Smoky Cogs

Thoughts on programming, life and anything else that floats through my brain

Tag: Health

Mathematical modelling of a zombie attack

Aug 14

I came across a very interesting story on Reddit today.

A team of mathematicians, Philip Munz, Ioan Hudea, Joe Imad and Robert J. Smith, from the University of Ottawa and Carleton University, have published a paper entitled When Zombies Attack!: Mathematical modelling of an outbreak of zomie infection.

Normally, the world tends to view mathematicians as a staid, humourless bunch of nerds hiding away in a musty office playing with numbers all day. I think this goes to prove otherwise…or at the very least, they have a sense of humour.

The research paper is written in a serious way, and for those who are braver than most, it includes a lot of mathematical formulae describing the infection rate when a zombie bites a human, taking into account factors such as susceptibility, quarantine and treatment.

The paper is not pointless though. Even though these guys have chosen a topic featured in just about every B-grade horror film since the 50′s, the paper does model how an infectious disease would be able to propagate through a population. So, for example, you could replace Zombie infection, with Swine flu infection. The principle remains the same, but I certainly think it makes for a much more fun to read research paper when we talk about zombies.

Don’t panic. It is only swine flu

Aug 8

The world has gone mad. Schools are closing, companies sending staff home, and people panicking. And I firmly believe the media are feeding this fear.

A few days ago I posted a blog post that showed that the statistics for swine flu are the same as for normal seasonal flu. It is no more severe than an ordinary bout of flu, but the way people are reacting, you would think the black death was upon us again.

As proof of this, a few days ago, there was a poll on news24.com as to whether the government should get out of the “Don’t panic” mindset and into the “Let’s start panicking” mindset. The results were overwhelming towards panicking.

The media is reporting in such a way that it seems that every death from swine flu heralds the doom of society. More people die every day from normal flu complications, TB or AIDS than swine flu is even capable of, yet no-one locks themselves away scared of TB, for example, which is also infectious.

Even at my work, and Cole’s school, letters have gone round on how to minimise the risk of contracting swine flu, and guess what, the guidelines are the same as if you had normal flu. If someone has flu, they should be at home and out of contact of people, and people coming into contact with them should be washing hands and being careful to avoid infection.

But do you think people care about the normal flu? No. It kills thousands of people a year, yet no=one thinks twice about going to work with normal flu……but because swine flu has hit the news, suddenly you should be quarantined.

What people need is a little bit of perspective, and for goodness sake, STOP listening to the sensationalistic media!

Swine flu – Out of control or out of proportion?

Aug 5

The Swine flu (H1N1) epidemic has certainly been gaining ground the last few weeks. This morning I heard of the second swine flu death in South Africa, with around 600 confirmed cases. Having a look on wikipedia, the total confirmed deaths worldwide has grown to almost 200,000 cases with 1500 deaths.

That sounds bad. But is it really?

First, let’s compare the severity of swine flu with the normal seasonal flu statistics. Worldwide, there are between 340 million – 1 billion cases a year, with 250,000 – 500,000 deaths. this gives a fatality rate of less than 0.05%.

Now taking swine flu, worldwide, we have 200,000 cases with 1500 cases which gives a fatality rate ofÂ  0.75%. In South Africa, the fatality rate is currently 0.67%. Bear in mind too, that these are confirmed cases only. One source indicates that at the time when the US had 40,000 confirmed cases, they suspected that there could be up to 1 million unconfirmed cases where people have not been sick enough to go see a doctor, or get tested, so let’s take a conservative figure of 2 million actual (but unconfirmed) cases, this brings the fatality rate down to 0.075% – barely higher than the normal seasonal flu.

Now, considering other severe flu outbreaks, the 1918 flue outbreak infected between 0.5 to 1 billion people and had a fatality rate of over 2.5%. The Asian flu epidemic in 1956-58 killed 1 million people but had a fatality rate of less than 0.1%. The same rate applied to the Hong Kong flu in 1968-69, where 2 million people died.

So, what do these stats say. Should we panic?

So far, the number of deaths is not much more than can be expected with any normal flu season, so I think that the worldwide panic that is gripping people is rather unjustified. It sounds scary when news reports start giving death tolls and people think that they may be next. The chances, however are tiny.

There is one scary point that the media keep reporting too……what if the virus mutates into a more virulent strain? So, let’s think about this one, you have a virus that kills only slightly more people than the regular flu, and there is exactly the same chance that the normal seasonal flu might mutate as with the swine flu, so why are we not more scared of seasonal flu then too? It is just as likely to mutate into a killer flu strain as the currently mild swine flu strain.

I think people just need a little bit of perspective. Swine flu is not about to bring about the end of civilization.