10/10 if you get the title reference! Forest fires in Chile have caused a plague of pygmy rice rats leading to the biggest outbreak of Hantavirus there in years. So what’s that got to do with global warming or the UK? Simple!

We don’t see much Hantavirus in the UK – there were a couple of cases last year leading to the HPA recommending you don’t snog your pet rat – but Hanta is rare. For now. But here’s the interesting bit – and I’m amazed that the folks that get all het up about anthropogenic global warming haven’t seized on this yet. Climate change and pestilence are linked more closely than one might suspect. For example: Hanta is increasing in Belgium: average temperature is rising which favours deciduous trees = more seeds = more voles = more Hanta. But there’s more.

  • The RSV (Respiratory Syncytial Virus) season is shortening in the UK by about a fortnight per 1°C rise in average temperature.
  • A 2°C degree rise in temperature could see dengue commonplace across the US as far north as Canada – and malaria all over Europe.
  • In 2007 the massive increase in mortgage defaults in California led to abandoned swimming pools > more mozzies > threefold increase in West Nile virus.
  • It’s not just mozzies. You don’t get Vibrio in water cooler than ~15°C. Rise in sea temperatures has seen V. parahaemolyticus cases increase: in the US the danger zone extends north by ~50 miles per year – followed by further marine-related outbreaks.

So, less RSV, more dengue, West Nile and malaria. And there is research suggestive that plagues reverse global warming. The theory is humans cut down trees, burn them and release CO2, plague comes along, trees grow back and sequester the CO2 again. But it’s got to be a proper, old-style plague that does for about 75% of us; not one of these petty annoyances like the 1918 ‘flu that only finished off 5% of the population. More than both World Wars in a single season, admittedly, but not your proper Biblical plague. (When I say there is some suggestive data remember that correlation is not necessarily causation but don’t let a logical fallacy get in the way of a good plague).

So, if you see a rat, resist the urge to kiss it. And move as far north as you can.

Hantavirus 101 (geeky bit)

Basics are it’s a RNA virus (like ‘flu) and causes ‘flu-like symptoms. Then you fell a bit better. Then you feel a lot worse as it can lead to haemorrhagic fever and hefty kidney and lung involvement, oedema and death. Oops.

The main reservoir is rodents and most people get it from inhaling aerosolised mouse or rat urine / faeces / saliva or dust contaminated therewith – one assumes they don’t do this deliberately but as it mainly affects outdoorsy types in the USA and rat breeders nothing would surprise me.  Human to human transmission is rare but has happened. And it’s a pretty rare disease which is probably a good thing as it can get pretty serious.