Health Precautions For the Amazon Region of South America

By Dr. Gary Laden*

The Peacock Doc

The following information has been acquired from the latest data from the Centers for Disease Control and Travel Medicine Clinics regarding health precautions when fishing in the Amazon/Orinoco regions of South America. This material is only presented as a guide to some of the health concerns and recommendations for medications and is not meant as a substitute for medical care. We strongly urge you to contact your personal physician or local travel medicine clinic for advice and recommendations that are tailored to your particular trip and health status.

Malaria

Malaria is caused by a protozoan that is transmitted from person to person by the bite of an infected Anopheles mosquito (see photo at right). The Anopheles mosquito is active only during the evening and nighttime hours – from approximately dusk to dawn – therefore, it is highly unlikely that you could be inoculated by this mosquito during daylight fishing hours. Malaria symptoms may develop as early as six days after the first exposure to infected mosquitoes in malaria endemic areas, or as late as several months after departure from an endemic area, even though preventative medications may have been taken. The symptoms of malaria include fever, chills, headache, muscle ache and malaise (feeling weak and run-down). These early symptoms can mimic the flu. It is important to contact your physician if these symptoms develop upon returning from an endemic area, especially if you were lax with either prophylactic medication or failure to use insect repellent. If left untreated, malaria can cause anemia, kidney failure, coma and death.

                The most effective method to repel the Anopheles mosquito is a multi-tiered defense. The first line of defense is to us an insect repellent on the skin. DEET, in a concentration of 30 to 50% has been proven to be very effective and safe. It is most effective when applied to the face, neck, exposed up chest, hands and ankles. It is better to apply a thin layer, with the application of additional thin layers of repellent, than to simply slosh the repellent on in large quantities. Reapply after profuse perspiration, showering or bathing. The 2nd line of defense consists of ones outwear. Consider lightweight, cotton long sleeve shirt or pants for protection from mosquitoes during the evening hours. Continued defense takes the form of personal hygiene. Mosquitoes are attracted to scents and body odors. Bathe at the end of a hot fishing day, but avoid the use of scented soaps, colognes or deodorants.

Malaria Prophylaxis – Prophylactic medication works by killing the parasites that may have been introduced by the mosquito. The drug of choice by many travel medicine clinics and infectious disease specialists is called Mefloquine, (trade name Lariam) and comes as a 250 mg pill. Lariam is a small pill, taken with a large glass of water one week prior to entering the tropical zone. Another pill is taken the day you enter the tropical zone. The regimen is completed by taking one pill a week (on the same day you took the other doses) for four more weeks. Lariam should not be taken - unless you first obtain clearance from your family physician or internist, especially if you are currently taking one of several cardiac medications, or if you are taking seizure or epileptic medication. Please read the product literature before taking this drug as this, and all other drugs, have potential side effects that need to be reviewed.

If you cannot take Lariam, there are now two alternative medications. The first alternative is Doxycycline. It is taken as 100 mg daily for 5 weeks, beginning the week before entering the tropical zone then once daily for five additional weeks. If you take Doxycycline, you have to be extra cautious in the sun, as tetracycline derivatives make one very sun-sensitive.

Malarone is another drug that has been approved to both prevent and treat malaria. It offers the shortest course of prophylaxis of the three drugs used for this purpose. Malarone has shown good prophylactic efficacy for prevention of P. falciparum malaria, including those infections acquired in areas with Chloroquine-resistant strains. Malarone has proven prophylactic activity in semi-immune persons (those who have had repeated malaria exposure because of living in malarious areas for extended periods). Recent data has demonstrated Malarone's efficacy in persons without antimalarial immunity (that is, in persons who have had little or no past exposure to malaria and including persons who formerly lived in malarious countries but who now live in non-malarious countries). The adult dosing regimen for prophylaxis with Malarone is one adult tablet daily starting 1 to 2 days before travel, taken daily during travel, and continuing daily for 7 days after leaving the malarious area.

Yellow Fever

Yellow fever occurs in certain jungle locations of South America, where the virus is maintained in a cycle among forests, mosquitoes, and monkeys. In South America sporadic infections occur almost exclusively in forestry and agricultural workers who are exposed occupationally in or near forests. Yellow fever is a viral disease transmitted between humans by a mosquito. General precautions to avoid mosquito bites should be followed. These include the use of insect repellent, protective clothing, and mosquito netting. Yellow fever is a very rare cause of illness in travelers, but most countries have regulations and requirements for yellow fever vaccination that must be met prior to entering the country.

Yellow Fever Vaccine - This vaccine is administered as a one single injection. It can be administered by your local health department or a travel medicine clinic at a nearby major hospital. Family physicians will not have access to this vaccine. Do not receive the vaccine if you are allergic to eggs or are pregnant. The immunization, and resultant certificate, is valid 10 days after vaccination. You will not need a booster for 10 years.

Hepatitis A&B

Hepatitis A transmission may occur by direct person-to-person contact, from contaminated water, ice, or shellfish harvested from sewage-contaminated water; or from fruits, vegetables or other foods which are eaten uncooked, but which may become contaminated during handling. Recent studies have shown that many cases of travel-related hepatitis A occur in travelers with “standard” tourist itineraries, accommodations, and food and beverage consumption behaviors. Depending on the particular vaccine you receive, it is typically given in two dozes, the second dose anywhere from 6-18 months after the first. Although much more difficult to contract (typically through IV drug use, sexual contact and other contacts with blood and body fluids), your local health department, travel medicine clinic or physician may advise a Hepatitis B vaccine as well.

