Climbing the ranks: social status changes gene expression in monkeys

Red carpet by chadmagiera.

Having low social status may suck for reasons beyond not getting invited to the swankiest parties; it could also be making you ill. A correlation between socioeconomic status and health in humans is well established. Most famously, the Whitehall studies of British civil servants found that workers in low status positions had worse health and earlier deaths than their higher-ranking managers.

But the reasons behind this relationship are not clear. Are low status individuals sicklier because their jobs expose them to grueling physical labor and dangerous chemicals? Do low wages make preventative medical care and good nutrition harder to obtain? Does the demoralizing experience of being ordered around all day stress the mind and body? Or perhaps we’re looking at it backward? Maybe healthier, fitter individuals naturally rise to the rank of CEO while less robust workers languish in the mailroom. Such are the chicken and egg conundrums facing human correlation studies, even large cohort studies like Whitehall. Sometime, when things get too muddled, it's best to grab some monkeys and head to the laboratory.

That’s what a group of scientists did in a study recently published in the Proceedings of the National Academy of Sciences. Their monkey of choice was the rhesus macaque – a species whose lowest-ranking members, like humans, also exhibit poorer health.  Working with 49 monkeys divided into 10 social groups, the researchers demonstrated that the animals’ social status affected gene expression, specifically in genes relating to immune function. The effect was so pronounced, in fact, that it could even be used to predict status. Gene expression data from blood samples indentified with 80% accuracy the relative rank of the individual from which they were taken.

In case your recollection of genetics is a bit hazy, this might be a good time to clarify what we mean by “gene expression”. With the exception of gametes, every nucleated cell in your body contains a full set of genes (46 chromosome worth, assuming you’re human), but not every inch of DNA in those cells is constantly expressed (that is, transcribed into RNA and eventually translated into the proteins that run our bodies).* So while an individual’s genome is set in stone, gene expression varies between cell types and can also be impacted by environmental conditions.

To sort out the connection between the environmental factor of social rank and gene expression, the authors of the study took medium-ranking female monkeys and assigned them to new hierarchical social groups comprised of five individuals. Rank in these experimental groups could be manipulated by the order in which each member was introduced – the first ones in generally ranked the highest, while latecomers were stuck with increasingly lower statuses. †

Looking at thousands of genes, the authors found greater gene expression related to rank in 987 of them. (535 genes were expressed more in high rankers, 452 in low rankers). Additionally, monkeys that switched ranks during the experiment experienced changes in their gene expression shortly thereafter. This suggests that not only is it rank that controls gene expression, rather than the other way around, but that negative effects of low status on health might be reversible through changes in the social environment.

How are we to interpret these results? Very carefully. Monkeys and humans differ genetically and socially, so we shouldn’t just assume the results apply to our own species and call it a day. Human civilization is a complicated affair, and status can’t easily be reduced to resource access and grooming privileges. What determines our status within society? Is it just economic? Does it extend to race and gender? To high school cliques and Hollywood A thru D lists? As they say in the science biz, more research is needed, but it’s an intriguing start.

* If that’s still too vague, or you’re just needing a break from your job, I found this website that lets you build your own virtual protein. Weeee! Internet!

† In the wild, female rhesus macaques typically stay with the social group and rank they’re born into.

Whales, trees wish you would shut up already

Image Credit: Thing Three.

The noisiest place I ever lived was an apartment at the corner of Sixth Avenue and 15th Street in Manhattan. It was the nexus of several bustling neighborhoods and a hub of public transportation, with subway stops mere blocks in each cardinal direction and even a New Jersey PATH train station within easy walking distance. New York City’s endless stream of vehicles gushed down the avenue day and night, and an array of 24-hour fast food establishments and markets ensured a steady flow of both gregarious revelers and ranting vagrants. On weekends, street festivals awoke us with their blaring music and electric generators. On rainy nights, the din of hydroplaning taxis made watching a DVD with the windows open impossible. It was effing loud.

