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What Outbreak gets wrong — and what it gets right — about viral spread

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Apr 15, 2020, 3:30 PM EDT

As the coronavirus continues to spread around the world, a large number of people are turning to, of all things, movies about fictional pandemics for entertainment — and, perhaps, some strange comfort. Rentals on iTunes and Amazon for movies like Contagion skyrocketed, and Outbreak was one of Netflix's most-streamed films. It also just so happens that March 10 was Outbreak’s 25-year anniversary.

Outbreak is old enough to rent a car, and it’s also apparently old enough to become entirely relevant again, now that the world has been wracked by a pandemic. So, in the spirit of celebration (and a little bit of self-punishment), for this week's edition of Science Behind the Fiction, we sat down to watch Outbreak again to see just what it got right, and what it got wrong.


Outbreak opens with an aggressive new disease popping up in the Motaba River Valley, Zaire, back in 1967. Members of the United States Army Medical Research Institute of Infectious Diseases (USAMRIID) briefly inspect the village and leave with promises of an airdrop of healthcare supplies. The plane arrives shortly after to make the drop, but instead of medical supplies, they drop a bomb.

The film cuts to the modern day (or rather 1995), and we see a monkey being transported from Africa to the United States, where it is eventually picked up by a young, twirly-haired, dangly-earring-ed McDreamy (Patrick Dempsey) for sale on the black market pet trade. That monkey, while adorable, is the virus’ host and progenitor of the titular outbreak.

All hell breaks loose.

The Motaba virus spreads quickly, first via direct human contact and later over the air — it multiplies quickly and kills quickly. The mortality rate is 100 percent.

It all makes for great storytelling. Even after 25 years, Outbreak works well as a story. It’s compelling, and there is a clear demarcation between good and bad. Sam Daniels (Dustin Hoffman), Robby Keough (Rene Russo), Major Salt (Cuba Gooding Jr.), and science: Good. General McClintock and the virus: Bad. And the movie, like the virus, moves so quickly there is little time to think too deeply. It is, first and foremost, an action movie with plenty of tension, explosions, and helicopter chases to pad it out. But, with the benefit of two and a half decades, and real-life pandemic experience, we can see this ‘90s blockbuster with clearer eyes.


The initial outbreak of the virus happens in the late '60s, and it doesn’t reappear for almost 30 years. Although we only tend to care when a virus is an "active threat," viruses do appear and "disappear" for extended periods of time. The flu tends to do this, to a lesser extent, as it is seasonal, its impact ebbing and flowing over time. The secret to Motaba’s long hibernation, though, is that it resides in a non-human animal without any negative effect. Because USAMRIID effectively quelled the initial outbreak (the ethics of those actions notwithstanding), the virus was able to lie in wait for another zoonotic jump.

This sort of viral relationship isn’t at all uncommon. Ebola, rabies, SARS, and countless other pathogens are able to live within non-human animals without any ill effect to the host. Those same diseases, when transmitted to humans, can be fatal. Many new diseases appear as a result of jumping from one species to another, and if that animal population is sufficiently separated from humans, it isn’t at all unlikely that outbreaks, if effectively contained, could have long periods of time between appearances. That’s one check for the reality column.

Once the virus makes its way to the United States, Daniels attempts to convince his friend and boss Billy (Morgan Freeman) to take drastic action by expounding the ferocity of the disease. Billy responds by saying Motaba’s lethality was working for them, as people don’t live long enough to spread it around. This, too, is true. While a virus with a shorter incubation period and more severe symptoms is more frightening, it can be much easier to contain.

A shorter incubation period means less time to unwittingly spread the disease to others. More severe symptoms mean an infected individual is either at home resting or in the hospital rather than being out and about, interacting with and infecting others.

One of the things that has made COVID-19 so difficult to contain is its long incubation period. The median incubation period for COVID-19 is five days, with some people not developing symptoms for more than 10 days. A small portion of people have tested positive while experiencing very minor or no symptoms. All of this means that people have extended periods wherein they don’t know they are sick but can transmit the virus to others. In short, the disease spreads easily and invisibly.

