s expected positive predictive value. Calibration for both probability of carriage and expected positive predictive value in the internal validation cohort was improved by applying the correction score.ConclusionsGiven a set of patient parameters, the presented models accurately predict a) probability of nasal carriage of MRSA and b) a rapid diagnostic test’s expected positive predictive value. While the former can inform decisions regarding empiric antibiotic treatment and infection control, the latter can influence choice of screening method.

Increasing resistance of specific-fishpathogenic and facultative-fishpathogenic bacteria against the main drugs licensed in Germany.With an average of yearly 600 examined cases-including the whole range of additional virological-, bacteriological-, histological-, water quality and residual. tests-the Fish Health Service (FHS) of Hannover of the Northern Federal State of LOWER SAXONY reached within the last years some representative experience dealing with the control and therapy of fish diseases in aquaculture. The control of the three notifiable viral epidemics of freshwater fish presently included in the pertinent legislation (Animal Epidemics Act) of the FRG-VHS, IPN and SVC-is the competence of the STATE FISH EPIDEMICS CONTROL SERVICE OF LOWER SAXONY from which the FHS mentioned above is a part. The therapy of bacterial diseases-essentially Aeromonas salmonicida infections (Furunculosis/Salmonids; Erythrodermatits/Cyprinids), vibriosis, from 1981 on increasingly Enteric Redmouth Disease/ERM (with an unexpected peak in late winter-, spring and summer 1984) as well as the mainly environment dependent-sometimes with septicemic development of the whole range of ubiquitous facultative-fishpathogenic bacteria from the aquatic environment-developed rather unprob lematic and successful in Lower Saxony for many years. From 1981 on a change in this situation with concomitant increasing resistance of specific-fishpathogenic as well as facultative-fishpathogenic bacteria. against the main drugs licensed in the FRG and used in the control of freshwater fish diseases mainly through medicated feed is observed. The bacterological examination with antibiogramme proved indispensable. In the FRG the presently licensed drugs for treatment of bacterial infections in fish are Chloramphenicol, Chlor-and Oxitetracycline, Furazolidone, Trimethoprim/Sulfadimethoxine and Nifurpracine. In the FRG Chloramphenicol was forbidden for use in domestic animals (homoeotherms) for human consumption in April 1984. It is to assume that Chloramphenicol will be withdrawn for use in fish soon. Only in few individual cases and strictly controlled by the veterinary authorities some other drugs can be experimentally tested under prescription and strict supervision of a veterinarian specialized in fish diseases and aquaculture. Besides the substances mentioned above antibiogrammes are routinely carried out with Oxolinic acid, "Lincospectin" (Lincomycine + Spectinomycine 1 : 2), Ampicilline, Erythromycine and very recently Flumequine.The results of 596 FHS-cases from which in 289 the bacteriological examination proceed necessaryfrom them in 162 cases the antibiogramme was feasible-carried out within the frame of the work of the FHS from January 1983 to May 1984 are discussed-, the increased resistance showed-, the effectivity and/or uselessness of some of the drugs presented. Flumequine, Oxolinic acid, Lincospectine (not yet licensed in the FRG) and last but not least the tetracyclines showed promising. The finding of few Aeromonas salmonicida subsp. sal...