Brazil requires proof of yellow fever vaccination for travelers arriving from countries with risk of yellow fever transmission. The requirement applies to travelers aged nine months and older who have transited through or visited endemic areas within 90 days prior to entry. The International Certificate of Vaccination or Prophylaxis must be presented at border control. Countries on Brazil's endemic list include most of sub-Saharan Africa and several South American nations including Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela. This requirement changed in 2017 when Brazil removed the 10-year validity limit, recognizing that a single dose of yellow fever vaccine provides lifelong immunity according to World Health Organization guidance.
Yellow fever vaccination is recommended for travelers visiting specific Brazilian states regardless of entry requirements. The endemic zone includes all of the following states: Acre, Amapá, Amazonas, Distrito Federal, Goiás, Maranhão, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Pará, Rondônia, Roraima, and Tocantins. São Paulo state outside the metropolitan area is also considered endemic. Espírito Santo and Rio de Janeiro states have partial risk areas. Travelers to Iguaçu National Park on the Brazilian side require vaccination due to confirmed transmission in that region since 2008. Major cities where vaccination is not typically recommended include Rio de Janeiro city proper, São Paulo city proper, Recife, Fortaleza, Salvador, and coastal resort areas including Fernando de Noronha and the beaches of Santa Catarina state.
Routine vaccinations should be current before travel to Brazil. The Centers for Disease Control and Prevention recommends measles-mumps-rubella vaccine for all travelers born after 1956 who lack immunity, with particular emphasis given that Brazil experienced measles outbreaks in 2018 and 2019 with over 10,000 confirmed cases concentrated in Amazonas and Roraima states. Tetanus-diphtheria-pertussis boosters are recommended every 10 years. Hepatitis A vaccination is recommended for all travelers to Brazil regardless of itinerary, as infection can occur through contaminated food or water even in high-end establishments. Hepatitis B is recommended for travelers who might have sexual contact with local residents, require medical procedures, or plan extended stays beyond three months.
Typhoid vaccination is recommended for travelers visiting smaller cities, rural areas, or staying with friends and relatives where food and water exposure carries higher risk. Two vaccine forms exist: an oral live-attenuated vaccine requiring four capsules taken on alternate days, effective for five years; and an injectable polysaccharide vaccine providing protection for two years. The oral vaccine cannot be taken concurrently with antibiotics or antimalarial medications. Rabies pre-exposure vaccination consists of three doses over 21 to 28 days and is recommended for travelers who will be in remote areas more than 24 hours from medical care, those working with animals, or travelers to the Amazon region where bat exposure risk exists. Brazil reported 3 to 5 human rabies cases annually from 2010 to 2020, primarily from bat contact rather than dog bites due to successful urban canine vaccination programs.
Malaria transmission occurs in the Amazon Basin region of Brazil, which comprises the states of Acre, Amapá, Amazonas, Maranhão, Mato Grosso, Pará, Rondônia, Roraima, and Tocantins. The risk is highest in rural areas and municipalities outside state capitals. Manaus city has minimal malaria risk despite its location in Amazonas state. Between 2015 and 2020, Brazil reported between 145,000 and 190,000 malaria cases annually, with over 99 percent caused by Plasmodium vivax, the species that produces recurring infections but rarely causes severe disease. Plasmodium falciparum, the species responsible for severe malaria and deaths, accounts for less than one percent of Brazilian cases, concentrated in specific municipalities in Amazonas, Acre, and Roraima states near borders with Peru, Bolivia, and Venezuela.
The Centers for Disease Control and Prevention recommends antimalarial medication for travelers to endemic areas in the Amazon Basin. Three medication options exist for Brazil. Atovaquone-proguanil is taken daily starting one to two days before arrival, throughout the stay, and for seven days after leaving the malaria zone. Doxycycline is taken daily starting two days before, during, and for 28 days after exposure. Mefloquine is taken weekly starting two weeks before travel, during exposure, and for four weeks after. Chloroquine is not recommended for Brazil due to documented resistance. Rural areas of the Pantanal wetlands in Mato Grosso do Sul have no malaria transmission. The Atlantic Forest, Cerrado, and southern Brazil regions including Iguazu Falls, Florianópolis, Porto Alegre, Curitiba, São Paulo, Rio de Janeiro, Salvador, Recife, and Fortaleza require no malaria prophylaxis.
The choice of antimalarial medication depends on individual factors. Atovaquone-proguanil has the advantage of requiring only seven days of post-travel dosing but costs more than alternatives. Side effects include nausea and headache. Doxycycline is less expensive but requires 28 days of continued use after leaving the endemic area. It causes photosensitivity requiring sun protection and cannot be used by pregnant women or children under eight years old. Mefloquine has the convenience of weekly dosing but carries contraindications for travelers with psychiatric conditions, seizure disorders, or cardiac conduction abnormalities. Neuropsychiatric side effects occur in approximately 10 to 25 percent of users. Selection should occur in consultation with a travel medicine physician.
