After reading The Vacation Gals’ service piece regarding prevention of Zika and other mosquito-borne viruses, scientist Pete Weis thought its counterpoint, how to catch tropical diseases, would provide additional insight for travelers to areas with vector-borne diseases in developing countries.
January 2008: My wife Judy and I, she an about-to-be-retired and I a recently retired Rutgers professor, were in a remote corner of Madagascar conducting field research. Our goal was to determine how, when, and which coral reef fishes spend their early juvenile stage hiding out from predators by seeking refuge in a mangrove swamp. We were guests of Blue Ventures, a British NGO (a non-governmental organization that is nonprofit and volunteer). This meant taking a 12-hour trip by 4×4 — also known as an SUV — from the end of the paved road, fording three rivers, stopping to fix a broken spring with a log and some rope, and repairing a bearing that had basically turned our vehicle into a 3×4…all while navigating a swamp. Soon after leaving the town of Tuliare at the end of the paved road, I noticed that the odometer of our hired vehicle was stuck at 245,000 kilometers – and this was mostly in first and second gears! I wondered how much more distance it had accumulated since the odometer broke.
Home for the month was a hut belonging to a run-down resort. Our hut had screens and bed nets, so mosquitoes were restricted to those few that sneaked in with us. We had running water for an hour in the morning and another hour in the evening, although it it looked more like muddy tea. When filtered water wasn’t available, we had to settle for beer to maintain our fluid balances. A pretty good beer, Three Horses Pilsner, was available, but believe me, it’s kind of weird for tooth-brushing. Electricity was supplied for six hours in the evening. Meals were in the dilapidated hotel: we ate “indoors” for breakfast and lunch, but dinner was al fresco.
The lack of window screens while dining became significant because the nearby village of Andavadoaka (population ~1200) had no bathrooms, so the people used the bushes along with their dogs and cattle. Needless to say, we had no idea where the flies had been before we shooed them off our food, but could imagine those flies were no strangers to the dogs, cattle, and outdoor “privies.” It was not surprising that a full third of the other volunteers became ill with a gastrointestinal bug after a while. My wife Judy got laid low on our last evening there. Luckily, I didn’t; I attributed this to doxycycline, the antibiotic I took daily to prevent malaria. Judy used the preferable Larium (generically known as mefloquine), but I had become allergic to it on a previous trip to the tropics. The gastrointestinal issue was quickly cured by the ciprofloxacin (“cipro”) that we usually pack when traveling to such an area.
Mosquitoes were a problem whenever we were not in our hut, so DEET was absolutely necessary every evening at dinner. Nevertheless, when back in Tuliare and its paved roads, I came down with night chills and sweats, which are the classic signs of malaria. Despite what I thought were my best efforts, DEET plus doxycycline had not prevented it. So, for our last three days in Madagascar, I had the chills/sweats every evening from 10:00 PM to 1:00 AM. But, as miserable as I felt, I didn’t worry about it: I knew that within 24 hours after the long trip home, I would be back on campus (Rutgers – N. J. Medical School), where I could seek out our specialist in tropical diseases. An additional 24 hours for traveling back to the United States, and one prescription later, I was thankfully symptom-free.
So, why is this story an example of how to catch tropical diseases? I realized, after a bit of thinking about it, that I had not followed directions. Doxycycline, like all tetracyclines, binds with – and is thus inactivated by – calcium. I should have taken it at least an hour before, instead of with, lunch. Most meals contain some calcium. Despite my best efforts, I missed this important detail! However, the only lasting effect is that I’m no longer allowed to donate blood.
Basically, anyone wondering how to catch tropical diseases should follow my lead and not follow directions to the smallest detail. Or, instead, consider these lessons learned: when traveling to less-developed tropical areas, make sure your injections are up-to-date including Hepatitis A and yellow fever; check out the CDC’s website for travelers for country-specific advice; apply the insect repellent — DEET — carefully; pack a good supply of preventative medicines (we did), and read the directions on the bottle (I didn’t). You’ll have a much more pleasant travel experience.
Oh, and by the way, our research was successful: Rapid changes in fish utilization of mangrove habitat in Western Madagascar was published in a journal called Wetlands Ecology and Management shortly after returning home.
Pete Weis is retired from Rutgers – N. J. Medical School, in Newark NJ, where he taught anatomy to medical and dental students. He still maintains a research laboratory where he analyzes responses to toxic metals in aquatic environments. He also travels a lot.