Travel to Developing Countries - Travel Precautions

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Of greater concern are studies suggesting that the prolonged time (8 hours or more) spent in the confined space of an airplane plus the close proximity to co-passengers from the entire world may facilitate the spread of serious contagious diseases, such as tuberculosis and SARS. The CDC and World Health Organization now have guidelines on when and how to determine the need for preventive treatments after possible exposure to infectious organisms. (Recirculated air, which is now common in new aircraft, does not increase the risk for respiratory infections.)

Preventing Jet Lag. Crossing time zones can throw off the body's natural rhythms, especially when travelers fly from west to east. But jet lag can be minimized. A few days before long flights, adjust sleeping and eating patterns:

• When traveling west, travelers might avoid outdoor light after 6 p.m.
• If traveling east, travelers might begin going to bed earlier a few days before the trip and avoid outdoor light until 10 a.m.
• If possible, flights should be completed well ahead of an important event requiring concentration.
• If crossing multiple time zones, the traveler should schedule overnight stopovers.
• The traveler should drink plenty of fluids, but avoid alcohol and coffee, which increase fluid loss.

Melatonin, a natural hormone associated with light changes, may help people recover from jet lag. Some people report good results by taking it on the day of departure a half hour before the expected sleeping time in the arrival city. Travelers might also ask their doctors about short-acting benzodiazepines ("sleeping pills") such as lorazepam (Ativan); benzodiazepine-receptor agonists such as zolpidem (Ambien) or eszoplicone (Lunesta); alprazolam (Xanax); or temazepam (Restoril). They have been known to cause short-term forgetfulness and other side effects, and should be tried at home before traveling.

Cruise Ships

Reports of illnesses aboard cruise ships, particularly gastrointestinal problems from contaminated food, have alarmed many travelers. A sanitation program conducted by the U.S. Public Health Service should significantly cut the risk for such problems. Cruise ships are inspected twice a year and are then rated. The CDC provides ratings to the public for all ships sailing from U.S. ports. At this time these ratings are the only guide for a healthy cruise. Meanwhile, cruise-ship travelers should avoid eating eggs and shellfish to help protect against diarrhea.

Aside from sanitation, health problems in general are common on cruise ships. A study of one major cruise ship reported that nearly 30% of the passengers were treated for skin disorders and 26% for respiratory problems while on board. The highly contagious norovirus, brought on board by one passenger, can quickly spread throughout the ship. Flu outbreaks sometimes occur even in summer. Older people who have not been immunized the previous flu season should ask their doctor about flu vaccinations. They add no value for people who had been previously immunized.

Preventing Skin Disorders

An estimated 3 - 10% of travelers experience some skin problem related to their trip, particularly when traveling to tropical and subtropical areas.

Avoiding Exposure to Sunlight. Many developing countries are in the tropics were sunlight is intense. Ultraviolet radiation from sunlight not only can cause sunburn but excessive sunlight and heat can cause toxic skin reactions in susceptible individuals. Everyone should avoid episodes of excessive sun exposure, particularly during the hours of 10 a.m. to 4 p.m., when sunlight pours down 80% of its daily dose of damaging ultraviolet radiation. Reflective surfaces like water, sand, concrete, and white-painted areas should be avoided. Clouds and haze are not protective. High altitudes increase the risk for burning in shorter time compared to sea level and lower altitudes. Sunscreens and sunblocks with an SPF of 15 or higher used generously are important, but they should not be relied on for complete protection. Wearing sun-protective clothing is equally important and protects even better than sunscreens. Everyone, including children, should wear hats with wide brims.

Preventing Skin Infections. People who visit the tropics or developing regions are at risk for a number of skin disorders, including fungal and other infections. Cleanliness is essential. Bathing or showering is very beneficial, but if there are no facilities, simply washing with soap and water (even if cold) is still helpful. (Note: Taking multiple daily showers can remove protective oils and is not recommended.)

The skin should also be kept dry in order to prevent fungal infections, which thrive in damp, warm climates. Take special care to clean and keep dry certain skin areas where infections are most likely to occur. They include creases in the skin, the armpits, the groin, buttocks, and areas between the toes. Use talcum powder in these areas. Keep socks dry.

Precautions when Traveling to High Altitudes

Acute high altitude illness, or mountain sickness, can affect the brain (mountain sickness, cerebral edema) or the lungs (pulmonary edema), or both. Studies suggest that about 25% of climbers experienced symptoms at 7,000 - 9,000 feet, and 42% of them have symptoms at 10,000 feet. Rapid ascension to high altitude, such as arrival by airplane, increases the risk. In most cases the condition is mild. Severe lack of oxygen at high altitudes, however, can cause serious problems in some people.

