The Week That Wasn't: Silent Transmission, Smart Distancing, Plague Squirrel

Victoria Giardina


July 17, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

This week in COVID-19 news, a new study said silent transmission may be responsible for half of cases, another study suggested people who practice social distancing may be more intelligent, and a squirrel has tested positive for the bubonic plague. But you didn't see these headlines on Medscape Medical News. Here's why.

Silent Transmission

More than half of the cases of COVID-19 in the United States may be caused by "silent transmission," the spread of virus by someone with no obvious symptoms, according to a recent study in the Proceedings of the National Academy of Sciences. The research team used information from previous studies to estimate the extent to which silent transmission ― mostly from infected people in the presymptomatic stage, but also from asymptomatic persons ― contributes to viral spread.

Medscape has previously reported on silent transmission, but we didn't cover this study because it was based on a model, not new experimental evidence. Models are important epidemiologic tools, but they are only as good as the numbers that go into them and represent estimates, not truth. We didn't think this study offered novel, conclusive information beyond what we've already covered.

Smart Distancing

Many public health agencies have explained why it's smart to practice social distancing, but a new study in the Proceedings of the National Academy of Sciences suggests that people who follow these guidelines may be smarter than those who don't.

Researchers provided questionnaires on demographics and social distancing practices to 850 participants and conducted tests of their personality and cognitive capacity. Participants who complied with social distancing guidelines scored better on tests of working memory. After controlling for education, moods, personality, and income levels, the researchers found that working memory scores predicted social distancing behavior.

"This suggests policy makers will need to consider individuals' general cognitive abilities when promoting compliance behaviors such as wearing a mask or engaging in physical distancing," Weiwei Zhang, study researcher, said in a press release. Zhang suggests public health campaigns should be "succinct, concise and brief" to avoid information overload and to effectively target more individuals.

Although this study provides an interesting psychological perspective on COVID-19, it's a stretch to conclude ― as some headlines have suggested ― that individuals who practice social distancing are "smarter" than those who don't follow the guidelines. We didn't think this finding, which is still somewhat theoretical, was of practice-changing priority for our audience.

Bubonic Plague Squirrel

A Colorado squirrel has tested positive for the bubonic plague, Jefferson County Public Health reported. Elsewhere, in Mongolia, a teenage boy died from bubonic plague after hunting and eating marmot this past week, CNN reported. Humans can become infected through bites from plague-ridden fleas or animals, but the risk of contracting the plague is "extremely low" if people take proper precautions, public health officials from Colorado wrote.

Although this story seems dramatic, the county public health department's announcement says the plague usually occurs in Colorado each year. Moreover, the reports of plague in these two locations don't directly affect a large segment of our Medscape audience, so we decided not to cover it.

Victoria Giardina is Medscape's editorial intern. She has previously written for "The Dr. Oz Show" and is currently a National Lifestyle Writer for Her Campus. She can be reached at or on Twitter @VickyRGiardina.

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