Unresting Flu

The Unresting Flu, commonly referred to as The Infection or The End Virus, is the name given to an unknown and incurable virus that had caused most humans and animals who came into contact with it to change into homicidal, zombie-like beings commonly referred to as The Infected. It is known and revealed in Lhasa, that the virus was only present within wolves and red foxes before spreading to an unnamed human in 2020. However it is also revealed in Albany, that the virus was present and spread rapidly during the time of the black death but was less effective. Those who had survived the effected areas had passed on genes that helped future generations to become immune. Due to the survivor rate being at around 20% of the world's population, it can be guessed that nearly all of the survivors were immune to the virus.

Spread
The Flu originally started somewhere outside of Tibet, China and only affected a small village with the population of 13. As emergencies and other health practitioners set to discover the new 'virus' in hopes to destroy it first, the only survivor of the attack initially killed the infected in secret in order to prevent the spread; a discovery that remains a mystery of why and how. The survivor then accidentally infected themselves and 'turned' during work in a nearby town.

Slowly, the virus spread throughout Eastern China and mostly avoided high mountainous areas and low-land swamps; making Tibet the perfect safe-zone for survivors. The biggest outbreak was recorded in Zhengzhou which officially created a nationwide panic throughout East and South Asia.

It is unknown exactly how it spread to other areas of the world but can be guessed due to transporation and globalization. However, in Thessaloniki, it is hinted the virus entered through Turkey or Bulgaria but mostly avoided Greece and other low countries in the Balkans. It was only after Thessaloniki's Outbreak did these areas become infected. It is also hinted that the virus first appeared in the United States in Philadelphia or somewhere within North-east USA. It only took up to two weeks before the virus spread all the way to California and Hawaii.

After most of the world's susceptible population was killed by the virus or humans and became cannibal-type beings, the immune humans were enforced into areas with hard living standards (mountains or swamps) or were forced to remain hidden in the cities. It is presumed that another 5% of the world's population (immune peoples) died from being devoured by the undead.

Spread by days

 * Day 1: A wolf or red fox attacks a village of 14, infecting 13 somewhere closeby to Tibet.
 * Day 2: Patient #13 attacks and kills the infected in the village, accidentally infecting himself in the process. At this point, most of the biologists and scientists had given up the search for a cure.
 * Day 3: Patient #13 'turns' and attacks people during work. The Chinese Military attempt to restrict the virus to the town but is stopped after a horde of undead attacks them.
 * Day 4: The virus reaches Xining; the public is officially warned of a 'minor virus in the West'.
 * Day 7-8: The virus reaches East China and hits Zhengzhou, the biggest outbreak recorded. About 80% of the city become casualties to the virus whilst the other 20% flees or remains hidden.
 * Day 11: The virus officially reaches Korea and Japan but doesn't remain a big threat.
 * Day 12: The Chinese government issues people to wear masks to prevent the spread due to airborne fears. Many cities such as Hong Kong and Shanghai are placed under severe protection following riots.
 * Day 21-4: The virus reaches South East Asia and India. It takes just under four days for the whole of India to be fully infected and for most of the population to be undead. Any survivors recall the outbreaks as a 'Black Hole' and that only a couple thousand had escaped to Tibet. It is presumed many immune survivors were killed in the process.
 * Day 28: Iran and Pakistan start a nuclear war beginning in the nuclear bombing of the Pakistani-Persian border. This helps prevent the undead from spreading to the Middle East.
 * Day 35: 11 days after the Great Collapse of India, parts of North-West India that survived the outbreak along with Nepal and Bhutan join the new nation 'Great Tibet' that promises to protect the population living amongst the mountains, away from the virus.
 * Day 36-42: The virus reaches Europe through Thrace and North America through Mexico or the United States.