Coronavirus: an epidemiologist’s view
*UPDATED 6 April 2020*
We are grateful to a member of our Reigatian community – a former Public Health Epidemiologist, with over 25 years experience of the pharmaceutical industry – for unpicking some of the stories we’ve heard in the press. If you have any further questions you’d like answered, please email the Foundation team.
If we don’t anticipate getting back to normal until we have a vaccine, and that a vaccine would take a year, is some form of lockdown likely to continue for another 12 months?
This is a hard question. In terms of official Government lockdown, I can’t see it lasting for an extended period unless things continue to deteriorate. That said, the length of time, and the severity of restrictions will be substantially affected by the public’s behaviour in adhering to the stay-at-home policy. Here are some reasons to be hopeful:
- The NHS is increasing its capacity to treat patients at what appears to be a remarkable pace
- By late spring/summer there should be lower seasonal demand for intensive care beds and ventilators
- Within weeks, faster and more extensive testing will make it easier to identify those infected
- Within months testing should help identify those who have already had the disease (development to produce a reliable antibody detection test is ongoing and even once developed, will take weeks to roll out)
- Within months we will have greater understanding of who is at greatest risk from this disease and what measures are required to protect them
- Within months we may have a better understanding of how the virus is transmitted within our population and more clarity on how to avoid infection
- Within months we are likely to have better knowledge of optimum treatment with current and developmental medicines
- We will learn from the experience of other countries such as Sweden that have taken a different approach to social isolation
I would, therefore, expect a gradual easing off of the lockdown once the initial crisis is deemed to be under control. Then, with guidance, each of us may have to decide for ourselves how we respond to this new risk. I have heard that after the Spanish flu pandemic of 1918, society did not return to complete ‘normality’ for at least three years, even though there was no official lockdown in force.
I have heard it suggested that coronavirus survives better in cold dry conditions. If so, can we expect any natural respite from the disease in the UK during the warmer months of summer?
Climate might have something to do with it, but it also looks like some countries, in particular Singapore, had learned lessons from the SARS outbreak in 2002-3 and were much better prepared. In Singapore, isolation hospitals had already been built and legislation was already in place to compel isolation of those infected. Before the WHO even declared a public health emergency, Singapore was testing and isolating all those found to be infected by the coronavirus. It looks like they recognised the threat earlier, and reacted very quickly.
There are other factors to consider. Scientists have discovered at least two main strains of the virus. The original ‘S-type’ and the now more prevalent ‘L-type.’ The higher prevalence of the ‘L-type’ strain, which is what is thought to be most common in Europe, may indicate that it is more aggressive in terms of transmission. The WHO reports no evidence that this mutation has impacted on the severity of the disease, but natural selection would obviously favour a mutation that made transmission easier. New Scientist has some good articles on this.
In terms of variation in mortality rates, one factor that will likely be investigated is rates of smoking. Smoking is known to cause diabetes, cardiovascular and respiratory disease and all of these are critical underlying medical conditions that increase mortality. Rates of smoking in Italian men (26%) and Spanish men (29%) are significantly higher that than in Singapore (16%) and thankfully the UK (16%). In South Korea, where a significant proportion of those infected turned out to be young women, the smoking rate of women is only 5% and this is one of the possible explanations for their lower mortality rate.
These are just two of many theories on why we are seeing different patterns of this new disease emerging. What the summer will undoubtably bring is a respite from other diseases such as seasonal flu, which in itself puts the NHS under tremendous strain every year. Whether we get a respite from coronavirus itself is yet to be seen.
If the current social distancing measures fail to limit the spread, what’s next?
In the absence of a vaccine or preventive treatment, social distancing is really the only tool we have at this stage to limit the natural speed and breadth of this epidemic. As we know, the Government strategy is to slow the spread so that the NHS does not become overwhelmed. We do know from what we have seen in China, that social distancing can work, at least in the short term. If we are not able to alter the natural progression of this disease we are likely to see a significant increase in infections, illness and mortality.
Why isn’t every suspected case being tested?
During the ‘containment’ phase of this epidemic, the Government strategy was to test suspected cases in the community in an attempt to identify them early and prevent transmission. This was an admirable, but difficult, task. As a Public Health Epidemiologist, I tried to implement this approach during the early phases of the HIV/AIDS epidemic. It makes sense to try to identify cases and all potential contacts, but it’s labour intensive, difficult to enforce and there comes a point, like in HIV/AIDS, when it just becomes impossible to do this without diverting resources from other priorities. The Government continues to test in high-risk environments such as prisons and care homes but we simply don’t have the resources in terms of testing kits or personnel to test everyone in the community and do the appropriate follow-up in terms of tracing, notification and isolation.
Interestingly, Germany is reportedly testing around 500,000 people a week. This likely explains their higher total infection rates and lower overall mortality rates – they are simply picking up the milder community cases that we are missing. I would expect the picture to be similar in the UK if we were testing more widely.
Now that we are in the ‘delay’ phase, we probably have enough information from other countries, such as Germany, and from modelling, to extrapolate infection rates and prepare for what is coming next.
