For example, the 1918 flu outbreak. What actually stops it being a ‘pandemic’? Is it that everyone catches it and either becomes immune or dies and if so then why do governments take such trouble over reducing infection (eg closing schools) if everyone is going to catch it eventually?
Also, I live in England and was wondering what the threat has to be before the decision is taken to close schools, public sporting events ect? Like how many have to catch it/die?
Sorry this sounds so pessimistic but its on my mind due to the media!
It stops being a pandemic when the virus dies and they close schools etc because it drops the rate of infection.
The UK is currently on a health alert and a man is being treated in London tonight with “flu like symptoms”. The decision to close schools and cancel public events is when the flu is at what is called a “crisis level” which means that’s millions are exposed to it and likely to die. we are overdue a pandemic and if we do get one millions of people around the world will die (normally 5% of every country)
Three influenza pandemics struck the world in the 20th century, including the Spanish flu of 1918 that claimed anywhere from 50 million to 100 million lives. (There were no effective flu vaccines available at the time.) When a flu that contagious spreads across the world, how does it ever die out?
It runs out of victims. Infectious diseases like the Spanish flu spread exponentially as more and more people are infected and become contagious. As people develop immunities, receive vaccines, or otherwise shield themselves from infection, the pool of possible victims dwindles until the virus can no longer sustain itself.
Epidemiologists often describe the rate of infection in terms of a reproduction number, the average number of new people whom each sick person will infect. If this number is higher than one, even by a small amount, the disease is still spreading. (One study estimates that the reproduction number of the Spanish flu was 1.49 when the disease first hit Geneva and a whopping 3.75 in the second wave, which came shortly thereafter.) If the number is less than one, the disease is on the decline.