As a species, humans excel at making noise. Not content to stick with the howling and growling of other animals, we’ve created machines to augment our collective clamor. And, thanks to our ever-increasing transformation of the planet’s landscape, we’re sharing that noise with other organisms. Everywhere we go, we bring sirens and jets and jackhammers. How is the rest of nature faring with this parade of sound? Sometimes not too well. And a pair of recent studies, each published in the Proceedings of the Royal Society B, highlights how the effects of our auditory intrusions are not limited to land-dwelling animals, or even animals.

Right place, right time

In the weeks following the September 11th, 2001 World Trade Center attacks, many New Yorkers were on edge. They jumped at the sound of car alarms, fretted over riding the subway, and had anxiety dreams filled with airplanes. Meanwhile, North Atlantic right whales (Eubalaena glacialis) were finally able to relax a bit. Why? Because for once they could hear each other without yelling. Ship traffic in the Bay of Fundy, Canada, where whale studies were underway, dropped following the attacks, and with it so did underwater noise levels. Ships produce low frequency sounds that interfere with right whales’ communication vocalizations. So while life on land was newly terrifying and chaotic, underwater an invisible wave of tranquility was sweeping through.

As you can imagine, the exact course of the research wasn’t planned. In the weeks prior September 11th, scientists were plodding along measuring underwater noise levels and also collecting samples of whale crap, unaware of the tragedy-borne opportunity lurking on the horizon. The audio data were collected from August to September of 2001, but the fecal sample study would continue through 2005, from the months of late July to early October (the whales aren’t in town year round).*

Consistent with the scientists’ empirical observations, underwater recordings made after September 11th showed a decrease in noise. But perhaps most interestingly, analysis of the fecal samples found that the post-911 poo had lower levels of glucocorticoid metabolites. Glucocorticoids are secreted in response to various kinds of stress, so the lower levels suggest that quieter waters resulted in calmer whales. Depressingly this might also indicate that, under normal, non-catastrophic circumstances, whales in the region are chronically stressed.

Soothing sounds of the forest

While I myself have never attended a grade school science fair (my childhood was sparse on extracurricular activities) I’m told that a popular experiment for such things is testing whether plants grow better in the presence of soothing classical music versus abrasive rock ’n’ roll. If you’ve read this far hoping to learn about laboratory scientists subjecting potted ferns to daily doses of death metal, I’m sorry to disappoint you. The study at hand dealt with the indirect effects of noise on plant pollination and seed dispersal. Both of these services are sometimes provided by animals, so while the plants themselves may be indifferent to manmade noise, animal reactions to it can influence the plants’ reproductive success.

The authors conducted their research in New Mexico in the Bureau of Land Management's Rattlesnake Canyon Wildlife Area, which houses not just wildlife, but also natural gas wells and the noise-making compressors used for extraction and transportation of the resource. This provided an ideal setting for the study, as the location had both quiet control areas (without compressors) and loud experimental areas (with compressors) and yet none of the confounding variables typically found in noisy spots (i.e., the various urban indignities discussed back in the opening paragraph).

To examine the effect of noise on seed dispersal, the scientists focused on the piñon pine (Pinus edulis), tracking the volume of seeds taken by different animals from both the loud and quiet spots. While some animals seemed to prefer snatching seeds in the noisy areas, the one most likely to help the seeds take root, the western scrub-jay (Aphelocoma californica), carried away more seeds in quieter locales. † This suggests that pines residing in noise-polluted districts may have less luck producing offspring.

Yet the effects of increased noise weren’t always negative. The pollination experiment looked at the auditory preferences of the black-chinned hummingbird (Archilochus alexandri). Unlike the scrub-jays, these birds visited flowers in the noisy sites more often, potentially conferring a reproductive advantage to hummingbird-pollinated plants in loud regions. However, the authors note that the cause of this was probably not the hummingbirds’ fondness for generator sounds, but their aversion to predators that stake out the quieter areas. Like humans choosing an inferior restaurant because it’s easier to get a table, hummingbirds likely hang out in less desirable neighborhoods to avoid the hassles of more popular ones.

