“We’re distinctly alarmed. It’s an all out hands-on-deck effort. We can’t get ahead of it at this point..” – Andrew Marx, spokesman for Partners in Health on the Haiti cholera outbreak. The cholera outbreak in Haiti killed over 8000 people from 2010 to 2013. These are terrible numbers, especially considering how incredibly treatable cholera is. The trick is the areas that suffer from outbreaks are in logistically difficult locations that impede distribution of proper treatments.  In this article, we’ll discuss basic information about Vibrio cholerae, we’ll give it some historical as well as current context, the signs and symptoms of an infection, and finally strategies for treatment and prevention.

Cholera Is a Little Shit

First, a little basic information of Vibrio cholerae. Vibrio cholerae is a gram-negative, highly motile curved rod with a single polar flagellum. They tolerate alkaline media that kill most intestinal bacteria.  Fresh isolates are prototrophic and have a generation time of less than 30 minutes.  They can grow anaerobically, but reach higher populations when grown with vigorous aeration. They are also sensitive to low pH and die rapidly in solutions pH 6.

Cholera is exclusively a disease of the small bowel, which is normally relatively free of bacteria due to peristalsis and mucus secretion. V. cholerae have one or more adherence factors that allow it to reside there. The growing cholerae create the cholera enterotoxin, a protein which is the actual cause of the symptoms. Studies in adult American volunteers show that 5 u g (micrograms) administered orally with bicarbonate causes 1 to 6 L of diarrhea.

Cholera Runs through History

So, Cholera has been a known disease for a pretty long time, at least as far as modern medicine goes. The first known cholera pandemic was from 1817 to 1824. It killed millions throughout all of Asia and up to the Mediterranean Sea. Cholera had spread across India several times prior to that, but this time it had a huge range. It affected almost every country in Asia. Flash forward to 1854 and we have the discovery of V. cholerae. Remember, this is at a time when we still didn’t really understand the connection between bacteria and diseases. The first proof of connection had only happened in 1813, with Agostino Bassi’s experiments.

Okay, so that’s important to remember when we talk about Dr John Snow. In the 1849 to 1855 time period, Miasma Theory (little nasty bugs cause diseases) was the predominant mode of thinking. Not for John Snow! In 1849, Snow published an essay on V. cholerae describing its affinity for water, the fecal-oral communication route and even describing how it lives in the small intestine. This guy was way ahead of his time. Without going into a ton of more detail, this was the guy who convinced English authorities to shut down the Broad Street Pump Station which helped curb the current cholera epidemic. Snow used maps dotted with cases and statistical analysis to help him determine the root cause of the outbreak. That is why this is considered one of the founding events of epidemiology (and why you should really learn more about this!)

Over 150 years of knowing how cholera works later, it’s still a major issue. We are currently in the 7th pandemic, which has been going on since 1961. Yeah, don’t drink the water in South Asia. Roughly between 3-5 million cases are reported annually and a little over 100,000 of them will die. If you live in an area with clean water, though, you really don’t have to worry that much. Between the years of 1995 and 2000, in my home country of the United States, only 61 cases were reported. Even further, though, 37 of those were travel associated and only 24 were acquired in country.

When I Found Out Who Was Defecating in the Water Supply, I Was All Hot Under the Cholera

What happens if you drink the water? It can get nasty. Diagnosing cholera is actually not terribly difficult. A simple rectal swab can be cultured for  V. cholerae. There is even a dipstick that can be used in the field when labs aren’t available. Even though the CDC calls these tests “less than optimal,” rapid diagnosis is still important and gives public health officials the chance to stem a potential outbreak. They recommend having it cultured by a qualified lab, where they’ll look for rapidly motile bacteria using direct microscopic examination. Unfortunately, for the patient, early diagnosis offers no help since the treatment remains the same.

Most cases of cholera are actually pretty mild and can even be asymptomatic all together. Of course, when you’re asymptomatic and don’t realize that you’re a vector, you’re not exactly watching yourself or protecting your neighbors from your fluids. If you’re of the unlucky 5-10% who experience severe symptoms, then things get pretty real.

As your GI tract attempts to purge the bacteria lodged in the small intestine, patients produce profuse watery diarrhea, up to 20 L per day. That’s like filling a gas can, every single day.  This is in addition to the vomiting (more fluid loss), and all the issues that are brought about by being dehydration – leg cramps, loss of skin elasticity, dry mucous membranes, thirst, and low blood pressure.  In many wards, special cots are used that basically have a hole with a buckets under it so you can just go.

If left untreated, death can occur within only several hours.  Your GI tract tries to get rid of this bacteria so hard that you basically dehydrate yourself to death.  Symptoms take a few hours or up to 5 days to present. If you beat it, though, you can be immune for at least 3 years.

What to Do About a Lot of Poo?

Treatment and prevention of cholera is actually not that tough, y’know, in a socioeconomic vacuum. Antibiotics to kick the bacteria and simple fluid therapy to keep the patient from dehydrating. Your body can take care of the bacteria on its own, so it’s really the fluid therapy that is so important. Virtually all rehydrated patients will survive. In fact, it has even recently been recognized that simple oral rehydration can suffice. Give them some water with glucose and some electrolytes and they should be good to go. Salt packets are being distributed by WHO and UNICEF currently. They made sure to mention that you can add flavoring. What kind of flavoring do you want when you’re busy losing 20 L a day?

Prevention is the real key here, though. This is a human vector only disease, so it could possibly disappear one day. Simple casual contact doesn’t really spread it, without the feces to mouth communication. It’s the dirty water and bad sanitation that we would really need to address. It has been well documented that tube-well water for cleaning will significantly lower infections. However, protecting water is not always feasible in many of the areas that are routinely affected by cholera.

Cholera have been traced to raw or undercooked shellfish, but that seems to also be related to the conditions in which they were caught.  It has also been known to live in brackish rivers and coastal waters, but it was unclear how that related to water conditions as well.

There are also two vaccines available – Dukoral and ShanChol. As of writing, WHO has recommended both of these and they are being made available. There is already evidence of Dukoral inducing herd protection – so long as no third world parent is worried about their kid getting autism from vaccine shots (heavy sarcasm there).