Everything you need to know about coronavirus
While the world battles the Covid-19 outbreak, there is another spread scientists and health officials are concerned about – what some are calling the first information pandemic. When SARS broke out in 2003, the first truly global social networking site, MySpace, was still months away from existence. There was no Facebook, no Twitter. But today, as novel coronavirus cases climb past 200,000, with more than 8000 deaths, there is a unique storm of access and information.
Researchers are racing to study, analyse and report on the different features of the virus; many journals and teams have brought their work out from behind a paywall to be read and dissected by everyone with an internet connection. Yet data and advice continue to be misinterpreted by some – or flat-out falsified.
The situation will change every day, as will the body of evidence, although some facts are worth preserving. The Saturday Paper has conducted interviews with epidemiologists and infectious disease physicians in Australia and around the world to answer some of the most common, and confused, Covid-19 questions.
They include University of Melbourne epidemiologist Dr Kathryn Snow, Monash University professor of infectious diseases epidemiology Allen Cheng and Queensland infectious diseases physician Dr Trent Yarwood, who is director of the state’s antimicrobial stewardship program. The information below includes input from University of Auckland microbiologist Associate Professor Siouxsie Wiles and Columbia University virologist Dr Angela Rasmussen. Interviews with these figures have been supplemented with official World Health Organization advice, the advice of Australia’s state chief medical officers and published research on evolving questions about the virus.
Can you infect other people if you’re not showing symptoms?
You can, although experts do not believe this is the main driver of Covid-19’s spread. There is some evidence people can be contagious – that is, to “shed the virus” and pass it on to others – in the day before they become sick. Dr Kathryn Snow says “maybe” this extends to 48 hours but, again, this is not the rule. “I think the sense is that that’s kind of like a pretty rare event … and that the major driver of transmission is happening when people are coughing.” Dr Trent Yarwood agrees. “How do you define symptomatic? It’s a difficult thing to define very carefully. All of the advice seems to be solidifying in the direction that, yes, there is probably asymptomatic transmission, but at the end of the day it’s not super important.”
What is the incubation period of the virus and how long can you be contagious after getting it?
There are two very important windows here. One is how long it takes after contracting the Covid-19 virus until you feel unwell, which is, on average, five to seven days. As with the above question, this does not mean you are necessarily contagious during that period, although you can be in the day before symptoms hit, and possibly in the two days before. These numbers do not include the outliers. Virologist Dr Angela Rasmussen says some people can develop symptoms up to 14 days after infection but notes this number will change as more cases are counted. The more cases we have, the more robust the data will become. The other crucial window is how long you remain infectious once symptoms show. Professor Allen Cheng says there have been cases where people have continued to shed the virus up to 30 days after infection, meaning they are still infectious, but these are extreme outliers and policy cannot be made at these extremes.
What are the symptoms of the virus and how does it differ from a cold?
If you are worried whether you have coronavirus, the two key symptoms to look out for are fever and a dry cough. These are not the only symptoms, but they are the two that most clearly indicate Covid-19. The symptoms of a cold are different, says Dr Snow. “It’s a runny nose and a sore throat; it’s not a cough and a fever,” she says. The confusion surrounding these symptoms is why, at least for now, Australian authorities say you should only get tested if you have likely symptoms and you have been overseas in the past 14 days – or you’ve had contact with someone who is a confirmed coronavirus case.
What do I do if I am feeling unwell?
At this stage, you are statistically far more likely to be feeling unwell for other reasons but that may change as coronavirus case numbers climb in Australia. As a precaution, you should self-isolate for 14 days and monitor your symptoms. In any case, unless you have been overseas, or had contact with a confirmed Covid-19 case, there is no need to go to a hospital. Call your local fever clinic (your state or territory health department will have contact details), GP or hospital for specific advice – and they may request that you come in for testing. Above all, if you are unwell, stay at home – do not risk infecting others.
How does coronavirus spread?
Covid-19 spreads through droplets. Unlike measles, the world’s most infectious disease, coronavirus is not airborne. The pathogen is coughed up, most often, and lives in these droplets waiting for its next host to ingest them through their nose, mouth and possibly even their eyes. Which brings us to the next question.
Why can’t I touch my face?
