Disease Risks and Precautions
in Temperate 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.



Argentina, Chile, Falkland Islands, Uruguay


Travelers to Temperate 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: In Argentina, the risk for malaria infection occurs only in rural areas of northern Argentina that border Bolivia (Salta and Jujuy Provinces). In Chile, Falkland Islands, and Uruguay, there is no risk of malaria.

Prevention: Travelers at risk for malaria 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. No other anti-malarial drugs are needed.

In addition to using drugs to prevent malaria and treat a possible malaria attack, 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: A low risk of yellow fever infection occurs only in the northeastern forest areas of Argentina. There is no risk of yellow fever in Chile, Falkland Islands, or Uruguay.

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 a yellow fever vaccination only if you are traveling to areas of risk (northeastern Argentina, Tropical South America, or Africa). Argentina, Chile, Falkland Islands, and Uruguay have no yellow fever vaccination requirements. If your travel plans include traveling to or from other countries in Africa or South America, then you should request and read the CDC document "Comprehensive Yellow Fever Requirements". You may be required to have a yellow fever vaccination. (Yellow fever vaccine is the ONLY vaccine that may be officially required for entry into certain 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.


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 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 Temperate South America are at risk for typhoid fever, especially when traveling to smaller cities, villages, or rural areas. Typhoid fever is more common in Chile.

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 Temperate 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 Temperate 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 modrate for Temperate 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: For most countries in Temperate 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.


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