J.T.D. Main, M.D.,DipSportMed

Veterans Affairs Canada

Birds of Paradise, Unit 524

jandjmain@hotmail.com

We have all discovered the joy and adventures of travel, and for the most part, these have been medically uneventful. However, the more we can learn about the possible pitfalls, the more we can take the appropriate steps to avoid unnecessary medical problems. Recently, we have witnessed the sudden appearance of HIV, SARS, West Nile virus, avian influenza, mad cow disease and monkeypox – all diseases that have emerged from animals to infect humans, and so it behooves us to be aware of the changing world-wide scene of new and developing infections – none of us is immune to any of these, whether we are living in Canada or in Mexico.

The following presentation is not intended to be an all-inclusive dissertation on travel medicine. I have tried to emphasize the more important health aspects of living in Mexico for part or all of the year. I have detailed several important and useful links that can be used to obtain more specific information concerning areas in which you might be interested.

A. PREPARATION FOR TRAVEL / IMMUNIZATION / MEDICAL KIT

Even though I feel that health care, dental care and eye care are excellent in Mexico, I suggest check-ups prior to your departure; make sure that you have appropriate health care insurance while you are away. As well, make sure that your immunizations are up to date, and, if you haven’t done so, prepare a medical kit of useful items. Your local travel clinic will be helpful in answering your questions about immunizations, whether it is updating previous immunizations, or recommending a necessary immunization. If you are traveling with medications, make sure they are in their original containers, with your physician’s name on the label.

There is no standard immunization recommendation for any destination. What is required is an individual risk assessment based on many factors, such as the individual traveler's itinerary and health situation, with strict attention paid to the possible risks and benefits of each vaccine. For adult travelers, routine immunizations refer to booster doses of childhood vaccines commonly recommended for use in Canada. The only required vaccine, under the International Health Regulation is yellow fever. In Canada, this vaccine is available usually at your local travel clinic.

I won’t discuss the routine immunizations that I expect everyone to have had over the years, other than to mention that a booster of Tetanus-diphtheria is advised every 10 years, and a booster for polio once in adulthood.

Influenza: a yearly flu shot is strongly recommended for everyone over 65 and in particular, for those with chronic illness; we tend to think of the flu as a relatively trivial infection, but for those with medical problems, this can be a potentially fatal infection. There has also been some concern that we may be due for a worldwide pandemic similar to the Spanish flue of 1918, which claimed millions of lives, many of them healthy young adults. In the southern hemisphere, influenza occurs year round; because travel, especially long plane trips and cruises, increases the risk of respiratory infections, this vaccine is recommended for travelers leaving Canada in the fall.

Hepatitis: there are three types of viral hepatitis – A, B, and C. Hepatitis A poses the greatest risk, but Hepatitis B and C pose the greatest hazard. Hepatitis A is highly endemic through the developing world and is spread person-to-person as well as by contaminated water (including ice cubes), food and shellfish.

Hepatitis C may be transmitted by inoculation (acupuncture, tattooing, blood transfusions, sharing needles), from person-to-person by fecal-oral contact, or by contaminated food or water. Like Hepatitis B, it frequently progresses to chronic hepatitis, which may lead to cirrhosis, and liver cancer; most people with Hepatitis C experience no symptoms and feel quite healthy; symptoms may not show up for 20 years or more. There is no vaccine for Hepatitis C.

There are combined vaccines for Hepatitis A and B, one being Twinrix, which involves a series of 3 doses, given over a 6 month period. I do feel it is most important to receive this vaccine. Many Canadians travel to ‘all-inclusive’ resorts, where they tend to eat and drink everything they have paid for. In spite of promises to the contrary, much more is included than just sand, surf and salsa – viruses and bacteria may also be included.

Other vaccines, like cholera, typhoid, and yellow fever, are not necessarily indicated unless you plan to be traveling in a rural area; your travel clinic will advise you of this. Dukoral is the only vaccine available in Canada to prevent traveler’s diarrhea caused by E.Coli; two doses are taken, orally, 1 week apart. It also protects against cholera, and is recommended primarily for travelers to Central and South America, the Caribbean, Southeast Asia, Africa, and Eastern or Southern Europe. For typhoid, there are 2 types of vaccine available in Canada - one oral, one injectable; both are 50-70% effective and recommended for those staying in endemic areas or venturing off the usual tourist routes. The vaccine for yellow fever is available at a travel clinic.

If you are spending more than 3 months in Mexico, it is a good idea to register with the Canadian embassy. This can be done online, and the web site is provided in the Useful Links section; this site is also an excellent source of information for travel anywhere in the world.

The following is a recommended checklist for a good general medical kit.

