Thursday, September 6, 2007

A Shot in the Arm is Worth Two in the Ass

Prior to this trip-preparation performance I was confident that we wouldn't need many more vaccinations. Having already travelled parts of Asia, South America, and Africa, we had been vaccinated against the usual: measles, mumps, rubella; polio and diptheria; tetanus; Hepatitis A & B; cholera/traveller's diarrhea (oral vaccine); typhoid, and finally, yellow fever. We are immune, invincible, bionic.

We showed up at the door of our favourite travel clinic to make sure we were good to go on all counts. When we arrived, we were inundated with warnings, statistics, and advisories about the countries we are going to be visiting, the time of year we'll be there, and the types of environments we'll be inhabiting. In the end, we signed ourselves up for even more vaccines: rabies, which is a series of three shots, and Japanese encephalitis, also three shots. We also walked out with prescriptions for more Cipro, Zithromax (to deal with the bugs that are now Cipro-resistant in parts of Asia), Malarone, doxycycline, more Diamox, dexamethasone, and levofloxacin. We were also educated ad nauseum about precautions against mosquito bites, the usage DEET bug repellents, and permethrin-impregnated bug nets. Oh, and dengue fever and tsetse flies. And bedbugs.


All of this medical mumbo-jumbo boils down to a completely insane exercise in risk-management. For example, Japanese encephalitis is a pretty serious disease that is transmitted by evil mosquitoes in the evening hours. One third of those that contract it will die. Another third will suffer serious and permanent neurological damage. It seems pretty obvious, right? Take the damn vaccine. Except -- the risk of actually contracting the disease is about 1/5000 per week IF you are in the right country at the right time of year (or wrong country and wrong time of year) and travelling in rural areas for more than 30 days. Still, the vaccine is available and offers protection, so why not take it? What if it costs us $800 to get it? Suddenly the risk-cost-benefit-analysis thing becomes complicated.

Let's talk about malaria for a second while we're talking about mosquitoes (damnable things!) Malaria is a serious disease with permanent consequences. We were offered three options: Malarone (atovaquone/proguanil), Lariam (mefloquine), and the antibiotic doxycycline. Malarone and doxycycline are taken daily, lariam weekly. Malarone needs to be taken for seven days post-malaria-exposure (or possible exposure); lariam and doxycycline, for 28 days. Malarone has hardly any side-effects to speak of. Doxycycline can lead to sun sensitivity and yeast infections because it's an antibiotic. And Lariam? Lariam is not recommended for those with anxious or depressive personalities, can lead to psychotic dreams, and has been associated with hallucinations, psychosis, seizures, and peripheral motor-sensory neuropathy. Also, Lariam is not useful against malaria in certain parts of south-east Asia, namely Thailand -- where we will be spending quite a bit of time.

Malarone costs about $5 CDN per day and doxycycline costs about $1 CDN per day (Lariam costs $10 per WEEK, if you're curious.) This is the major deciding factor for many travellers, side-effects or not. For travellers like us, we could be spending upwards of $2500 on anti-malarial medications alone if not for private drug plans. The cost of the drugs is covered for us, to a point, so we're going to get as much Malarone as we can (covered) and protect ourselves the rest of the time with doxycycline. Yeast infections, here I come!

The other interesting vaccine is the oral vaccine Dukoral, which protects completely against cholera and also against the generically-named Traveller's Diarrhea (TD). Protection from cholera is pegged at 100% and for TD, Montezuma's Revenge, or Delhi Belly (or whatever you call it), 80%, presumably because so many different bugs can cause the same sickness. The initial dose is a series of two pouches of pseudo-raspberry flavoured powder mixed with water. On consecutive trips, only one pouch is required to maintain protection. Obviously, regular travel-safety precautions need to be taken, as protection against traveller's diarrhea is only 80% -- one can't quite roll in raw sewage and expect to walk away without consequence.

In the event of Dukoral failure, we have also purchased Imodium (lomperamide) in two styles: fast acting and long lasting, and oral rehyration salts. Imodium serves to decrease the motility of the circular and longitudinal smooth muscles of the intestinal wall, which is a fancy way of saying that it stops your body from moving waste too quickly, which is what happens during a bout of TD. This can be handy if you're going to be away from a toilet for any length of time, like, say, on a bus. Cross-country. In India. The bad thing about Imodium is that too much of it can cause your body to slow down to the point that it doesn't do anything at all, which is my delicate way of saying that you will become more constipated than a Bactrian camel in the Gobi desert (isn't that why they have TWO humps?) The oral rehydration salts are a simple and disagreeable-tasting mixture of salts, glucose, and electrolytes that are reconstituted with water and given to someone suffering from Traveller's Diarrhea, and they serve to replace electrolytes and fluids lost during a bout of TD.

