There's a parasite that infects dead insects and turns them undead! It's Cordyceps. It has been known to infect ants and wipe out entire colonies! We don't eat ants, but other animals do. And other animals eat those animals and somewhere on the food chain are Humans. We could be eating infected animals without us knowing and 60% of the world's population (4.6 billion) will be infected. So in about 20 years, there could a Zombie Apocalypse.
Hoax or Fact:
The message talks about a parasite called Cordyceps, claiming that it infects dead insects and turns them undead. It is also said that this parasitic infection can spread from those ants to humans, through food chain, and that there can be a Zombie Apocalypse in about 20 years. The message is only partially fact.
Cordyceps is a genus of fungi which are endoparasitoids, i.e. parasites that eventually kill their hosts. They mainly attack insects and other arthropods, while few are parasitic on other fungi. There are about 400 such identified species worldwide and many are yet to be described.
What makes them really interesting is the fact that these parasites turn their hosts into Zombies. One such parasitic fungus species is the Ophiocordyceps unilateralis, which takes over the brain of ants like Camponotus leonardi, making them climb up to 25 centimeters above the ground, hold onto a block of grass or leaf, and then die. Soon, the fungus grows a spore stalk out of the ant's head, and spreads across the insect colonies. Such parasites are believed to either release chemicals or manipulate the genes of their host, making them change their behaviors. Most Cordyceps do this by changing the brain's chemicals of their host, or by inducing "sickness behaviors" by attacking the immune system of host. But no, as mentioned in the message, these Cordyceps cannot infect dead insects and turn them undead.
The video shown is a documentary that briefly explains about this Cordyceps parasitic fungus. From the reference section below, you can read about few other species of this genus - These Animals are Zombified by Parasites. And as far as the Human Zombification is concerned, no, it is not a fact. Scientists have found marks of these Cordyceps on fossilized leaves, which suggests that their ability to modify the host's behaviour has evolved more than 48 million years ago. If they were capable to spread to human brain through food chain, it should have happened long time back. But there are no such reports, and moreover, the temperature differences between insects and humans, and the strong body immunity and internal acids of humans do not allow the life of such parasites. Therefore, humans cannot be zombified by these parasites.
Zombies is an interesting and scary phenomenon to grab the attention of people, so come such hoax stories around them. A recent warning talked about dead bodies rising from graves - calling it a Zombie Apocalypse.