Sunglasses; sunscreen SPF = 15 or greater

Insect repellent with DEET 30%

Medic Alert tags for serious allergies or medical conditions

Medication in prescription bottles

Water purification supplies, if not readily available

A brief health history, with a list of your medication, your blood group, & names of physician & next-of-kin

Additional recommended medication:

Cipro 500mg tabs: 6 – 12 tabs, sufficient for 1-2 complete courses of treatment

Imodium and/or Pepto Bismol, although these can be purchased in Mexico

Antihistamines: ChlorTripolon, 4mg, or Benadryl, 25 or 50mg, for scorpion stings, or allergic reactions

Gravol for nausea & vomiting, or dizziness

Tylenol for aches and pains

Antibiotic ointment and eye drops: Polysporin is a good product

Tensor bandage, band-aids, a few 2x2 gauze for a dressing, tape

Thermometer, scissors, tweezers

As many as 25% of those traveling to high-risk areas develop a diarrheal illness. For the most part, this is a self-limited illness; however, 30% of sufferers are confined to bed, and a further 40% are forced to change their itinerary. This is not only a problem in developing countries. We have recently witnessed a number of serious incidents, such as the contamination of the town’s water supply with E.Coli 0157:H7 in Walkerton, Ontario, resulting in 7 deaths, and more than 2,000 sick, as well as a Cryptosporidium infestation of municipal drinking water in North Battleford, Saskatchewan, resulting in 3 deaths. These tragic events shook the foundations of Canadian government control over small, communal water systems, and serve as a reminder of the ever-present risk of exposure to contaminated water. We need to be vigilant; knowing how to identify and prevent problems, when traveling, can go a long way to enjoying one’s holiday.

While the general treatment of diarrhea is the same, regardless of the cause, it is important to understand how to deal appropriately with different situations, as well as to understand the rationale for the different treatments, which will be outlined.

There are both infectious and non-infectious causes of diarrhea; for the purposes of this presentation, we will deal only with the infectious causes, of which there are two broad categories resulting in acute adult diarrhea – community-acquired diarrhea, that is, diarrhea acquired in the community in which one normally lives (an example would be sick patients on antibiotics in hospital acquiring C. difficile infection), and traveler’s diarrhea, acquired during the course of travel.

Infectious diarrhea can be caused by bacteria, viruses, or parasites; the symptoms and treatments are different for each class of infectious agent. However, with all of them, you have to ingest organisms that have contaminated food, water or your fingers. It can be confusing to understand where the different organisms fit into this picture, so I thought it would be helpful to give you a brief description of the more common ones.

The commonest bacterial causes are E. Coli, Vibrio cholera, Salmonella, Shigella,Campylobacter, Clostridium, Difficile. The most common cause of traveler’s diarrhea is E.Coli.

Escherichia coli represents hundreds of strains of bacteria that are considered to be fecal coliform, coming from human or animal intestinal tracts. Ecoli 0157 represents one of the strains, which can cause severe illness; it is spread to humans by healthy cattle, in which this bacteria lives harmlessly; children under age 5 and the elderly are most susceptible. It is present in raw or rare ground meats (beef), or unpasteurized milk or apple cider; livestock manure infecting water sources can give rise to bloody diarrhea, and kidney failure through the production of a powerful toxin (Walkerton!).

Cholera is found in contaminated water or food; the risk is low for most travelers. High-risk groups are those providing disaster relief, or refugee camp workers; the best prevention is strict water and food precautions.

Salmonella is found in raw or undercooked meats, poultry, eggs, unpasteurized milk, alfalfa sprouts.

Typhoid fever, caused by S. typhii, is transmitted by contaminated food, water and also person-to-person contact by the fecal-oral route; it is a serious illness that can be fatal if untreated. Typhoid vaccine is recommended for those traveling in high-risk areas or if staying in rural areas.

Shigella results from fecal contamination of food by humans (lack of hand washing).

Campylobacter is found in animals and birds; it is commonly spread through direct contact with animals, particularly puppies, kittens and fowl; drinking unpasteurized milk, contaminated water, or eating undercooked poultry or meats are other sources of infection; also infection may occur from storing potentially hazardous foods at room temperatures.

Clostridium Difficile is found in the intestinal tract, and is one of the most common hospital infections, frequently related to antibiotic use; it releases toxins, which cause the diarrhea. Treatment is stopping the antibiotic.

Norwalk is associated with outbreaks in nursing homes; it is also linked to banquets, cruise ships, swimming pools, schools, and restaurants. It is very contagious, and spreads by the fecal-oral route; shellfish and salad ingredients in contact with contaminated water, are the foods most often implicated. For you golfers in Ontario who wonder what happened to the watering stations on the golf courses, they have been removed because of a concern with this virus contaminating the water.

