It’s almost legendary among Eco-Challenge elites—the race of 2000—where so many got sick. “They had a river swim in the middle of the race, and of the teams that jumped in, at least one person from each got leptospirosis,” says Lawrence Foster, who helped his Canadian team to a ninth-place finish—only to discover how much it would cost him. Within days of returning to Canada, he developed symptoms, and by the time he saw a travel health expert, he was seriously ill. “I had to crawl into his office with my head below my knees,” says Foster. So sick was he that the doctor called an ambulance, and Foster spent the next several days in a hospital bed in a semi-conscious state. Turns out, he didn’t only have leptospirosis but also dengue fever—a serious, sometimes fatal disease transmitted by mosquitoes.
The severity of his illness took Foster by surprise since he thought he had been prudent, using an anti-malarial while in Borneo and getting checked out medically upon return. Initial blood tests proved negative for any infection. And when a fellow Eco-Challenger emailed from Britain with news he had been diagnosed with leptospirosis, Foster again took proactive action—he went to a hospital, asked to be specifically tested for leptospirosis, then was given the appointment with the specialist. (It was while waiting for the appointment that symptoms erupted.)
Yet it wasn’t just word spreading through the Eco community that alerted officials to the outbreak of the disease among the athletes, which is what it became. In fact, after a number of American athletes began showing up in hospitals with the disease, the U.S. Centers for Disease Control and Prevention (CDC) immediately launched an investigation. Of the 189 Eco-Challenge athletes who were contacted by the CDC, 80 were found to have leptospirosis, which is caused by bacteria found in urine from rodents and other animals that contaminate soil, food and water. High bacterial counts often arise in tropical environments after heavy rainfall, when the jungle floor can turn to muck or rain washes surface soil, with all its contaminates, into any nearby body of water. This is exactly what happened in Borneo, where it rained both before and during the race—so that by the time contestants were jumping into the Segama River it was incredibly polluted. “Looking at the water I knew there was some serious erosion happening,” Fosters says now. “It was brown and full of mud and we were jumping into [it] with our open sores and mouths.” The CDC eventually concluded the river was not the only source of infection, and that athletes had been exposed to the bacteria during “kayaking, trekking or contact with mud along the riverbanks.”
Soil, water and insects are the three major vehicles of dangerous disease-causing microbes that live in the rainforest and tropical environments. With water, it’s often about fecal contamination (both animal and human), says Dr. Kevin Kain, an internationally recognized tropical disease expert, who credits a tip-to-top trip in Africa with sparking his interest in the specialty. Insects are the big player since most jungle diseases are ‘vector-borne’—where a microbe is hosted and then transmitted to one party by another. The most potent disease-transmitting vector is the mosquito—it’s the granddaddy of ’em all, with thousands of different species conveying countless diseases—but so too are ticks, mites, lice, fleas, flies (especially tsetse and sandflies), kissing bugs and leeches, all of which can transmit bacteria, viruses or parasites.
Apart from some specific tips, two key points should be made about vectors in the jungle. Though not every bite will kill you, it’s best to view these little buggers as you would a charging lion. That is to say, avoid them like the plague—which incidentally, was caused in the Middle Ages by tiny biting rat fleas who managed to wipe out millions. Secondly, don’t convince yourself taking precautions will cramp your style. Kain has never contracted malaria, though he’s been in jungles all over the world and has travelled with people who have. This includes being wary of advice that goes against what you thought to be true, as Kain found out when he reached Lake Malawi on his African trek. “The locals tell you there is no schistosomiasis [in it], but it’s basically rubbish,” he says. In fact, thousands of travellers were getting infected.
It’s not actually bad to assume “everything in the jungle is out to get you,” says Foster, who, as an outdoor instructor, tells people to disinfect any cut no matter how minor. Such simple measures can help keep you protected, and if you heed such advice, adds Kain, the odds of getting infected by a parasite that will wander through your brain—or across your pupil like the African eye worm!—are mercifully small.