Because this is how droplets get into your system. “If you get some virus on your hand,” Dr Yarwood says, “it’s not going to make you sick – unless you stick your finger up your nose or in your eyes. It’s something we do hundreds of times a day: you scratch the side of your nose; you adjust your glasses or give your eyes a rub.” Covid-19 is a respiratory illness; its method of entry to the body is through a specific protein called angiotensin-converting enzyme 2 (ACE2), which is found in the lungs as well as the blood system, kidneys and intestines. There is also evidence that it is found in an enriched state in certain cells of the tongue. If you want to keep it out of your body, don’t touch your face. Or, better yet, wash your hands.
How long does the virus live on surfaces such as door handles, etc?
Dr Yarwood notes one study has found the coronavirus can survive on plastic, metal and similar material for up to nine days. But that was in a lab. “What that means in the real world is very difficult to know,” he says. “In a real-world setting where someone coughs onto a handrailing or something which is sitting in the sun, well, you know viruses – the droplets – get dried out by the sun. The ultraviolet light damages them. So, it’s probably going to be much less than that.” That said though, there “probably is some persistence of the virus in a way that is practically important, so potentially causing transmission,” Dr Yarwood says. It’s certainly hours, possibly days. And if you touch a surface holding coronavirus, and then apply your hand to your face, that’s a problem. So, don’t touch your face – and wash your hands.
Does antibacterial hand sanitiser work, given this is a virus?
It does. As does soap and water. With hand sanitiser, the higher the alcohol content, the better. If you’re washing hands for 20 seconds at a minimum – preferably 30 seconds – this is all you need. By way of explanation, Dr Snow offers a metaphor: “So, you know how if you have a layer of oil on a dish in the sink and you squeeze detergent on it and it just goes whoosh, it goes away. It’s that.” Like all viruses, Covid-19 is protected by a little fatty layer – a lipid bio-layer, to be precise – and using soap or sanitiser on it breaks this down. “It just gets busted apart,” says Dr Snow. Bacteria are actually harder to kill than viruses because they are more complex, so antibacterial sanitiser is more than enough for the job.
Is it true that you have to be in a room for an hour to catch it?
No, not really. You could be standing next to someone for 30 seconds and, if they cough near you or on you, that could be enough. As a general rule, the longer you spend in a room with someone who has coronavirus, the more likely it is you will get droplets on you, and then in you. But there are no absolute thresholds.
What happens if I find out I’ve been near someone who has it?
You need to get tested. Call the federal government’s Coronavirus Hotline, which is open 24 hours a day, seven days a week, for advice. The number is 1800 020 080. Test results can be done in half a day but typically take days.
How does mass testing work and is it effective?
Professor Cheng says specialised swabs – not just ordinary cotton buds – are used to take samples from the nose and throat. These cells are then sent to laboratories, which run tests on the samples. Basically, they are looking for a very specific sequence of the virus code, which is only present in Covid-19. Both the swabs and the testing agents are in short supply. “Clearly everyone is doing millions and millions of these tests around the world,” Professor Cheng says. “Unfortunately, a lot of the swabs that we use come from Italy [the latest worst case for the disease outbreak].” More than 90,000 extra kits have arrived in Australia but due to limited supply it is not possible to test the entire population. This is a real catch 22 because the World Health Organization says the key measure in control and suppression of this outbreak is to “test, test, test, test”. South Korea has tested more than a quarter-million people. Australia has tested more than 80,000 people nationally, a number that is climbing. Professor Cheng says only about 1 per cent of tests are positive, so there could be ways to combine them in batches. For example, you could run four samples at once and if they are all negative then you have eliminated four potential cases. Occasionally, the sample would return a positive and you’d have to test all four individually, but the numbers would work out over time.
With restrictions on who can be tested, could you have it and not even know?
It is likely there are people who have coronavirus and do not know. The restrictions on testing in Australia – confined to those who’ve recently travelled overseas or been in contact with known cases – essentially ensures this. If everyone who is unwell follows the self-isolation advice, this will help, but still, it’s not an ideal situation.
Are you immune to Covid-19 after you’ve had it?
It does seem likely that once you’ve had Covid-19 you are at a much-reduced chance of getting it again, possibly even immune. Dr Snow says there has been some evidence that individuals have been reinfected. But we do not yet know if this was because they were falsely confirmed as having coronavirus the first time around, before actually getting it – giving the impression of two infections. More research is being done on this.
Can you test retrospectively to see if you once had Covid-19 but now don’t?
This kind of test is in development, but it is different from current arrangements. This would be a blood test that determines if the disease was present based on antibodies produced to fight the infection, a sort of clue that it was once there. It has been suggested that all suspected cases should have blood samples taken as well as swabs, but some clinics are not doing this because it slows healthcare workers down in the immediate fight.