So while the exact effect may be difficult to predict, noise pollution – like other more publicized forms of pollution – does have an impact on both flora and fauna, on land and in water. Repercussions of the increasing cacophony of daily life on our own species might also merit examination. Anecdotally, I can tell you that I felt less stressed out after vacating the Manhattan apartment. Though perhaps the toxic fumes emitted by the Cheesesteak Factory (yes, such an establishment exists) were the bigger problem.

* If you’re wondering how one goes about finding whale droppings, as with drugs and bombs, it’s done with the help of trained dogs.

† The scrub-jay stores some of the seeds it swipes, and not all these are eaten later. Thus the unconsumed seeds have a shot at becoming new trees.

Paint it White: How New York City is getting cooler

New York vista by Tim Pearce.

It’s official: white roofs are cool. The declaration comes from the tastemakers at NASA, and, as always, New York City is at the vanguard of the new trend. In fact, the city’s recently brightened rooftops were found to be over 40 degrees Fahrenheit cooler than traditional dark roofs at the height of summer heat waves.

If you’ve weathered a NYC summer and were lucky enough to escape to the country for a weekend, you probably noticed that it feels several degrees cooler once outside the city – and consequently several degrees insufferably hotter upon reluctant reentry. Having myself spent over a decade in the city, I’d assumed this temperature gradient was caused by the fact the New York summers were literally Hell and the months of July and August a period of non-eternal damnation, but it turns out there’s a simpler explanation.

New York City is crowded, not just with people, but with buildings. Lots of buildings, built close together and typically topped with dark roofs that excel at absorbing the sun’s rays. Outside of the city, manmade structures are interspersed with these things called trees. The green of suburban and rural foliage reflects back some of that solar radiation, resulting in cooler ground temperatures. Meanwhile cities bake in their black asphalt casing. The phenomenon is called the “urban heat island” effect, and, scientifically speaking, it thoroughly and unequivocally sucks.

Higher temperatures not only make city dwellers miserable and irritable, they also result in greater energy usage and higher greenhouse gas emissions, which ultimately makes things even hotter. Hoping to reign in this unfortunate positive feedback loop, city planners have been working to replace traditional dark roofs – made of conveniently waterproof and durable asphalt and tar – with new fangled white materials (household staples like ethylene–propylene–diene monomer (EPDM) and a thermoplastic polyolefin (TPO)). Since not every building owner is willing and/or able to replace an otherwise functional black roof, the NYC CoolRoofs program is also promoting a less involved option – “retrofitting” existing dark roofs with old-fashioned white paint.

So is it working? A multi-year study recently published online in the journal Environmental Research Letters examined how the high-tech versus DIY brightened roofs fared against each other and as well as compared to standard dark roofs. Initially, both the two professionally-installed membranes and the civilian-applied white paint performed admirably – with white surfaces measuring an average of 43 degrees Fahrenheit cooler on hot summer days than dark samples. (Those asphalt rooftops can reach a disheartening 170 degrees Fahrenheit.) However, while the fancy whites were resistant to the ravages of time, the humble white paint lost some of its luster (and, more measurably, its reflectance) by the second year… not unlike the interior paintjobs in Manhattan apartments. Still, even the two-year old paint was an improvement over the dark roofs, and you can’t beat the price (about 50 cents per square foot, whereas the pro roofs ran between $15 to $28 per square foot).

So that’s all pretty impressive, but I seem to recall that New York has not just one but two problem seasons, in terms of both human suffering and energy usage. What about winter? Is white after Labor Day as gauche on rooftops as it is in ensembles?* The EPA, whose standards for roof reflectivity these white materials are striving to meet, acknowledges that brightening roofs in colder climates may come with a “winter heat penalty”. That is, in reducing unwanted summer heat, the more welcome heat that would have been generated by sunlight-absorbing dark roofs in winter is also forfeited, and gas or electric heaters must work harder to make up the deficit. However, since fewer hours of sunlight are available during the coldest months, it’s not a major loss (relative to the improved efficiency in summer) unless you’re dealing with frigid locations where heaters run 9 months out of the year. †

Additionally, the authors of the current study found that at least one of their measured materials (our friend EPDM) seemed to avoid the winter heat penalty entirely. They attribute this to the material’s emissivity level. Here’s the deal (in as much detail as I’m willing to tackle), white roof initiatives are looking only at a material’s reflectivity. This is the amount of sunlight reflected back instead of absorbed. To qualify for the EPA’s “energy star” rating, a material must have a solar reflectance of 0.65 or greater upon initial installation, and 0.50 or greater after three years. (It’s a zero to one scale, with 0.0 absorbing all light, and 1.0 reflecting all light.)

