— NIN, Happiness In Slavery

"...and he starts coughing like a mad monkey, spewing stuff left and right - right then it was that I noticed the little greenish wiggly stuck in his left calf. Blam! One shot took his leg clean off...we got him bandaged and evacced in 10 minutes. Bugger lived. Thanked me 'fterwards, of course. Without my expert marksmanship, he'd 'ave been chewing his own leg off in ten minutes after that burrowmite got to his guts..."
— Sergeant Joe Malmer, 3rd Battalion (SOCOM BlueEyes) describing another successful incursion into the Sumatran Denied Area

If you thought a metre-long flukeworm living in some poor Third World bugger's stomach was bad, think again. In the super-evolved climate of 2038, all the little nasties that gave you such bad nightmares have crawled out from under their rocks, ready to sink their little teeth into any part of your anatomy - but preferably your insides.

It all started with those wonderful "How to Cripple a Regiment in Thirty Minutes" lab studies by well-meaning military scientists in China, America, Russia, and Europe, and ended up with kids wearing transparent body-suits to school and adults undergoing 3 hours of decontamination procedures at O'Hare just to get on a local flight. You can imagine what that did to global tourism. You can almost get used to the unobtrusive hourly tissue-sampling done in Intercon offices. Almost. Nowadays the dedicated staff of the Medical Collegium, aided by hyperaware Great Minds, have reduced contamination levels to those approaching the TwenCen - in the rich cities, that is. If you happen to be travelling through Belgrade or Louisiana, you'd better bone up on parasites, or you're worse than dogfood.

'Parasites' is a generic term used to describe all manner of infectious bacteria, microparasites, worms, fungi, amoebas, and other types of small-scale flora and fauna which damage or kill people. Macroparasites are the mutated large-scale versions of these small-fry, but they're rare. Parasites come in an amazing variety of forms and functions. Two examples are given here:

Little Colonecrile

An unpleasant and aggressive gut-worm which latches onto any small wound in the lower body, injecting the host with thousands of tiny baby worms which eventually migrate to the colon and the intestines. After a gestation period of several days during which they feed on nutrients from the host, these worms grow to lengths of 20-30cm and eventually begin feeding on internal organs towards the surface. These process is, of course, agonizing unless subdued with strong painkillers. People often mistake an infection for stomach cramps and take painkiller pharms, thereby ensuring their own deaths.

ENTRY: blood contact or dermal abrasion area
RANGE: any but boreal climates
VECTOR: any fluid during reproduction; blood->intestine during gestation
GESTATION: 48-72 hours
EFFECTS: 0-48 hours : mild itching in entry area. 48-60 hours: hunger not satiated by consumption, stomach cramps. 60-72 hours: intense pain in abdominal area, followed by internal bleeding, and eventual death unless removed.
REPRODUCTION: asexual blood-water interface contact
TREATMENT: 10 ccs of bihydrated sulphates to induce dormant state, followed by invasive surgery to remove parasite.