What treatment options are being explored and what affect will these have?
The medical community, in partnership with patients and the pharmaceutical industry, have moved with tremendous speed to investigate treatment options for this virus. Most clinical trials are registered and available for us to monitor on clinicaltrials.gov. Today there are 178 registered studies evaluating everything from traditional Chinese remedies to a number of more established medicines. There has been a lot of speculation and hope resting on two medicines: hydroxychloroquine, a chemical relative to quinine, and remdesivir, a biologic therapy originally developed as a treatment for Ebola. Many more are being evaluated.
While there is a great deal of speculation about the potential effectiveness of these medicines, it is essential that we learn more before they are widely used to treat patients. No medicine is risk free, so we must be as sure as we can be that the benefit outweighs the risk before widespread use. Much of the information that we have so far is either theoretical, based on animal studies or based on very small sample sizes. We need to know more about what the correct dose should be, what type of people might benefit, and any potential interactions with other medicines. Remember that most of the high-risk patients requiring treatment will likely be taking other medicines for existing conditions.
The first trial information should start to appear mid-April. Because the knowledge on how to treat this disease is growing as exponentially as the epidemic itself, my personal preferred tactic is to avoid catching it for as long as I can!
While I am not expecting a miracle cure, I am confident that in the coming months we will identify medicines that can better treat this disease, increasing survival rates and speeding recovery.
What we really need is a vaccine that can prevent the development of COVID-19 in the first place. Developing an effective and safe vaccine will take time: the most positive estimate I have heard is nine months and the average estimate is at least a year. Because vaccines are given to millions of healthy people it is essential that they are proven to be as safe as possible. This is a process that we don’t want to rush. Even when a vaccine is deemed to be safe and effective by the regulators, and granted a licence, it will take time to manufacture and distribute in large quantities.
My speculative bet, based on my faith in science and human ingenuity, is that we will have some better treatment options available within three months and vaccines available to the most vulnerable within a year.
How long does the virus stay on surfaces and how infectious are these particles?
The US National Institutes of Health (NIH) has conducted a study on how long the virus remains in the air and on surfaces. You can read the study on nih.gov. It found that the virus can be detected on aerosols for up to three hours, on cardboard for up to 24 hours and on plastic and stainless-steel surfaces for up to three days. In practice, these will all vary according to temperature, humidity, ventilation and the amount of virus present.
Rather than get too paranoid, it’s worth noting that the NIH concludes that the most probable form of transmission is from inhaling contaminated droplets from someone sneezing or coughing near you.
Face masks: are they a help or a hindrance?
Face masks are tricky to use properly and need to be used in conjunction with other equipment such as eye protectors and gloves, changed frequently in a clean environment and used while breathing slowly, not walking around doing the shopping. For a mask to filter air there has to be a good seal between the mask and face. Air will obviously follow the path of least resistance, so if you have facial hair or anything other than an average-shaped face or if you are breathing harder than at rest, masks tend not to work – air just rushes in from the sides. Most of us are not used to wearing a mask, so we tend to fiddle with it, and I have seen many people wearing them around their necks or pushing them aside to eat, drink or talk. There are clearly better things to do to protect yourself than wear a mask; in particular social distancing, avoiding people who are ill, washing your hands and not touching your face.
If you suspect that you have the virus and are coughing or sneezing, a mask might reduce your risk of spreading the disease. However, if you have these symptoms, you shouldn’t be out in public anyway. I have also heard that wearing a mask might deter you from touching your face. If you choose to wear a mask for this reason just make sure to wash your hands before you put it on or take it off!
So, while maybe not being a hindrance, masks are better off in the hands of healthcare professionals who will know how to use them in conjunction with other personal protective equipment.
How will we know when it’s safe to resume ‘normal’ contact?
Safe for who? Depends on your definition of ‘normal’! For most of us, it is not necessarily our safety that we should be preoccupied with, but rather the safety of those at high risk, i.e. the elderly and those with pre-existing conditions (1.5 million in our society of all ages, including children).
The first hurdle will be increasing the NHS’s capacity to treat patients with optimal care. This, coupled with the availability of some new, fairly good treatment options, would be a big step forward.
Once a vaccine is available, life will begin to get back to normal. The first to be vaccinated will likely be healthcare professionals and the vulnerable. Of course, while we in the UK may receive the vaccine relatively quickly once it becomes available, this will not be the case for the majority of people in the world who have no, or very limited, access to healthcare, so their risk may remain high and their ‘normal’ may be some time away.
On a sombre note, statistics are not that comforting if you happen to be one of those who become seriously ill, or you have a relative or friend die, as a result of this disease. Sadly, as we have already seen, many lives will never be exactly the same again even if the majority of us began the rebuilding process and get back to normal quite soon.
If you have any further questions for our epidemiologist, or you have expertise in this field that you’d like to add, please email the Foundation team on email@example.com.
The above is intended as guidance only. We recommend that you contact relevant professionals with any specific health-related concerns you may have. Reigate Grammar School Foundation cannot be held responsible for any decisions or actions taken, based on the guidance provided.