Herpes simplex is the virus responsible for cold sores, and genital sores; it may also give rise to diarrhea.

Cytomegalovirus is a member of the herpes virus group, and infects between 50-80% of adults by age 40. For most healthy persons, there are no symptoms and it’s not a serious problem; symptoms are similar to mononucleosis, with fever and mild hepatitis. It is most important in immuno-compromised individuals (following an organ transplant, HIV), pregnant mothers, and people working with children. The virus is shed in bodily fluids, and spreads easily in households or in day care centers.

Adenovirus affects children more than adults; it accounts for about 10% of all acute respiratory infections in children, so is frequent in day care centers and schools; it also causes episodes of diarrhea.

Rotavirus is the most common cause of diarrhea among children, resulting in the death of over 600,000 children annually worldwide! It is acquired through the ingestion of contaminated food or water, and is transmitted through the fecal-oral route; adults can be affected, although the disease is milder.

The commonest parasite infections are Giardia, Crytosporidium, Cyclospora, and Amebiasis.

Giardia, also known as ‘beaver fever’, in Canada, is found in humans and animals, particularly beaver, and is a common source of infection in my area in Canada (cottagers and canoe trippers). Diarrhea can become chronic; this parasite is usually spread through contaminated water, so a caution against drinking untreated surface water (lakes, streams, etc). It can be spread by infected individuals to others (e.g. daycare centers, where children have close contact with one another).

Cryptosporidium is usually contracted by drinking contaminated water, particularly water from surface sources (feces of infected animals).

Cyclospora is transmitted through infected feces by the fecal-oral route, and can then contaminate water or food.

Amebiasis (Entamaeba histolytica) results from the ingestion of fecally contaminated food or water; man is the only reservoir. It can be virulent in Mexico; most infected indigenous people have few if any symptoms; it can occur where human feces are used as fertilizer for crops!

Note: it is rare for travelers to acquire intestinal worm infections serious enough to cause symptoms; however, the same cannot be said of the indigenous population of most developing countries. This therefore is not a common reason for the development of traveler’s diarrhea.

Water is easily contaminated because of either inadequate sanitation systems in many third world countries, or inadequate or improper management in developed countries (farm run-off contaminated with E.Coli, allowed to mix with drinking water in Walkerton!). As well, because of recurrent exposures, the locals have frequently developed an immunity to these organisms that we don’t possess. Note that ice does not kill viruses (hepatitis), bacteria (typhoid) or parasites (Giardia), so that ice cubes should be made from ‘clean’ water. Be cautious when drinking water found in pitchers in hotel rooms unless you have checked to make sure that it is ‘safe’.

Shellfish are natural reservoirs of bacteria and viruses because they filter large volumes of seawater.

Salads and uncooked fresh vegetables are risky because of the possibility of their contamination during transit, storage or preparation; be aware of the widespread use of human excrement (‘night soil’) as fertilizer in the tropics. Vegetables can be made safe if they are cooked and eaten hot.

Rice that has been reheated for use at another meal may be contaminated with bacteria, which multiply rapidly, if the rice is only warmed, and inadequately cooked.

Unpasteurized milk products (including yogurt and ice cream) may contain bacteria, which produce disease such as tuberculosis, brucellosis and toxoplasmosis; eating these products from street vendors can be risky.

Your own hands may be the source of food contamination. After a busy day of shopping at the tianguis, or Mercado, there is a significant chance that your hands will contain a multitude of organisms that are not ‘friendlies’.

Traveler’s diarrhea becomes significant when it lasts for more than 48 hours, and is associated with fever, dehydration, or blood or pus in the stool. Review of the literature reveals inconsistent and sometimes contradictory advice, confusion and controversy with regards to the management; what follows are the most recent recommendations.

Adopt the motto: ‘COOK IT, PEEL IT, or LEAVE IT’.

Good hand washing before eating is obviously very important.

The safest foods are those that are well cooked and eaten steaming hot. Remember, microwaving may not destroy bacteria. Any raw foods could be contaminated and are unsafe; avoid using leftovers – food spoils rapidly due to heat and humidity, and minimal contamination can lead to dangerous bacterial levels within a few hours. Note that re-heating food may not destroy certain heat-resistant toxins produced by bacteria, even though the bacteria may be killed by higher temperatures.

Fruits and vegetables, which you wash with safe water and peel yourself, are safe to eat. Avoid fresh fruit with broken skins. Watermelon and cantaloupe should be avoided because unsafe water is sometimes injected into them to make them weigh more.

Avoid ice cream, custards, meringues, unbaked pastries and soft cheeses. Avoid unpasteurized milk products (including yogurt and ice cream); milk may be boiled, although this destroys much of the protein. Powdered milk products are safe.

