Behaviors Children Daycare Social Distancing

COVID19 infections among kids…

Kids (<18 years) make up of 10% of COVID19 infections in the United States. Because of that, it’s taken a bit more time to have enough infected kids for meaningful analyses (compared to adults). The CDC published an important study Tuesday assessing school, community, and close contact exposures associated with child and adolescent COVID-19 infection.

The study took place from Sept to Nov 2020 in Mississippi. 397 parents of children who recently had a COVID19 test completed a phone survey. They answered questions about symptoms, close contact with a person with known COVID-19, school or child care attendance, and family or community exposures ≤14 days before the COVID test. Then, scientists compared the answers across kids with a COVID19- test to kids with a COVID19+ test. There were a couple things they found…

COVID+ kids were MORE likely to have…

  • Had close contact with a person with known COVID-19. And, this close contact was more likely to be a family member than someone at school
  • Attended gatherings with people outside their home, including social gatherings (weddings, parties, funerals, birthday parties), playdates, or to have had visitors at home

COVID+ kids were LESS likely to have…

  • Consistent mask use by students and staff members inside school or child care facilities

Interestingly, there were essentially no difference between COVID+ and kids going to…

  • Sports events or concerts (18% COVID+ vs. 20% COVID- kids)
  • In-person school or child care (62% COVID+ vs. 68% COVID-)
  • Religious services (13% COVID+ vs. 18% COVID-)
  • Restaurants (20% COVID+ vs. 16% COVID-)
  • Travel with others (5% COVID+ vs. 3% COVID-)
  • Household member working in health care (24% COVID+ vs. 21% COVID-)

Before I get the comments, here are a few important notes…

1. This doesn’t mean, for example, you have carte blanche to go to indoor restaurants. This is a study of kids. This does not mean you, as a parent, won’t get it or spread it

2. No, there is no data on teachers or staff. Yes, that would be a needed analysis. I’m sure it’s coming.

3. Yes, masks work. This study showed that adults wearing masks helps kids, especially within schools and child care center. If you need more evidence, check out my previous post (

4. Opening schools is a bit more complex than kids getting infected. Kids are less likely to get sick (and not go get a test), but they harbor the disease and have the potential to spread it to others. Unfortunately, we still don’t know the rate of transmission from kids to adults.

Finally, I would like to take a moment to recognize how quickly and hard these scientists had to have worked to get this information out to the public. Data collection ended November 5, 2020. That means, within a MONTH, they cleaned the data, analyzed the data, came to meaningful conclusions, wrote up the science, sent it up the CDC ranks for approval, responded to feedback, and submitted for publishing. For the record, this typically takes 1-2 YEARS. Absolutely incredible.

Love, YLE

Data Source: Hobbs CV, Martin LM, Kim SS, et al. Factors Associated with Positive SARS-CoV-2 Test Results in Outpatient Health Facilities and Emergency Departments Among Children and Adolescents Aged <18 Years — Mississippi, September–November 2020. MMWR Morb Mortal Wkly Rep 2020;69:1925-1929. DOI:

Deaths FL Hospitalizations National changes Social Distancing Testing Texas update

Thanksgiving Surge?

It’s been 2 weeks since Thanksgiving and I was curious if we had a “surge upon a surge”.

In other words, did our acceleration (the rate of cases) change after Thanksgiving? Unfortunately, it’s a very simple question with a very complicated answer. If this blog were my day job, I could statistically figure this out. But it’s not, so I triangulated a few other data sources instead. This is what I found…


TPR is now 20.3% in the United States. It increased 15% since Thanksgiving. TPR is particularly concerning in the Southeast, where it’s increasing at higher rates since Thanksgiving than the rest of the country. While the Midwest finally seems to be moving past their peaks, their TPR’s are increasing again (likely related to Thanksgiving), which will slow their decline. The WHO has stated that countries need a TPR below 5%. While testing does not have a direct benefit because there is no cure, there are a number of indirect benefits: 1) public health officials know the “true” rate of infection and can deploy resources to the right areas to stop spread; 2) psychologically if someone tests positive then they are more likely to quarantine (hopefully).


Cases have increased 21% since Thanksgiving. Cases increased 22% two weeks before Thanksgiving. New hot spots have popped up since Thanksgiving, particularly along the Sun Belt (southern CA, AZ, TX) and the Northeast. Boston, in particular, has surpassed 100 daily cases per 100,000. And while Vermont and Maine have been more than impressive this entire pandemic, they too are seeing doubling rates.


