Update IV: March 4th 2020: Travel Suggestions
I have received plenty of questions regarding travel. What things look like tomorrow, or in a few weeks is pure speculation, but I thought I would share with you some science and how that affects my PERSONAL thoughts about travel during this time of uncertainty. My assessment could change quickly, if case numbers increase dramatically.
First, we need a little bit of science to assess the risk of travel.
Attack Rate: If 100 people are exposed to the virus how many catch it.
R naught: If one person is infected, how many people do they infect.
Case to fatality rate (c/f): how many people get it and how many die.
How is it spread: It’s definitely a respiratory virus, so sneezing and coughing certainly spreads the virus. The virus is also found in feces. The virus can persist on surfaces for hours to days (surface dependent), and on your cloths for hours. It appears to be able to enter any mucous membrane; mouth, nose, and eyes.
What we know: The attack rate of this virus is low; ~1% for a short encounter with an infected person (10 minutes) and ~15% for household members (longer encounters). These numbers should be treated with caution, they are bouncing around, but what it indicates is that it is quite difficult to be infected from quick social encounters. The reproduction rate is modest, sitting around R naught of 4. One infected person, on average, infects 4 people. For comparison, seasonal influenza is 1.4, mumps is 10, and measles is 15.
We have really good data to show that once the infection is in your area and spreading, case numbers will double every week. So we can predict the future a little bit.
Pulling this information together: it is hard to catch the virus from just casual encounters, but longer encounters, and when it enters your home the chances of being infected increases 10 fold. This stresses the importance of good hand hygiene, not touching your face, and a little bit of social distancing (do you really need to sit so close).
The case to fatality ratio is a little sobering. Yesterday, WHO released that the c/f is 3.4% worldwide. But there are important nuances to this data. The C/F rate in people older than 80 is 18%, the rate drops to 0.2% in people under 30.
There is also a regional effect. In Wuhan, the epicenter, the C/F was really high, outside of Wuhan, but still in China it was 0.7%. The C/F in Italy and Iran are worrisome, but dropping, as more mild cases are caught in the surveillance. Much of the differences in the c/f in different regions are due to levels of comorbidities in the community (how many sick people are already there), as well as the availability to, and quality of, healthcare.
Now to Travel......
Worst case scenario: Where do you want to be hospitalized? If the healthcare is not up to par in the region you would like to travel, stay home!
Travelling in the US: plenty of people have asked about Florida. As of yesterday, it only has two cases reported. If that number is real, and we will get a handle on that pretty soon, numbers will double every week or so, but they will still be quite small (6 weeks from now 100 or so cases). In a population of 22 million people, your chance of encountering them is minimal. Then consider the secondary attack rate of 1% and your behavior modification that you have been practicing, your risk of infection drops substantially. I would go…
I have the same feeling for visiting any other state in the USA, with the exception of California and Washington. Those two states do not have a handle on numbers, and the prevalence of the virus within pockets of those states will be higher. The risk is still low, but I personally would not go until we have a better idea of what’s going on.
Foreign travel: ask yourself, what is the current situation in that country? And most importantly, where do you want to be hospitalized (sobering, but important).
Personally, • I would not be going to Europe. Blanket statement. But me, nope, not going. Great hospitals, but uncertain and rising prevalence throughout the region. • Nope to all countries that have sustained community spread, OR poor hospitals (even if there are no cases). • Australia to US, or US to Australia. Risk is low in both countries right now, hospitals are great. Yep, I would travel. I back my words up… we are going.
Precautions I’m taking for travelling: we are taking Clorox/Lysol wipes to clean the surfaces we come in contact with during our flight. Lots of handwashing and hand sanitizing. Social distancing in airport. Slapping my kids hands when they touch anything. Just super vigilant behavior.
We are also bringing a change of clothes for after the flight. We will change out of our gear and wash hands arms face really well before coming in contact with family at the airport.
When we hit Australia, we will immediately buy toilet paper, and find a comfortable spot on the beach.