• Acute Mountain Sickness. This syndrome is defined as headache and at least one other relevant symptom when a person travels to about 8,000 feet. Other symptoms include upset stomach, dizziness, weakness, fatigue, and difficulty sleeping. It typically develops in the first 12 hours, and may resolve spontaneously if the traveler remains at the same altitude.
• High Altitude Cerebral Edema (HACE). HACE is a life-threatening brain swelling and the severe endpoint of acute mountain sickness. Symptoms include altered consciousness, loss of coordination, difficulty concentrating, and lethargy. In extreme cases, it can lead to coma and death.
• High Altitude Pulmonary Edema (HAPE). HAPE is fluid in the lungs that in rare cases can be severe. In one study, about 75% of mountain climbers who went to 15,000 feet had some mild form of HAPE. Worse performance and a dry cough suggest the onset of HAPE. In extreme cases it can cause severe lung deterioration. (If it is going to develop at all, HAPE usually occurs in the first 2 days and rarely after 4 days at a given altitude.)

Luckily, symptoms of the more severe complications come on slowly, are easily recognized, and resolve when returning to a lower altitude.

Risk Factors for High Altitude Sickness. The risk for high altitude sickness is determined by certain characteristics: The rate at which a person ascends; the altitude reached; altitude during sleep; and individual physiology. People who live yearlong at low altitudes are much more likely to be ill at greater heights. Being physically stronger is not protective. Certain common conditions (heart disease, diabetes, hypertension, mild emphysema, and pregnancy) play no role in a person's risk for high altitude sickness. (Upper respiratory infections, however, do increase the risk for HAPE.)

Precautions against Mountain Sickness. Acclimatization by staying several days at increasingly higher altitudes is recommended. If you take high blood pressure medication, ask your doctor about increasing dosage if traveling to high altitudes. And anyone with a chronic medical condition should check with his or her doctor.

The following are some measures for preventing mountain sickness.

• As a rule, ascend no more than 1,000 feet per day at altitudes of 8,000 feet and above. Drink 6 - 8 glasses of water or juice a day and avoid alcohol.
• Stop climbing when experiencing any symptoms of acute mountain sickness. Descend if symptoms worsen. Also descend immediately if there are any symptoms of HACE or HAPE.
• Supplementary oxygen may be required for people who show signs of these conditions.
• People who are hiking to very high altitudes may consider an inflatable chamber (Gamow bag and others). Such devices enclose a person, and when pumped up they simulate air pressure found at low altitudes.

Medications Preventing and Managing Mountain Sickness. Some medications are available for prevention or treatment of acute mountain sickness.

• Ibuprofen (Advil) may be sufficient to manage headache associated with acute mountain sickness.
• Acetazolamide (Ak-Zol, Diamox) taken one day before, and continued during initial exposure to high altitude, can reduce symptoms of acute mountain sickness, improve exercise performance and sleep, and reduce muscle and body fat loss. It may be used to treat minor symptoms of acute mountain sickness, but if symptoms persist, the traveler should descend to a lower altitude.
• Dexamethasone (Decadron Phosphate, Dexasone, Hexadrol Phosphate) is used to treat acute mountain sickness and cerebral edema (HACE). Dexamethasone is not recommended for prevention, however, because of potentially dangerous side effects.
• Nifedipine (Adalat) is used to treat pulmonary edema (HAPE) and may be used for prevention in people who know they are at high risk for HAPE.
• Preventive use of salmeterol (Serevent), a long-acting inhaled asthma drug known as a beta-adrenergic agonist, may reduce the risk for HAPE by over 50%.

Precautions for Divers

Travelers planning to descend rather than ascend must also take precautions. Individuals with the following conditions should not scuba dive:

• Heart and lung diseases
• Bleeding disorders
• Chronic ear infections or sinus infections blocking the ears
• Diabetes
• Pregnancy
• History of seizures
• History of migraine headaches

Diving, in fact, is becoming known as a cause of many types of headaches, and anyone with a history of chronic or frequent headaches should discuss these issues with a health professional familiar with this sport.

Avoiding Air Embolism. Air embolisms are bubbles that obstruct blood vessels and can occur in divers who hold their breath while swimming up to the surface. They can be life threatening and cause long-term neurologic impairment, including memory lapses, impaired thinking, and emotional disorders. Even tiny bubbles may do some harm over time. One study found that in amateur divers who dive frequently, tiny bubbles appeared to increase the risk for small brain lesions and degenerating spinal disks.

To eliminate these bubbles, experts recommend that you:

• Ascend no faster than 30 feet per minute
• Remain 15 feet below the surface for 3 - 5 minutes before surfacing
• Avoid air travel for 24 hours after diving.

Drowning. The other major cause of scuba diving deaths is drowning in underwater caves due to improper training and poor equipment.

Review Date: 01/23/2007
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital