RESEARCH BRIEFING

French study finds daycare does not increase spread of covid-19 in young children

For working parents of young children, the covid-19 pandemic has not been kind from a productivity standpoint. Reliable, affordable childcare is something of a myth in the United States, and the pandemic strained what limited options existed before. Daycares closed at the start of the United States outbreak, out of fear that children would be efficient viral vectors. Since then, a mounting body of evidence has found that children are in fact less commonly associated with viral spread, at least in some settings (as covered in Brief19 as early as May of last year). But less is known about SARS-CoV-2 transmission in daycare or preschool settings, precisely because fears around the disease led most such facilities to close, and in many instances stay closed for months at a time. In short, because of covid-19 fears, there have been few opportunities to study this question rigorously. However, a new French study has shown such fears have not in fact been borne out.

At the end of the first coronavirus stay-at-home period last June, researchers in France wanted to know how many young children between 3 months old and 5 years of age who attended daycares had evidence of prior SARS-CoV-2 infection. They focused their efforts on 22 daycare centers in three major cities in France: Annecy, Rouen and Paris. They also studied daycare staff for signs of previous infection. 

At the time of the study, nearly 10 percent of the Parisian population was estimated to have been affected by covid-19. (Rouen is a two-hour drive and Annency is approximately a 7-hour drive from Paris, respectively. Editor's note: Annency looks absolutely beautiful and the Brief19 team would quite like to visit the area when this is all over). The researchers examined blood samples from 327 children along with 197 daycare staff in an effort to detect antibodies which would indicate a previous infection. Fourteen of the children (accounting for four percent) were found to have evidence of active covid-19 (based on particular antibodies that arise early in the disease, rather than the nasal PCR testing that most health officials and researchers use to track active or recent infection). According to information gathered from their parents, 43 percent of those children were asymptomatic. The cases were spread across 13 daycares, so no clusters of positivity were identified. There was, however, a correlation between adults testing positive in their homes beforehand. Furthermore, roughly seven percent of daycare staff were exposed to covid-19 across eight different daycares, two of which had small clusters of infection.

Ultimately, the researchers concluded that young children are more likely to get covid-19 at home than at daycare, adding to a growing body of evidence asserting that congregant settings for children such as daycare or preschools are not responsible for the majority of community spread so far. 

On the other hand, the spread of any infectious disease increases when people are together for longer, so it could be that these data reflect the simple fact that despite daycare being a destination for these French children, they still spend a majority of their time at hone. 

Nevertheless, these data may be helpful in the push to reopen childcare and learning centers across the country and the globe in areas where it is otherwise safe to do so and the proper safety mechanisms are in place. 

It should be noted, however, that this study was conducted in June, prior to the introduction of new, more infectious variants. It is possible that children could be more effective spreaders of the viral variants currently in circulation. But if these data hold up, given what we know about the importance of getting children socialized and educated, and how difficult it is to accomplish the latter in remote learning environments, it may be both safe and advisable to get the little ones back to in-person learning settings, whenever possible.


POLICY BRIEFING

WHO: covid-19 not leaked from a Chinese lab

At a news conference this week, World Health Organization (WHO) experts visiting Wuhan, China dismissed the notion that SARS-CoV-2 was leaked from a Chinese virology lab. Rumors to this effect have circulated over the past year. 

The WHO team's visit did not substantially change the known facts about the initial stages of the outbreak, though some new details were uncovered. The experts concluded that an accidental release of the virus from the lab in question, The Wuhan Institute of Virology, was very unlikely and also that no evidence had been found to suggest any purposeful release. 

The Chinese scientists involved in the site visits also noted that the virus had not been known to exist in any lab worldwide before it was discovered in patients in Wuhan late in 2019. The team, composed of experts from 10 countries, visited multiple sites throughout Wuhan, including a food market where an early cluster of cases was discovered, grabbing international headlines. 

The investigators also experienced significantly more cooperation from the Chinese government than initially expected, noting that all sites and personnel that had been requested for access during the visit had been made available to them. More research into the virus's origination and outbreak is expected in the future. The leading theory remains that the virus jumped from an animal vector, such as a pangolin or a fruit bat, similar to other important causes of infectious diseases.


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