Avoid buffets, especially foods made with mayonnaise, cream or custard; also, cold buffets are risky if held on an open terrace, because of flies. This can be a tough one, as we’ve all eaten at salad bars! Be cautious! If it looks like the salads have been there for a while, you might want to pass on them!

Avoid raw, marinated or smoked fish, as they may contain parasites. Ceviche (marinated raw fish) has been associated with cholera outbreaks. Some species of fish and shellfish can contain a poison, even if well cooked (ciguatera).

Ciguatera is caused by eating fish which contain a toxin, produced by plants in some tropical waters; the toxin becomes more concentrated in larger fish, and there are no tests to detect the toxin; it is not destroyed by cooking or freezing. Symptoms include abdominal pain, nausea, vomiting, diarrhea, slow heart rate, numbness and tingling in the face and extremities, as well as severe itching, joint and muscle pain; symptoms last 2-3 weeks, but may persist for years.

So, don’t eat large predatory reef fish, such as grouper, snapper, jack, or barracuda. Eat fish in a reputable restaurant; avoid fish considered to be harmful by the local population.

Food Preparation: It is important to use safe water for drinking, washing fruit and vegetables, and in making ice cubes. Treatment with iodine products is preferable, as they are effective against bacteria, viruses and bacteria; chlorine products may not kill Giardia (beaver fever) – a parasite found all over the world.

Treating water. Drink only water that has been bottled, or boiled or disinfected with chlorine or iodine. If you choose to boil the water, it is sufficient to bring the water to a rolling boil, then cool and store it.

Our drinking water, at Birds, is first chlorinated in San Antonio, then, the potable water is directed through a reverse osmosis system (a water purification system that uses a semi-permeable membrane to allow purified water to pass through without allowing bacteria and contaminants to pass); finally, the water is treated with ultra violet light, at each building block.

There are a number of chemical products that are available locally – we have used Biopur, and Microbicida; these can be used for cleaning fresh fruit or vegetables, as per the instructions. There are a number of other products, which are essentially either iodine or chlorine-based; tincture of iodine 2.5%; 5 drops/liter, and let sit for 30 minutes; (if the water is cloudy, add 10 drops). Halzone tablets (chlorine) are available in Canada at pharmacies and sporting goods stores (for cottagers, canoe trippers). Household bleach (chlorine) 4-6% is also effective, although less reliable than iodine; use 2 drops/liter of clear water (4 drops/liter cloudy water).

Portable water filters consist of a fine filter, which removes bacteria and parasites; few, if any, have pore sizes small enough to keep out tiny virus particles, which produce hepatitis. Iodine is used to remove viruses; chemicals require a charcoal filter for removal.

I would recommend avoiding meals bought from street vendors, as the level of hygiene practiced in the preparation of the food is questionable at best; there is no point asking for problems!

These precautions become second nature after a while; I have to say, after all this, that we’ve really enjoyed our culinary experiences in Mexico, whether it’s trying out a new restaurant or checking out the mercado or tianguis for the best produce and best price! We appreciate being able to buy fresh produce, meat, fish, and enjoy the adventures of eating in Mexico. It’s impossible to follow all these guidelines all the time, and occasionally you have to make a judgment call that can prove to be an incorrect decision. However, we all need a heightened sense of awareness. These precautions and guidelines are applicable wherever you might be. BUEN PROVECHO!!!

‘One can do everything wrong with respect to food and water, and still remain well. On the other hand, one can do everything right and develop diarrhea. Whether or not one stay healthy depends somewhat on the body’s defenses against infecting organisms and to a large extent on good luck!’ Remember that ‘travel expands the mind … and loosens the bowels!!’ 

The milder self-limiting diarrhea may not require any treatment. However, there are a number of things you can do at the outset to minimize symptoms. Self-medication, in otherwise healthy people, is safe. However, those with the following presentations require aggressive medical evaluation and monitoring: profuse watery diarrhea lasting more than 24-48 hours, diarrhea associated with fever higher than 38.5C (101.3F), severe abdominal pain, or blood or pus in the stool.

1. Anti-diarrheal drugs:

There are non-antibiotic products that are effective in reducing the frequency and intensity of the diarrhea.

Imodium (Loperamide 2mg) slows bowel contractions and reduces diarrhea without affecting the cause. Imodium is safe, and effective, with no abuse potential; it improves symptoms (cramps, urgency), and when used with antibiotics, significantly shortens diarrhea states. The dosage is two caps (4mg) to start, then one after each loose movement, up to a maximum of 8 caps daily. I would suggest Imodium to start, as it is a non-narcotic, and frequently quite effective.