Resistance patterns in Brazil differ from other malaria regions. Chloroquine resistance in Plasmodium vivax is present but not universal. Primaquine, the medication used to eliminate dormant liver-stage parasites of P. vivax and prevent relapses, requires glucose-6-phosphate dehydrogenase testing before administration because patients with G6PD deficiency can experience severe hemolytic anemia. Approximately 3 to 10 percent of males of African, Mediterranean, or Southeast Asian ancestry have G6PD deficiency. Women are less commonly affected but can be carriers. Brazil's Ministry of Health protocols since 2015 include primaquine in treatment regimens for P. vivax after G6PD status is determined.
Dengue fever is endemic throughout Brazil below 2,200 meters elevation. The country reported between 1.5 million and 2.4 million dengue cases annually from 2015 to 2020, with the highest incidence in 2019. Transmission occurs year-round but peaks during the rainy season from December to May in most regions. All four dengue serotypes circulate in Brazil. The Aedes aegypti mosquito transmits dengue primarily in urban and peri-urban areas, breeding in artificial containers near human habitation. High-incidence states include Acre, Goiás, Minas Gerais, Mato Grosso do Sul, São Paulo, Paraná, Espírito Santo, and Tocantins. Rio de Janeiro experienced major outbreaks in 2008, 2012, and 2019. Secondary infections with a different serotype carry increased risk of severe dengue with plasma leakage, the condition formerly called dengue hemorrhagic fever.
Zika virus emerged in Brazil in 2015, with the first confirmed cases in Bahia and Rio Grande do Norte states. The 2015-2016 outbreak affected an estimated 440,000 to 1.3 million people. Zika gained international attention when Brazilian physicians in Recife and Salvador identified a surge in microcephaly cases in infants born to mothers infected during pregnancy. Between November 2015 and January 2018, Brazil reported 3,590 confirmed cases of congenital Zika syndrome. Transmission declined sharply after 2017, with fewer than 15,000 confirmed cases in 2018 and continued low levels through 2020. The same Aedes aegypti mosquito transmits Zika. Sexual transmission is documented, with virus present in semen for up to six months after infection. Pregnant women should consult with physicians before travel to Brazil. Male partners of pregnant women should use barrier protection for the duration of pregnancy if they travel to areas with Zika transmission.
Chikungunya arrived in Brazil in 2014, first detected in Amapá and Bahia states. Annual cases grew from 13,000 in 2014 to peaks of 271,000 in 2016 and 185,000 in 2019. The disease causes acute fever and severe joint pain, with chronic arthralgias persisting for months or years in 30 to 40 percent of cases. Aedes aegypti is the primary vector, with Aedes albopictus serving as a secondary vector in some regions. States with highest transmission include Ceará, Rio de Janeiro, Bahia, Minas Gerais, and Pernambuco. Unlike dengue, chikungunya does not have hemorrhagic manifestations, but the debilitating joint symptoms create substantial morbidity. No specific antiviral treatment exists for dengue, Zika, or chikungunya. Management consists of supportive care, hydration, and pain control.
Prevention of mosquito-borne diseases in Brazil requires multiple measures. Aedes aegypti bites primarily during daylight hours, with peak feeding periods from morning until mid-afternoon and again before dusk. DEET-based insect repellents with concentrations of 20 to 30 percent provide four to six hours of protection. Picaridin at 20 percent concentration offers similar duration. Oil of lemon eucalyptus at 30 percent concentration is effective but requires more frequent application. Permethrin treatment of clothing, shoes, and bed nets kills mosquitoes on contact and survives multiple washings. Air conditioning and screens reduce indoor exposure. Aedes mosquitoes breed in small water collections, so travelers have limited ability to control breeding sites, but eliminating standing water around accommodations reduces local mosquito density.
Foodborne and waterborne diseases represent the most common health problem for travelers to Brazil. Traveler's diarrhea affects 30 to 50 percent of visitors, typically within the first two weeks of arrival. Bacterial pathogens account for 80 percent of cases, with enterotoxigenic Escherichia coli as the leading cause. Campylobacter, Salmonella, and Shigella species cause approximately 15 to 20 percent of cases. Viral gastroenteritis from norovirus occurs in outbreaks. Parasitic infections from Giardia lamblia and Entamoeba histolytica are less common but produce prolonged symptoms. Water quality varies substantially between Brazilian cities. Tap water in São Paulo, Rio de Janeiro, Brasília, and Curitiba undergoes chlorination and filtration, but aging distribution infrastructure can introduce contamination. Northern and northeastern cities including Manaus, Belém, Recife, and Salvador have less reliable water treatment.