But materials also have an emissivity factor. Emissivity is the amount of heat something emits after absorbing solar radiation. Since close to half of that sunlight is being absorbed by the white surfaces (still far better than black, which is typically around 0.05 in reflectivity) how much of it they emit will also affect a building’s surface temperature. The white materials tested were assumed to have a high emissivity in addition to their high reflectivity (i.e., whatever sunlight got in would quickly be booted back out), but the EPDM seemed to cling a bit harder to its absorbed heat, thus keeping its surface toastier in the winter.

The authors therefore suggest that materials with high reflectivity but middling emissivity may be the best fit for colder climates. Got all that? Don’t worry, I’m not sure I understand it either. Emissivity is a tricky concept to get a handle on. Apparently even the folks manufacturing the EPDM couldn’t figure out how much heat their product would emit.‡

In any event, it’s nice to see that New York City is getting its environmental act together. When I left the place in July of 2008, it was a sweltering cesspool with insufficient bike lanes and a surfeit of Sex in the City-spawned shopping zombies. Less than four years later and, well, at least two out of those three problems are being addressed. While the world could do without some East Coast fads (I had to endure a second round of Brooklyn’s ironic mustaches when I moved to Austin), one can only hope that the trend of going green by way of white will soon fan out to other cities. Especially those in the south, where I currently reside. It's totally uncool here.

* Yes, I’m aware that no white after Labor Day is an outmoded fashion rule. Austin isn’t that behind the curve.

† And if you’re living somewhere truly freezing, isn’t your roof covered with snow most of the time anyway? Now if we could just get it to snow in summer instead of winter, then all our problems would be solved.

‡ The product was rated as having an emissivity of 0.90 (high), but the authors estimated it to be closer to 0.48 (not so high).

America's grossest invasive species

As if 12-foot pythons and lizards capable of biting off limbs weren’t enough for Americans (especially Floridians) to worry about, now comes a nonnative species that is not only harmful to indigenous flora and fauna, but also thoroughly disgusting. Meet the European earthworm (species of the genus Lumbricus) a grotesquely-long squirming squishy blob of an animal that is responsible for the decline in populations of the completely non-revolting ovenbird (Seiurus aurocapilla). It’s a bit backward sounding, I know, as birds typically eat worms, but the problem is more complex than ordinary predation or resource competition.

Happy, earthworm-free woods. Image: Duane Burdick.

The worms aren’t attacking the birds (they’re not that big) or even nosing in on their food supply. You see, the issue is that ovenbirds – a migratory species that nests in North America and flies south during the colder months – build their nests on the ground, and they do so in what was previously earthworm-free hardwood forest, which normally has a thick layer of understory plants. The abundance of low plants helps conceal ovenbird nests from predators, but now these nauseating euro-worms are ruining the delicate environmental balance.

Personally, I feel a titch misled. Being none too keen on earthworms from day one, I’d been told many times that we must appreciate (or at least tolerate) the slimy bastards because of all the good they do for plants. You’ve surely heard the same spiel. Worms’ subterranean writhing tills the soil, distributes nutrients, and makes gardens flourish. But such pro-worm propaganda, while true, is only part of the story. And what’s good for the garden isn’t necessarily good for the forest. That important understory foliage grows from the slow decomposition of leaf litter on the forest floor. Earthworms, which happily eat all sorts of rotting vegetation, feed on this litter and hasten the decomposition process. As a result, there is less fertilizer for the understory plants and subsequently less protective cover for ovenbird nests.

