Pandemic: What would happen next?

Story Highlights
The world hasn't seen a pandemic since 1968

A pandemic could skip across the world in 18 to 24 months

Hospitals would face overcrowding as millions seek treatment

Based on the past pandemic and current population, as many as 7 million could die
By Kevin Voigt
CNN
(CNN) -- The world hasn't seen a pandemic in 41 years, when the "Hong Kong" flu crossed the globe and killed about one million people worldwide. If swine flu reaches pandemic levels, what would happen next?

Recurrent outbreaks of Avian Influenza and the outbreak of SARS in 2003 rang alarm bells as potential pandemics.

Although both jumped the "animal-to-human" barrier, neither disease mutated enough to enable sustained human-to-human infection, said Dr. K.Y. Yuen, head of microbiology at Hong Kong University.

Strictly speaking, Avian Influenza and SARS did not become pandemics because they were too good at killing their hosts.

"For a sustained pandemic, it needs to be able to maintain human-to-human contact without killing its host off," he said.

Avian influenza "never became a man-to-man disease," said Dr. Lo Wing-Luk, an infectious disease expert.

"Swine flu is already a man-to-man disease, which makes it much more difficult to manage . and swine flu appears much more infectious than SARS."

But the WHO cautions, it cannot say whether or not it will indeed cause a pandemic. According to epidemiologists and health experts, here's what the world might see if there is another pandemic, based on past experience:

The disease would skip from city to city over an 18-to-24 month period, infecting more than a third of the population. World health Organization officials believe as many as 1.5 billion people around the globe would seek medical care and nearly 30 million would seek hospitalization. Based on the last pandemic and current world population, as many as 7 million people could die, epidemiologists said.

"Hospitals will become overcrowded, schools will close, businesses will close, airports will be empty," Dr. Lo said.

"Business will become very bad, as people avoid as much social contact as possible," added Dr. Yuen.

Health facilities will become overrun with patients and there would be less-than-adequate staffing, as medical health professionals fall ill themselves, experts say. "We saw cases in SARS where people who should have gone to the hospital for things like cancer treatment didn't go, and that resulted in higher deaths," Dr. Lo said.

The very young and very old will likely be the most susceptible to the illness.

Experts caution, much is still unknown about the current swine flu virus and its severity and it is too early to say whether it will lead to a pandemic. Right now, the focus is on finding answers and containing the spread.