Canadian Consulting Engineer

Health Watch

January 1, 1999
By Mark Wise, M.D.

Correct me if I'm wrong, but when most engineers were in university I doubt that they saw their future profession as a ticket to see the world. Over the past decade, however, much has changed. Not onl...

Correct me if I’m wrong, but when most engineers were in university I doubt that they saw their future profession as a ticket to see the world. Over the past decade, however, much has changed. Not only has it become necessary to seek work abroad, but also, due to the growth of economies in many less developed countries, there has been no shortage of work to seek. As well, I suppose the great expertise of Canadian engineers has helped to open up these international opportunities.

Engineering graduates from Canadian universities are now building airports in Burma, cable lines in China, gold mines in Mali, and trying to clean up the air and the water in India. While this international diversification has its benefits, it also has its risks–particularly health risks. A hard hat and steel-toed boots will not protect you from malaria, dengue fever and Montezuma’s Revenge. Each engineer, and his or her employer, must be prepared for the particular health risks of working abroad.

There is no shortage of information regarding these health risks, but unfortunately, much of it is inaccurate, conflicting or misleading. So let me now try to prepare you for that next great adventure abroad, with an aim towards keeping you healthy.

It’s all about risk

Though I hate to sound like an insurance salesman, a lot of what I do as a travel medicine specialist is to evaluate risk. Each individual’s risk is different, and the factors that I take into consideration include:

–the person’s destination(s)

–length of time to be spent abroad

–the time of year

–whether he or she will be working in an urban or rural area

–the nature of the work he or she will be doing and their particular exposure

–any underlying personal medical problems and medications.

To make a long story short, the engineer who has just got over his coronary bypass and is now being sent to the jungles of Borneo for two years to build a dam might be at higher risk than the lucky new graduate just off to witness the opening of a new airport in Hong Kong.

Do I need any shots?

An ounce of prevention is worth a pound of cure, and who wants to get typhoid anywise? Pre-travel inoculation effectively reduces or totally prevents many infectious diseases that are encountered abroad, especially in the tropics. Some confusion surrounds the issue of “shots,” and you may not hear the same answer to your questions twice. Perhaps the easiest way to look at the myriad of vaccinations available is to divide them into those that are:

routine–vaccines with which all Canadians should be kept up to date (e.g. tetanus, diphtheria, polio)

required–vaccines needed to enter a foreign country (e.g. yellow fever)

recommended–vaccines suggested for each individual’s protection depending upon their risk factors (e.g. hepatitis A and B, typhoid, meningitis, Japanese encephalitis, rabies, influenza).

The travel medicine specialist, after taking a careful medical and travel history, will advise the patient which inoculations would be worthwhile. However, the doctor only advises, the patient decides which shots he or she will receive.

Hepatitis A is the most common “tropical” disease for which we have an effective vaccine. The disease is a viral infection of the liver passed via infected food or water. It is not unusual for the infection to occur even in people staying and eating in first-class hotels. Symptoms include fever, fatigue, nausea and jaundice, or a yellowing of the skin. While rarely fatal, the symptoms can be quite debilitating for more than a month.

Hepatitis B may cause similar symptoms to Hepatitis A but it has the potential to be much more serious in both the short and long term as some people develop chronic infections. It may be passed through contaminated blood or blood products, and unprotected sex.

Typhoid fever is transmitted in the same way as Hepatitis A. Though it occurs much less frequently than that disease it is potentially a lot more serious. Symptoms include fever, headache, cough, fatigue and intestinal problems, including bleeding. It is usually treatable with antibiotics. Both oral and injectable vaccines are available against this infection, but neither provides perfect protection.

In general, all the vaccines we use are safe and well tolerated. Yes, your arm might be sore for a day or two, but you needn’t expect much more. Several vaccines may be administered simultaneously, so even for the last-minute traveller, protection is available.

There is no shortage of frightening books and sensational movies which illustrate the dangers of emerging diseases like the Ebola virus and Lassa Fever. While these make for good reading and watching, in fact they pose very little risk to the average travelling engineer. Much more important is that you take precautions to avoid the more common and familiar threats below.

Malaria, mosquitoes and more

Most of us are familiar with mosquitoes and other biting insects here in Canada. Fortunately here they are only a nuisance, but in most tropical countries, they may be the vectors for infections such as, yellow fever, dengue fever, Japanese encephalitis, and most importantly, malaria.

Personal protective measures are extremely important in reducing the risk of these infections. Consider taking the following precautions.

Limit your outdoor exposure between dusk and dawn, which is when the malaria mosquito bites (not always practical).

Wear long sleeves and pants (not always comfortable).

Sleep under an insect net, which may be impregnated with the insecticide permethrin.

Use DEET-containing insect repellents.

Malaria is the most important infectious threat to those working in the tropics. There are four strains of this parasite, and one of them, P. falciparum, has become resistant to several antimalarials. It is the only strain which may prove fatal. It is widespread throughout sub-Saharan Africa, in the Amazon Basin, in Asia and in rural areas of Southeast Asia. More than two million deaths occur worldwide from malaria each year, and the number of Canadians becoming infected has climbed to more than 1,000 annually. A few Canadians even die each year from this largely preventable and treatable disease.

The symptoms of malaria are fever, headache and chills, symptoms which may resemble the flu–and almost any other ailment. The illness may occur within eight days of exposure, though the parasite may also lie dormant in the liver for weeks or months and not cause any symptoms until you are comfortably back at home watching NFL football on T.V.! Malaria may prove fatal in as little as three days if not quickly diagnosed and properly treated.