Pepto-Bismol is more effective than Imodium for nausea, but less effective for diarrhea and cramps; it has an antibacterial effect, but does not reduce bowel motility; you can take two tabs (or 1 ounce) every ½ hour, up to 8 doses daily. Note that Pepto-Bismol contains salicylate (the component in Aspirin), and should be avoided by someone on blood thinners.

Lomotil 2.5mg tab, is also another agent, somewhat stronger than Imodium, that can be very helpful; it requires a prescription in Canada, but can be purchased, by requesting it at the pharmacy in Mexico. The recommended dosage is two tabs three to four times daily.

Probiotics, such as Lactobacillus acidophilus, found in yogurt, maintain or restore normal gut flora. There are two types of human bacteria – the ‘good’ or friendly types, and the ‘bad’ or harmful types. Each human requires about 85% of good bacteria to nourish the body and keep it healthy. Although the body is created with the proper ratio of good and bad bacteria, our modern lifestyle frequently alters this ratio; for example, antibiotics can kill both good and bad bacteria, allowing bad bacteria to multiply, disturbing the delicate balance. Other things like steroids, stress, an unhealthy diet, as well as toxins and proliferation of bad bacteria from contaminated food or water, can also disturb this balance. A prolonged episode of diarrhea can be helped by adding yogurt, or Lactobacillus, which can be purchased in capsule form, to your treatment regimen.

2. Rehydration

During a severe bout of diarrhea, you frequently not only feel unwell, you don’t feel like eating or drinking. It doesn’t take long to become dehydrated through the loss of fluids and electrolytes (sodium, chloride, potassium); it is important to replace these before this loss becomes problematic. If you want, you can prepare your own fluid replacement by following this rehydration formula;

Prepare two separate glasses of the following:

Glass number 1:

Orange, apple or other fruit juice (rich in potassium) = 8 ounces

Honey or corn syrup (glucose for absorption of necessary salts) = ½ teaspoon

Table salt (sodium and chloride) = 1 pinch

Glass number 2:

Water = 8 ounces

Baking soda (sodium bicarbonate) = ¼ teaspoon

Drink alternately from each glass until thirst is quenched; supplement as desired with carbonated beverages, water or tea.

There are also commercial rehydration formulas, such as Gastrolyte, which are expensive, and I believe, don’t usually warrant the cost in an otherwise healthy individual; frequently, if you are able to keep down fluids, sticking to clear fluids, no matter what kind (lemonade, herbal tea, fruit juices, soups), usually will work.

3. Diet

There is some controversy as to when to resume solid food; if the diarrhea is associated with nausea and vomiting, I would suggest staying on fluids only; otherwise resume eating solid food, guided by your appetite; start with small lighter meals. It is still recommended to restrict milk and dairy products for 1-2 weeks following a severe episode of diarrhea, because the enzyme that breaks down lactose is often diminished by damage to the bowel lining; milk or milk products are then not digested properly, giving rise to excessive gas, bloating and further diarrhea. Spicy foods, alcohol and caffeinated beverages are best avoided during the early convalescent period.

4. Antibiotics:

Community-acquired diarrhea is frequently viral, and so the routine use of antibiotics is not recommended. Traveler’s diarrhea, however, is frequently bacterial; the resulting illness can be severe and prolonged; the early use of antibiotics is now recommended!!

Quinolones are the empiric antibiotics of choice:

Cipro (Ciprofloxacin) 500mg twice daily for 2-3 days, depending on the severity; this can be safely combined with Loperamide.

Alternates are Noroxin (Norfloxacin) 400mg one daily or Septra (Trimethoprim/sulfamethoxazole) one double-strength, or two regular strength tabs daily.

My recommendation is to start with Imodium and Pepto Bismol on the first day, unless you also have a fever; if the diarrhea doesn’t seem to be improving by the second day you might consider adding the antibiotic. However, seek medical attention if there seems to be no improvement after 48 hours, and there is persistent, severe vomiting, dehydration, persistent fever, or blood in the stool.

Diarrhea persisting for longer than 7 days may be due to parasites, such as Giardia, amebiasis, or cryptosporidiosis, and will require evaluation by a health care professional.

C. SUN-RELATED PROBLEMS: ‘SLIP, SLAP, SLOP’ 

Overexposure to the sun’s ultraviolet rays can have detrimental effects not only on your skin, but also on your eyes; one needs to be concerned about premature aging of the skin, with subsequent increase in wrinkling, and the possible development of skin cancer. UVB is responsible for sunburn and the development of skin cancers, while UVA is responsible for the aging changes of the skin. Sun damage is cumulative – it builds up with each exposure. Clouds do not offer total protection from sun exposure; you get sun damage in the shade if you are near reflective surfaces. Note that the number of cases of skin cancer in Canada has increased by two-thirds since 1990.

