So I'm busy rushing around walking up hills in the hot sun. I'm feeling a little uncomfortable I've somehow got my part of my shirt-tale tucked into my underpants and the sweat is feeling slimey.

Anyway after a couple of hours I'm in a public park. I walk up through the forest to a viewpoint and sit on the floor. Then it becomes apparent that there what's making me feel uncomfortable is actually there is a small strip of plastic like a bread label in my underpants; so since there is no one around I reach down and grab it.

What a shock ... it's fleshly and slimey ...what the hell is it ? Have I got an insect or slug in my pants ? It's wrapped into the hair on my scrotum I pull it, but feel resistance as it appeared to be coming out of my bum

..... what's happening? Is my instestine coming out ? I look down ... in my hand I have a long tube of flesh ...like a earthworm.

What's this ? I thought the Alien was pure fiction. I have a live animal coming out of my body ! It's bloody alive !

Real human worms are tiny aren't they ?

I sit down in confusion. I have a long worm half inside of me with a least 10cm hanging outside. If I pull it will my intestine come with it ? Should I go to hospital ... 1, it's Saturday afternoon and 2. I don't want to end up with huge medical bills.

I'll try one more time to pull it out. I retreat to the bushes and disentangle the free end from my pubic hair and pull. Slgh.... With resistance it slides out ... and I'm left with a 20cm earthworm in my hand.

Surely it's not possible an earthworm has crawled inside me when I was digging a hole the previous day ?.... no it's not, this thing has grown inside me I knew. I had had the tell tale itching a few days ago and had been thinking of buying of worm tablets. Normally when I get back to the UK I take a dose just as a precaution. But I must have taken it mid-cycle so that new eggs were coming into my body at the time; so it hadn't erradicated all the worms.

Relief I got home and checked on the internet. I was very relieved. Yes round worms look exactly like earth worms and are 20cm long. They are usually harmless (I hadn't noticed any signs of ill health) . And they are very very common more than a billion people or 1 in 5 of the world's population have them. In fact though they are less common in western countries 80-85% of people in them carry some kind of parasite. I had read of studies in the UK relating increased rates of bowel cancer to reduced rates of worms.

I knew that you have to keep your nails short as the eggs are usually transferred from the anus to the mouth. What I didn't know was that the eggs can grow in the lungs and swim into the mouth and down into the stomach. So presumably you should be careful when you pick your nose. (when you have large numbers of worms in your lungs it can give you pneumonia)

I'll get the tablets and take another dose a month later.

I have instinctly never liked touching people and have always thought that handshaking to be unhygienic; now I feel vindicated !

It's enough to put you off your food. But remember they are common and normally harmless.