Antimalarial medications can greatly reduce the risk of becoming ill with the disease. They act by killing the parasite as it enters your red blood cells, thus suppressing any symptoms, though not truly preventing infection. The drug mefloquine (Lariam) is currently recommended for most travellers going off to malarious areas, though there still are areas such as rural parts of Central America and the Middle East where the older drug chloroquine remains effective.

Mefloquine is well known for its side effects, perhaps better known than it deserves to be. The side effects include stomach upset, dizziness, insomnia, vivid dreams, anxiety and, sometimes, depression. While these effects may occur in up to 15 per cent of those who take the medication, they are usual mild, tolerable, and self-limited. More serious side effects, such as seizures and psychosis, are exceedingly rare. Keep in mind that mefloquine is probably the most effective antimalarial we have at this time. There are alternatives, however, such as the above-mentioned chloroquine in combination with paludrine, or doxycycline, but these too have their potential problems. For those who would rather not take regular prophylactic antimalarials, a nurse or doctor might recommend various self-treatment regimens.

It is absolutely crucial that engineers going off to work in malarious areas fully understand the disease, how to prevent it and the treatment.
Anyone working in a malarious area must be aware that if they develop a fever while they are away, or upon their return, they must seek medical attention–make that good medical attention–immediately.

Dengue fever is another mosquito-borne infection which has become increasingly prevalent in many areas of the tropics, including the Caribbean. The offending mosquito prefers to bite during the day in this case. Dengue’s victim will usually suffer from a high fever, a severe headache and horrible pains in the bones, hence its nickname “breakbone fever.” There is no specific treatment other than acetaminophen, and no vaccine, so once again, avoiding the mosquito is highly worthwhile.

Montezuma and me

While not always the most serious medical problems, illnesses transmitted through contaminated food and water will be the most common malady that you might encounter. Traveller’s Diarrhea, also known as Montezuma’s Revenge, Delhi Belly or Seeping Slickness, will strike at least 30 per cent of travellers. Working off in some remote part of Tadjikistan for six months probably boosts this percentage up a few points! Typhoid fever, hepatitis A and E are other infections lurking in the kitchen.

If you are working abroad, you must learn to be proactive when it comes to what enters your stomach. “Boil it, bottle it, peel it, cook it … or forget it!” should ring in the ears of everyone heading off to countries where the quality of the food and water might be less than adequate. Iodine, which is available in liquid or tablet form, is an effective way to purify your drinking water. Several good water purifiers are available to do the job. Cleanliness is next to godliness, so don’t forget to wash your hands!

Unsanitary conditions are not restricted to the tropics, but are also found in Eastern Europe and the states of the former Soviet Union. This is not to suggest you practice total culinary paranoia, considering that local conditions or common courtesy does not always allow you to pull out the handy water filter when dining with your local host! Let common sense rule.

In most instances, a case of the “runs” can be dealt with without seeking medical care. If you become ill, stop eating and try to hydrate yourself with clear and clean fluids. Imodium is an antiperistaltic, which means it will slow down the rate at which things pass through your bowels. This is generally a good thing, especially when local toilets leave something to be desired. Most, though not all, bowel infections are caused by bacteria. Hence, the addition of an antibiotic such as Cipro will likely further shorten your suffering.

Personal safety

While infectious diseases cause illness and disability, they are not usually killers. Motor vehicle accidents, however, are. We may be suffering from “road rage” over here, but things are even worse in less developed countries. Poorly maintained cars and buses, a scarcity of seat belts, pockmarked roads and a lack of lighting at night, all contribute to the dangers. It is probably best to avoid travelling after dark in rural areas whenever possible. If a local driver is available, take him! At least look for a seat belt. And remember, alcohol and driving don’t mix, anywhere.

Personal security is another issue which to keep in mind. Muggings, kidnappings and bombings are becoming more frequent in many countries. As the Canadian government puts it, “There remains the risk of being in the wrong place at the wrong time. We urge Canadians to be vigilant at all times.”

Of all the deaths that occur in travellers abroad, cardiovascular deaths lead the way. What this means is that you or your employees should be in as good health as possible before embarking on an overseas assignment. An adequate supply of medications, a good first aid kit, and the name of a local doctor, might all be indispensable.

Let’s not beat around the bush when it comes to sexually transmitted diseases. The risk of acquiring HIV and numerous other venereal infections in most less developed countries is much higher. Higher too is the likelihood of unsafe, irresponsible and risky behaviour. Condoms or abstinence are your only protection.

There are many other issues important to the travelling engineer. Perhaps jet lag is your greatest problem. Or motion sickness. Are you digging a mine in the Andes at 4,500 metres? Then you need to be prepared for altitude sickness. For longer term travellers, the effects of culture shock can sometimes be debilitating. The list goes on and on.

Preparing for an international assignment need not be a lengthy process, but it must be thorough. Having a travel medicine specialist make a careful assessment of your individual risks is the best way to begin. Through pre-travel inoculation, paying careful attention to food and water, avoiding insects, attending to your personal safety–and with a bit of good luck–working abroad should be a productive and healthy experience. CCE

Dr. Mark R. Wise, M.D., D.T.M.&H (Lond.) is a family physician and specialist in travel and tropical medicine at The Travel Clinic in Thornhill, Ontario. He is the editor of The Travel Clinic News.


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