This first post in Naturally Speaking’s new COVID Q&A blog series is about Transmission and Prevention. If we don’t answer all your most pressing questions, please feel free to ask them in the Comments section below – we’ll do our best to respond. We’ll also aim to provide any updates as advice and knowledge evolves. Click here to switch to the more complete version of this post (with extra details and links).
Disclaimer: Some of the guidance refers specifically to the situation in the UK, although most of the content is relevant regardless of where you hail from.
Q. Can people pass on the virus BEFORE showing any symptoms?
A. Yes. It is not yet clear how often this happens, but some people who show few/no symptoms (asymptomatic) can be infectious with the virus (they can spread it to others). As many as 60% of all infections could be asymptomatic. Additionally, some people can infect others before they show any disease signs. We don’t fully know how long this ‘pre-clinical infectious period’ can last. What we do know, however, is that even with this element of pre-symptomatic transmission, enough people do show signs when they’re sick that it can be possible to control the virus based on targeting visible or symptomatic cases. This has been demonstrated in places like South Korea, Singapore etc., if rapid testing and quarantining is enforced.
Q. Should we be worried about take-away food? How about food from supermarkets?
A. As a general rule, standing in line with lots of people is not advisable! If take-away means a busy queue, it would be better to consider delivery, or to sharpen your own culinary skills. While there are likely some minor risks from food prepared by others, including handling the outer packaging, the risks of contracting the virus from touching surfaces decline over time and can be mitigated by washing hands and not touching your face. Over the past several weeks, we’ve seen positive actions being taken by supermarkets to minimize contact among customers, both in the queues which are now more spread out, and inside the stores by limiting the number of customers who can enter at a time. Consider wearing gloves when shopping, and always wash your hands before entering and after leaving public areas. Generally, highest transmission risks are from household contacts and travelling with infected people (e.g. public transportation).
Q. Does the mode of transmission affect the severity of disease?
A. We’re not aware of any research on this yet. For many viruses the severity of disease is dose-dependent: the larger the viral dose, the more severe the disease. But this is not always true, so it’s difficult to extrapolate.
Q. Why the 7 or 14 day isolation?
A. If you are sick with suspected COVID-19, UK government recommendations are to wait 7 days until you recover and can interact safely with others (cease being infectious). If you have been in contact with someone who is sick, particularly another member of the household, you should self-isolate for 14 days, as it can take this long for symptoms to appear. If someone develops symptoms during this period, they should continue to self-isolate for 7 days from the start of the symptoms.
Q. Is it worth buying N95 face masks? Do they really work?
A. Yes, they work. At the beginning of the pandemic, personal protective equipment (PPE), including N95 masks, was in short supply, so it was important for it go to frontline health workers who urgently needed it, i.e. those putting themselves at risk through their work, but who ultimately protect many more people. For this reason they were not being recommended for the general public. N95 masks should be fitted by someone trained to do so, and are not for use by kids or folk with beards! While other types of face masks aren’t as effective at protecting people from infection, that can help reduce the spread of the virus via aerosol droplets from those who are infected (including asymptomatic cases who don’t know that they are infected!). Masks might also help remind people not to touch their faces. DELVE, an independent scientific group convened by the Royal Society, published a valuable report on May 4th that summarises the evidence about the potential value of face masks in tackling the pandemic.
Q. Any idea whatsoever on timings of length of quarantine(s)?
A. Likely 3 months or longer. We can’t know at present. Governments will aim to keep this as short as possible, but if compliance is low and the epidemic worsens, stricter enforcement will be likely, and for longer periods. Beyond 3 months is very unclear for many reasons.
Critically, the effects of severe restrictions won’t even start to be seen for approximately 2 weeks or more, so we need to be both compliant and patient.
Q. Why are some countries making people stay indoors? Shouldn’t going for a walk be low/no risk if you stay 2m apart?
A. Generally, keeping 2m distance outdoors should be fine and is working in some countries. But if people don’t comply with social distancing guidance, the disease will escalate and more severe measures will be inevitable – beyond a tipping point, any opportunity to reduce transmission will be crucial.
For more information and an up-to-date full Q&A: please check here.
Feature image is original artwork by PhD candidate Chiara Crestani, ©2020.