As one ages, there is a tendency to develop brownish lesions, called actinic keratoses. These skin lesions are also called solar or senile keratoses, and are precancerous growths that develop from prolonged cumulative sun damage; about 50% of people over 50 have actinic keratoses. They are potential precursors of squamous cell carcinoma (about 10-25% of them will become cancerous); they look like a rough spot which may look red or brown, and eventually become scaly, scabbed or crusted; they are most common on sun-exposed skin of pale-skinned, blue-eyed, fair-haired people. If this lesion begins to itch or bleed, it is possible that a squamous cell carcinoma is beginning to develop.

Actinic keratoses needs to be differentiated from seborrheic keratoses, which can be mistaken for cancerous growths; they feel waxy and appear to be ‘stuck on’; they also tend to appear in middle age, and do not need to be treated.

Basal cell skin cancer is the most common type of skin cancer; it grows slowly, and also appears on areas of the body exposed to sun. They tend to look like either a small bump with a pearly appearance, that may bleed, or crust over, or a red tender flat spot that bleeds easily.

Squamous cell carcinoma is the second most common skin cancer, and usually appears as a firm red bump, or a patch of skin that feels scaly, bleeds, or develops a crust; as they get larger, they can spread to nearby lymph nodes.

Malignant melanoma is a serious form of skin cancer that can quickly spread. A ‘mole’ that turns color, becoming darker brown or black, begins to grow, become irritated or bleed, requires early diagnosis and treatment.

The risk of skin cancer is higher for people who have light-colored skin, work, play or exercise in the sun for long periods of time, or who have had several blistering sunburns as a child, or a family history of skin cancer.

Tanning is not healthy; over time, tanned skin becomes more wrinkled and blotchy. A tan is a sign of damage to your skin; it does not protect you from sunburn. Tanning lamps emit UVA radiation and produce a deeper dermal tan, which will likely not protect against more superficial UVB effects of solar radiation.

Ultraviolet light is the component of sunlight most responsible for eye damage, which may present itself as cataracts (clouding of the lens) or macular degeneration (breakdown of the part of the retina that focuses images); sunglasses that block UV rays are the obvious answer.

Prevention by avoiding midday sun (from 10am to 4pm), using a sunscreen of SPF 15, wearing a hat, and if you are prone to sunburn, clothing that will cover exposed arms and legs.

Note that sunscreens are products that absorb, reflect, or scatter ultraviolet radiation; sunblocks are opaque products, which provide a microfilm barrier that blocks both UVA and UVB radiation. There is a 78% reduction in lifetime incidence of nonmelanoma skin cancers with regular use of sun protection products!

SPF = sun protective factor, an SPF of 15 allows you to stay in the sun 15 times longer than without the sunscreen before you burn; after reviewing the literature, I concluded that anything with an SPF greater than 15 was not likely to be more effective; in other words, a product with SPF 15 is adequate.

To summarize:

SLIP on clothing to cover arms and legs.

SLAP on a wide-brimmed hat.

SLOP on a sunscreen with SPF 15 or greater; look for ‘broad spectrum’, meaning that the sunscreen protects against both UVA and UVB ultraviolet rays; reapply every 2 hours, or after swimming or exercise.

Wear sunglasses with UVA and UVB protection.

D. HEAT – RELATED PROBLEMS:

Overexposure to heat, particularly with humidity, can lead to a heat-related illness, which can be as mild as heat cramps, or as severe and potentially fatal as heat stroke. The body’s adaptation process to heat can take from one to several weeks. The danger of heat injury increases with humidity and age, or if one has ingested alcohol or certain drugs. In hot climates, the body’s main defence against heat is perspiration. IN THE ABSENCE OF STRENUOUS EXERCISE, the average person must replace at least 1.5 liters of fluid per day in hot weather; by the time you feel thirsty, you are already becoming dehydrated, sweat contains a high concentration of salt, which also must be replaced by eating salty foods, or adding salt to your food.

Heat cramps are painful muscle spasms due to fluid and salt imbalance and frequently occur after strenuous exercise in hot weather. A high level of humidity, recent ingestion of alcohol, or being over the age of forty may increase the likelihood of developing heat cramps. For those who are exercising (playing tennis, golf, hiking) in hot weather, fluid and salt replacement are paramount; Gatorade is a good commercial preparation that addresses this issue. Treat by getting the person into the shade; have them gently stretch the affected muscle; encourage them to drink tomato/orange juice or Gatorade (to replace electrolytes) – don’t overdo the water, since this may further dilute the salt levels in the body; sponge down with a cool damp cloth.