Something like Motaba, while utterly terrifying, would be a tragedy for those who are infected, but easier to contain. One of the most frightening aspects of Motaba is how quickly patients transition from infection to death. It’s shown to spread throughout cells, killing and liquefying everything in its path, in just a few hours. Death occurs in just a day or two.

Most viruses move much more slowly, giving doctors time to intervene, but there are real viruses that can kill just as quickly. Most notable is Ebola, which served as a real-life model for Motaba. It has many of the same symptoms, including hemorrhagic fever, and a similar structure. Some victims of Ebola can die within hours of the first symptoms.

Luckily for all of humanity, that’s where Motaba goes directly off the rails into the land of fiction.


Let’s just get this out of the way up front. It’s a little nitpicky but, seeing as there was no reason for it, we’re going to talk about it anyway.

The monkey. Outbreak makes it very clear that Motaba is a virus that originated in Africa, even deriving its name from its place of origin (we could get into the problematic nature of that sort of naming, but that’s another conversation entirely). It is baffling, then, that Betsy, the host monkey, is a capuchin.

Capuchins are New World monkeys who live in such places as Argentina, Brazil, and Costa Rica, among other locales, none of which are in Africa. There are plenty of African monkeys the filmmakers could have chosen, or they could have changed the virus' place of origin. But they didn’t. We’re left to assume that Betsy is a globetrotting monkey with incredibly bad luck. And that’s just the tip of the nonsense iceberg.

Motaba is scary enough but becomes even more frightening when it mutates and becomes airborne. Truly, a disease like Motaba (or Ebola) with an over-the-air transmission method would be a worst-case scenario. Thankfully, such a mutation is unlikely. Such a change would likely not be the result of a single mutation and would require the virus to change in substantial ways. Fears over Ebola becoming airborne have been the topic of some discussion, and while the notion is good for making headlines, not many healthcare professionals are concerned that it will happen.

First, the disease would have to alter itself to take up residence in the lungs or airways. Even if this were to happen, it still might not become airborne, and we have natural selection to thank for that. Ebola is already successful; it transmits between individuals sufficiently to survive, and that’s all evolution really cares about. In order for the virus to become airborne, it would have to have less cost, to the virus, than its current transmission method. According to professionals, this is unlikely ever to occur.

Speaking of mutation, in the movie, Salt (Gooding Jr.) identifies the mutation via light microscopy, the sort of microscopes most of us have likely used in school. This is total fiction. There are very few viruses large enough to be seen in any real detail via light microscopes. Something like Ebola or Motaba would need an electron microscope to examine in detail.

Even then, it’s unlikely that a mutation would be so readily apparent to the eye. Rather than a visible signal, we usually have to sequence the genome to find mutations. The sequence, as it’s laid out in the film, it entirely unrealistic, but it makes for good cinema.

Lastly — and most egregiously — the speed at which USAMRIID synthesizes an antiserum for the Motaba variant is totally impossible. Once the host animal is captured, Salt is able to whip up a drug treatment in a couple of hours. While it was narratively necessary, lest central characters succumb to the disease, it’s the most unrealistic thing that happens in a movie riddled with unrealistic things. As we’ve seen with COVID-19, the development of effective drug treatments takes a long time. Moreover, there are plenty of diseases that have been around for decades for which we still don’t have cures.

Even if he were some sort of wunderkind, capable of coming to an effective treatment in so short a time, there are myriad legal hurdles you would have to jump through before you could just start pumping it into people’s veins. The sad truth is, even in the best-case scenario, the town of Cedar Creek was doomed, whether Donald Sutherland dropped his bomb or not.

In the end, Outbreak is much more a movie about action and human moral failings than it is about the reality of viral outbreaks. Still, that monkey was cute. And in times like these, when things can feel a little desperate, it’s nice to have an enemy we can defeat with a few helicopter acrobatics.


You can stream Outbreak on Netflix, from the safety of your own home. Stay safe out there.