Cutting the links

The New York Times ran an explanation of the importance of “cutting the chain of transmission” of a virus.  The author, Siobhan Roberts, talked to two epidemiologists who drew a “tree diagram.”  Let’s say that on the first day an infected person transmits the virus to two people, and each day for the six days each of those people transmit the virus to another two people 

At the end of six days 64 people will be infected.  Now let’s say on the first day the infected person only transmits to one other person.  That person transmits to two people and so on for the six day period.  At the end of the six days, 32 people will have the disease.  While 32 is a large number, those 32 will be easier to treat than 64 would have been.  And that is why there is all this “social distancing,” stay in place orders, and quarantines.