The last couple of prescriptions are pretty specific drugs for altitude sickness or Acute Mountain Sickness. This is a fairly common phenomenon that strikes at over 2400m and is characterized by headache, fatigue, nausea, dizziness, and sleep disturbance. If a person has these symptoms and continues to ascend, AMS can lead to High Altitude Pulmonary Edema (HAPE) or High Altitude Cerebral Edema (HACE), when fluids accumulate in either the lungs (HAPE) or brain (HACE), which can cause permanent damage and possibly death.

The best way to prevent AMS is to ascend slowly. If trekking, the golden rule is to hike to higher elevations during the day, and return to lower elevations to sleep. AMS is caused by exposure to low air pressure and reduced oxygen levels. Gradual acclimatization allows the accumulation of more red blood cells and the ability to more efficiently use the oxygen that is available. Sleeping at a lower elevation gives the body a chance to recover from the day's exertions and helps blood oxygen and carbon dioxide levels to regulate. Also, above 3000m, breathing during sleep becomes shallower, with periods when breathing may even cease for up to 10-15 seconds. This disrupts sleep and also further reduces blood oxygen levels.

In any case, taking Diamox (acetazolomide) can help prevent the onset of AMS, as sometimes a fast ascent cannot be avoided, and sometimes the slowest ascent in the world still causes some to fall ill. Diamox speeds up the acclimatization process, so it's most useful when taken in preparation for an ascent. Diamox is a diuretic and works by causing an increase in the amount of bicarbonate excreted in the urine. This causes the blood to become more acidic (carbonic acid) and increases ventilation (increases blood oxygen levels.) However, Diamox is contraindicated in certain individuals with sensitivities to certain drugs, specifically sulfa-based drugs. I am one of those people, so I can't take Diamox. Luckily, I seem to be largely unaffected by altitude... so far.

Because I can't take Diamox, I have been given a prescription for dexamethasone "just in case". Dexamethasone is a steroid anti-inflammatory and immunosuppressant. The difference is that dex. does not actually help or speed up the acclimatization process in any way, it just masks the symptoms. If you have symptoms of AMS and take dex., you shouldn't continue to ascend. This is key. To continue an ascent while taking dex. could still lead to HAPE, HACE, and possibly death.

There are no immediate cures for altitude sickness... except to descend. In emergency situations, a pressurized hyperbaric body bag can be used to help a severely affected person to descend to a safer altitude.

We can speak from a little bit of experience with the altitude. We have had two opportunities to see what life above 3500m is like, once in Peru, and once in Tanzania at Mt. Kilimanjaro. In Peru, we started in Puno, on the edge of Lake Titicaca. The first impression of Puno was that the air was clean, dry... and very, very thin. Within a couple of hours of arriving, two members of our tour group had fallen prey to altitude with headaches and nausea. In Tanzania, we ascended over the course of four days to an altitude of 5895m. After two days of hiking, I noticed that my resting heart rate was abnormally high. Tests indicated that my blood oxygen levels were at 75% (normally 100% at home.) By day four, my heart was racing and the act of sitting up in my sleeping bag caused me to gasp for breath. Unfortunately, by this point, BG was very, very sick. He had it all -- nausea, headache, dizziness, the works. Neither of us could sleep. Even with the Diamox, BG was unable to ascend to Uhuru Peak, and his recovery on descent was amazing. At 4700m he was in agony; by 4200m he had been downgraded to miserable; by 3500m, he was dancing. I have never seen such a thing in my life, and I am so grateful that he had such a rapid return to hale and hearty.

This time around, we're capping our quest for altitude at 4200m. Life above 4200 is not very much fun, even if the views are gorgeous.

Final medical-type preparations include Gravol for nausea, antibacterial hand gel, bandages, certification in standard First Aid and CPR, and in a fit of insanity, a quantity of sterile needles and syringes. We're prepared for almost any eventuality... I say almost, because I discovered recently that certain blood types are so rare in Asia that they are not even banked. Guess who has said rare blood type -- BG. Between the altitude sickness, the sensitive stomach, and now this, BG is officially the Trip Canary. If anything is going to happen, it's going to happen to him. We must somehow make sure he stays below 4200m, doesn't eat anything too spicy or otherwise aggravating, or bleed.

I wonder if I can fit a roll of bubble-wrap into the First Aid kit.

1 comment:

Anonymous said...

Oh my... I'm hoping that the meds are all for naught. Can't wait to keep reading!