EXPERT REACTION: Coronavirus - Answers to your latest questions on social distancing and epidemiology

Why is mortality rate apparently higher in Europe than in China?

There may be some reasons for this: 1) higher proportion of older population in Europe as most people who died of COVID-19 are older; 2) lots of mild cases that were not detected so the denominator (total patients) was smaller; 3) the measures taken by the public health systems to stop  the transmission as perhaps no other country can make the drastic lockdown of tens of millions people as China government did.

Without serious action, will Australia will run out of intensive care beds between 7 and 9 April?

As you can see that there are a few assumptions of the modelling. It is hard to predict what would happen in the next few weeks. Personally, I think the likelihood for Australia to have 44, 580 cases by 7 April is still low. Australia shutdown the board to all foreigners, which would give us more chances to flat the curve. But we still need to be prepared for a sudden surge of severe cases.

Will the social distancing measures enable society to eradicate COVID-19 or is it going to continue existing in the community but eventually the herd immunity will build up and it won't be a crisis?

I don’t think social distancing alone can work and it must be complemented with other government measures to avoid people gathering and therefore reduce the chance to get infected. Also, social distancing is hard to practice as behaviour changes of humans take time. We need herd immunisation but should take more active actions to achieve it, e.g. vaccination.

What is the worth in temperature checking kids at school to make sure they're not unwell? Is it even practical?

I think it would be better to ask parents to keep unwell kids at home rather than checking temperatures at school. There are a few practical issues too. Who are capable and can feasibly take this task in a timely manner and for how long? However, if kids are still attending school, we should provide extra protection, e.g. a higher standard of personal hygiene for both teachers and students, to   ensure their health. Kids can get pretty sick even though the mortality rate for this age group is very low.

Why is mortality rate apparently higher in Europe than in China?

It is not entirely clear and likely a result a number of things, including how quickly the response was, the type of containment measures that were put in place and when that happened etc.

Without serious action, will Australia will run out of intensive care beds between 7 and 9 April?

That is not entirely correct. It is clear at some point if we continue with the expect increase in case then we dont have enough ICU beds. When that occurs is not entirely clear. However the major hospitals are gearing up  to increase ICU type beds as we speak.

Will the social distancing measures enable society to eradicate COVID-19 or is it going to continue existing in the community but eventually the herd immunity will build up and it won't be a crisis?

Social distancing will not eradicate the virus by itself and until we have a vaccine it will be difficult to get the effect of a herd immunity. It is not possible just to allow the virus spread as the health consequences are far too great. The virus will always exist similar to other major viruses however it will be controlled with appropriate vaccination.

Should schools close given the situation is getting worse?

At this stage there is no evidence to suggest that schools closed hence the reason why the Chief Medical Officer has not recommended it and the government hasn’t done it. However this is a rapidly changing story.

What is the worth in temperature checking kids at school to make sure they're not unwell? Is it even practical?

It is practical and quite easy to do and has been done before.

Questions relevant to the Aboriginal and Torres Strait Islander Community

I'm wondering if smoking ceremonies have been used before to help respiratory problems? I've seen them used to keep away infection.

It is unlikely smoking ceremonies would keep away infections and depending what is burnt potentially could do harm with people who already have respiratory disease.

What are the risks with attending Sorry business/Funeral services and how can I safeguard myself?

The risks are similar to someone having a really nasty virus such as a horrible cold or influenza. It is really difficult especially when at these the times you want to give someone a hug. The problem is if someone has the virus then there is a significant chance it would spread. In these circumstances it is horrible.

Social distancing/reducing spread

Is it okay to go bushwalking/hiking?

Yes

What are good household cleaning products for surfaces ? Can I use a steam cleaner to sterilise? And what’s a good cleaning routine?

Simple standard cleaning measures are fine. Wiping benches with standard cleaning products.

If you and your family are put into isolation are you provided with masks? Given the national shortage, the increased price per unit and the assumption that we need more than one per person, will we need to buy our own and where will we get them?

I don’t  know the answer to whether you get given a mask. The main thing is that we don’t use masks when we don’t need to as the hospitals need them.

If we have chronic illness and weak immune systems, should we just self isolate with our families as soon as we can?

Again follow standard universal precautions. Make sure you hands are washed regular and isolate as practical.

My child is having a birthday party this weekend, do I need to cancel it?

This is a risk issue. The more we interact with people, there is a heightened risk. However, if no one is symptomatic and the gathering is a small crowd (3-4 people as opposed to 50-60 people), then that’s okay.

