Viral Dynamics of Omicron and Delta Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Variants With Implications for Timing of Release from Isolation: A Longitudinal Cohort Study.

BACKGROUND: In January 2022, US guidelines shifted to recommend isolation for 5 days from symptom onset, followed by 5 days of mask-wearing. However, viral dynamics and variant and vaccination impact on culture conversion are largely unknown. METHODS: We conducted a longitudinal study on a university campus, collecting daily anterior nasal swabs for at least 10 days for reverse-transcription polymerase chain reaction (RT-PCR) testing and culture, with antigen rapid diagnostic testing (RDT) on a subset. We compared culture positivity beyond day 5, time to culture conversion, and cycle threshold trend when calculated from diagnostic test, from symptom onset, by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, and by vaccination status. We evaluated sensitivity and specificity of RDT on days 4-6 compared with culture. RESULTS: Among 92 SARS-CoV-2 RT-PCR-positive participants, all completed the initial vaccine series; 17 (18.5%) were infected with Delta and 75 (81.5%) with Omicron. Seventeen percent of participants had positive cultures beyond day 5 from symptom onset, with the latest on day 12. There was no difference in time to culture conversion by variant or vaccination status. For 14 substudy participants, sensitivity and specificity of day 4-6 RDT were 100% and 86%, respectively. CONCLUSIONS: The majority of our Delta- and Omicron-infected cohort culture-converted by day 6, with no further impact of booster vaccination on sterilization or cycle threshold decay. We found that rapid antigen testing may provide reassurance of lack of infectiousness, though guidance to mask for days 6-10 is supported by our finding that 17% of participants remained culture-positive after isolation.

Analysis of Interview Breakoff in the Behavioral Risk Factor Surveillance System, 2018 and 2019.

Introduction: Survey breakoff is an important source of total survey error. Most studies of breakoff have been of web surveys-less is known about telephone surveys. In the past decade, the breakoff rate has increased in the Behavioral Risk Factor Surveillance System, the world's largest annual telephone survey. Analysis of breakoff in Behavioral Risk Factor Surveillance System can improve the quality of Behavioral Risk Factor Surveillance System. It will also provide evidence in research of total survey error on telephone surveys. Methods: We used data recorded as breakoff in the 2018 and 2019 Behavioral Risk Factor Surveillance System. We converted questions and modules to a time variable and applied Kaplan-Meier method and a proportional hazard model to estimate the conditional and cumulative probabilities of breakoff and study the potential risk factors associated with breakoff. Results: Cumulative probability of breakoffs up to the end of the core questionnaire was 7.03% in 2018 and 9.56% in 2019. The highest conditional probability of breakoffs in the core was 2.85% for the physical activity section. Cumulative probability of breakoffs up to the end of the core was higher among those states that inserted their own questions or optional modules than among those that did not in both years. The median risk ratio of breakoff among all states was 5.70 in 2018 and 3.01 in 2019. Survey breakoff was associated with the length of the questionnaire, the extent of expected recollection, and the location of questions. Conclusions: Breakoff is not an ignorable component of total survey error and should be considered in Behavioral Risk Factor Surveillance System data analyses when variables have higher breakoff rates.

Effects of a Multidisciplinary Stewardship Program on the Prevention of Delirium in the Pediatric Intensive Care Unit.

OBJECTIVE: To evaluate the effect of a multidisciplinary practice bundle on the incidence of delirium in the pediatric intensive care unit (PICU). METHODS: This retrospective observational study evaluated patients admitted to the PICU with Cornell Assessment of Pediatric Delirium (CAPD) scoring. A multidisciplinary practice bundle was implemented involving pharmacists, nurses, and providers. Study endpoints included CAPD scores greater than or equal to 9, length of hospital stay, and days spent in the PICU. RESULTS: The study included 192 patients. The pre-intervention mean CAPD score was 3.59, maximum of 24 (range, 0-24), and 4.5% of patients had a score ≥9. The post-intervention mean score was 4.04, maximum of 21 (range, 0-21), and 9.6% of patients had a score ≥9. The pre-intervention mean total length of hospital stay was 8.7 days, maximum of 149 days (range, 0-149); the mean number of days spent in PICU was 4.5 days, and maximum days in PICU was 89 days (range, 0-89). The post-intervention mean total length of hospital stay was 8.8 days, maximum of 57 days (range, 0-57); the mean number of days spent in PICU was 3.9 days, and maximum days in PICU was 31 days (range, 0-31). CONCLUSIONS: Implementation of a multidisciplinary practice bundle, the use of CAPD scores, and the stewardship of high-risk patients increased overall awareness of the occurrence of pediatric delirium in the PICU and reduced length of stay in the intensive care unit and therefore reduced cost for families and the institute.

Viral dynamics of Omicron and Delta SARS-CoV-2 variants with implications for timing of release from isolation: a longitudinal cohort study.

Background: In January 2022, United States guidelines shifted to recommend isolation for 5 days from symptom onset, followed by 5 days of mask wearing. However, viral dynamics and variant and vaccination impact on culture conversion are largely unknown. Methods: We conducted a longitudinal study on a university campus, collecting daily anterior nasal swabs for at least 10 days for RT-PCR and culture, with antigen rapid diagnostic testing (RDT) on a subset. We compared culture positivity beyond day 5, time to culture conversion, and cycle threshold trend when calculated from diagnostic test, from symptom onset, by SARS-CoV-2 variant, and by vaccination status. We evaluated sensitivity and specificity of RDT on days 4-6 compared to culture. Results: Among 92 SARS-CoV-2 RT-PCR positive participants, all completed the initial vaccine series, 17 (18.5%) were infected with Delta and 75 (81.5%) with Omicron. Seventeen percent of participants had positive cultures beyond day 5 from symptom onset with the latest on day 12. There was no difference in time to culture conversion by variant or vaccination status. For the 14 sub-study participants, sensitivity and specificity of RDT were 100% and 86% respectively. Conclusions: The majority of our Delta- and Omicron-infected cohort culture-converted by day 6, with no further impact of booster vaccination on sterilization or cycle threshold decay. We found that rapid antigen testing may provide reassurance of lack of infectiousness, though masking for a full 10 days is necessary to prevent transmission from the 17% of individuals who remain culture positive after isolation. Main Point: Beyond day 5, 17% of our Delta and Omicron-infected cohort were culture positive. We saw no significant impact of booster vaccination on within-host Omicron viral dynamics. Additionally, we found that rapid antigen testing may provide reassurance of lack of infectiousness.