Disease Risks and Precautions
in Tropical South America

The material provided below is for informational purposes only.
It may not be current, and it should not be considered definitive.

All travelers should check the Center for Disease Control (CDC) website
for the most current disease risk and disease prevention information.



Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname, and Venezuela


Travelers to Tropical South America may be exposed to potential diseases from a number of sources. The most frequently reported illness is traveler's diarrhea, but there are other diseases which are unique to Mexico and Central America or the tropics. These diseases are transmitted by insects, contaminated food and water, or close contact with infected people. Specific diseases are discussed under each of these topical headings.

In order to reduce the risk of infection travelers must (1) protect themselves from insects, (2) ensure the quality of their food and drinking water, and (3) be knowledgeable about potential diseases in the region to be visited. Finally, diseases are not restricted to cleanly defined geographical areas, i.e. mosquitoes can fly over city or country borders, therefore, all travelers should protect themselves by taking the basic preventive precautions.


Many diseases are transmitted through the bite of infected insects such as mosquitoes, flies, fleas, ticks, and lice. In general travelers must protect themselves from insect bites by wearing proper clothing, using bednets, applying an insect repellent to exposed skin and clothing, and if possible, avoiding high risk situations, i.e. outdoor activities during night time hours from dusk to dawn when mosquitoes bite, unscreened living accommodations, etc. If a mosquito net is unlikely to be available, consideration should be given to purchasing a portable mosquito net.


Risk: Malaria exists throughout the year in many parts of the Tropical South American countries including some urban areas. P. falciparum (the most dangerous type), which has been reported to be resistant to the drug chloroquine, has been confirmed in most of these countries. Detailed risk
information: Bolivia: Malaria risk in rural areas only, except no risk in the highland areas, i.e. Departments of Oruro, Southern and Central Potosi, La Paz, and the Provinces of Ingavi, Los Andes, Omasuyos, and Pacajes. Brazil: Malaria risk in Acre and Rondonia States, Territories of Amapa and Roraima, and in rural areas of Amazonas, Goia s, Maranahao, Mato Grosso,
and Para States. Travelers who will only visit the coastal states from the "horn" south to the Uruguay border, including Iguassu Falls, are not at risk and need not take preventive drugs. Colombia: Malaria risk in rural areas only except no risk in Bogota and vicinity. Malaria risk in the rural areas of Uraba (Antioquia Dept.), Bajo Cauca-Nechi (Cauca and Antioquia Dept.), Magdalena Medio, Caqueta (Caqueta Intendencia), Sarare (Arauca Intendencia), Catatumbo (Norte de Santander Dept.), Pacifico Central and Sur, Putumayo (Putumayo Intendencia), Ariari (Meta Dept.), Alto Vaupes(Vaupes Comisaria), Amazonas, and Guainia (Comisarias). Ecuador: Malaria risk in all areas in the providences along the eastern border and the Pacific coast, i.e., El Oro, Esmeraldas, Guayas (including Guayaquil), Los Rios, Manabi, Morona-Santiago, Napo, Pastaza, Pichincha, and
Zamora-Chinchipe provinces. Travelers who visit only Quito and vicinity, the central highlands tourist areas, or the Galapagos Islands are not at risk and need not take preventive drugs. French Guiana: Malaria risk in all areas. Guyana: Malaria risk in rural areas in the southern interior and northwest coast, i.e., Rupununi and North West Regions. Paraguay: Malaria risk in rural areas bordering Brazil. Peru: Malaria risk exists in rural areas. Travelers who will only visit Lima and vicinity, coastal areas south of Lima, or the highland tourist areas of Cuzco, Machu Picchu, or Lake Titicaca are not at risk and need not take preventive drugs. Risk exists in rural areas of Departments of Amazonas, Cajamarca (except Hualgayoc Prov.), La Libertad (except Otuxco, Santiago de Chuco Prov.) Lambayeque, Loreto, Piura, (except Talara Prov.) San Martin and Tumbes, Provinces of Santa (Ancash Dept.); parts of La Convension (Cuzco Dept.), Tayacaja (Huancavelica Dept.), Satipo (Junin Dept.). Suriname: Malaria risk exist in rural areas, except no risk in the Paramaribo District and the coastal area north of 5o N. Lat. Venezuela: Malaria risk exists in rural areas of all border states and territories and the states of Barinas, Merida, and Portuguesa. Travelers should note that regardless of preventive method employed, it is still possible to
contract malaria. P. falciparum is reported in all these countries, but less so in Peru and Paraguay. P. falciparum highly resistant to chloroquine and Fansidar is reported.

