Some things I've learnt from almost ceaseless updates we pick up here:
- the death rate is not known. The current estimate figure of 2-3% is based on total deaths divided by cases diagnosed so far. However, there is a time lag between diagnosis and death, so as people increasingly die the mortality rate might increase . Conversely, there may be many undiagnosed because they are asymptomatic or who have had such mild symptoms they do not present themselves for diagnosis.
- Of those diagnosed, about 20% have become serious enough to require hospitalisation, including 5% who have been put in the ICU.
- So far the best laboratory of likely outcome is from the Diamond Princess, from which there were 691 diagnosed. They tested everyone on board, regardless of whether or not they had symptoms. About 50% who showed positive results were asyptomatic at the time they were tested.
- People are more likely to have contracted Covid if they are elderly or have weakened immunity - people with heart disease, undergoing cancer treatment, with diabetes or HIV. The most serious cases end up with viral pneumonia. The nature of viral pneumonia from Covid-19 seems to be no different than viral pneumonia from other sources (such as flu) - it's just that Covid makes it more likely to happen. Once you have viral pneumonia you should expect 30-40% mortality. Key mortality predictors once you have viral pneumonia are age (>60 years), low immunity, high blood pressure or a history of smoking.
- it is viral. Antibiotics are of limited help, apart from keeping opportunistic bacteria from infecting weakened lungs during the viral pneumonia
- There seems to be low contagion and fatality among children.
- Having said that, fit young people have succumbed.
- Even if it is now impossible to contain this from a pandemic, it is important to reduce the rate of transmission as much as possible. This will help public health is not overloaded. It also gives time for vaccine and/or treatment development.
- More and less serious strains will evolve. The less serious ones will be more likely to disperse as people tend to self-isolate when they can't leave bed. So over time (who knows how long), theoretically this will become no more dangerous than flu or the cold.