What treatment is available to people who contract Covid-19?
For about 80 per cent of cases, no treatment will be required, because the symptoms will be a mild to moderate fever and cough. At its worst, the disease manifests as a viral pneumonia. People in hospital are put on ventilators, or given oxygen; doctors may prescribe antiviral medication, in some cases. Mostly, however, you’ll just need to rest and let your body figure out how to fight this new pathogen.
What is the mortality rate, and how does this compare with other viruses?
It isn’t particularly high, but it is much higher than the seasonal flu. The mortality rate for Covid-19 is context dependent. For example, it was higher in Italy and higher in Wuhan at its peak because the health system was overwhelmed. Dr Snow says you shouldn’t pin the mortality rate down to one number because this number, like how fast the virus spreads, can be brought down by our response. That said, “it’s looking like it is 1 to 3 per cent,” says Dr Snow. “That is much deadlier than flu. Flu is a fraction of a per cent.”
What is the thinking behind Britain’s herd immunity response?
There was not much thinking, as it turned out. Again, there is no herd immunity without a vaccine. A vaccine is nine months away, at best. Most likely a year or 18 months. If the virus were allowed to sweep through any population, say Britain for example, it would kill hundreds of thousands of people. This so-called “strategy” was based on a misreading of Imperial College of London advice, which very clearly noted a “do-nothing approach” would claim 510,000 lives in Great Britain and 2.2 million in the United States – before even accounting for hospital systems being overwhelmed.
Should people keep going to work?
If you can work from home, you should. And employers should allow it where possible. Otherwise, the same principles should apply: if you are feeling unwell, self-isolate.
Should schools close?
This is the most contentious question. All the epidemiologists and experts we spoke to agreed it wasn’t necessary, based on the available evidence. That may change. Professor Cheng says children “don’t seem to be the vector for this disease, even though they are for everything else”. Crucially, he notes, “We can’t shut everything because what we are doing now, we need to do for six months.” None of the experts are saying that transmission doesn’t occur in schools – the Imperial College of London modelling, for example, assumes that it does – but closing schools would have, at most, a modest effect on the shape of the disease outbreak curve. Dr Snow agrees and says the evidence is clear that, right now, “closing schools is not obviously the right thing to do”. If your child is sick, keep them home. Additionally, even though schools will not close, authorities aren’t stopping parents from choosing to take their kids out of school for the time being. So, if you live with an elderly relative or someone who’s immunosuppressed, it’s a relevant consideration.
What is the risk of an outbreak at an aged-care facility?
It is extremely high. Older Australians, those with disabilities and people with compromised immune systems are the most at risk of this virus. In any setting where care is undertaken, especially clinical or close-contact care, such as a nursing home or disability group home, the risks are higher. The government has placed limits on visitors to aged-care facilities, banning children under 16 unless authorised, as well as anyone who has been overseas in the past two weeks. However, little advice has been provided about disability home visits or work.
Do masks help prevent it?
Yes, especially for healthcare workers. But if you are a regular person and do not have a mask, or do not have symptoms, you do not need to wear one. They can help prevent touching of the nose and mouth but are not a silver bullet.
Should I avoid seeing my grandparents?
For now, yes. Limiting all social contact is the best control strategy we have.
Do supplements such as vitamin C help avoid the virus?
No. Just, no.
What happens to the virus once winter begins?
This is of concern. Professor Cheng says the spread of the virus may be dependent on some environmental factors, such as temperature and humidity – especially when it is on a surface exposed to the open air – but the most pressing issue is what happens when the normal flu season starts. Those cases will begin to cross over with Covid-19 in the already-strained public health system. Dr Yarwood says it is “very likely” that the number of people needing intensive care unit beds will be well above capacity. “So, you know, all of the different models show that if you assume that half of people get infected, 20 per cent of people get severe disease, 5 per cent of them need intensive care and that the mortality rate will be maybe 1 or 2 per cent – that is still going to significantly exceed our current ICU bed capacity.”
Where can I get reliable information about Covid-19?
There is no doubt the sharing of information has been fractured, and advice occasionally differs between states and territories and the federal government. They are working together, however, and for now your first port of call for information should be the government’s site – www.health.gov.au. Your state and territory health departments are also offering regular updates via their own websites.
This article was first published in the print edition of The Saturday Paper on Mar 21, 2020 as "Fact-checking Covid-19".
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