Not enough time has passed since Thanksgiving to see the impact on hospitalizations/deaths. But there is no reason to believe they will not continue to mirror case trends. Fatality rate (number dead out of the number with positive COVID19 tests) continues to remain steady in the United States at ~1.9%. We should continue to see this, unless out health systems are strained too much. Then hospitals will have to start making hard decisions on who to save and who not to save. In April, Italy had to make these decisions (they decided not to treat those 80+ years) and fatality rate increased.


  1. Airports. The CHOP Policy Lab found circumstantial evidence that the most concerning areas of the country post-Thanksgiving are adjacent to our busiest airports: Los Angeles, Boston, DC, Atlanta, and Dallas. In other words, Thanksgiving air travel led to increased local transmission. For example, in Clayton County, Georgia (home to the Delta Hub and Atlanta airport), cases are doubling compared to surrounding counties.
  2. Distance Traveled. Interestingly, distance traveled did not change, on average, by much. We see an increase right before Thanksgiving, but honestly not as high as I would have expected. This only means people, on average, didn’t travel far. This doesn’t mean that family wasn’t close by and people didn’t get together. It was also very obvious that distance traveled varied by states too (see Figures). Wish I had more time to look into this. But still adds a little piece to the puzzle.

Conclusion: Right before Thanksgiving we were starting to see a plateau in cases. Then, after data reporting caught up, our cases continued exponentially increasing after Thanksgiving. So, I don’t think we saw a surge upon a surge. But we definitely didn’t stop our original surge. The pandemic continues to ravage our communities across the United States.

Love, YLE

Data Sources: I triangulated many sources of data for this report. I couldn’t have done it without the beautifully clean and workable data and graphs from the following sites:

COVID19 Tracking Project:

CHOP Policy Lab:


Behaviors Social Distancing


…is coming during the highest peak of COVID19 cases (and hospitalizations) the U.S. has ever seen. This holiday’s potential impact on transmission, hospital strain, and mortality cannot be understated.

Here are three published, peer-reviewed case studies that illustrate COVID19 transmission at family gatherings:

•In February 2020, a funeral was held for family in Illinois. The evening before the funeral, the index case (with mild cold-like symptoms) shared a takeout meal, eaten from common serving dishes, with two family members of the decedent at their home. At the meal, which lasted approximately 3 hours, and the funeral, which lasted about 2 hours and involved a shared “potluck-style” meal. The index patient also embraced family members of the decedent and others attending the funeral. Three days after the funeral, the same index case (who was still experiencing symptoms) went to a family birthday party. They embraced each other and shared food during the 3-hour party. Between the funeral and the birthday, 16 family members were infected and 3 died.

• Back in June, a family (two parents, two sons, and one daughter with a stuffy nose) traveled to a vacation home to meet with 15 other relatives. These relatives were from five households from several states whose ages ranged from 9-72. During this vacation, relatives did not wear face masks or practice physical distancing. Another 6 relatives (aunt, uncle, and four cousins) visited a few days later but stayed outdoors and maintained physical distance from the other 15 relatives. What happened? Well the stuffy nose was actually a COVID19 infection. She proceeded to infect 11 other relatives, 2 of which went to the hospital. The 6 relatives that stayed outdoors and physically distanced did NOT get infected.

• In January, a Chinese elderly couple celebrated the Chinese Spring Festival in public. Neither had symptoms when, a few days later, the couple’s daughter, son-in-law, and 2 grandchildren visited them. A few days after this visit, the daughter went to have dinner with another family unit. The grandma (who went to the Chinese Spring Festival) was infected with COVID19 without knowing it. She directly or indirectly infect all (but one) family members. One, of which, was admitted to the ICU.

We are all tired of this disease. But I hope these examples show you how easily this is spread, even if you aren’t experiencing symptoms. With all the good news this week (vaccine, new task force, new antibody treatment) we know there’s light at the end of the tunnel. We will be through these dark times. But, we aren’t at the end of the tunnel yet.

It’s time to re-evaluate your Thanksgiving plans. This may mean reorganizing (go to a park instead of a home), having conversations with family/friends to set expectations (yes this may be awkward), cancelling plane tickets (this will avoid spreading clusters), and cancelling plans (stick with immediate family). It’s hard. And heartbreaking. But it’s the reality of the situation.