Is it safe for my child to visit their grandparents at this time?

It depends, there is no simple answer here. It depends on how old the grandparents are, their mobilities etc. Again, this is a risk issue, we are trying to limit the risk. Older people are more susceptible to the virus so we need to look after them and this is one way of doing that.

• Why is mortality rate apparently higher in Europe than in China?

"Two major reasons I am aware of:  In Italy the fraction of elderly people is significantly higher, and the death rate in the elderly is much higher. China is a large country, and the epidemic affected a relatively small part given the scale of China.  They were able to bring many resources to the region from the rest of the country from other areas that were not affected.  In comparison, Europe has a much more disperse epidemic and so they cannot bring massive resources to the specific hot spots that are causing many deaths."

• Without serious action, will Australia run out of intensive care beds between 7 and 9 April?

"I do not agree with all parts of this analysis, largely because much of the infection being recorded is coming from outside, so it is harder to say how much growth is within Australia.  But, the general conclusion the ICU beds will run out without serious action soon is robust."

• Will the social distancing measures enable society to eradicate COVID-19 or is it going to continue existing in the community but eventually the herd immunity will build up and it won't be a crisis?

"Great question.  We'd love to know the answer to it."

• Is it okay to go bushwalking/hiking?

"Yes, as long as you are not in close contact with others."

• My child is having a birthday party this weekend, do I need to cancel it?

"Will parents be attending?  Will it increase interactions between children from different schools, or just within the same school?  We did not have our daughter's party last week."

• Is it safe for my child to visit their grandparents at this time?

"I can't answer this question well, but definitely avoid contact with elderly if you or your children have any signs of illness.  The symptoms may be quite mild.

• Without serious action, will Australia will run out of intensive care beds between 7 and 9 April?

"The strategy still is to control the outbreak if possible or to delay its peak affect.

It all depends on the peak incidence. At present there are fewer than one case in every 25,000 people. However, if extensive community transmission occurs then this proportion will rise considerably. It should be noted however, that in Hubei province the incidence was about 1 case per 1000 population."

• Should schools close given the situation is getting worse?

"The public health position on this is that schools should not close at this time for several reasons:
At this time, in the absence of substantial community-based transmission, the risk to those who have not travelled abroad or those who have had contact with those who have travelled remains very small and the chance of casual contact with someone with COVID 19 is negligible.

According to the US CDC, unsupervised children might engage in social mixing without adults keeping track of who is meeting who. "Longer closures may result in more students congregating outside of school [eg. other students' homes, shopping malls], which will increase risk to older adults or those with co-morbidities," it warns.

Robert Booy, from the Centre for Research Excellence in Population Health, said a review of scientific literature of school closures and epidemics found closing schools had an "equivocal benefit" on stopping transmission.

Researchers at the Imperial College London have undertaken modelling of the impact of various public interventions based on data from Hubei and their previous work with Influenza. They have reached the conclusion that while school closure may amplify social distancing, it is not enough in itself to break transmission. This is quite different to that which occurs with Influenza and this is based on established community transmission.

Closing schools has consequences as parents need to stay home from work; some of whom will be essential workers including health workers. Or the kids will either end up accumulating in shopping malls or with grandparents who are at particular risk from this disease.

Should this disease break out into the community then it may last months, and prolonged closure of schools may have significant impacts onto the children and their education.

Additionally, this disease is a little different. The children are usually the super-spreaders of respiratory infection as they lack the capacity to exercise social distancing and are not good on personal hygiene. However, with this disease they are being infected at a much lower rate and do not appear to get serious disease.

However, the situation is very fluid and if this does break out further into the community then much more aggressive social distancing measures will need to be taken including closing schools."

• What is the worth in temperature checking kids at school to make sure they're not unwell? Is it even practical?

Random testing of temperatures is widespread now, but the evidence is limited that it is a useful means of detecting cases.
It is unlikely to be a useful measure to detect cases but may be a way of reassuring parents and teachers.

• Is it okay to go bushwalking/hiking?

"Social distancing means keeping away form other people. Bushwalking alone or in the company of your immediate contact should not increase risk provided you don’t stop at the coffee shop on the way home."

• If you and your family are put into isolation are you provided with masks? Given the national shortage, the increased price per unit and the assumption that we need more than one per person, will we need to buy our own and where will we get them?

"You do not need to wear masks if you are in isolation because you are at risk of, have been in contact with someone with the disease but do not have it yourself at present.