Prevention: Most travelers to tropical South America (including travelers to Peru's eastern and northern border provinces) at risk for malaria should take MEFLOQUINE to prevent malaria. This drug is marketed in the United States under the name Lariam. The adult dosage is 250 mg (one tablet) once a week. MEFLOQUINE should be taken one week before leaving, weekly while in the malarious area, and weekly for 4 weeks after leaving the malarious area.

Minor side effects one may experience while taking MEFLOQUINE include gastrointestinal disturbances and dizziness. More serious side effects at the recommended dosage have rarely occurred. Consult a physician for other precautions.

Mefloquine should NOT be used by:
- travelers with a history of epilepsy or psychiatric disorder,
- travelers with a known hypersensitivity to mefloquine.

In consultation with a physician, mefloquine may be used by pregnant women and children less than 30 pounds, when travel to an area with choloroquine- resistant malaria is unavoidable

Travelers to all areas of Peru, except the eastern and northern border provinces, and Paraguay should take CHLOROQUINE to prevent malaria. The weekly dosage for an adult is 500 mg once a week. This drug should be taken one week before entering a malarious area, weekly while there, and
weekly for 4 weeks after leaving the malarious area. For these areas in Peru, no other anti-malarial drugs are needed.

In addition to using drugs to prevent malaria, travelers should use measures to reduce exposure to malaria-carrying mosquitoes, and protect themselves from mosquito bites. These mosquitoes bite mainly during the evening and night, from dusk to dawn.


Risk: Outbreaks of yellow fever have occurred in Bolivia, and Peru. Yellow fever is not always active in all countries of this region, but there is a significant risk to all travelers throughout the year, especially in travel or visits to rural settings. Areas of higher risk: Bolivia: the Departments of Beni, Chuquisaca, Cochabamba, Pando, Santa Cruz, Tarija, and part of La Paz. Brazil: rural areas of Acre, Amazonas, Goias, Maranhao, Mato Grosso, Mato Grosso do Sul, Para, and Rondonia States; and the Territories of Amapa and Roraima. Colombia: middle valley of the Magdalena River, foothills of the Cordllera Oriental from border of Ecuador to Venezuela, Uraba, foothills of Sierra Nevada, Orinoquia, and Amazonia. Peru: central and northern jungle regions. Venezuela: State of Bolivar, forest around Lake Maracaibo, and San Camilo jungle. Ecuador, French Guiana, Guyana, Paraguay, and Suriname have reported only a few cases.

Prevention: In general, if you are traveling to an area of risk, the easiest and safest thing to do is to get a yellow fever vaccination and a signed certificate. Yellow fever vaccination, a one dose shot, may be administered to adults and children over 9 months of age. The vaccine is not recommended for persons who are pregnant or whose immune systems are not functioning normally. In addition to the vaccine, travelers should use measures to reduce exposure to mosquitoes, and protect themselves from mosquito bites. These mosquitoes bite mainly during the evening and morning hours.

CDC recommends and many countries require a yellow fever vaccination.

French Guiana requires a yellow fever certificate for all travelers.

Bolivia, Brazil (age 6 months), Ecuador, Guyana, Peru (age 6 months), and Suriname, require a yellow fever vaccination for all travelers (Age > 1) arriving from all "Infected Countries".

Paraguay requires a certificate for travelers leaving the country to "Infected Countries".

Brazil, Bolivia, Colombia and Peru, recommend a vaccination, especially if visiting rural areas.

In addition if you are traveling TO / FROM a country listed below you are required to have a yellow fever vaccination.



Burkina Faso
Central African
Cote d'Ivoire,
(Ivory Coast)
Equatorial Guinea
Guinea Bissau
Sao Tome and Principe
Sierra Leone

South America:

French Guiana


French Guiana

**for Guyana, add Belize, Costa Rica, Guatemala, Honduras, and Nicaragua to the list of "FROM" countries

Yellow Fever Certificate: After immunization an International Certificate of Vaccination is issued and is valid 10 days after vaccination to meet entry and exit requirements for all countries. The Certificate is good for 10 years. You must take the certificate with you. Yellow fever vaccine is the ONLY vaccine that may be officially required for entry into certain countries.


Risk: Dengue fever occurs naturally throughout Tropical South America with recent epidemics in Brazil, Colombia, Ecuador, French Guiana, Surinam, Venezuela, and the tropical parts of Bolivia, Paraguay and Peru. The risk of infection is small for most travelers except during periods of epidemic transmission.

Prevention: There is no vaccine for dengue fever therefore the traveler should avoid mosquito bites. These mosquitoes bite mainly in the daytime.


Risks: Other diseases spread by mosquitoes, sand flies, black flies, or other insects are prevalent, especially in rural areas. These diseases include: Filariasis (mosquito), leishmaniasis (sandfly), Onchocerciasis (blackflies), Trypanosomiasis, American Chagas' Disease ("cone nose or kissing" bug), Oropouche Virus (gnats or midges), typhus (lice), and Plague (fleas).


