COVID-19 test-to-stay strategies found safe, effective for students
A study today in Pediatrics suggests a test-to-stay (TTS) strategy, as opposed to quarantine, was a safe and effective tool for Massachusetts public schools for the 2021-22 school year, as it was associated with both limited COVID-19 transmission and increased in-person learning days for students.
The TTS program required all students exposed to a COVID-19 case in the classroom to use a rapid antigen test for 7 days following the last exposure date. If the test was negative, students could remain in school. The program was opt-in, and for students who chose not to participate, an exposure resulted in at-home quarantine for at least 7 days following any in-school close contact if the student was not fully vaccinated.
A total of 2,298 schools signed up for TTS, and during the first 13 weeks of the program (September to December 2021) 1,959 schools used TTS for 102,373 individual, exposed students. Out of 328,271 tests performed, 2,943 positive cases were identified, for a per-person positivity rate of 2.9%, similar to during mandatory quarantine the year before.
The authors said the TTS program resulted in a minimum of 325,328 and a maximum of 497,150 days of in-person school for participants that could have been lost to quarantine.
While the study results were encouraging, a commentary in the same journal argued that TTS may not work for under-resourced schools and students. The authors are John Neatherlin, MPH, and Lisa Barrios, DrPH, ScM, of the Centers for Disease Control and Prevention, and Ebony Thomas, MPH, of Emory University.
"If TTS participants must seek testing in the community, barriers including out-of-pocket costs, transportation logistics, and access to health care provider-based testing need to be addressed," the commentators wrote.
"Unvaccinated students in school districts without the capacity to implement TTS, and students in TTS districts who have barriers to opt in to these programs, may not have equal access to in-person learning. Increasing access to and uptake of COVID-19 vaccines will allow more students to stay in the classroom."
Apr 8 Pediatrics study and commentary
Omicron COVID-19 infections appear milder, shorter than Delta cases
An observational study yesterday in The Lancet suggests that COVID-19 infections with the Omicron subvariant have less involvement of the lower respiratory tract, lower odds of hospitalization, and shorter duration of illness and infectiousness than Delta cases.
Led by King's College London researchers, the prospective study recruited 63,002 UK residents aged 16 years and older reporting their COVID-19 test results and symptoms in a smartphone app from Jun 1, 2021, to Jan 17, 2022. Participants had tested positive for COVID-19, were symptomatic, and had received at least two doses of any COVID-19 vaccine.
The primary study outcome was the likelihood of having any of 32 symptoms monitored in the app or being hospitalized within 7 days before or after testing positive during the period of Delta (Jun 1 to Nov 27, 2021) versus Omicron (Dec 20, 2021, to Jan 17, 2022) dominance.
In the first period, Delta was responsible for more than 70% of all cases in the United Kingdom and for COVID-19 infections among 4,990 participants matched for age, sex, and vaccine dose with 4,990 infected during the period in which Omicron was responsible for more than 70% of infections.
Participants reported less loss of smell during the Omicron period than during Delta (16.7% vs 52.7%; odds ratio [OR], 0.17), but sore throat was more common during Omicron than Delta (70.5% vs 60.8%; OR, 1.55). Hospitalization was less common during Omicron than Delta (1.9% vs 2.6%; OR, 0.75).
"The prevalence of symptoms that characterise an omicron infection differs from those of the delta SARS-CoV-2 variant," the study authors wrote. "Our data indicate a shorter period of illness and potentially of infectiousness, which should impact work–health policies and public health advice."
In a related commentary, Linda Houhamdi, PharmD, PhD, and Pierre-Edouard Fournier, MD, PhD, both of Aix-Marseille Universite in France, noted that people younger than 16 years and those who were obese were excluded from the study. "Indeed, omicron cases have been reported in patients younger than 16 years, and obesity is an indisputable comorbidity factor in the severity of COVID-19."
Apr 7 Lancet study and commentary