Love, YLE

Data Sources:

Funeral/Birthday party:


Chinese family:

More from the CDC:…/daily…/holidays/thanksgiving.html

Social Distancing


I was going to give a very scientific explanation about the risks associated with Fall/Halloween activities. But then my “human” side weighed in. So I would say this is an opinion piece from a mom who loves the holidays but who’s also an epidemiologist during a global pandemic…

Don’t cancel Halloween. We have all been through enough this year. Buy those costumes, go to the pumpkin patch, carve pumpkins, decorate your house, spike the apple cider, and give out candy. Do this all with a VERY important caveat in mind… be smart and be creative.

For example….

1. Wear a darn mask if you go to the pumpkin patch. Sanitize hands before and after touching pumpkins. Don’t touch your face. Skip the hayride with strangers, but go for the outdoor corn maze if it’s not crowded. If people are screaming in a haunted maze, keep your distance even more.

2. Don’t allow your kid to go with a big trick-or-treat gang this year. Keep it to a friend or two. Make sure they all have masks. Don’t let them eat candy on the road. When the kids are “sorting candy” after and you look to steal a piece, maybe wipe the wrappers down in one sweep. Don’t make it a big deal.

3. If you’re handing out candy, be creative. Wash your hands before touching candy. Don’t allow kids to reach in a candy bowl. In fact, no need to hand directly to kids at all. I’ve seen people making PVC pipes from their window so kids can be on the other end to grab candy. Don’t let kids bunch at your door, maybe make a one-way path for kids as you sit outside with a candy fishing pole.

4. Skip the big indoor party. Instead, get together with a few friends for a backyard bonfire. Instead of buffet style, have one person serve plates of food to everyone. Don’t forget the wine.

And, for the love of everything, if you have a diagnosis, symptoms, or recently exposed to someone with COVID19, skip this year.

This pandemic is not new anymore. We know what works. The only thing we can do, as epidemiologists, is make you aware that there is STILL a pandemic. There is STILL COVID19 risk, at differing levels, for all activities. It’s your turn to be smart, be creative, and weigh those risks to protect yourself, your family, and the community around you WHILE enjoying Fall at the same time.

Love, YLE

Data Source: I created this infograph using recently published CDC guidelines. I thought it may be easier to digest than all the text on their website:…/daily-life-coping/holidays.html

Behaviors National changes Social Distancing

Protective measures in the US

While quite a bit of research has reported which COVID19 policies work and don’t work on a country or state-level, VERY little peer-reviewed research has reported what individuals are doing to curb spread. In other words, are individuals conforming with the recommended protective health measures?

A study was just published in the International Journal of Environmental Research and Public Health.

Scientists used data from the COVID19 Impact Survey. This survey was designed carefully to pick a random set of households in the US to participate. They did this extra work so the results of the study could be generalized to the entire U.S. (instead of just one state/city or type of state/city). This survey was done three consecutive times (April, May, and June of 2020) and 25,269 people participated.

What did they find?

  • In the United States, 95% wash their hands, 90% kept 6 feet away, 86% wore a mask, and 82% avoided crowded places (Figure 1)
  • Of 19 protective measures, an average of 7 protective measures were taken
  • Who took protective measures more? Higher incomes, insurance, higher education levels, large household size, age 60+, females, minorities, those who have asthma, have hypertension, overweight or obese, and those who suffer from mental health issues during the pandemic
  • Who took protective measures less? Suburban and rural areas, and the Midwest and West
  • People who wore masks increased from April to June 2020 (Figure 2)
  • Participants who were positive for COVID19, knew an individual with COVID19, or knew someone who died from COVID19 had a stricter lifestyle. This was especially true regarding washing hands, avoiding public places, and canceling social events.
  • Some protective measures are linked to others (Figure 3)

Now, what people say they do may be different from what they actually do. However, this still makes my little epidemiologist heart happy. People know the social desirability of our community, which lines up with effective protective measures. Also, this data uncovers patterns that would otherwise have been obscured. Epidemiologists can leverage this knowledge to more quickly and effectively curb COVID19 spread.

I’m hoping that COVID19 Impact Survey’s hard work continues because I would love to see numbers for July-September too.

Love, YLE


COVID19 Impact Survey:

Behaviors Social Distancing

Spread on a bus

Back in January, there was an outside worship event at a Buddhist temple in China. 293 people attended, of which, 126 traveled to the temple in 2 buses.

