What Is Lyme Disease?

My Weekly’s favourite GP from TV and radio writes for you.

- Dr Sarah Jarvis

Lyme disease has probably been around for a long time, but it was only recognised about 40 years ago. It’s due to an infection from a germ called borrelia, which lives in the guts of small ticks. These ticks are usually around the size of a pin-head, but they can swell up to almost a centimetre long when they’re full of food. That food is blood, which they suck when they lock onto the skin of their host.

So here’s how the lifecycle goes. Ticks hatch from eggs, usually in spring. These develop into larvae, which latch onto a host (like mice or birds). That’s where they can get infected with the borrelia germ. From there they develop into “nymphs” and then adult ticks. Both of these can bite humans, although they also feed on other mammals like mice, rats or deer.