To reduce mosquito bites travelers should remain in well-screened areas, use mosquito nets, and wear clothes that cover most of the body. Travelers should also take insect repellent with them to use on any exposed areas of the skin. The most effective repellent is DEET (N,N-diethyl meta-toluamide) an ingredient in most insect repellents. Travelers should also purchase a flying insect-killing spray to use in living and sleeping areas during the evening and night. For greater protection clothing and bednets can be soaked in or sprayed with PERMETHRIN, which is an insect repellent licensed for use on clothing. If applied according to the directions, permethrin will repel insects
from clothing for several weeks.


Food and waterborne diseases are the number one cause of illness to travelers and are very common in Temperate South America. Traveler's diarrhea is the most frequent health problem for travelers. It can be caused by viruses, bacteria, or parasites which are found universally throughout the region.
Transmission is most often through contaminated food or water. Infections cause diarrhea and vomiting (typhoid fever, cholera, and parasites), liver damage (hepatitis), or muscle paralysis (polio).


Risk: A recent epidemic of cholera has swept through the entire Tropical South American area. The majority of cases have been reported from Peru, Ecuador, Colombia, Guatemala, and Mexico. Cholera has been reported in coastal cities and inland areas of most of these countries. Cholera has also been reported in Cuzco in Peru and in the Galapagos Islands of Ecuador. Other countries to report cases include Argentina, Belize, Bolivia, Brazil, Chile, Costa Rica, El Salvador, French Guiana, Guyana, Honduras, Nicaragua, Panama, Suriname, and Venezuela. Bolivia has reported cases from the departments of Oruro and La Paz. Cholera has been reported from five states in Brazil: Amazonas, Mato Grosso, Rondonia, Amapa, and Para. Several municipalities near the mouth of the Amazon River have been affected. Cholera cases were first recognized in Peru in the last week of January 1991. Cholera has been reported in a small number of U.S. residents traveling to Peru and Ecuador. The risk of infection to the U. S. traveler is very low, especially those that are following the usual tourist itineraries and staying in standard accommodations. Travelers should consider the vaccine if they have any problems with their stomach, such as anti-acid therapy, ulcers, or if they will be living in less than sanitary conditions in areas of high cholera activity.

Prevention: Travelers to cholera infected areas should follow the standard food and water precautions of eating only thoroughly cooked food, peeling their own fruit, and drinking either boiled water, bottled carbonated water, or bottled carbonated soft drinks. Persons with severe cases respond well to simple fluid and electrolyte-replacement therapy, but medical attention must be sought quickly when cholera is suspected. The available vaccine is only 50% effective in reducing the illness, and is not recommended routinely for travelers.


Risk: Travelers to Tropical South America are at risk for typhoid fever, especially when traveling to smaller cities, villages, or rural areas. Typhoid fever is more common in Brazil, Colombia, Ecuador, French Guiana, and Peru.

Prevention: By drinking only bottled or boiled water and eating only thoroughly cooked food, a traveler lowers the risk of infection. Currently available vaccines have been shown to protect 70- 90% of the recipients. Therefore, even vaccinated travelers should be cautious in selecting their food and water. Two available vaccines provide equivalent protection against typhoid fever- oral and injectable.

Recommendations: CDC recommends a typhoid vaccination for those travelers who are going off the usual tourist itineraries, traveling to smaller cities and rural areas, or staying long term, that is, a traveler for six weeks or more. Typhoid vaccination is not required for international travel.


Risk: Travelers are at high risk for Hepatitis A, especially if travel plans include visiting rural areas and extensive travel in the countryside, frequent close contact with local persons, or eating in settings of poor sanitation. A study has shown that many cases of travel-related hepatitis A occur in travelers to developing countries with "standard" itineraries, accommodations, and food consumption behaviors.

Prevention: The virus is inactivated by boiling or cooking to 85 degrees centigrade for one minute, therefore eating thoroughly cooked foods and drinking only treated water serve as general precautions. Havrix, the hepatitis A vaccine currently licensed for use in the U.S., or immune globulin (IG) is recommended before travel for persons 2 years of age orolder. Hepatitis A vaccine is preferred for persons who plan to travel repeatedly or reside for long periods of time in intermediate or high risk areas.

Recommendations: CDC recommends hepatitis A vaccine or IG for protection against hepatitis A. Immune globulin should be used for travelers < 2 years of age. Immune globulin is recommended for persons of all ages who desire only short term protection.


Parasitic infections are acquired by eating or drinking contaminated food or water, through direct contact with soil or water containing parasites or their larva, or by contact with biting insects.

Symptoms and evidence of infection may include, but are not limited to fever, swollen lymph nodes, rashes or itchy skin, digestive problems such as abdominal pain or diarrhea, eye problems, and anaemia.

