Tournament of Pandemics - Cholera vs Yellow Fever - Part One

(photo credit: Julien Harneis)

Cholera could be considered the grande dame of the classic infectious disease bugs.  It has played a central role in the development of our modern understanding of how infection is transmitted and our management of infectious disease.  It gives yellow fever, with deep historical roots in its own right, especially in the Americas, a good run for its money.

Each of these diseases may have a venerable history, but amid today's competition which of them has the skills to survive to the final round of the tourney?

Cholera

Cholera is the player here who has attained pandemic status before, and not just once or twice, but officially seven times, most recently in the 1960s-70s.

For a long time, cholera succeeded thanks to the fact that humans didn't understand how it was spread.  Now that we do, typically in both industrialized and developing countries we are able fairly consistently to do what's required to keep it at bay.  In the wealthiest countries, we even manage with few exceptions to prevent the disease from appearing at all.

As John Snow first argued, cholera is caused by a water-borne bacterium (Vibrio cholerae).  It's a bug with a smart strategy: it gets into a person's gut and infects the lining of his or her intestine, creating a pretty effective bacterial distribution system by bringing on severe diarrhea.  But through a combination of personal hygiene and communal sanitation techniques, we humans are able to get the better of it: we've learned to disinfect everything that the patient has had contact with, we know it's safest to ingest only boiled or filtered water, and in the best scenarios we now organize the treatment of sewage and water systems for communities.  Prevention is pretty straightforward and can lean heavily on the individual: as the US CDC reminds us, "boil it, peel it, or forget it" describes an effective prevention method when you're not sure what's happening with the water around you.

There are vaccines for cholera, but mainly we rely on prevention, good surveillance and early detection, and the simple treatment regime of oral rehydration therapy.   Cholera's ability to kill and spread rises quickly if it's not detected.  But cholera isn't a sneaky bug that can achieve a pandemic by virtue of hidden infections; it's pretty hard to hide that diarrhea thing.