By
Ryan Maves, M.D.

Part of the beauty of Perú, beyond its wonderful people, history, and cuisine, is the diversity of its climates. From the stark coastal deserts to the stunning Andean highlands, there are few other parts of the world where a traveler can see such environmental variety. Each of these different climates brings unique challenges for tourists. The risk of serious illness is small, but mild illnesses are relatively common, and even experienced expatriates with long histories of residence in Lima can find themselves exposed to new and potentially dangerous diseases when moving around the country. Fortunately, there are a number of strategies that one can use to reduce risk and enjoy their travels with a minimum of difficulty.
One of the major attractions of Perú is the Amazon basin, particularly Iquitos and the Department of Loreto. Iquitos is a city of roughly 400,000 people that first rose to prominence as a center of the rubber boom in the early 20th century. It is the largest city in the world inaccessible by road and can be reached only by air or boat.
In recent years, it has emerged as an important tourist destination in Perú, with 30,000-40,000 annual visitors. Other Amazon destinations such as Puerto Maldonado have similar health issues and are attracting ever larger tourist populations. Consistently hot and humid, Iquitos and the Amazon have a dry season with relatively little rainfall around May-August, with heavier rains and higher river levels in October-January.
Before considering vaccines and medications, though, it’s important to recognize the leading two causes of death among tourists: car accidents and heart attacks. The World Health Organization (WHO) estimates that 50 million people are injured every year in motor vehicles, with 1.3 million killed. No resident of Lima will be surprised to learn that traffic laws in the developing world may be haphazardly enforced and that road quality is often poor.
The smaller amount traffic and the preference for smaller, slower motorcycle taxis in cities like Iquitos may reduce some of this danger, but always exercise caution when riding in any vehicle. Try to favor reputable forms of transportation (like taxis called by your hotel), use seatbelts, never drink and drive, and stick to well-populated, well-traveled parts of unfamiliar cities.
Similarly, you didn’t leave your high cholesterol at home when you came to Perú. Be sure to travel with an adequate supply of any routine medications you take, look into obtaining medical insurance that will cover you in the event of serious illness of injury during your travel, and investigate where you can obtain medical care in the event of an emergency.
Your options for medical care are limited, and evacuation to Lima or your home country may be necessary if you become sick. Ensure that your routine vaccines are up to date as well: influenza, MMR, tetanus, and (for some people) pneumococcal vaccinations.
When I see patients in a travel clinic, I often divide their infectious risks into two categories: “things that you bite,” and “things that bite you.” Starting with “things that you bite,” we find a number of infections that tend to track together and are common throughout the developing world. These are the result of contaminated food and water and can be difficult to avoid, even when eating in reputable establishments. Among them is the most common infectious disease of travelers, diarrhea.
The average tourist in the developing world will suffer from diarrhea once every two weeks. Most cases of adult diarrhea in Europe and North America are viral and resolve quickly with merely rest and fluids. Unfortunately, bacterial diarrhea (due to some types of the infamous E. coli as well as Salmonella, Shigella, Campylobacter, and many others) is more common in Perú. These infections take longer to resolve on their own, but they can also be readily treated with antibiotics.
Antibiotics such as levofloxacin or ciprofloxacin generally work well in Perú, although children and some adults are better treated with azithromycin. I usually recommend that travelers keep a small supply and to start a course after the third watery bowel movement in an eight-hour period.
Mild cases can be treated effectively with bismuth subsalicylate (Pepto-Bismol), but be prepared for the black tongue and black stools that follow a dose of this. Loperamide (Imodium) is a useful way to “slow down” the diarrhea, especially when you lack easy access to a restroom (like on the river or in a bus), but I mostly use it for reasons of convenience rather than to treat the underlying problem.
Other important food-borne infections include typhoid, and hepatitis A. Hepatitis A is easily prevented with a highly effective vaccine, coming in two doses that lead to lifelong immunity. There are two vaccines for typhoid, one oral and one injected; both are between 60-75% effective and require periodic booster doses. While imperfect, they are useful. I recommend them not just for the Amazon but for visitors to any part of Latin America.