Bus ride: The ride was 50 minutes each way. The buses had an air-conditioned system, windows (that were kept shut), and there was no bathroom on board. Everyone remained seated and no one wore masks (this is before public awareness of COVID19). Everyone sat in their original seats on the ride back.

The event: Once the buses arrived at the temple, worship took 150 minutes and the event included a luncheon (10 people at each round table). Bus riders were randomly mixed with others at the event. There was a slight breeze and everyone had close contact.

What happened?

• Bus #1 (59 passengers+1 driver) had no index case.

• Bus #2 (67 passengers+1 driver) had an index case. The index case was asymptomatic. He sat in the middle of the bus (3rd seat in the 8th row).

• Bus #2 had an attack rate of 35%. In other words, 24 other passengers were infected during the 50-minute drive there or back. Bus #1 had an attack rate of 0% (even though they mingled with everyone at the event).

• Cases were scattered on Bus #2. There was no apparent pattern, other than distance from index case

• Among the worshipers that attended the event (but were not in one of these two buses), 7 tested positive (4% attack rate).


• There is airborne transmission with recycled air.

• In closed environments, COVID19 is highly transmissible.

• The index case, who was asymptomatic, achieved enough viral shedding by just breathing to cause a high secondary transmission rate

Translation: Even if you don’t feel symptoms, it’s important to wear a mask. You could be spreading the disease without even knowing it. And, be sure you’re in a space with air circulation (that is not recycled); open your window on the bus.

Love, YLE

Data Source: Published 3 days ago in JAMA:

Antibodies Children GA Innovative Solutions National changes Social Distancing


Buckle up. In true 2020 fashion, several scientific developments popped up while I was on vacation…

1. Teachers’ and parents’ risk for severe COVID19

• 2.95 million teachers (50.6%) have risk factors for severe COVID19. This is mostly driven by obesity or heart conditions

• 37.7 million adults living with school-aged children (54%) have risk factors for severe COVID19. This is mostly driven by age, heart problems, or diabetes

• Risk is the same for those living with younger children compared to older children.

• So… what? “Without adequate safeguards, reopening schools could put millions of vulnerable adults at risk for severe COVID-19 illness”.

2. First global case of COVID19 re-infection

• In March, a 33-year-old man in Hong Kong was infected with COVID19. He had mild symptoms.

• Last week, he was infected with a different COVID19 strain and tested positive upon his arrival to Hong Kong from Spain. He is asymptomatic.


• After the first infection, he had no antibodies. But we already know that not everyone gets antibodies (especially mild symptoms; see my previous posts)

• After the second infection, he did produce antibodies. This is consistent with the immune system building stronger with each exposure to a pathogen, so second and third exposures may increase the chances to develop antibodies.

• In the words of immunologist Dr. Akiko Iwasaki, “This is no cause for alarm – this is a textbook example of how immunity should work.”

• Vaccination (and social distancing and masking) needs to be considered among people that have already been infected with COVID19

3. Wearing masks works (I feel like this is no duh, but in case you needed more ammunition)

• US states with high mask wearing compliance were more likely to have a R(t) less than 1 (control of community transmission)

• Mask wearing was higher among women, elderly, non-white or Hispanic, lower income people

• Mask wearing is highest along the coasts, southern border, and urban areas (see Figure)

• Mask wearing is even more important when (or if) social distancing is relaxed

4. Super-spreaders played a key role in MERS and Ebola. Their role in COVID19 was just revealed in Georgia:

• 2% of the population is responsible for 20% of infections• Super-spreaders likely explain major outbreaks in rural areas • Younger people are more likely to be super-spreaders

Love, YLE





Children Social Distancing Vaccine

Upcoming Flu and COVID19 Season

Flu season is around the corner. This, combined with COVID19, will have an impact on the health our community and capacity of our health systems.

Although COVID19 and influenza are vastly different pathogens, they do have areas of overlap:

• Both transmitted through respiratory droplets • Similar symptoms in the beginning

There are also drastic differences:

• COVID19 much more contagious than flu • COVID19 higher fatality rate (COVID19 IFR ~2.5 times- to 300 times deadlier than the flu, depending where you are in the globe; In the US, it’s 6.8 times deadlier than the flu) • Flu: most infectious AFTER symptoms; COVID19: most infectious BEFORE symptoms. • Flu: high risk for kids; COVID19: uncommon among kids or mild disease • Flu: Symptoms peak during 2-7 days; COVID19: symptoms peak 2-3 weeks • Flu: We have a vaccine; COVID19: no vaccine

Solomon et al., (2020). Influenza in the COVID-19 Era. JAMA.