Risk: Travelers to Tropical South America are at risk of parasitic infections. There are many types of parasites and infection may occur in several ways: by eating undercooked meats infected with parasites or their larva; by eating food or drinking water contaminated with parasites or their eggs; by contact with soil or water infected with parasites; or through insect bites. Several types of parasites can penetrate intact skin and travelers are advised to wear shoes and avoid swimming, wading, or washing in fresh water.

Prevention: Travelers should eat only thoroughly cooked food, drink safe water, wear shoes, refrain from swimming in fresh water, and avoid contact with insects, particularly mosquitoes, biting flies, gnats, and midges.



Risk: AIDS is found throughout the region. In Tropical America, heterosexual transmission is now the predominant mode of transmission, with the largest number of cases in males, and there are high numbers of HIV-positive injecting drug users. The risk to a traveler depends on whether the traveler will be involved in sexual or needle-sharing contact with a person who is infected with HIV. Receipt of unscreened blood for transfusion poses a risk for HIV infection.

Prevention: No effective vaccine has been developed for HIV. Travelers should avoid sexual or needle-sharing contact with a person who is infected with HIV. If a blood transfusion is necessary, screened blood should be from an HIV-negative blood donor.

Recommendations: Travelers should avoid activities known to carry risks for infection with HIV.


Risk: The risk of Hepatitis B virus infection is highest in the interior Amazon Region and moderate for the rest of Tropical South America. The risk to the individual international traveler is determined by the extent of: (1) direct contact with blood or other body fluids, etc.; (2) intimate sexual contact with an infected person; (3) the duration of travel.

Prevention: The primary prevention consists of either vaccination and/or reducing intimate contact with those suspected of being infected. For those travelers expecting to reside in countries of high risk, as well as all health workers, vaccination is strongly recommended. Vaccination should ideally begin 6 months before travel.

Recommendations: CDC recommends vaccination for any of the following people: any health care worker (medical, dental, or laboratory) whose activities might result in blood exposure; any traveler who may have intimate sexual contact with the local population; any long-term (6 months or more)
traveler, e.g. teachers, who will reside in rural areas or have daily physical contact with the local population; or any traveler who is likely to seek either medical, dental, or other treatment in local facilities during their stay. Hepatitis B vaccination is not required for travel to any country.



Risk: In Tropical South America, schistosomiasis infection may be found in parts of Brazil, Suriname, and Venezuela. For travelers visiting these areas, the risk is a function of the frequency and degree of contact with contaminated fresh water for bathing, wading, or swimming.

Prevention: The traveler cannot distinguish between infested and non-infested water. Therefore, swimming in fresh water in rural areas should be avoided. Bath water should either be heated to 50 degrees C (122 degrees F) for five minutes or treated with chlorine or iodine as done for drinking
water. If exposed, immediate and vigorous towel drying or application of rubbing alcohol to the exposed areas may reduce the risk of infection. Screening procedures are available for those who suspect infection, and schistosomiasis is treatable with drugs.

Recommendations: Avoid contact with potentially contaminated water.


Risk: For most countries in Tropical South America, there is a risk of rabies infection particularly in rural areas, or in areas where large numbers of dogs are found.

Prevention: Do not handle any animals! Any animal bite should receive prompt attention. When wounds are thoroughly cleaned with large amounts of soap and water, the risk of rabies infection is reduced. Exposed individuals should receive prompt medical attention and advice on post-exposure preventive treatment.

Recommendations: There are no requirements for vaccination, but pre-exposure vaccination is recommended for:

- travelers visiting, for more than 30 days, foreign areas where rabies is known to exist;
- veterinarians and animal handlers;
- spelunkers; and
- certain laboratory workers.

Pre-exposure vaccination does not nullify the need for post exposure vaccine, but reduces the number of injections.

Recommendations for TROPICAL SOUTH AMERICA

Travelers should (1) take appropriate country specific malaria prevention measures (chloroquine - in northern Argentina only), (2) follow precautions to prevent insect bites, (3) pay attention to the quality of their drinking water and food, (4) have a dose of Immune Globulin (IG) or the Hepatitis A vaccine, and (5) consider booster doses of tetanus (Td) and polio (eIPV) vaccines. (6) Depending on the locations to be visited, planned activities, and health of the traveler, the following vaccines should be considered: Hepatitis B, Japanese Encephalitis, Typhoid, Rabies (pre-exposure), and Cholera. (7) Finally, the normal "childhood" vaccines should be up-to-date: Measles, Mumps, Rubella (MMR Vaccine); Diphtheria, Tetanus, Pertussis (DTP Vaccine) [ < 7 years of age], and Polio vaccine.

Disease risks and precautions