Floods in the Deep South. Homegrown terrorists and al-Qaida. An economy on the brink. So much for Americans to worry about.

Now a top US health official has added a new fear: "Zombie Apocalypse".

The assistant surgeon general, Ali Khan, has posted advice on the website of the government's health and safety agency, the Centres for Disease Control and Prevention, on how to prepare for Night of the Living Dead popping up in the backyard.

"There are all kinds of emergencies out there that we can prepare for," Khan writes under the heading Preparedness 101: Zombie Apocalypse. "Take a zombie apocalypse for example. That's right, I said z-o-m-b-i-e a-p-o-c-a-l-y-p-s-e. You may laugh now, but when it happens you'll be happy you read this."

Khan offers no advice on how best to fight off the Zombie hordes – chainsaw or shotgun? Instead he recommends preparing a survival strategy "to get you through the first couple of days before you can locate a zombie-free refugee camp".

"You should sit down with your family and come up with an emergency plan. This includes where you would go and who you would call if zombies started appearing outside your doorstep," Khan writes.

"Plan your evacuation route. When zombies are hungry they won't stop until they get food (ie brains), which means you need to get out of town fast! Plan where you would go and multiple routes you would take ahead of time so that the flesh eaters don't have a chance!"

Khan is not expecting anyone to have to fight their mothers trying to devour them any time soon but he thinks preparation for that unlikely if terrifying scenario is as good a way as any to be ready to face a whole load of disasters from hurricanes and earthquakes to pandemics and nuclear accidents.

In fact, some of the advice – such as making sure you have your driving licence when you flee – reflects a touching faith in a return to normality that seems unlikely if half of humankind is trying to eat the other half.

The CDC, which has its headquarters in Druid Hills, has described the campaign as "kind of tongue-in-cheek" after officials bemoaned the difficulty of getting the general public to pay attention to calls to prepare for disasters. It appears to have worked. The blog post became the most read on the CDC website in just two days.