Coronavirus and travel

1918 flu pandemic. Just a reminder of what could happen

Image from 1918 - looks familiar?

The novel Wuhan coronavirus in China is all over the news and there appears to be quite a bit of panic around this virus. As a virologist/microbiologist who spends quite a bit of my time traveling around the world consulting on disease control in a post antibiotic era, I am particularly interested in this novel virus. I lecture to 3rd year microbiology students at a university and the subject which I lecture in is "Pathogens and immunity", so pretty much right up my alley! For the last few years, I have been discussing the likelihood of a major disease pandemic in the world with my class. My prediction  has been that the next major pandemic (that is a world wide infection) would be caused by an Influenza virus, which has either developed in birds or pigs. I have a particular interest in the 1918 flu pandemic, as I believe that this virus was actually the reason that the first world war ended. The virus was killing more soldiers then the two opposing armies could do - and they were pretty good at killing each other!  Looks like mother nature had other ideas and we now appear to be on the verge of a pandemic caused by a novel Coronavirus.This virus appears to have started in a live food market in China and it appears to have come from bats. Normally when a virus crosses the species barrier (that is spreads from one species like bats to another like man) the virus is normally highly virulent.

1918 flu virus

So before discussing the implication of travel in this pandemic, lets first look at what is known about the virus.

The recent rapid outbreak of what appears to be a completely novel strain of Coronavirus in the city of Wuhan in China is causing much concern around the world. This virus has tentatively been called Wuhan Coronavirus, and this terminology will be used in this document. The world just needs to be reminded of the outbreak of Severe Acute Respiratory Syndrome  (SARS) virus and the devastating consequences that virus caused.  The Wuhan virus, like SARS, are both Coronaviruses. Both viruses started off in China. SARS had a human mortality rate of around 15% and increasing to 50% in people older than 60 years of age.  What eventually brought the SARS outbreak under control was the fact that infected persons were not infectious until they were showing clinical signs of infection. It was thus possible to control the spread of the disease by isolating people showing clinical signs. It is yet to be determined if the Wuhan Coronavirus also spreads in the same manner. It has been established that human to human transmission is possible with the Wuhan Coronavirus. If this virus spreads in a manner similar to Influenza virus – in other words - before the infected people show clinical signs, the world could be on the verge of a major and serious pandemic.

Coronavirus

Image from https://www.kbia.org/post/how-does-wuhan-coronavirus-compare-mers-sars-and-common-cold#stream/0

The family of viruses known as Coronavirus have been known for a long time. Characteristics of this virus, and the main characteristic which gives this group of family it name, is the crown like structure which make this virus look like a crown. These are known as the spike protein.  The genome (genetic material) of this virus is made up of RNA. This means that the virus is highly likely to have mutations and therefore evolve and change. In many of the known Coronaviruses, there are hypervariable regions in the spike protein which can result in the virus changing serologically. This can make vaccine development difficulty. 

Electron microscope image of a Coronavirus https://www.dw.com/en/everything-you-need-to-know-about-the-new-coronavirus/a-52102486

Coronaviruses are enveloped viruses. The enveloped viruses are generally much more susceptible to the action of disinfectants than the highly resistant naked viruses. If the viral envelope can be disrupted, the virus can no longer infect the host cell and the virus is effectively neutralized. Good biosecurity and disinfection is going to be your very best defense against this virus.

So how does this virus influence travel? At this stage, I think we are still very much in the early stages of this pandemic and the virus has not yet shown its true colours. It is still not absolutely clear if the virus spreads from people before they show clinical signs. If this is indeed the case, it will be all but impossible to stop the virus from spreading. Lets look at the example of an infected person on a plane. If the virus can only spread once a person is showing clinical signs (like a high temperature), then if an infected person is on the plane, but not showing clinical signs, he or she will not infect anyone on the plane. If, however, on the other, the virus spreads like Influenza virus, in other words the person can spread the virus as soon as they become infected, this same person on the plane will infect others on the plane. These people in turn will infect everyone they come into contact with before they start showing clinical signs and soon and so on until the whole world is infected. Scary  stuff!

At this stage, from the current data, it appears that the virus is highly infectious but not highly pathogenic. So what does this mean? It means every indication is that the virus spreads very easily - (there are around 9000 people infected in about 18 different countries to date), but there are not than many people who have died. Is this just because we are still in the early stages of the pandemic or will the mortality rate rise? Even at the current low mortality rate of around 2.4%, this virus could cause around 1.8 million deaths worldwide!

So the multi-million dollar question is would I still travel? Maybe I am not the right person to ask. My wife and I was in Singapore right in the middle of the SARS outbreak. We had my trusted disinfectant with us - even on the plane. There was a very sick person in the seat behind us and every time he coughed, we sprayed disinfectant into the air an sniffed it! Obviously the disinfectant is non-toxic!  I will be traveling in March to Brazil and Kenya and at this stage, I have no plans to cancel my trip. But we will need to wait and see. In the next week or so, we will have a much clearer idea of what this virus is planning to do. Many of the airlines are cancelling flights to China, so the option of traveling or not might be taken by the airlines!