Heat exhaustion is characterized by excessive sweating, fatigue, dizziness, headache, nausea, and sometimes by vomiting, cramps and fainting; the initial signs occur when dehydration occurs. This is a more urgent situation that requires replacement of fluids and salt, as well as removing the individual from direct sunlight and cooling him down.

Heat stroke is quite dangerous, potentially fatal, and requires emergency treatment. An older person may be affected even without exercising. The person has lost the ability to sweat, the body temperature becomes dangerously elevated, and if not treated, the person may become comatose and die; this situation usually requires emergency medical attention, which includes rapid cooling, in a hospital setting. One way that this condition can be differentiated from heat exhaustion is that the person’s skin is hot, flushed and very dry – his body has lost the ability to sweat; the individual will have a rapid pulse and a fever, up to 106F; brain damage may occur.

Certain drugs, like antihistamines, can increase the susceptibility to heat stroke, which is usually of abrupt onset.

E. HIKING in the SIERRA MADRES:

Hiking in the Sierra Madres is an activity that I have enjoyed over the past several years. To my mind, there is nothing more spectacular than to be able to stand at the top of a peak and view the lake in its entirety, from Jocotopec to La Barca, to take in the splendour of the Colima volcano, and, in early March, the purple blossoms of the jacarandas. The satisfaction at having ‘made it’ can only be shared with and appreciated by fellow hikers!! What I also find enjoyable are the different types of terrain to be found in Mexico; I recently had the chance to hike in the Copper Canyon area, around Chihuahua, and, not only was it spectacular and very different than around Lake Chapala, I was also reminded of Algonquin park, near our home in Canada, with the pines, rock formations, and bird life. For those of you that enjoy the adventure and exploration possibilities, the sky’s the limit!

However, serious hiking requires some forethought and planning; one has to be aware that this is not a totally benign activity, and that if something untoward happens, you can be several hours from help. For starters, you should be in reasonably good shape. Remember that you’re starting from an elevation of about 5000 feet, and that the highest elevation in the area is around 8000 feet. Because of this elevation, there is less oxygen available to muscles (including the heart muscle), and it doesn’t take long to become aware of this – you become quickly short of breath, your heart pounds, and you find that you have to proceed at a slower pace. For those with medical conditions, whether this might be heart or lung disease, arthritis, or diabetes, it’s a good idea to start out with walks into Ajijic, gradually going from 30 minutes, and working up to 60-90 minutes; this will give you some idea whether you can tolerate adding some mountain climbing to your regimen. If you do have medical conditions that are not stable, it is not wise to attempt any significant amount of hiking.

It is important therefore to become acclimatized; for beginners, you can start with a relatively easy hike to the chapel above the top of Colon street in Ajijic, an elevation of about 500 feet that should take you from 30-45 minutes; if you feel up to continuing, you can take a number of trails from this point, ending at the ceremonial grounds, or at the Tepalo waterfall; for the really hardy and adventurous – the top of the Chupanaya; however, if you are planning a longer hike, make sure you go with an experienced hiker.

What hiking preparations do I recommend? First of all, layer your clothing, as you usually start in the cool of the morning, and by noon, the temperature has increased significantly. Good hiking boots, a pack, and plenty of water, are essentials. Anything other than hiking boots just don’t provide adequate footing, so these are definitely a wise investment. You can either use a fanny pack, or back pack, depending on your preferences. It’s most important to drink frequently, before you notice yourself getting thirsty – if this happens, it indicates that you are already mildly dehydrated; alcohol and caffeinated drinks are poor choices because they increase urine production. Make sure that you have enough water; if you’re hiking for 6-7 hours, you will likely need at least 2 liters. I personally like to use a walking stick; I find it most helpful particularly on my way down – that’s the time a lot of stress is placed on the knees; two walking sticks can also be used in fashioning a stretcher, if this situation arises

A first aid kit is also a good idea – even if it only contains bandages, tensor, and antihistamine. Bring your camera and binoculars; you will see different hawks, vultures, falcons, although not much in the way of wildlife. Optional items are a GPS and/or compass; in our area, it is not difficult to orient yourself to the lake.

Gigi has assured me that there are no African killer bees in the area; there are some scorpions and the very occasional snake, so you need to watch where you’re sitting! It’s a good idea to let someone know where you are hiking and when you are expected to return. Don’t hike alone.

