You are the virus, as an infected you can infect others, which will then carry your virus giving them the ability to unknowingly infecting others.

But be careful, watch out for the antibacterial spray!

Made in GameMaker 8 as I cannot code well at all :)

*I apologise for the size of the download, I also apologise if anyone gets lag from the game, it plays fine on my computers but I didn't have a chance to test it on any other machines.

After looking at my game for a second without stress I've come to realise maybe the types of bacteria should switch colours in a later version in the future, as the healthy bacteria current have red tails

*UPDATE* 23/08/2010

Thanks to everyone for the great comments, after reading your comments it's made me realise how little explanation the game gives and it raises way more questions than I thought it would.

After thinking about it, it would have worked nicely if I had the infected bacteria leave a trail of virus behind it, and then if the ones that have been infected do the same, so the spray then removes that when it's hit. There's a lot more I could do with it, but I'm still fairly happy with what it turned out like, even if the main goal is score based.