How did these clammy wriggling beasts from abroad worm their way into American soil? Like pretty much every other invasive species, they were delivered here courtesy of human sloppiness and/or cluelessness. European earthworms have been in the country as long as European humans, (you know, pilgrims and founding fathers and the like), brought in accidently by boat or deliberately by ambitious gardeners. More recent activities, logging and the dumping of fishing bait, delivered the pests into hardwood forests, where they’re currently running amuck. Yuck.

I don’t claim that earthworms have no place on our planet, or even in North America. Nor would I profess that any one animal was superior to another. I can only present to you the facts as I have uncovered them....

Images: U.S. Fish and Wildlife Service (L) and Michael Linnenbach (R)

I rest my case.

How to be a better liar

Rice by babbagecabbage, Photoshoppery by yours truly.

Listen up, liars. Society is onto you. Well, its machines are anyway. Computers can spot your fake online hotel reviews, and they know when you’re shaving ten pounds off your weight on your Match.com profile. They’re sharpening their skills daily and, with their help, even the human brain (a device notoriously terrible at truth detection tasks) might get wise to your chicanery. So if you’re not going to change your wicked ways, you can at least try to improve your technique a bit.

But how? Researchers say the telltale signs of deception are difficult to hide. Even in written form – where the author has the opportunity to edit his or her appalling untruths – liars still leave behind linguistic clues. But I say, what kind of defeatist attitude is that? We can make our résumés more appealing to employers by replacing passive phrasing with exciting ACTION words. Why should lying about the rest of our lives be any different? Before we throw in the towel and resort to honesty, shouldn’t we at least try to apply what science has learned to our own deceitful endeavors? Of course we should. Let’s have a go at it.

Mind your language

Certain outward signs can draw attention to a poorly executed lie: fidgeting, stammering, sweating, shaking, heartbeats audible from two rooms away. Humans took note of this and have concocted lie-detecting technologies that attempt to exploit such physiological cues. The earliest example usually given is China, circa 1000 B.C., where suspected criminals were asked to place rice powder (or rice, by some accounts) in their mouths and then spit it out during interrogations. The idea behind this test was that the stress of lying dried out one’s mouth. Thus those answering honestly should be able to spit out more than liars, whose mouths the starchy stuff would stick to like feathers on tar.

The modern polygraph, which measures pulse, blood pressure, and other indicators while suspects answer questions of varying stakes (“Is today Tuesday?” vs. “Did you kill your wife?”), is basically a twentieth century upgrade of the rice test.* Both rely on finding signs of nervousness exhibited by guilty liars. Problematically, both also risk merely capturing the anxiety of innocent people freaking out over being accused of a crime.

A more novel way of discerning between factual and fabricated statement involves not measuring the body, but analyzing the words used by the speaker (or writer). While not initially conceived as lie detectors, computer algorithms that examine linguistic patterns have been used experimentally to search for hallmarks of deception. Linguistic Inquiry and Word Count (LIWC), software designed by James Pennebaker, Roger Booth, and Martha Francis is one such tool. It sifts through documents (written text or transcribed speech) and tallies the instance of various word categories, including significant but harder to control “function words” - pronouns, articles, and the like.

LIWC was most recently unloosed in the jungle of online dating and proved superior to human judges at assessing “trustworthiness” from the content of daters’ profiles.

Thinking cues and feeling cues

Having spent some time tackling this idea of liars’ linguistic cues, scientists have come up with a few observations. The giveaways can be divided into two types: cognitive (thinking) and emotional (feeling). These distinctions are based on the proposed causes of the cues. The idea is that lying is 1) morally troubling and 2) intellectually difficult. Let’s tackle the second one first.

Because liars have the challenge of creating and managing the details of a fictional tale, their accounts should theoretically reflect this by being shorter and simpler. Experimental analysis has found that false statements generally do have lower overall word counts. They also contain fewer exclusion words. These are words like “except” and “but”, which are used to make the kind of fine distinctions in stories that can be a headache to keep track of when they’re not actually true. For instance, when playing hooky from work, the cognitively-taxed liar might claim, “I have a cold.” or even, “I have a cough and a sore throat.” But you can improve upon this by throwing in an exclusion, “I have a cough and a sore throat, but I’m not feeling feverish.” Just make sure you have more symptoms than exclusions, else your employers will think you’re being lazy.

