By Kelly Young

Edited by André Sofair, MD, MPH, and William E. Chavey, MD, MS

Here are some of the latest developments in COVID-19:

Mask comparisons: Researchers in Australia used high-speed cameras to photograph light scattered by aerosols and respiratory droplets that were expelled during speaking, coughing, and sneezing when a volunteer wore different masks. A three-layer surgical mask was the most effective at limiting droplet spread. A two-layer cloth cotton mask was more effective during coughing and sneezing than one made from a single layer, but even the single-layer mask was better than no mask. The authors write in Thorax: “Guidelines on home-made cloth masks should stipulate multiple layers (at least 3).”

Return-to-sports guidance: The American Academy of Pediatrics has released a set of recommendations for youth athletes. To limit the spread of COVID-19, the group recommends cloth face coverings for coaches, officials, spectators, and volunteers, as well as for athletes on the sidelines. Facial coverings are also recommended during non-vigorous exercise when physical distancing isn’t feasible. For athletes exposed to COVID-19, the AAP recommends a minimum of 2 weeks without exercise or competition. Youths who are symptomatic should take a 2–4-week break and should be cleared for participation by a clinician. Those with severe presentations should be treated as if they have myocarditis and should not exercise for 3–6 months.

Perinatal transmission: Women positive for SARS-CoV-2 when they give birth are at low risk for transmitting the virus to their newborns when proper precautions are taken, according to a study in The Lancet Child & Adolescent Medicine. Researchers studied some 80 neonates whose mothers were positive for SARS-CoV-2 at delivery in New York. Roughly 80% of the neonates roomed with their mothers. Mothers wore a surgical mask when they were near their infant and practiced hand and breast hygiene when handling or breast-feeding the child. None of the neonates tested positive through 14 days of follow-up. The authors conclude: “In view of the benefits of early mother–neonate bonding and breastfeeding, rooming in with the mother and direct breastfeeding are safe and should be promoted, but these procedures need to be paired with effective parental education of infant protective strategies.”