At present in Queensland, all patients diagnosed with the disease are being admitted to hospital, but this will not be possible when/if we have substantial community transmission of the disease.

At that stage patients with mild symptoms will be sent home to isolate and this is occurring in other states now.
The normal (surgical) masks that are freely available usually are only useful to prevent the spread of the disease from someone who is infected. The patient with the infection should wear a mask to reduce the number of droplets containing viruses that are expelled into the atmosphere."

• If we have chronic illness and weak immune systems, should we just self-isolate with our families as soon as we can?

"The current recommendation is that people who are at increased risk from this disease because they are elderly or have chronic diseases or are immunocompromised should start to take precautions. That includes isolation. The risk is very low at present, but this could change any day."

• My child is having a birthday party this weekend; do I need to cancel it?

"The risk is very small (but never absolute zero) provided no parents bring along children who may be exhibiting symptoms or are in the at-risk categories; namely travelled overseas or been in close contact with someone who has travelled overseas. However, this may change if substantial community transmission begins to occur. ( See comments above regarding the risk to children.)
Remember there are more people in the community with common colds and influenza at present than COVID 19 but this may change.

• Is it safe for my child to visit their grandparents at this time?

"The risk remains low at present provided no one has been travelling overseas or in close contact with someone who has or with some who has been diagnosed with the disease.

• Why is the mortality rate apparently higher in Europe than in China?

"It is important to understand that what we are getting right now are crude mortality rates and that these numbers are pretty uncertain across the board. We probably won’t get more certainty on this until later on when we have more accurate and complete data globally.

There are a number of things that we need to understand when we try and interpret these rates and understand why they may be different in different countries. Some of the main reasons for the differences are as follows:

Firstly, the denominator for this rate; that is the number of people that have had COVID-19, is not going to be accurate anywhere and in some places it is going to be less accurate than others. That is, we are clearly underestimating the prevalence of disease in many countries which will serve to inflate the mortality rate calculation. The reasons for this is the lack of testing in many places and also the fact that many asymptomatic individuals are probably not even being suspected as possibly being infected. So the testing rates and the strategy for testing; that is, who are being tested, are both going to influence the mortality rate calculations.

Second, clearly if a country has had its healthcare system overwhelmed, like Italy, where they have had to make decisions about who to ventilate, the death rate is going to be higher. So you have a much higher rate of survival if you get ill in a country that has a good healthcare system and can deal with the amount of disease being seen.

Third, it is very apparent that older individuals are more vulnerable to COVID-19. Therefore some of the this elevated mortality rate in regions is going to be a reflection of the fact that some places have an older age distribution. Italy, for example, has the oldest population in Europe.

Other factors influencing the mortality rate calculation include the stage of the epidemic in various regions and also the accuracy of the reporting of cases and deaths.

It is quite possible that the difference mortality rates seen in different countries is going to largely disappear as the pandemic progresses and more data is collected.

• Without serious action, will Australia will run out of intensive care beds between 7 and 9 April?

"There is not a country or health system in the world that will be able to cope with the demands placed on it without effective public health measures to reduce the spread of coronavirus. We are better placed than most countries, with one of the best health systems in the world, but we still need to intervene decisively to reduce the spread of illness and ‘flatten the curve’ to ensure that our health system can cope."

• Will the social distancing measures enable society to eradicate COVID-19 or is it going to continue existing in the community but eventually the herd immunity will build up and it won't be a crisis?

"Identification of those that are ill, contact tracing and testing people, along with border restrictions, quarantines, closing public spaces, banning mass gatherings and providing good advice to the public about hygiene and social distancing are all designed to slow the spread of infection and to flatten the curve so that we can look after those that need to be taken care of during this crisis, especially the most vulnerable.

All of the focus for now is to slow the spread of disease."

• Is it okay to go bush walking/hiking?

"Yes, I think we should be all taking sensible precautions and be doing things to keep us physically and mentally healthy. Being in the outdoors - whether for a bushwalk, a hike, or just a walk around our neighbourhoods - is one of the best things we can do for our health at this time when a lot of other avenues for relaxing are not available.

It would be sensible not do this if you are feeling unwell, to always take hand sanitiser with you, follow social distancing guidelines if you come across other people or groups of people, bring plenty of your own water, and to pack your own rubbish and take it with you."

• What are good household cleaning products for surfaces ? Can I use a steam cleaner to sterilise? And what’s a good cleaning routine?