Due to ease of handling, motion verbs are also common in dishonest accounts. “I fell and sprained my ankle; I won’t be coming in today.” “The car ran over a nail and got a flat; I won’t be coming in today.” And so on. You may not want to lean too heavily on motion verbs. Try adding a little detail about what it was that caused you to fall in the first place, or the crummy pot-hole-strewn road you driving on. Be careful though. As a child, my instinct when lying was to construct elaborate narratives with well-developed characters and lengthy passages of dialogue designed to answer questions no reasonable person would think to ask. It was perhaps overkill, as I can report anecdotally that my results were not stellar.

Emotional cues stem from feelings of guilt and fear related to lying, rather than its cognitive demands. These are especially important in our modern computer-driven world, because they’re harder for the liar to filter out, even when given the chance to edit their work (the online dating profiles found more emotional than cognitive giveaways of deceit). Unhappy words and negations both crop up more frequently in the ramblings of the untruthful. Though you might have a hard time eliminating these entirely when you’re lying about a dour subject. I mean, is it better to say, “I feel lousy” or “ I don’t feel well”?

Perhaps we should focus instead on paring down instances of “distancing”. Apparently, liars want to detach as much as possible from their ghastly falsehoods and often do so by avoiding first person pronouns. So make sure to use, “I” and “me” whenever possible.

Of course, as with physiological measures, none of the above pitfalls are likely to affect an evil genius (clinical definition: high functioning antisocial personality with IQ of 140 or greater). But, given that you’re sitting around reading this rather than out devising a kryptonite trap for Superman, you’re probably not in that category.

Man vs. machine

Something else you might want to keep in mind in all this wordsmithing, is who or what you are trying to dupe. So far, everything we’ve discussed relates to outwitting computer algorithms. But humans and machines rely on different cues to decide whether or not to trust you. And even though humans suck at spotting a lie (we tend to fare at about the rate of chance), that shouldn’t stop you from peppering your fictions with the very elements we incorrectly perceive as signs of honesty.

The only linguistic trait that both evokes distrust in humans and actually correlates to lying is word count. Shorter stories are more likely to be false and more likely to be perceived as false by a human audience. † But from that point on, our poor species gets lost and gravitates toward linguistic patterns that have nothing to do with honesty. While we like long descriptions with plenty of details, we also want individual sentences to be on the short side. Got it? Use lots of words. Make short sentences.

Also popular is concrete language. Abstract or convoluted sentences inspire suspicion (not to mention boredom). And do try to use the word “we”. The plural first person pronoun “we” makes listeners feel included, whereas the second person “you” or third person “they” makes us feel like outsiders. To test this, I made a point of using “we” in describing human lie-catching ineptitude, so that you wouldn’t think me a snob accusing you of being a bumbling simpleton. Did it help? Were you filled with trust? Perhaps an urge to lend me money?

And Now the Caveats

WARNING: Don’t try this in a language other than English. All the studies I looked at were conducted in English and, as anyone who has struggled to learn a new language knows, grammar varies considerably between languages. Culture likely has an effect too. Who knows if first person pronouns have the same appeal outside of the egocentric U.S.

Also, results may vary with the degree of the lie being told. A lie created to conceal a major transgression will likely leave more clues in its wake than one told to praise an unremarkable meal.

And while we’re on the subject, those big lies about where we were and who did or didn’t kill aren’t the most common type of dishonesty. The majority of our deceptions work to mask our socially unacceptable opinions and feelings, or to hide our perceived shortcomings. Given the banality of our lies and the effort required to tell them convincingly, it might be easiest to just fess up to those unpopular attitudes and lackluster achievements.

* Bonus trivia: The man who invented the blood pressure measuring component of the lie detector, William Moulton Marston, was also the creator of Lasso-of-Truth-wielding comic book heroine Wonder Woman (under the name Charles Moulton).

† This is not to say that any short sentence is false. It’s all relative. And, relative to a truthful account on a similar topic, an untruthful one is likely to be shorter.

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.

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).