The authors calculated likelihood ratios for individual symptoms and found that almost all individual symptoms had likelihood ratios of 1:1.8 for testing positive. However, nausea and vomiting had a likelihood ratio of 5.5, and for anosmia it was 7.3. The combination of symptoms of nausea, nausea and vomiting, and headache produced a likelihood ratio of nearly 66. The authors suggest that these data on ambulatory children indicate that, in general, respiratory symptoms are not helpful for distinguishing patients who are likely to be positive, although the symptoms of nausea, headache, and both along with fever can be highly predictive. The authors propose that it may be more helpful for schools to focus on identifying children with combinations of these high-yield symptoms for potential testing and exclusion from school rather than on random or isolated respiratory symptoms.
COVID-19 in schools
Transmission risk in different settings is certainly something parents quiz pediatricians about, so data released in January and February 2021 may help provide some context. A CDC report on the experience of 17 schools in Wisconsin from August to November 2020 is illuminating. In that study, the SARS-CoV-2 case rate in students, school teachers, and staff members was 63% of the rate in the general public at the time, suggesting that the mitigation strategies used by the schools were effective. In addition, among the students who contracted SARS-CoV-2, only 5% of cases were attributable to school exposure. No cases of SARS-CoV-2 among faculty or staff were linked to school exposure.
Indeed, data released on Feb. 2, 2021, demonstrate that younger adults are the largest source of sustaining the epidemic. On the basis of data from August to October 2020, the opening of schools does not appear to be associated with population-level changes in SARS-CoV-2–attributable deaths. For October 2020, the authors estimate that 2.7% of infections were from children 0-9 years old, 7.1% from those ages 10-19 years, but 34% from those 20-34 years old and 38% from those 35-49 years old, by far the largest two groups contributing to spread. It should be noted that ages 20-49 years are the peak working years for adults, but the source of the data did not allow the authors to conclude whether infections were work related or social activity related. Their data do suggest that prioritizing vaccination of younger working-age adults may put more of a dent in the pandemic spread than vaccinating older individuals.
In a similar vein, a systematic review and meta-analysis of recent studies looked at household transmission of SARS-CoV-2 and demonstrated an attack rate within households of 16.6%. Of note, secondary household attack rates were only 0.7% from asymptomatic cases and 18% from symptomatic cases, with spouses and adult household contacts having higher secondary attack rates than children in the household.
COVID-19 in student athletes
A recent MMWR report described a SARS-CoV-2 outbreak associated with a series of wrestling tournaments in Florida, held in December and January 2021. While everyone would like children to be able to participate in sports, such events potentially violate several of the precepts for preventing spread: Avoid close contact and don’t mix contacts from different schools. Moreover, the events occurred during some of the highest incident case rates in the counties where the tournaments took place.
On Dec. 4, 2020, the AAP released updated guidance for athletic activities and recommended cloth face coverings for student athletes during training, in competition, while traveling, and even while waiting on the sidelines and not actively playing. Notable exceptions to the recommendation were competitive cheerleading, gymnastics, wrestling, and water sports, where the risk for entanglement from face coverings was too high or was not practical.
Taken as a whole, the evolving data continue to show that school mitigation practices can be effective in reducing the risk for SARS-CoV-2 infection. In addition, SARS-CoV-2 rates among schoolchildren more closely mirror community rates and are probably more influenced by what happens outside the schools than inside the schools.
A version of this article first appeared on Medscape.com.