Thursday, January 26, 2012

Eek-o-tourism: Belize’s diseases and other holiday hazards

My Central American vacation is rapidly approaching, and I’m giddy with anticipation and light-headed from attempting to complete the many long-put-off tasks on my pre-departure checklist. The other day I spent an hour at the travel clinic getting vaccines and chatting with their awesome nurse, who seemed almost as obsessed with creepy microorganism as I am. Some of the pathogens we discussed were familiar favorites, others complete surprises. And germs aren’t the only things to worry about. Belize offers up a glorious buffet of perils for those prone to worrying (btw, avoid buffets, especially if you haven’t been vaccinated for hepatitis A). You might be wondering why such a polyphobic person would elect to vacation in the tropics in the first place. Well, like many a hapless traveler, I was lured by pretty pictures. The flora, the fauna. Belize’s biodiversity is hard to resist. Let’s have a look at some…

Image: Andrew Coyle
Large, carnivorous biodiversity
Jaguars are the largest wild cats in the Americas. Males can reach upwards of 300 lbs. They are stalk and ambush predators that can hunt day or night, sometimes going so far as to climb trees to get a jump on their prey. Also good swimmers, they can even kill things in the water – big things, like caimans. A jaguar’s bite is strong enough to pierce skulls and break turtle shells. They’re such impressive killing machines, that someone named a luxury car after them. Not to mention a Macintosh operating system.
ROAR!!!     Image: digiclad

Troubleshooting: While Cockscomb Basin Wildlife Sanctuary (the third stop on our itinerary) is touted as a “jaguar reserve” it’s not exactly overrun with the majestic cats. Seeing a jaguar in the wild is an uncommon event, and attacks on humans seldom occur. Being eaten by a jaguar is a rare privilege bestowed on precious few lucky tourists.

Venomous biodiversity
Like many warm, rainforesty places, Belize has its share of snakes, some of which are capable of injecting lethal venom with their fangs. I could sit here and enumerate the various species of scary, slithering reptiles found in the region, but it would just upset us both. For me, perhaps the most disconcerting piece of information is that, once one leaves the herpetologically well-organized U.S., coral snakes sometimes fail to adhere to the rhyming rule of “Red on yellow, kills a fellow. Red on black, friend of Jack.” Head south, and everything you thought you knew about snakes is wrong. Even those with the should-be-harmless, red-touching-black striped pattern can kill you. Best to revise the pneumonic to, “Red, yellow, black in whatever configuration… you’re screwed”.

Troubleshooting: Coral snakes aren’t especially aggressive, so if they see you first, they’ll run for the hills. They’ve also got teeny little fangs. Leather boots are usually sufficient to thwart any defensive attacks that might be provoked by flailing and screaming instead of backing away slowly. I wish I could say the same about the fer-de-lance, a snake noted for being both grumpy and jumpy.

Parasitic biodiversity
Christ, who knew there were so many insect-vector-spread diseases out there? I’ve rambled at length about malaria here before, so I won’t spend too much time on it now. Compared to sub-Sahara Africa, Belize is a malarial lightweight. But the disease does occur, and it has the extra bonus of being primarily caused by the P. vivax parasite. While less deadly than the more famous P. falciparum variety, this parasite can hang out in a latent form in the liver and cause relapses months after the initial fever has faded. Super.

Malaria is, of course, spread by mosquitos, but there are other blood-sucking insects to watch out for. Sand flies carry parasites of the genus Leishmania, which cause cutaneous leishmaniasis. There’s a more serious form of leishmaniasis in other parts of the world, but the Belizean version just causes skin ulcers. Still, not the ideal vacation souvenir.

Kissing bug. Image: Dr. Erwin Huebner
But wait, there’s more… Chagas’ disease! The illness – named for its discoverer, Brazilian physician Carlos Chagas – is caused by the Trypanosoma cruzi parasite and spread by a comparatively cute vector, the triatomine bug. It’s also called the “kissing bug”. Quaint, no? If you see one, kill it.

Troubleshooting: Bug spray. Lots of bug spray. For whatever silly reason, I opted not to bother with malaria “chemoprophylaxis” (drugs that prevent the disease by rendering your body too harsh an environment for the parasite to survive). It wouldn’t protect against the other germ-toting insects anyway. I’ve wisely avoided reading anything about possible harmful effects of excessive DEET application. The information would only confuse me. I’ll worry about it when I come home.

