I have been thinking about how long we will be confined to quarters as they say. My partner thinks it will all be over in a couple of months at the most. Authorities and organisations have been postponing events for a month and sometimes until end of April. None of this seems real to me so I thought I would use some of the existing data to do some of my own calculations. Some have already done some calculations and have made it a lot easier. https://www.statnews.com/2020/03/10/simple-math-alarming-answers-covid-19/ But I thought about the number ICU (Intensive Care Unit - usually with Ventilators) beds available and that the authorities will be trying to ensure we don't overload these beds so that those that need care will get it. However I am going to assume that we have twice the number of people requiring bed than bed available. I am also going to assume that no one else is sick for other reasons as our ICU beds are normally 65%-95% occupied. There are about 2000 ICU beds in Australia and they are trying to double this now to 4000. So I will model this on 8000 people needing a ICU bed at any one time. I person usually needs a bed for 2-8 weeks but I will model on 2 weeks. In China about 5% of the cases required hospitalisation. In Italy however it is 10%. For modelling purposes I will use the lower Chinese figure of 5%. So how many people can get sick at once. If 8000 is 5% then the total infected at that time is 100%/5% x 8000 = 160000. Then we have to wait for two weeks before those people are well and ICU beds are available again. So what is the ongoing number. Well lets break it into days. So 8000 for 14 days so per day that would be 8000 / 14 = 572. So lets revise our total infected patients to 160000 / 14 = 11429. This means that 11429 people could get infected each day. But hey you say we only 350 plus people who are infected. Well that number is a little deceptive and these are only the people that have been tested. The report about the Italian situation is interesting reading for those interested. https://jamanetwork.com/journals/jama/fullarticle/2763188 But I refer you back to the earlier reference from statnews. Herd immunity - how many people need to be immune to prevent widespread transmission of a disease within a community. i.e. we can get back to our normal lives as the spread will be like the flu. It will still be around but there wont be large explosions in numbers. references https://www.sciencemediacentre.org/expert-comments-about-herd-immunity/ https://www.afr.com/politics/federa...covid-19-herd-immunity-policy-20200316-p54akv The average suggests 58%-61% and I will use 60% to make the maths a little simpler. So 60% of the Australia population of 25,000,000 is 15,000,000. So bringing it all together. If we have 11429 people per day infected for 365 days in a year we would have 4171585 infected in one year. It would take 3.6 years to reach herd immunity naturally. All 3.6 years we would have twice the number of people requiring ICU beds than we actually have and we would be doing well as we would only have 5% of patients requiring ICU like in China - not the 10% required in Italy. But you say again how could we get to 11429 people getting infected every day. I point you to another reference aside from the statnews calculations. https://ourworldindata.org/coronavirus#trajectories-since-the-100th-confirmed-case Basically Infectious diseases have a doubling rate. I.e. how long does it take for the number of infected to double. For COVID-19 it has been between 3 days and 35 days. The average is closer to 3 days. But China has dramatically slowed the rate with their measures (if you believe the numbers). Its currently 3 days here in Australia. At 6.00am 17th March there were 375 cases Projections 20 March - 750 23 March - 1500 26 March - 3000 29 March - 6000 1 April - 12000 4 April - 24000 7 April - 48000 10 April - 96000 13 April - 192,000 16 April - 384,000 19 April - 768,000 So by the 4th of April we will have exceeded our 11429 infected per day. You can see the numbers get quite out of hand after that. So containment measures make a lot of sense if you want to be able to treat those who get critically sick. I have two young children so school holidays are something I think of. Term one in Canberra concludes on the 9th of April - hmmm doesn't seem like waiting until then for a lock down would be a good idea. The USA has about 3500 cases at the time of writing this and they are moving quickly into a full lock-down. We would be close to that by the end of next week. I expect all schools and businesses (except those consider critical e.g. supermarkets, pharmacies etc) to be closed by the end of next week. More importantly I don't believe this will change for at least a year and likely longer unless some other solution becomes available. I will stop there as this may be quite shocking to some. No doubt others know this already.