Malaria is a major public health issue in Perú but is thankfully unusual among tourists, with fewer than 50 documented cases in travelers between 2000-2005 (source: Behrens et al. Malaria Journal 2007, 6:114 ). Unfortunately, mosquitoes carry other infections that threaten travelers, with dengue fever and yellow fever being the most important.
The malaria parasite is largely a rural infection, spread by a mosquito (Anopheles) that bites during between dusk and dawn. Dengue, on the other hand, is a virus spread by a mosquito that is concentrated in urban areas and bites during the day. Yellow fever is historically a rural infection, but recent outbreaks in South America have occurred on the outskirts of urban areas.
For malaria, there are a number of excellent medications that help prevent infection in travelers: doxycycline, atovaquone/proguanil (marketed as Malarone), and mefloquine. Their widespread use is no doubt why malaria is so rare in travelers. The choice of which medication to use should be based on cost, convenience, and potential side effects and this decision can be easily made in consultation with an experienced travel physician. All are effective and safe in the majority of patients.
Equally important is the use of general insect precautions. Minimizing exposed skin with long sleeves and pants, treating your clothing with a repellent spray like permethrin, and applying a DEET-containing repellent (about 30% concentration) every four hours will help protect against not only malaria but against dengue, yellow fever, and many other potential infections from insects.
The yellow fever vaccine has a long and successful history but should be avoided by very young children, people with weakened immune systems, pregnant women, and patients above 65 years of age in most situations. Unfortunately, there is currently no vaccine for dengue, and avoiding bites is the best prevention.
A few passing thoughts:
1. Sexually-transmitted infections like gonorrhea, chlamydia, and HIV affect tourists frequently. Risky behavior like unprotected sex, frequenting prostitutes, and even more reprehensible acts like child prostitution are sadly not unusual among visitors to Perú. Obviously, we need to observe both good sense and the laws of Perú and our home countries when traveling, but even if you happen to meet someone innocently at a bar, remember to use a condom.
2. A good travel kit is valuable. It should include insect repellant, your routine medications, treatment for diarrhea, suitable remedies for minor ailments (like ibuprofen, acetaminophen, and a decongestant), a list of emergency contacts, and a high-SPF sunscreen.
3. Try to plan a visit to your travel clinic 4-8 weeks before departing. This will allow for enough time to get your medications and to complete any needed vaccinations.
4. A variety of “natural” remedies are on sale in many markets in Iquitos, most famously at the Belen market. These are purported to treat every ailment under the sun, including cancer, HIV, gallstones, ulcers, rashes, erectile dysfunction, and malaria in one convenient bottle. As my father once told me: if you don’t know what it is, don’t put it in your mouth. Let the buyer beware.
5. Swimming in the Amazon River should be avoided. Between the piranha, the candirú, the bull sharks, and the snakes, there are already enough things swimming in the Amazon. Other sources of fresh water, including lakes and ponds, are also best avoided due to the high rates of common infections such as leptospirosis.
Reliable information can be found on the Internet at both the CDC (www.cdc.gov) and World Health Organization (www.who.int) websites. The Peruvian Amazon is a beautiful, exciting place to visit. Your travel experience will be all the better if you can enjoy it in good health.
-----
Dr. Maves is a graduate of the University of Washington School of Medicine in Seattle, Washington, and is board-certified in internal medicine and infectious diseases. He is an active-duty lieutenant commander in the U.S. Navy and presently serves as the head of the Department of Bacteriology at the U.S. Naval Medical Research Center Detachment in Callao, Perú. He is an assistant professor of medicine at the Uniformed Services University of Health Sciences in Bethesda, Maryland, and lives in Lima with his wife, Robin, and their three children.
The views expressed in this article are those of the author and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government.
The author would like to thank Dr. Joel Sklar, Dr. Eric Halsey, and Dr. John Sanders of NMRCD for their critical review of this article.
Copyright statement: Ryan Maves is a U.S. military service member. This work was prepared as part of his official duties. Title 17 U.S.C. 1 105 provides that ‘Copyright protection under this title is not available for any work of the United States Government’. Title 17 U.S.C. 1 101 defines a U.S. Government work as a work prepared by a military service members or employees of the U.S. Government as part of those person’s official duties.
Add to del.icio.us |
|