Typhoid Fever

Typhoid fever is caused by the bacteria called Salmonella Typhi. You can contract this disease if you eat food or drink beverages that have been handled by a person who is shedding S. Typhi, or if sewage contaminated with S. Typhi bacteria gets into the water you use for drinking, washing food or inadvertently swallow while swimming or taking a shower and using water pumped into the lodge or houseboat from a lake or river. Pumping river water into your shower is a very common practice at many houseboat operations and lodges in Venezuela and Brazil. Once S. Typhi bacteria are eaten or drunk, they multiply and spread into the bloodstream. The body reacts with fever and other signs and symptoms.  Persons with typhoid fever usually have a sustained fever as high as 103° to 104° F. They may also feel weak, or have stomach pains, headache, or loss of appetite. In some cases, patients have a rash of flat, rose-colored spots. The only way to know for sure if an illness is typhoid fever is to have samples of stool or blood tested for the presence of S. Typhi. Three antibiotics (ampicillin, trimethoprim-sulfamethoxazole, and ciprofloxacin) can be used to treat this illness. Persons given antibiotics usually begin to feel better within 2 to 3 days, and deaths rarely occur. However, persons who do not get treatment may continue to have fever for weeks or months, and as many as 20% may die from complications of the infection. It is wise to receive the vaccine, a minimum of a week before traveling on a peacock bass trip.  A new oral typhoid vaccine and a new single dose injectable vaccine produces fewer side effects than the older two dose  vaccine and are 65-75% effective against the disease.

Tetanus Booster

As a standard precaution for all fishing trips, it is recommended that you obtain a current tetanus booster shot. See your personal physician for details regarding this booster.

Diarrhea

Traveler’s diarrhea is typically caused by introducing different microbes (not necessarily harmful ones) into your intestinal tract through food and drinks.  Simple cases of traveler’s diarrhea can be handled by taking Imodium tablets, two capsules at the onset of diarrhea and then one capsule after each loose stool. Not to exceed 8 capsules in one day.  If the diarrhea persists, and is accompanied by severe cramping, it may be advisable to obtain a prescription for Cipro 500 mg to take twice daily until the diarrhea stops.  One preventive measure might be to start Acidophelus bacteria (the healthy kind found in yogurt) tablets. This may fortify your intestinal tract and may kill off some of the “bugs” that might cause more serious intestinal problems.

First Aid Kit

Coordinate with your fishing companions about compiling a group first aid kit for your trip in the event of cuts or other minor injuries. This kit should include a topical antibacterial like betadine, polysporin, sterile gauze pads, sterile gauze roll, bandaids, butterfly bandaids, ace bandages, tape and definitely an Epipen (adrenaline injector) for those allergic to bee and wasp stings or with serious allergies to various food groups. 

Sunburn

Because of the intense tropical sun of the Amazon Watershed, we strongly suggest precautions to prevent excessive exposure. We recommend wearing long sleeve shirts and pants, preferably of a lightweight cotton material or one of the new fast drying materials available. A wide brimmed hat will protect the ears and neck region. Consider wearing sun gloves (Mangrove sun protection gloves offer SPF 50 for the hands and are available at MonsterPeacockBassLures.com) to protect the hands, which are often overlooked and can burn easily. Sunscreen, of at least a sun protection factor (SPF) of 30, should be applied early in the morning, long before perspiration occurs. It is also prudent to apply a protective lip balm as well. When sunburn does occur, we recommend applying 100% Aloe Vera gel, with no additives, to the skin.  Additionally, 1% (no stronger should be used repeatedly on the skin) topical hydrocortisone cream will also help the tender skin of a sunburn.

Allergic Reactions

If you have severe allergic reactions to insects or food, you should talk to your personal physician about prescribing EpiPens to bring on your trip. An Epipen is a self-injection device, filled with what might be a life-saving drug called epinephrine (adrenaline). Epinephrine can help stop or delay a severe allergic reaction. 

You should inform your booking agent, as well as the lodge, boat or camp manager and cook, to make sure that they are aware of any insect, chemical or food allergies. In some cases, you will fish watersheds that possess annoying, albeit not dangerous, noseeums. For those allergic to them, they will create a terrible itching.  If you are sensitive to biting insects, ask your physician to write for a Medrol Dosepak, which you can take to alleviate non life threatening reactions and allergies. These are cortisone tablets and are relatively safe with few side effects. For further information about severe allergic reactions, visit Epipen.com.

A peacock bass trip to tropical South America should be a fantastic and safe experience, offering years of fond memories to the visiting angler. While the risk of contracting a tropical disease is rare, the possibility does exist. There have been documented cases of several anglers in the past decade dying of Yellow Fever (they did not receive the vaccine).  Others have contracted malaria. Do not neglect consulting with your personal physician and travel medicine clinic about what medications might be appropriate for you to take prior to and during your fishing trip. Remember, every person is different and a medication that might be prescribed for you, might not be appropriate for your fishing buddy with a different medical history.  Also, make sure your personal health insurance policy will cover you in the event of an illness or injury while in a foreign country, including air ambulance evacuation. There are relatively inexpensive policies that you can obtain prior to your trip.

*Dr. Gary Laden is a board certified foot and ankle surgeon, practicing in Atlanta, GA. His specialty is sports medicine. He is also a fanatic angler, especially for peacock bass. Gary holds the current National Freshwater Fishing Hall of Fame 4 lb line class record for peacock bass, as he landed a 15 lb fish on the Unini River in Brazil.