Impaired humoral immunity to BQ.1.1 in convalescent and vaccinated patients.

Determining SARS-CoV-2 immunity is critical to assess COVID-19 risk and the need for prevention and mitigation strategies. We measured SARS-CoV-2 Spike/Nucleocapsid seroprevalence and serum neutralizing activity against Wu01, BA.4/5 and BQ.1.1 in a convenience sample of 1,411 patients receiving medical treatment in the emergency departments of five university hospitals in North Rhine-Westphalia, Germany, in August/September 2022. 62% reported underlying medical conditions and 67.7% were vaccinated according to German COVID-19 vaccination recommendations (13.9% fully vaccinated, 54.3% one booster, 23.4% two boosters). We detected Spike-IgG in 95.6%, Nucleocapsid-IgG in 24.0%, and neutralization against Wu01, BA.4/5 and BQ.1.1 in 94.4%, 85.0%, and 73.8% of participants, respectively. Neutralization against BA.4/5 and BQ.1.1 was 5.6- and 23.4-fold lower compared to Wu01. Accuracy of S-IgG detection for determination of neutralizing activity against BQ.1.1 was reduced substantially. We explored previous vaccinations and infections as correlates of BQ.1.1 neutralization using multivariable and Bayesian network analyses. Given a rather moderate adherence to COVID-19 vaccination recommendations, this analysis highlights the need to improve vaccine-uptake to reduce the COVID-19 risk of immune evasive variants. The study was registered as clinical trial (DRKS00029414).

Evaluation of a new COVID-19 triage algorithm in the emergency department including combined antigen and PCR-testing: A case-control study.

The coronavirus disease 2019 (COVID-19) pandemic is a major challenge for global healthcare systems. Early and safe triage in the emergency department (ED) is crucial for proper therapy. However, differential diagnosis remains challenging. Rapid antigen testing (RAT) may help to improve early triage and patient safety. We performed a retrospective study of 234 consecutive patients with suspected COVID-19 who presented to our ED in November 2020. All underwent SARS-CoV-2-nasopharyngeal swab testing using both RAT and reverse transcription polymerase chain reaction (RT-PCR). The inpatient treatment was established according to an empirically developed triage algorithm. The accuracy of the suggested algorithm was analyzed based on the rate of outpatients returning within 7 days and inpatients staying for less than 48 hours. COVID-19 inpatients and outpatients were compared for symptoms, vital signs, and C-reactive protein levels. Of the 221 included patients with suspected COVID-19 infection, the diagnosis could be confirmed in 120 patients (54.3%) by a positive RT-PCR result, whereas only 72% of those had a positive antigen test. Of the 56 COVID-19 outpatients, three returned within 7 days with the need for hospital treatment due to clinical deterioration. Among the 64 COVID-19 inpatients, 4 were discharged within 48 hours, whereas 60 stayed longer (mean duration 10.2 days). The suggested triage algorithm was safe and efficient in the first 234 consecutive patients. RAT can confirm a diagnosis in 72% of PCR proven COVID-19 patients and allows early cohort isolation as an important way to save hospital capacity.

What about the others: differential diagnosis of COVID-19 in a German emergency department.

BACKGROUND: The ongoing COVID-19 pandemic remains a major challenge for worldwide health care systems and in particular emergency medicine. An early and safe triage in the emergency department (ED) is especially crucial for proper therapy. Clinical symptoms of COVID-19 comprise those of many common diseases; thus, differential diagnosis remains challenging. METHOD: We performed a retrospective study of 314 ED patients presenting with conceivable COVID-19 symptoms during the first wave in Germany. All were tested for COVID-19 with SARS-Cov-2-nasopharyngeal swabs. Forty-seven patients were positive. We analyzed the 267 COVID-19 negative patients for their main diagnosis and compared COVID-19 patients with COVID-19 negative respiratory infections for differences in laboratory parameters, symptoms, and vital signs. RESULTS: Among the 267 COVID-19 negative patients, 42.7% had respiratory, 14.2% had other infectious, and 11.2% had cardiovascular diseases. Further, 9.0% and 6.7% had oncological and gastroenterological diagnoses, respectively. Compared to COVID-19 negative airway infections, COVID-19 patients showed less dyspnea (OR 0.440; p = 0.024) but more dysgeusia (OR 7.631; p = 0.005). Their hospital stay was significantly longer (9.0 vs. 5.6 days; p = 0.014), and their mortality significantly higher (OR 3.979; p = 0.014). CONCLUSION: For many common ED diagnoses, COVID-19 should be considered a differential diagnosis. COVID-19 cannot be distinguished from COVID-19 negative respiratory infections by clinical signs, symptoms, or laboratory results. When hospitalization is necessary, the clinical course of COVID-19 airway infections seems to be more severe compared to other respiratory infections. TRIAL REGISTRATION: German Clinical Trial Registry DRKS, DRKS-ID of the study: DRKS00021675 date of registration: May 8th, 2020, retrospectively registered.

SARS-CoV-2 rapid antigen test: Fast-safe or dangerous? An analysis in the emergency department of an university hospital.

The use of Antigen point of care tests (AgPOCT) might be an essential tool to fight the coronavirus disease 2019 (COVID-19) pandemic. Manufacturer information indicates a specificity of about 95% and there is a growing interest to use these tests area-wide. Therefore, it is necessary to clarify whether AgPOCT can be used safely for "rule-in" (detection of positive patients) and for "rule-out" (valid negative testing). Two thousand three hundred and seventy-five patients received polymerase chain reaction (PCR) testing and AgPOCT for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) regardless of symptoms. The positive predictive value of symptomatic and asymptomatic patients was compared with a cut-off threshold cycle (C t ) value of ≤30 and in total. Five hundrded and fifty-one patients tested positive for the SARS-CoV-2 virus by PCR, of whom 35.2% presented without symptoms. In all patients, regardless of their symptoms or C t values, a sensitivity of 68.9% and a specificity of 99.6% were calculated for AgPOCT. In patients with C t values ≤30, a sensitivity of 80.5% (95% confidence interval: ±1.62) and a specificity of 99.6% were shown for all tests (symptomatic/asymptomatic). Highly infectious patients (C t ≤ 20), regardless of symptoms, were reliably detected by the AgPOCT. In infectious patients with C t values ≤30, the test has a sensitivity of about 80% regardless of COVID-19 typical symptoms, which is apparently less than the 96.52% specificity indicated by the manufacturer. Relevant improvement in test sensitivity by querying the patients who are symptomatic and asymptomatic is also not feasible. We strongly suggest that we critically question the use of AgPOCT for "rule-out," as they only provide a supposed safety.