A light flickers unpredictably overhead. It’s hard to make out any definite shapes, but you know there are bodies at your feet. You press on cautiously, hand on the wall, towards what you will hope will be the hospital’s storeroom. A snag on your tattered jeans. This time it happened. Your companions stomp the biting mouth making clicking sounds under a gurney. You just stare at your leg. It has to come off.
But how quickly?
For all intents and purposes, most zombies in fiction are just vectors – agents that carry and transmit an infectious pathogen – for some pandemic disease. And like other vectors such as mosquitoes, the transfer of pathogens is only complete once they circulate enough in your bloodstream and get where they need to go. In theory, if a bitten limb were removed from the body before your circulatory system distributed the pathogen, you wouldn’t contract the disease.
Your body’s circulation time, as with most of your vital statistics, depends on your age, height, weight, etc. However, it doesn’t vary widely. The amount of time it would take a blood cell to make a round-trip from lungs to heart to body and back to heart and lungs is somewhere between 20 seconds and one minute.
What your circulation time means for stopping a zombie infection after a bite is that you are fighting the clock. If you were bit in the leg, you certainly have your circulation time to remove the limb, probably even less as amputation at the thigh or hip is not really an option in the apocalypse. Conservatively, you’d have less than 10 seconds. Sorry, Hershel.
It doesn’t really matter if The Walking Dead’s zombie virus has further to go – it does its work in the brain. Once the viral particles ride your veins into the torso, there is nothing to amputate. Of course, The Walking Dead is a special case. A zombie bite isn’t what actually kills characters in that show.
So, you’re bit. You have five seconds or less to amputate. Your heart is racing, pumping blood even faster from the wound. I hope your group is prepared.
Kyle Hill is the Science Editor at Nerdist Industries. Follow on Twitter @Sci_Phile.
IMAGES: AMC; Rogeriopfm