De-isolation of vaccinated COVID-19 health care workers using rapid antigen detection test.

BACKGROUND: COVID-19 de-isolation guidelines of health care workers (HCW) were formulated based on evidence describing the duration of infectious viral shedding of the wild SARS-CoV-2 virus. During the periods of COVID-19 vaccination and variants, a test-based approach was recommended to end isolation of HCW, based on emerging data describing the viral kinetics of COVID-19 variants. While Rapid antigen detection tests (RADT) are increasingly used in the diagnosis of COVID-19, their use is limited in de-isolation. METHODS: We described the use of RADT in the de-isolation of COVID-19 vaccinated HCW with mild infection who were asymptomatic on day 7 post diagnosis in a single center retrospective cohort study during the Omicron surge. RESULTS: Of the 480 HCWs, 173 (36%) had positive RADT. The positivity rate of RADT was not different in HCW who received two doses versus three doses of vaccine (34.4% versus 40.3%, p = 0.239). CONCLUSIONS: A symptom based, test-based approach using RADT is a useful tool in the de-isolation of HCW, with mild disease, in the era of Omicron. Further studies are required to evaluate the role of RADT in de-isolation of patients with severe COVID-19 disease.

Molecular epidemiology and outcome of carbapenem-resistant Enterobacterales in Saudi Arabia.

BACKGROUND: The burden of carbapenem resistance is not well studied in the Middle East. We aimed to describe the molecular epidemiology and outcome of carbapenem-resistant Enterobacterales (CRE) infections from several Saudi Arabian Centers. METHODS: This is a multicenter prospective cohort study conducted over a 28-month period. Patients older than 14 years of age with a positive CRE Escherichia coli or Klebsiella pneumoniae culture and a clinically established infection were included in this study. Univariate and multivariable logistic models were constructed to assess the relationship between the outcome of 30-day all-cause mortality and possible continuous and categorical predictor variables. RESULTS: A total of 189 patients were included. The median patient age was 62.8 years and 54.0% were male. The most common CRE infections were nosocomial pneumonia (23.8%) and complicated urinary tract infection (23.8%) and 77 patients (40.7%) had CRE bacteremia. OXA-48 was the most prevalent gene (69.3%). While 100 patients (52.9%) had a clinical cure, 57 patients (30.2%) had died within 30 days and 23 patients (12.2%) relapsed. Univariate analysis to predict 30-day mortality revealed that the following variables are associated with mortality: older age, high Charlson comorbidity index, increased Pitt bacteremia score, nosocomial pneumonia, CRE bacteremia and diabetes mellitus. In multivariable analysis, CRE bacteremia remained as an independent predictor of 30 day all-cause mortality [AOR and 95% CI = 2.81(1.26-6.24), p = 0.01]. CONCLUSIONS: These data highlight the molecular epidemiology and outcomes of CRE infection in Saudi Arabia and will inform future studies to address preventive and management interventions.

Test-based de-isolation in COVID-19 immunocompromised patients: Cycle threshold value versus SARS-CoV-2 viral culture.

BACKGROUND: Immunocompromised patients with coronavirus disease 2019 (COVID-19) have prolonged infectious viral shedding for more than 20 days. A test-based approach is suggested for de-isolation of these patients. METHODS: The strategy was evaluated by comparing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral load (cycle threshold (Ct) values) and viral culture at the time of hospital discharge in a series of 13 COVID-19 patients: six immunocompetent and seven immunocompromised (five solid organ transplant patients, one lymphoma patient, and one hepatocellular carcinoma patient). RESULTS: Three of the 13 (23%) patients had positive viral cultures: one patient with lymphoma (on day 16) and two immunocompetent patients (on day 7 and day 11). Eighty percent of the patients had negative viral cultures and had a mean Ct value of 20.5. None of the solid organ transplant recipients had positive viral cultures. CONCLUSIONS: The mean Ct value for negative viral cultures was 20.5 in this case series of immunocompromised patients. Unlike those with hematological malignancies, none of the solid organ transplant patients had positive viral cultures. Adopting the test-based approach for all immunocompromised patients may lead to prolonged quarantine. Large-scale studies in disease-specific populations are needed to determine whether a test-based approach versus a symptom-based approach or a combination is applicable for the de-isolation of various immunocompromised patients.