"There is quite a bit of evidence now about how coronavirus can survive for extended periods of time on surfaces, so paying more attention to cleaning at this time makes sense. It’s also good to know that coronavirus, however, is killed pretty easily.

Any good disinfectant will be effective for cleaning surfaces,but the important thing is  to make sure you cover surfaces properly with disinfectant and scrub with pressure using a sponge or towel. Currently, cleaning surfaces more often than usual is good practice, as is paying more attention to personal hygiene.

Heat kills pretty much all bacteria and viruses, so a steam cleaner will work well to clean surfaces too."

• If we have chronic illness and weak immune systems, should we just self isolate with our families as soon as we can?

"All of us should be following the advice of the government and taking all the precautions we can to protect our health. This is especially true for those with specific vulnerabilities, for example those who are elderly or immunocompromised.

We are in this for the long haul. I would advise against people going as far as putting themselves in voluntary isolation right now. We need to look after our physical as well as our mental health, and right now, your chances of being exposed to coronavirus is still relatively low. I would advise people to, as best as they can, try and get on with their lives as normally as they can, while taking sensible precautions.

There are extra precautions that the most vulnerable – like the elderly and immunocompromised - should be taking. If you fall into a vulnerable group, or have close contact with someone who does, you must be vigilant with hygiene. The recommendations from the government and leading health authorities include sanitising your hands wherever possible, including entering and leaving buildings, using ‘tap and pay’ to make purchases rather than handling money, travelling at quiet times and trying to avoid crowds, asking public transport workers and taxi drivers to open vehicle windows where possible, regularly cleaning and disinfecting surfaces that are touched a lot. You may even want to limit your public transport use and non-essential travel to reduce your chance of coming into contact with the virus. It’s also reasonable to ask family or friends not to visit you when they’re ill."

• My child is having a birthday party this weekend, do I need to cancel it?

"The guidelines from the government at this stage are pretty clear. Indoor gatherings of less than 100 indoors are allowed. However, this assumes close adherence to hygiene and social distancing measures. At a children’s party, it is going to be really hard to ensure that these measures are adhered to, so in the current circumstances, I would probably cancel it. This is clearly a difficult call to make, and requires you to take into account a lot of variables, including the age of the children and the size of the party."

• Should I keep taking my child to swimming lessons?

"There is some contention about the issue of using swimming pools in general. A properly chlorinated pool should kill coronavirus, but the more pressing issue relates to people having close contact with others in the context of attending a swimming pool and swimming lessons. If you are in a public swimming space, I would recommend practicing the social distancing measures of 1.5 metres per person."

• Can I take my child to the park to play with friends?

"I think playing in the park with siblings is a good thing, ensuring that good hygiene practices are enforced. However, we should probably be limiting play with lots of friends at this time as it is going to be pretty hard to instruct children to maintain 1.5m distance during play."

• Is it safe for my child to visit their grandparents at this time?

"As difficult as this is going to be, the safest thing may be to limit visiting of children with grandparents. The evidence seems to be accumulating that children can be asymptomatic carriers and, given that older people are much more vulnerable to serious illness, it is worth being cautious for the time being. This is a good time for children to take advantage of their affinity for technology and stay in touch with grandparents this way. It is still really important for this intergenerational interaction to occur.

• Why is the mortality rate apparently higher in Europe than in China?

"The short answer is that we don’t know just at the moment. What we do know is that there are multiple factors that can influence disease transmission, ranging from geographical considerations and population density to factors such as the extent of intergenerational families living in the same households, a history of being a smoker, etc. It is for this reason that we need to be very careful in extrapolating what we see happening in one country to apply it to our own. Australia’s outbreak of COVID-19 has already been very different from what many other countries have experienced, and that will likely continue to be the case."

• Without serious action, will Australia run out of intensive care beds between 7 and 9 April?

"These estimates have been based on modelling. The problem with modelling is that it operates on a number of assumptions similar to economics, and often fails to take into account the impact of various public health interventions that can influence the level and extent of disease transmission. A good example of this was the modelling that the US Centres for Disease Control and Prevention released about the West African Ebola outbreak that predicted 1.4 million cases by January 2015 based on the epidemiological curve. Of course, in reality the public health measures that were implemented witnessed a significant reduction of cases by November 2014, and the total number of cases was 28,616."

• Will the social distancing measures enable society to eradicate COVID-19 or is it going to continue existing in the community but eventually the herd immunity will build up and it won't be a crisis?

"The aim of social distancing measures is to halt transmission of the virus between people. In so doing, we will help “flatten the curve”. While we suspect the virus may now become endemic (always circulating in the community) it is unclear whether further outbreaks of severe illness will occur."

