Badenoch virologist's advice on coronavirus
As the world waits to see just how the Wuhan coronavirus pans out, the Strathy has consulted Badenoch’s own time-served observer on deadly viruses.
Dr Anne Bridgen, of Newtonmore, is a retired molecular virologist well-versed in the sphere of the now named Covid-19 which has so far claimed the lives of more than 1100 people worldwide.
She has written innumerable learned medical papers over the years and we asked her if the virus was likely to have any impact here in the Highlands.
Firstly, just what is it?
Coronaviruses are large RNA viruses whose impact until relatively recently was mainly in the veterinary field. Their genomes are made of single stranded RNA, which has the following implications 1) they can mutate relatively quickly 2) they tend to cause relatively severe disease (think measles, flu, Ebola) and 3) drug treatment is hard to develop.
Why have we been getting all these coronavirus outbreaks this millenium?
Most viruses develop in one particular host and may only cause disease when introduced into another species.
Genetic analysis suggests that the recent human coronavirus outbreaks (caused by the SARS- CoV, Severe acute respiratory syndrome-related coronavirus of 2002-3 and MERS-CoV, Middle East respiratory syndrome-related coronavirus, of 2012) were endemic in bats and came to the human population via an intermediate species, civet cats for SARS-CoV and camels for MERS-CoV.
Likewise, the Wuhan virus called 2019-nCoV, also originated in bats but an intermediate host has not yet been identified. Such infection is almost inevitable as human populations increase.
Why doesn't anyone know how dangerous it might be?
When viruses are first introduced into a new host, they generally don’t replicate well, and humans (in this case) are often dead-end hosts. But this is where the quick mutation comes into play, as often only a few mutations can lead to
effective human to human transmission, when the virus becomes a much bigger risk. Virus 2019- nCoV does appear to transmit relatively readily between people.
Several factors increase the possibility of a pandemic with this virus: the mortality rate is low, around 2% according to Chinese sources, with many people having a mild disease that may go undetected. The incubation period is quite long, 5-10 days, and transmission may occur during this time. A recent paper (Wu et al., Lancet, Jan 31 2020) suggests that on average each infected person infects 2.68 other people which, unless checked, will cause the virus to spread rapidly. So we will see more of this virus.
What can we do about it?
In the longer-term it is likely that a vaccine will be developed, but this is a long term prospect. Drugs may be developed against stable regions of the viral replication protein, but this is also not immediate. So patient treatment is symptom relieving. But right now, the measures needed to contain the outbreak are more traditional public health measures for dealing with infectious disease outbreaks – quarantining cases and contacts, travel restrictions or bans,
and individual precautions.
Essentially, we need to trust the government to do the right thing and follow their advice; this approach may seem drastic but is already reducing case numbers in China.
Will it affect us here?
Economically yes due to reduced Chinese and other tourism. Healthwise, hopefully not; there are still no confirmed cases in Scotland.
Should we worry?
We should keep things in context. Flu is still a much more severe virus killer, and is preventable.
Should we be prepared?
Dr Bridgen spent 30 years in virology, in Edinburgh, Zurich, Ulster and Glasgow looking to develop vaccines.
She and Ian Bradbury – a recently retired statistician from Kincraig's Frontier Science, Scotland – are current owners of Croft Holidays, Newtonmore and Kingussie's Chapel House Arts.