According to the WHO Ebola is now at epidemic proportions and no longer a mere outbreak. And it’s true – we’re all going to die. Just not from sodding Ebola.
I was back-of-house in a very exclusive London hotel last week where the kitchens have been festooned with Ebola posters by a chemical manufacturer. This is idiocy on a grand scale – it doesn’t just display a jaw-dropping ignorance of Ebola virology, epidemiology and how public health operates in the developed world, it’s egregious fear-mongering. In fairness, it does give one important piece of useful information: that whoever thought this stunt up is so monolithically dense light will bend around them.
Ebola Virus Disease isn’t going to take hold in the UK, USA or other developed countries anytime soon. It’s just not plausible. The only way such scaremongering is relevant to food handlers in London England or London Ontario is if they are preparing Chimp Carpaccio or Tartare of Fruit Bat.
Tartare de Roussette
Take one fruit bat. Cut the wings off. Wipe its arse.
Serve.
So how can I be so sure?
Well, I’ve written before about how Ebola isn’t a very efficient virus: its victims don’t shed it before they show symptoms, it’s not airborne and outbreaks associated with those of Our Microbial Overlords that are rapidly fatal tend to burn out quickly. So the only way to get it (apart from its reservoir in fruit bats and possibly a couple of other species you won’t find over here) is to come into contact with the body fluids of someone in the active stage of the disease. You won’t get it from someone who’s infected but not showing any symptoms yet sneezing on a bus.
Yes, it’s bad in Africa and it’s past the point where we can predict numbers based on those from previous outbreaks. But some rules of fag-packet epidemiology still apply. You can work out the number of people each person who has an infectious disease is likely to infect. It’s called R0 – the basic reproduction rate. It’s a simple measure of likelihood of contagion for a given bug. (There are more sophisticated calculations accounting for other factors like how much of a population is susceptible but let’s keep it simple). The R0 value for Ebola is just under 2. So, each person that gets it is likely to infect two more. If you want something properly contagious try measles….
Disease | Transmission | R0 |
---|---|---|
Measles | Airborne | 17 |
Pertussis | Airborne droplet | 15 |
Mumps | Airborne droplet | 10 |
Diphtheria | Saliva | 7 |
Polio | Faeco-oral | 6 |
Smallpox | Airborne droplet | 6 |
Rubella | Airborne droplet | 5 |
HIV/AIDS | Sexual contact | 4 |
SARS | Airborne droplet | 4 |
Crikey! That means it will double and double and double! That’s an exponential curve from one case!
No it doesn’t. Given the sort of contact tracing and surveillance that will be in place for anyone presenting with Ebola, if all their contacts are identified and isolated before they show symptoms that stops it in its tracks. And the R0 goes to zero. That’s what happened to all those exposed to the idiot in Texas who apparently lied about his exposure history on his return to the US. His family are under armed guard just in case they are as stupid as he is.
We can isolate index cases of Ebola and their contacts. Shame we can’t do the same for the idiots whose refractory Dunning-Kruger has them fuelling unfounded fears of a Zombie Plague starting in London’s restaurant kitchens.
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