• Is it okay to go bush walking/hiking?

"If you have been told to self-isolate, then the answer is no. You must remain in-doors. If you have not been advised to self-isolate, at the moment you can continue to go about your life while practicing social distancing. This advice may change in the event of widespread community transmission.

• Why is mortality rate apparently higher in Europe than in China?

The mortality rate depends not just on the virus, but on how many cases are in specific hospitals and how well those hospitals are able to cope. 100 cases in one over-stretched hospital is a very different scenario to 100 cases spread over several hospitals."

• Without serious action, will Australia run out of intensive care beds between 7 and 9 April?

"Serious action is being taken, with unprecedented restrictions on travel and large gatherings. Everybody is being asked to keep their distance from others, wash their hands, and do their bit to slow the spread of the virus. Many predictions circulating online currently are based on back-of-the-envelope calculations by non-experts, which assume that we are doing nothing to stop the virus - this is clearly not the case."

• Will the social distancing measures enable society to eradicate COVID-19 or is it going to continue existing in the community but eventually the herd immunity will build up and it won't be a crisis?

"Eventually we will have a vaccine. It's not likely that we can completely stop transmission, but we can slow it down. The more we can slow the virus down, the better our health system will be able to cope with the increased demand. We want to avoid a huge spike in cases that could overwhelm the health system - that's why everybody in Australia is being asked to do their bit, not just the elderly or those at higher risk."

• Is it okay to go bush walking/hiking?

"Outdoor activities are much safer than indoor activities, although big groups could still be a risk especially if somebody is sick. Anybody who is unwell should stay at home. Everybody needs to keep their distance from others - no shaking hands or hugging and kissing 'hello'. We all need to wash our hands regularly and thoroughly with soap and water, especially before we eat and after using the bathroom."

• If you and your family are put into isolation are you provided with masks? Given the national shortage, the increased price per unit and the assumption that we need more than one per person, will we need to buy our own and where will we get them?

"There will be instructions from state governments about exactly how to manage household risks if someone in the household is isolated with the virus or due to travel, but all the usual advice still applies: wash your hands thoroughly and often, cough into your elbow or a tissue rather than your hands, and keep a physical distance when you can. Obviously 'keeping your distance' is impossible with small children or anybody else who needs physical assistance with self-care, so washing our hands and good coughing practices will be most important in those situations."

• If we have chronic illness and weak immune systems, should we just self isolate with our families as soon as we can?

"People with weakened immune systems are obviously especially worried at the moment, and it makes sense to take extra precautions. The exact degree of extra risk will vary depending on people's specific circumstances, and people who are worried about these issues should get specific advice for their personal situation. People who are especially vulnerable can take extra precautions by avoiding any large social events, and making it very clear to friends and family to please stay away if they are unwell, even if it's 'just a bit of a cough'. It's hard to reduce the risk to zero, but we can limit it by washing our hands, keeping a physical distance when possible, and encouraging all of those around us to do the same. Obviously we will sometimes need to balance these things against other needs - many people need care and physical assistance from others, and isolation is very hard on people emotionally. Older and more vulnerable people can stay connected by having more frequent discussions on the phone with friends and family, reducing their risk but staying connected socially."

• My child is having a birthday party this weekend, do I need to cancel it? Should I keep taking my child to swimming lessons? Can I take my child to the park to play with friends?

"All of these are valid questions and everybody is trying to work out the right thing to do in all these different situations. Understandably, many parents are worried at the moment. The biggest thing to emphasise is that we think this disease is usually mild in children, much milder than in older adults. Keeping up with the latest advice from the health authorities is very important. Obviously some recommendations are harder for younger children to follow, for example keeping their hands clean and keeping their fingers out of their noses! I think it's important to note that by adults limiting our own risk, we are helping to keep kids safer. If adults are avoiding large social events, working from home if and when possible, keeping our hands as clean as we can, and keeping our distance from other adults when we can, all of that will help lower the risk of kids picking the virus up from us."

• Is it safe for my child to visit their grandparents at this time?

"We don't want to completely socially isolate older people right now, but we do need to be mindful and do what we can to keep them safe. We all need to abide by the new restrictions on visiting aged care facilities, as difficult as this is for many families. For families visiting grandparents or other elderly in the community, keeping our hands clean will be very important. If anybody is feeling unwell, even if it's 'just a bit of a cough', they should not be visiting older relatives in person - a phone call would be better.