07/10/2013 - 21:54

Zombie lessons

Laura H. Kahn

Laura H. Kahn

A general internist who began her career in health care as a registered nurse, Kahn works on the research staff of Princeton University's ...

More

This summer a new blockbuster movie, World War Z, entered the zombie canon. Based on Max Brooks’s novel of the same name and starring Brad Pitt, it has stoked fascination with the undead all over again while raking in enough at the box office—its North American opening brought in $66 million—that Paramount is already planning a sequel

A zombie apocalypse, though, is good for more than just mindless summer entertainment. It’s an engaging way to promote better global public and animal health, which might help humanity survive the next all-too-real pandemic or a bioterror attack.

The pandemic that rages through World War Z, though fictional, has elements in common with real-life threats. From the beginning, the movie hints that a zoonotic agent—that is, an animal disease that is communicable to humans—is the cause of zombie infection. News reports show dolphins and porpoises beaching themselves before dying, and dogs are shown tearing each other apart. The presumably viral cause is never revealed; however, the real disease that zombie symptoms most closely resemble is rabies.

Before Louis Pasteur developed the rabies vaccine, a bite from a rabid animal was a certain death sentence. Deaths from rabies are horrific. Victims develop violent, painful muscle spasms. Swallowing becomes so excruciating that victims wind up drooling. As the disease progresses, patients develop mania, hallucinations, delirium, and finally respiratory failure leading to death. A series of rabies vaccine shots can prevent the disease from developing if it is delivered before symptoms begin, but even so, the disease kills more than 55,000 people each year, mostly in Africa and Asia.

Epidemic essentials. Unlike the actual rabies virus, which typically takes around two to 12 weeks after exposure to cause disease, the infectious agent in World War Z works incredibly quickly. It takes only 12 seconds to transform a normal human being into a crazed, jaw-chomping zombie bent on infecting others.

A critical difference, to be sure, but both scenarios—zombies and rabies—could benefit from similar solutions.

The smartest way to prevent human rabies is to vaccinate the animals—mostly dogs—that transmit it. Some governments, like that of the Indian state of Tamil Nadu, have begun to implement rabies control efforts through animal disease surveillance, vaccination, and population control programs. This kind of animal health program could save many human lives.

To address epidemics, bioterror attacks, and other public health crises—fictional or real—it’s also critical to have trained epidemiologists on hand. Epidemiology is the study of how diseases spread through populations. Figuring out how to stop them doesn’t require knowing the causative agent. For example, John Snow, the father of epidemiology, stopped a deadly cholera epidemic in London in 1854 by going door-to-door, asking who was sick and who was healthy, and creating a map of the cases. By doing this, he figured out that the disease was spread by water. He stopped the epidemic when he removed the pump handle to a contaminated well.

Today, when faced with a new bio-threat, the Centers for Disease Control and Prevention (CDC) sends a team of trained epidemiologists to investigate the source, mode of transmission, incubation period, and other relevant factors. In fact, the CDC began training epidemiologists in its Epidemic Intelligence Service during the Korean War, in response to the threat of biological warfare.

In World War Z, bites from infected individuals spread the disease. The movie showed two countries that successfully halted transmission: North Korea and Israel. North Korea removed all the teeth from it citizens to prevent bites. Aside from being unethical, this sort of strategy would not be logistically feasible. Israel built a high wall to keep the zombies out, and the Israelis and Palestinians safe—a type of sequestration and a more plausible strategy.

Fictional guides to real life. The novel World War Z was a follow-up to Brooks’s 2003 bestseller, The Zombie Survival Guide: Complete Protection from the Living Dead. The irony is that actual disaster preparedness guides aren’t nearly as popular as zombie survival guides. Perhaps preparing for a zombie invasion is more fun and interesting than preparing for a hurricane, flu epidemic, or nuclear power plant meltdown. Fatigued by the litany of real disasters reported by 24-hour news, the public tunes out. If World War Z had been a documentary about rabies, the theaters would be empty—even if Brad Pitt narrated. But fiction still has access to our attention spans.

To its credit, the CDC’s Office of Public Health Preparedness and Response recognized what grabs people’s attention and in 2011 set up a zombie preparedness website. As the office’s director Ali Khan observed, “if you are generally well equipped to deal with a zombie apocalypse, you will be prepared for a hurricane, pandemic, earthquake, or terrorist attack.” When it first launched, the website proved so popular that it crashed from thousands of visits.

A new real-world threat. Since World War Z hit screens, a new deadly disease has been gaining attention as it spreads: MERS-CoV, the Middle East Respiratory Syndrome Coronavirus. Caused by a coronavirus (a type of virus similar to the one that causes SARS), it was first discovered in June 2012 in Saudi Arabia, where doctors have now encountered 65 of 80 cases globally. While not very many people have gotten sick from MERS-CoV, more than half of those infected have died, making it deadlier than SARS, which killed 774 out of 8,096 people infected. As with rabies, SARS, and, apparently, World War Z’s zombie pandemic, MERS-CoV originated in the animal kingdom. So far, there is no vaccine, drug, or diagnostic test available.

Health officials worry that the annual hajj in the fall, during which millions of devout Muslim pilgrims descend upon Saudi Arabia, could spark a global pandemic if infection control measures are not strictly implemented. Unfortunately, Saudi Arabia’s Ministry of Health is underfunded and understaffed, a common situation for public health departments around the world. Without an effective public health workforce, an epidemic such as MERS-CoV can easily spiral out of control. That would be a truly scary scenario.

Does World War Z—set in the Middle East, Europe, the Americas, and Asia—have anything to tell us about MERS-CoV, which has so far been found only in patients in the Middle East and Europe? Yes. The takeaway should be that diseases that first appear in far flung lands are only a plane ride away; that every nation needs strong public and animal health programs; and that nations need to work closely together, because microbes don’t care about borders. After all, it’s not a matter of if, but when, the next pandemic—like the next zombie movie—comes along.