New Rabies Strain Still Can't Create Zombies

A sadly common question I get asked too frequently is "What virus can turn someone into a zombie?" The answer is that no virus can turn one into a zombie anymore than it can turn one into unicorn. However, if I were to name a disease that causes a person to behave in a manner that might be zombie-like, I would say it is the illness caused by the bat-borne rabies virus. For a great historical treatment of the mystique surrounding the illness see Rabid: A Cultural History of the World's Most Diabolical Virus.  

Rabies is a disease that evokes, to those who are familiar with it, fear and was an infection that the great Louis Pasteur trained his genius mind on to formulate a vaccine: the subject of my favorite children's book. In the US, just two human cases occurred in 2010 and most animal cases are in wildlife, though it is important to remember that cats are one of the more common domestic species to contract rabies (see this video of a zombie-like rabid cat). Once infection has set in, only 5 people are known to have survived despite the Herculean Milwaukee Protocol that has been developed in recent years. Rabies in humans, because of its severity and transmission characteristics (blood/body fluid) in humans it is rarely transmitted human-to-human, though organ transplantation is one potential route. 

So with the news of a new rabies strain being found in New Mexico is there a possibility that this could be akin the rage virus of 28 Days Later fame? 

Not a chance.

New lineages of viruses evolve naturally and rarely confer wholly new transmission characteristics. What is likely is that since the ultimate reservoir for rabies are the exceedingly prolific bat species, we know only a small fraction about all the strains of rabies that circulate amongst them. This poor rabid fox likely came into contact with a bat and acquired the new strain providing an opportunity to study the virus.

Sorry to disappoint but no zombie apocalypse in the offing...yet. 




If Zombies Taught Epidemiology

Many people who are interested in the spread of infectious diseases have co-opted the zombie craze in order to emphasize key preparedness messages that are "common" to both, including the  CDC (I even have a CDC zombie hunter shirt).

One of the best known popular culture items in this social phenomena is the novel and movie World War Z which depicts an outbreak of an unknown infection that turns individuals into rabid zombies. There are many epidemiological points made in the movie but the one that I want to focus on regards who is susceptible to infection and who is immune. 

This is a major question in any outbreak and, just as in World War Z, figuring out the reason why is often a game-changing discovery. For example, in HIV there is a well known mutation that a portion of the populate harbors in CCR5, HIV's co-receptor, that can render one unable to be infected (see The Berlin patient). In a similar fashion, sickle cell trait confers resistance to malaria. 

In the case of HIV, understanding the role of the CCR5 co-receptor led not only to The Berlin Patient's path-breaking bone marrow transplant, but to the development of the drug mariviroc. Mariviroc blocks CCR5 thwarting the ability to the virus to infect cells and is a component of modern HIV drug cocktails.

So, in the early days of an outbreak understanding who is being spared is as important as understanding who is being infected--a little bit of zombie pedagogy.