For the sake of completion, I would like to mention altitude sickness, or acute mountain sickness, which is seen in people who have recently arrived at high altitude or have just gained altitude. It is caused by the body’s attempt to compensate for the lower oxygen levels that occur at high altitude; about 25% travelers who live at sea level experience altitude sickness when visiting destinations at elevations over 7500 feet; above 10,000 feet, 50% of travelers are affected! Headache, nausea, and light-headedness can progress to the more serious and potential fatal syndromes of HAPE (high altitude pulmonary edema, and HACE (high altitude cerebral edema); the variety of medical problems which may occur, are related to lowered blood oxygen with increased altitude, and the body’s attempt to compensate for this lower oxygen level. This is not a problem that I would expect a hiker to experience in our area, but someone who is a serious hiker, should be aware of this potential problem. The most effective prevention is graded ascent, adequate hydration, and appropriate use of medication (Diamox); ‘getting in shape’ prior to climbing doesn’t provide protection against altitude sickness; the definitive treatment for severe altitude sickness is immediate descent.

Hikers in our area are usually below the significant altitude. However, I have had the personal experience of developing mild acute pulmonary edema when I flew into Cuzco, Peru, at an altitude of over 11,000 feet, and I can attest to my unhappy state of affairs, involving shortness of breath, extreme fatigue with minimal exertion, insomnia, and cough. This is correctable with Diamox, which is a diuretic, so that anyone anticipating traveling to an area where they may be at an altitude of over 10,000 feet, would be advised to have a supply of Diamox.

These problems usually don’t occur if you are below 8,000 feet, and will usually settle with a few days of acclimatization.

F. BITES / STINGS

El alacran; The common striped scorpion is the most common and widespread scorpion in North America, and is often found indoors. Most kinds of scorpions deliver stings that are painful, like a wasp or bee sting, but not dangerous unless one is allergic; most reactions include intense burning, swelling and numbness for several hours. Only the bark scorpion, found in Arizona, New Mexico and Mexico, is a dangerous threat to life; I’m not aware that they are a significant problem in our area. Around houses, scorpions hide in crawl spaces, or inside clothing (shoes) where they have crawled to avoid sunlight.

Always shake out shoes, socks, pants and other clothing before dressing; check bedding and towels before using. An Epipen is a must for those with previous severe allergic reactions to stinging insects, such as wasps or bees; use it immediately after being stung, and then seek medical attention at once. Icing the bite site, and elevating the involved extremity will provide some comfort. Most people will have local reactions only; if, however, systemic symptoms occur, such as a rapid heart rate, breathing problems, trouble swallowing, restlessness, or involuntary muscle jerking, you will require hospital treatment. The bottom line is that, unless you have severe allergies, a scorpion bite is essentially an unpleasant inconvenience.

Antihistamines can also minimize the reaction. Locally, there is a product called Avapena (chloropiramina), usually available at the guardhouse, although, when I checked, it wasn’t! This is comparable to Chlor-Tripolon 4mg (chlorpheniramine) or Benadryl 25 or 50mg (diphenhydramine), which you can purchase over the counter in Canada. You can also use INSECTRIN to spray around doors and windows to discourage entry; your unit is also fumigated several times a year.

A few words concerning mosquitoes: they carry many diseases – malaria, dengue fever, yellow fever, Japanese encephalitis. Malaria is the most important – one strain, Plasmodium falciparum may be fatal if improperly treated. There was an outbreak of dengue fever in Puerto Vallarta, with deaths of young healthy people, in 2003; dengue is carried by mosquitoes that bite after sunrise and before sunset. The main defense against many of these diseases is prevention – clothing that covers arms, legs, the use of DEET 30%, use of a bednet if necessary, or a closed room; remember, for malaria, mosquitoes are most active from dusk to dawn. Check with your travel clinic as to the prevalence of these, and if they recommend medication, it is started before departure, taken during the time of your stay, and for a time after returning home; most cases of malaria in travelers occurs in people who have stopped taking their medication too soon!!

DEET/sunscreen combinations should not be used because DEET can decrease the efficacy of sunscreens by up to 34%. If the application of both products is required, apply the sunscreen first, allowing it to penetrate the skin for 20 minutes before the application of the DEET.

The following personal measures are very important: limit outdoor exposure from dusk to dawn, use protective clothing, use an insect repellent containing DEET (eg Muskol), use an insect net at night (when necessary). Antimalarial medications lower your risk of becoming ill; they do not prevent an infection; they merely suppress it. SEEK IMMEDIATE MEDICAL CARE FOR ANY FEVER DURING AND AFTER TRAVEL TO A MALARIA AREA (up to a year, but usually within the first three months)!! Malaria is preventable!!

G. USEFUL LINKS:

This site provides country-specific information, including travel warnings, health threats and a listing of Canadian embassies/consulates, as well as general advice about travel safety; you can register on-line, at this site, with the Canadian consulate.

Don’t Drink the Water, a Canadian publication co-published by the Canadian Public Health Association and the Canadian Society for International Health