Dr. Kevin Kain, Director of the McLaughlin-Rotman Centre for Global Health and the Centre for Travel and Tropical Medicine at Toronto General Hospital Outpost: What’s the difference between parasites and other microbes? Dr. Kevin Kain: A parasite is more like a human. It has a cell that looks like mammalian cells and has more genetic horsepower than a virus or bacteria. It has a lot more genes. Viruses sometimes have only 10, but [the parasite] that causes malaria has 5,000, which means it’s much smarter at figuring out how to outfox your immune system…Parasites [also have] different life stages. If a vaccine only kills one life stage, the parasite just flips to the next one…[They also] shed. If they have a surface coat and your immune system starts to recognize that coat to kill it, they just change it…Some [parasites] are quite challenging to treat, like the guinea worm, which is about a metre long…If you put your foot in water and the head pops out, you have to wrap it around a match stick and it can take weeks to pull out.
OP: Should travellers get tested for these infections when they return?
KK: Anyone who has travelled in an exotic destination for more than a month, [has] spent a long time backpacking or [has] been an expat in sub-Saharan Africa or rural Asia might be screened. There are some serious parasitic infections, and if we find them we can get rid of them easily. If they’re not looked for, they can stay in your body for your whole life, wait until your immune system takes a beating, [then] all of a sudden be life threatening.
OP: Fever is the big indicator of serious infection, correct?
KK: Yes. Fever needs to be dealt with urgently. If it’s Friday, you can’t wait until Monday to see if it’s going to go away. If you’re in the tropics and have a fever, assume it’s malaria. And be an advocate, tell a doctor, “I think it can be malaria.”
OP: Does DEET repel all insects?
KK: It has the most effect on mosquitoes and a decreasing effect on other insects. It’s not very effective against tsetse flies. Permethrin [an insecticide] works on most insects…So for people who are going to be in the bush or on safari, it’s not a bad idea [to bring permethrin].
OP: We know DEET is very effective—but some people don’t like it.
KK: It’s pretty safe, despite the way it smells, and it’s surprisingly not toxic, even though it has a weird sounding chemical name. But it’s been used by two billion people and the number of serious side effects has been incredibly small. If people don’t like it, there is a new and effective mosquito repellent called picaridin. It’s been in Europe for a while and has just been approved in the United States. It goes under the name Bayrepel or Autan and doesn’t have the smell or do the things to plastic and synthetics [that DEET can do].
OP: What’s your opinion on the claim that Vitamin B1 or citronella-based products are effective repellents?
KK: It’s not just opinion. There’ve been trials on B1 and it has no measurable effect on preventing mosquito bites! Citronella does inhibit bites, but not very well, and it only lasts a few minutes. It’s just not feasible [for travellers].
Pack these for protection
• ANTI-MALARIAL MEDICATION Also, speak to a doctor about bringing a self-treating kit for malaria with you on your trip.
• BED NET Most outdoor and camping-equipment stores carry bed nets. Consider getting nets that are treated with insecticide, which kills insects on contact and is effective for six months.
• REPELLENT WITH DEET Apply sunscreen first, wait 20 minutes, then apply DEET.
• INSECTICIDE An insecticide, such as permethrin, can be applied to clothing, bed nets, sleeping bags and tents (never apply to skin). Note: although permethrin is not currently sold in Canada, it can be imported for personal use.
• DOXYCYCLINE Ask a travel doctor about doxycycline, which can protect against malaria, leptospirosis and African tick-typhus.
When you get home, get checked for these infections:
• Strongyloidiasis: caused by a parasite in soil that penetrates skin; travellers often don't know they have it, but a blood test can detect it; is treatable if caught in time; fatality rate is very high
• Schistosomiasis: caused by parasitic larvae in freshwater snails that penetrate skin, become worms in body; worms produce eggs, which then cause infection; is treatable, rarely life-threatening; get tested if you've been in fresh water as is very prevalent
• Chagas’ disease: Trypanosoma cruzi is a parasite from kissing bugs that infest straw, mud and abode homes in Latin and South America and bite at night; bugs defecate the parasite, which causes infection when it enters the broken skin; travellers often don’t know they have an infection, as it can lay dormant for years, then become life-threatening when it damages heart muscle; is treatable with medication so early detection is advised
Note: This is a guideline only. Always get individualized advice from a doctor or travel health clinic before travelling. For more info, see Statement on Personal Protective Measures to Prevent Arthropod Bites, by CATMAT at the Public Health Agency of Canada, www.phac-aspc.gc.ca. Can be downloaded for free. Lawrence Foster is a Chase Producer for Mantracker on the Outdoor Life Network.