Islands, Italy and the Upper Bound of COVID-19

The hardest-hit COVID-19 locations in the world are the islands of San Marino and Andorra and the countries of Italy and Spain.

San Marino has a population of 33,000. This is eight times the population of the Diamond Princess cruise ship (3700, 700 cases). Ten of the people who had been on the ships, the Diamond Princess and the Grand Princess (3400 passengers, 103 cases), have died.

San Marino has found 223 cases, 21 deaths and 15 new cases were added yesterday. San Marino seems on pace to add 600 to 2000 cases. Those would be 20000 to 80000 cases per million.

This would mean that the hope that there are vast percentages of people who caught COVID-19 and became immune would not be as large as some hope. China found that 85% had no symptoms or mild symptoms. If 8% of population tests positive for active coronavirus then that larger pool might only be twice as big as what China detected. Hitting a 0.3% active case detection might mean that there are 50 times as many hidden infections and recoveries.

Andorra has a population of 76,000. Andorra has 267 cases and added 43 new cases yesterday. Andorra seems on pace to add 2000 to 8000 cases. If Andorra matched the Diamond Princess they would have 14,000 cases.

Italy has a population of 61 million. Italy has 1431 official cases per 1 million people.
The Lombardy region of Italy has 10 million people. Lombardy has 3500 cases per 1 million people.

New York state has found 45,000 cases and has a population of 20 million. This is 444 cases per million. New York City has 23000 cases and has a population of 8.6 million. This is 374 cases per million. New York can get 50 to 200 times more cases before full saturation limited the spread. New York City could hit 180000 to 700,000 cases as an upper bound. However, there will not be 100% of people getting the disease.

This is an estimation before we get the serosurveys that find the exact percentage of people with COVID-19 antibodies. Those surveys will indicate when we will get to herd immunity limits.

SOURCES – Worldometers
Written By Brian Wang,