“I know I shouldn’t fly, but I’m supposed to meet my most important client in DC on Thursday. Do I cancel?” asked a worried friend. Another texted me over the weekend, “Do I need to keep Adrian home from school on Monday?” It is rarely cool to be an epidemiologist. Usually, I’m lucky if people don’t assume that I treat skin disease. But nothing conveys cachet like an actual epidemic. So, just how worried should you be?
As I have been saying in earlier posts, these questions are impossible to answer with certainty because of the woefully inadequate testing for the virus. I experienced this firsthand today, when I called the King County Health Department today about my son, who has had a dry cough for the past 8 days, a symptom profile that could easily be consistent with Covid-19. After 20 minutes on hold, I got to a helpful, but protocol-bound public health worker. There are only three reasons they test: 1.)A cough with a fever above 103 degrees after a negative test for the flu, 2) someone with known contact with a covid-19 patient, or 3.) people with recent travel to China, South Korea, Iran, or Italy. To be clear, I firmly believe that the Health Department is doing the best they can with the resources available. The problem is lack of resources. Hopefully that is changing, but disease prevention works best if it happens before the disease.
For now, we still have no clear idea how many cases are present in the community. As a result, we have to look elsewhere for our answers. As I mentioned yesterday, age is a key factor in judging the risk posed by this disease. If we look at the data from China and Korea, it is clear that the risk to healthy young people is relatively low. The deaths are occurring almost exclusively in the elderly and infirm. (see note below for full discussion)
It’s almost as if there are two diseases. If you are under the age of 60, the disease has a severity comparable to the flu. If you are under the age of 20, it appears to be even less risky than the flu. BUT, if you are older than 60 or have underlying chronic disease, this is nothing like the flu. The lower rate in kids is a puzzle, but your risk of death if you are over 60 soars by between 10 and 30-fold. If you are over 80, it is 60-70 times higher than those under 60. Nothing demonstrates this more clearly than the fact that fourteen of nineteen deaths in Washington State occurred among nursing home residents.
My friend, who is in her late 50’s, is relatively healthy, so I initially told her to go ahead and fly. I figured the number of cases is still relatively low, so she is highly unlikely to get infected and, if she does, as someone who is relatively healthy, she will survive. Then I saw a recent paper on the first case diagnosed in the state, a 35-year-old man who had been in Wuhan, but had NOT been to the market that appears to be the source of the outbreak and had NOT had any contact with a known case. He survived the ICU, but barely. Wandering around Seattle, I still believe the risk is very low. The number of carriers is still limited and reasonable precautions are easy to maintain.
In a tube in the sky, there is no social distance. I texted her and said don’t go. Be cautious, save the carbon, and Skype. She texted me back that someone in the office building she was supposed to visit in DC had just been diagnosed. Case closed.
Which brings me to the other question. Send the kids to school? Many schools in the Seattle area are closing, but the city’s public schools are remaining open, due, in part to equity issues. In the wealthier suburbs or at private schools, universal online learning is a possibility. In Seattle’s urban core it is not. A substantial number of kids have limited access to the internet and many parents do not have the option of staying home with their children. And, as noted above, the kids are not at great risk from Covid-19 unless they have some sort of chronic disease. The challenge with children is that they can become infected as easily as adults, so, they can pick up the virus in school, and bring it home to their parents. A pattern every parent knows.
With that in mind, I suggest schools figure out a way to allow parents who can keep their kids home from school to do so. That will not only reduce their child’s risk, but it will reduce the risk for those who need to go to school by reducing the number of kids in school.
Answering these questions will become much simpler as testing becomes easily available. It is cold and flu season and there are thousands of kids out there like my son. Some of them are almost certainly positive. We have had a concession worker at the stadium and a worker at a coffee shop test positive in recent days. Lack of knowledge breeds fear and overly cautious decision making. The announcement that the Gates Foundation will be providing free testing starting sometime this week marks a desperately needed and most welcome step in the right direction.
Addendum: Details and references for the nerdy
- Among children (under age 20), there was one death in China and none in South Korea.
- Another study in China found that children with known exposures were just as likely to become infected as adults, but tended to have few if any symptoms.
- A study of hospitalized patients in China found only nine children were hospitalized and none required artificial respiration or ICU care.
- The CFR for this age group was 0.6% in China and 0.1% in South Korea, much closer to that for children than for the elderly.
- Only 5% of hospitalized patients in this age group required aggressive care.
Adults over 60
- Among those over 60, the story is completely different. In China, the case fatality rate (CFR-per cent of cases with the disease who died) was 6.0%. In Korea, the CFR for patients over 60 was 2.8%.
- Among those over 65 in China, 21% required aggressive care.