Oh, and there’s also zoonotic hookworm. Ugh. I’d totally forgotten about this thing prior to my briefing at the travel clinic. A human-hosted form of hookworm exists too, but the one common to Belize shacks up in dogs and cats. The eggs are shed in the animals’ feces and can hatch and grow into larvae on a lovely, sandy beach where a canine or feline host did its business. The larva can enter the human body through the skin (i.e., walking barefoot on the above-mentioned lovely, sandy beach). And they don’t even need an open wound to gain entry, they just grab on and burrow their way in. What an organism! Once inside, though, they can’t mature and are stuck wandering aimlessly through the epidermis. This results in an itchy skin condition called “cutaneous larvae migrans”. It’s not remotely life-threatening, just uncomfortable and disgust inspiring. According to the CDC, the stranded larvae will die off even without medical intervention in 5-6 weeks. Five to six. Weeks. Gross.

Troubleshooting: Flip flops. Oh, the indignity.

Bon Voyage
Even with all that in mind, I’m still psyched about leaving the country. After all, if the only priority was feeling safe and comfortable, we could have just booked an all-inclusive package trip to Disneyworld. Part of the excitement of foreign travel is getting away from one’s normal routine and being exposed to the unfamiliar (and sometimes also the anxiety-provoking). And there’s something fun and novel about staying in places where “24 hour electricity” is considered an amenity worth boasting about on the website. Now if I can just remember to call my aggressively paternalistic bank and let them know I’ll be accessing ATM machines in a foreign land. I’ll go do that now.

Wednesday, January 11, 2012

Wall of Death: Why You Shouldn’t Put a Fountain in a Hospital

Image Credit: star5112

The dastardly duo of water and bacteria have teamed up again to assault our species. Not content to sicken and/or kill us when we drink water or pour it up our noses, the pair have now conspired to stage their ambush from a vector few would suspect - decorative “water wall” fountains. An investigation into a 2010 outbreak of Legionnaires disease in Wisconsin concluded that the source of the deadly bacteria was the soothing, cascading water of a fountain situated in a hospital lobby.

In case you don’t spend as much time as I do reading about obscure illnesses, allow me to bring you up to speed. Legionnaires disease is an acute and potentially fatal respiratory ailment caused by Legionella bacteria (mostly the Legionella pneumophila species, if you like to keep your microorganisms straight). Both disease and pathogen got their names in 1976, when a particularly large and well-publicized outbreak occurred at the Philadelphia convention of the American Legion. 

The disease causes pneumonia, along with other symptoms that usually accompany it, including high fever, chills, and a cough. According to the CDC, Legionnaires disease kills between 5% and 30% of those afflicted with it. A less severe form of infection – without the troublesome pneumonia – called Pontiac fever can also result from the same bacteria. Collectively the two maladies are known as Legionellosis.

A person contracts Legionellosis by breathing in tiny aerosolized droplets of water contaminated with Legionella. The bacteria thrive in warm water, so any poorly cleaned water system may harbor them. Swimming pools, hot tubs, and cooling towers for large air conditioning systems have all been culprits in previous outbreaks. 

It’s uncertain just how much pathogenic mist one needs to breathe in to get Legionnaires disease. Of the eight individuals sickened by the Wisconsin hospital fountain (all recovered, by the way) most had only minimal contact with the bubbling bacterial menace, such as picking up prescriptions at the hospital pharmacy or delivering a package to the lobby.

The CDC reports that in the United States 8,000-18,000 people are hospitalized for Legionnaires disease annually. But given that the country’s population is estimated at over 310 million, even 18,000 is really nothing. This water wall fiasco is a fluke then, right? I mean it’s not like this has happened before or anything? 

Well, actually, the Wisconsin incident is the second documented outbreak of its kind. In 2007, at the National Institutes of Health in Bethesda, two cancer patients contracted Legionnaires disease following exposure to a similar fountain. Notice a pattern yet? Sick people and those with weakened immune systems are more susceptible to this disease.† And where’s a good place to find sick people? Yep.

It seems like it might be a wise for decorative fountains to stay the hell away from hospitals, doctors’ offices and any other haunts of the under-the-weather set. The Wisconsin hospital that was the source of the 2010 outbreak ditched its fountain, and many others in the state have followed suit. Farewell water walls.  You were a bit too Las Vegas for hospitals anyway.

* Named for a 1968 outbreak in Pontiac, Michigan.

† All eight of the Wisconsin Legionnaires disease sufferers had some underlying condition that rendered them vulnerable to the bacteria.

Note: Due to phonetic similarities to the term “water wall”, I’ve had the song “Wonderwall” by Oasis going through my head the entire time I was writing this. It’s not a happy feeling. I will now use the power of suggestion to inflict the same curse on you – “Wonderwall” is going through your head (unless you’re unfamiliar with the song, in which case consider yourself lucky).