As I am writing this article there are 2,961 confirmed cases of COVID-19 in CA (6 in Madera County) and 56 deaths across the state.

Jonathan Penrose

These seem like small numbers when compared to a CA population of over 40 million and may lead one to believe that social distancing and shelter in place is a scare tactic and an over-reaction and just isn’t that important to those of us who live here in YLP.

I can understand that. Most of us are accustomed to looking at the size of the numbers and not the rate they are changing.

But consider the contrast between CA and New York.

10 days ago social distancing and shelter in place directives began being put in place in CA — NY did not take similar actions until today.

At the time, the number of confirmed cases in both states was about the same, and now cases in NY are vastly larger. NY experienced more new cases today than the total number of cases in CA!

DATECANY
3/151,224729
3/252,961>25,000

The primary point of social distancing and sheltering in place is to ‘flatten the curve’ and avoid overwhelming our medical facilities. This, hopefully, gives us time to expand our medical resources and avoid thousands of preventable deaths due to lack of proper medical care.

The data is still ‘messy’ and there are other factors that affect the number differences between CA and NY – but social distancing is a critical strategy to limit the rate of spread.

Here is why social distancing matters:

1) The EXPONENTIAL RATE at which the virus spreads.

2) The current number of confirmed cases is very low compared to actual cases, given the slow pace of testing.

3) Scientific data indicates that 1/3 (or more) of those with the virus show no symptoms but are still contagious and can spread it to others. This is called covert transmission.

EXPONENTIAL GROWTH:

When infections double in a short time, it doesn’t matter how small the number is to start with. In a very short time the number of infections grows very large.

If you start with a single case and the infection doubles every 4 days (similar to Coronavirus growth rates without intervention), then after 30 days you have 181 cases – not very scary. After 30 more days you would have 32,768 cases (roughly where NY is now – still not that scary). However, if things continue at the same rate, the number of cases after 90 days would be right about 6,000,000. In 100 days it would reach in excess of 24,000,000 – almost 60% of the CA population. (this is the curve New York has been on)

If the mortality rate is only 1% that is 240,000 deaths in less than 4 months! And completely overwhelms our available medical facilities.

However, if you can slow the rate of spread to doubling every 6 days instead of every 4 days, then the virus only spreads to 104,000 people and a mortality rate of 1% is about 1,000 deaths in the same 100 day period.

The actual epidemiological models are more complicated than this, of course, and include factors like population density, current % of population infected, patterns of social interaction, etc. But the point is, slowing the rate the virus is spread is HUGELY important.

This is where social distancing plays a critical role. It SLOWS the rate at which COVID-19 is spread through the population.

ASYMPTOMATIC CARRIERS:

If that isn’t enough to convince you to take social distancing seriously, please be aware that many people with the virus are asymptomatic. That means they show no symptoms and don’t know they have the virus, BUT they are still contagious and can spread the virus to you and to other people.

The Princess Cruise from Japan that was sequestered off the coast of San Francisco is a small microcosm of how Covid-19 spreads.

This was the source of the first positive cases in Madera and Fresno. Those passengers were immediately quarantined in their homes, which prevented social transmission.

The passengers and crew members on the cruise ship were closely monitored and repeatedly tested. Of the 700 people who tested positive for the virus, 18% showed zero symptoms or signs of infection.

Keep in mind that this was an elderly population which is more likely to experience and show symptoms of Coronavirus.

In Japan, 700 people were evacuated from Wuhan during the early stages of the outbreak there. 13 of the evacuees eventually tested positive, but 31% showed zero symptoms.

Data from Wuhan indicates the percentage of asymptomatic infections may be even higher.

Again, the data isn’t perfect, but the conclusion is clear and consistent. A high percentage of people that are contagious with the virus – show no symptoms of infection.

This means it is almost impossible that the spread will stop on its own, as people that don’t even feel or appear sick will continue transmitting the virus.

PRUDENCE, NOT PANIC

Does this mean we are doomed and there is nothing we can do? Of course not.

But it does mean that practicing social distancing, washing our hands, avoiding crowds and self isolating if we show symptoms REALLY can make a difference in how rapidly this spreads.

Be smart. Be safe. And PLEASE take the recommendations from the CDC and health professionals seriously.

Jonathan Penrose
General Manager
YLOA/YSPUC