99.1% of close contacts of Omicron-infected patients diagnosed by 10 days
Late last week in Emerging Infectious Diseases, South Korean researchers reported that average time from exposure to COVID-19 diagnosis was 3.7 days in quarantined close contacts of patients infected by the SARS-CoV-2 Omicron variant and that 99.1% of diagnoses occurred by day 10, supporting a 10-day quarantine.
The study evaluated time from exposure to diagnosis among 107 close contacts from two Omicron clusters on Nov 24 and 25, 2021. In South Korea, close contacts of Omicron patients were mandated to quarantine for 14 days amid surges, regardless of symptom and vaccination status. Contacts were tested for COVID-19 on days 1, 9, and 13.
Average time from exposure to diagnosis was 3.7 days. Of all contacts, 50% were diagnosed on day 3, while 70% were diagnosed on day 5 and 99.1% by day 10. One diagnosis occurred on day 13 in an unvaccinated child who had previously tested negative.
Half of contacts in all age-groups were diagnosed on day 3. Of contacts with COVID-19 symptoms, half of diagnoses occurred on day 3, and 70% on day 5. COVID-19 diagnoses among contacts without symptoms occurred in 50% on day 5 and 70% on day 8.
The study findings led the South Korean government to shorten quarantine from 14 to 10 days and to 7 days in times of surge-related limited capacity at quarantine facilities.
The researchers noted that unpublished data from a previous study suggested that the incubation period for Omicron could be shorter than that for the Delta variant. "Estimating the duration of infectiousness is more challenging than measuring incubation periods; one study that measured viral load of Omicron suggested that viral load had diminished by days 10–13, which is in line with our findings."
While the most effective COVID-19 containment measures are isolation and quarantine, the authors noted that these strategies come with personal and socioeconomic costs. "A 10-day quarantine period may encompass most persons exposed to Omicron; however, quarantine duration may become shorter after balancing societal cost with public health benefit," they concluded.
Mar 11 Emerg Infect Dis research letter
Support tool tied to better antibiotic prescribing for pneumonia patients
A real-time electronic decision support tool helped clinicians at community hospitals provide best practice care for emergency department (ED) patients with pneumonia and was associated with decreased intensive care unit (ICU) admission, more appropriate antibiotic use, and 38% lower overall death according to a study last week in the American Journal of Respiratory and Critical Care Medicine.
For the study, researchers at Intermountain Healthcare in Salt Lake City, Utah, deployed the health system's electronic, open loop, clinical decision support (ePNa) system to 16 of its community hospitals from December 2017 to June 2019. During that span, those hospitals had 6,848 pneumonia cases, and a treating clinician used ePNa in 67% of eligible patients.
The support tool gathers more than 50 key patient indicators, including age, fever, oxygen saturation, laboratory and chest imaging results, and vital signs to make care decisions, including appropriate antibiotic therapy, lab studies, and treatment setting recommendations, such as ICU admittance, hospital admittance, or discharge. Median patient age was 67 years, 48% were female, and 64.8% were admitted to the hospital.
Using the tool, Intermountain researchers found a range of positive outcomes for patients, including a 38% relative reduction in mortality 30 days after a pneumonia diagnosis, with the largest reduction in death rates in patients admitted directly from the ED to the ICU. Guideline-concordant antibiotic prescribing increased from 83.5% to 90.2% (P < 0.001).
Other findings were a 61% increase in patients treated as outpatients (increasing from 29.2% to 46.9%), decreased ICU admissions without safety concerns, and lowered mean time from ED admission to start of first antibiotic, dropping from 159.4 minutes to 150.9 minutes.
The researchers say the findings are consistent with a previous study involving use of the ePNa system in Intermountain's larger hospitals.
"Our study found that clinicians were able to make better treatment decisions with this resource," said first author Nathan Dean, MD, in an Intermountain news release. "Some of our community hospitals have as little as 20 beds. We wanted to validate the effectiveness of ePNa in very different healthcare settings."
Mar 9 Am J Respir Crit Care Med study
Mar 9 Intermountain Healthcare news release