So… what?

• Because both are spread through droplets, non-pharmaceutical interventions (masks, social distancing, movement restrictions) will be equally, if not more, important in the upcoming months.

• Flu vaccine is even more important to get this year. National coverage is lower than 50% in adults. We need to change this.

• No specific symptoms distinguish flu with COVID19, so it’s important for physicians to identify etiology

• Managing pediatric populations will differ depending on the virus

The strength of our collective public health response will directly influence morbidity and mortality this Fall. Do your part.

Love, YLE

Data Source: Solomon et al., (2020). Influenza in the COVID-19 Era. JAMA.

Children Daycare Social Distancing

K-12 School Relative Risk Index

I don’t intend to flood your news feed today, but many (at least in Texas) are headed to school this week.

This infograph categories school activities within a spectrum of risk.

This is based on CDC and National Academy of Science recommendations. The recommendations were summarized and translated by three scientists (two MD’s and one PhD in epidemiology), resulting in this infograph.

At this time, the only thing we, epidemiologists, can suggest is risk reduction. This is an approach that abolishes the all-or-nothing approach to COVID19, acknowledging the lack rigorous data, the lack of a national, coordinated response, and that abstinence-only is not possible for everyone in this long, drawn out process.

Love, your local epidemiologist

Data Source: Infograph

Long-term effects National changes Social Distancing

Pitting public health against economic health

Pitting public health against economic health through a simple trade-off (saving lives vs. saving the economy) is unhelpful and simply not accurate.

Something that gets lost in public conversation is how interdependent the two are. Health systems know that financial health is a critical part of people’s well-being. On the flip side, the financial community knows that having healthy workers and families is vital for productivity and viability. It’s just time to get the public (and policy makers) to understand the interdependence.

A study was just published that asked: Do nationwide shut-downs negatively impact the economy? Scientists compared spending patterns (bank records of more than 800,000 people) in Denmark (who had strict shut-down) compared to spending patterns in Sweden (who didn’t have a lock down). And yes, they compared spending patterns AFTER taking into account things like stock market indexes, unemployment claims, cross-country spending, time of year, etc., etc..

What did they find?

  • There was only a 4% difference in spending between the two countries (Denmark saw a 29% drop in spending; and Sweden saw a 25% drop in spending) after the pandemic was declared
  • There was a bigger drop in spending among 18-29 years olds in Denmark compared to Sweden. In other words, a shutdown constrains the young, who in the absence of a shutdown, would contribute the most to spreading the disease
  • There was a bigger drop in spending among 70+ year olds in Sweden compared to Denmark. In other words, a shutdown contained the spread of the disease and reduce the need for extreme isolation among the most at risk (and reduced mortality).  
Sheridan et al. (Aug 2020). Social Distancing Laws Cause Only Small Losses of Economic Activity during the COVID-19 Pandemic in Scandinavia. Proceedings of the National Academy of Sciences of the United States of America.
Sheridan et al. (Aug 2020). Social Distancing Laws Cause Only Small Losses of Economic Activity during the COVID-19 Pandemic in Scandinavia. Proceedings of the National Academy of Sciences of the United States of America.

Translation? Social distancing laws only cause small losses in the economy while having major benefits on morbidity and mortality. Instead, the virus itself causes economic turmoil (people cut back on consumption, cut back on work due to personal health risks, social norms, or a sense of civic duty). By reducing the spread of disease quickly (through shut downs in this case), more people will be comfortable with going outside, spending money, and working.

How does this apply to other countries? The authors comment on this too. Unfortunately, in the US, we have three things going against us:

  1. Our national “strategy” is a long, drawn out, uncoordinated response
  2. Lack of social insurance policies
  3. A diverse range of civic and social responsibility

The authors state, “A combination of these factors may correlate with reductions in economic activity and, hence, results in the impact of government-mandated shutdowns.”

Love, your local epidemiologist

Data Source: Sheridan et al. (Aug 2020). Social Distancing Laws Cause Only Small Losses of Economic Activity during the COVID-19 Pandemic in Scandinavia. Proceedings of the National Academy of Sciences of the United States of America.