Bottled water is widely available throughout Brazil. The mineral water market includes brands such as Minalba, São Lourenço, and Crystal, sold in sealed bottles at stores, restaurants, and street vendors. Ice in tourist restaurants and hotels in major cities typically comes from purified water sources, but ice in street vendors and small establishments may use tap water. Beverages in sealed containers, including carbonated drinks, beer, and wine, are safe. Fresh fruit juices blended with water carry risk if the water source is untreated. Açaí, a popular Brazilian beverage made from palm fruit, is traditionally mixed with water and consumed immediately. Contaminated açaí has transmitted Chagas disease through oral route in Pará and Amazonas states, with 37 documented outbreaks between 1999 and 2017 affecting over 1,000 people. Commercial açaí products from established vendors using pasteurized preparations have not been associated with transmission.
Food safety depends on preparation and handling practices. Thoroughly cooked foods served hot present minimal risk. Salads, raw vegetables, and fruit washed in tap water can carry pathogens. Fruit with intact peels that can be removed by the traveler—bananas, oranges, mangoes—are safe. Street food quality varies. Acarajé, the fried bean fritter sold in Salvador, is cooked in hot oil that kills pathogens, but accompanying sauces may sit at room temperature for extended periods. Pastel, a fried pastry filled with meat, cheese, or vegetables, is generally safe when consumed immediately after frying. Churrascarias serving grilled meats operate at temperatures that eliminate foodborne pathogens. Seafood carries specific risks. Moqueca, a fish stew from Bahia and Espírito Santo states, should be consumed at reputable restaurants. Raw shellfish can accumulate toxins and pathogens. Ciguatera poisoning from reef fish occurs but is uncommon in Brazil.
Hepatitis A transmission through food and water remains a risk throughout Brazil despite declining incidence. The country transitioned from high to intermediate endemicity between 2000 and 2020. Vaccination provides the most reliable protection. Typhoid fever occurs at rates of approximately 2 to 5 cases per 100,000 population. Risk is higher in the North and Northeast regions. The oral typhoid vaccine provides 50 to 80 percent protection, the injectable vaccine 50 to 70 percent. Cholera is rare in Brazil, with sporadic cases reported. The most recent significant outbreak occurred in the Amazon region in the 1990s. Schistosomiasis affects certain freshwater areas in Brazil. The parasite enters through skin contact with contaminated water in lakes, ponds, and slow-moving streams in Bahia, Pernambuco, Alagoas, and Minas Gerais states. Coastal beaches and chlorinated pools do not transmit schistosomiasis. Ocean water is safe. The Amazon River and its tributaries do not typically harbor schistosomiasis, as the specific freshwater snail host is absent from most Amazonian waterways.
Brazil's elevation profile poses minimal altitude illness risk compared to neighboring Andean countries. The country's highest peak, Pico da Neblina, reaches 2,994 meters on the Venezuelan border in Amazonas state. The Pico da Bandeira on the Minas Gerais and Espírito Santo border reaches 2,892 meters. Chapada dos Veadeiros in Goiás state has elevations near 1,800 meters. Campos do Jordão in São Paulo state sits at 1,628 meters. These elevations rarely cause acute mountain sickness, which typically begins above 2,500 meters. Brasília, the capital, lies at 1,172 meters. São Paulo city sits at approximately 760 meters. Most tourist destinations including Rio de Janeiro, Salvador, Recife, Fortaleza, Manaus, and coastal areas are near sea level. Mount Roraima, the tepui reaching 2,810 meters on the Brazil-Venezuela-Guyana border, can be approached from the Brazilian side but the actual summit climb occurs primarily in Venezuelan territory.
Travelers with pre-existing cardiac or pulmonary conditions should consult with physicians before visiting areas above 1,500 meters, not due to acute mountain sickness but because reduced oxygen availability increases cardiovascular strain. The reduced atmospheric pressure at Brasília's elevation decreases oxygen partial pressure by approximately 12 percent compared to sea level. This reduction has minimal effect on healthy individuals but may affect those with compromised cardiopulmonary function. The Pantanal wetlands lie at elevations between 80 and 200 meters. The Amazon Basin sits largely below 200 meters elevation, with Manaus at 92 meters. The heat and humidity in these lowland regions create physiologic stress independent of altitude.
Brazil spans latitudes from 5 degrees north to 33 degrees south of the equator. Ultraviolet radiation intensity is high throughout the year. The country has one of the world's highest incidence rates of skin cancer, with the National Cancer Institute estimating 185,000 new cases of non-melanoma skin cancer annually. The UV index in equatorial regions including Fortaleza, Recife, and the Amazon reaches 11 to 12 year-round, classified as extreme. Southern cities including Porto Alegre and Curitiba reach UV index 9 to 10 in summer months from December to February. Rio de Janeiro and São Paulo experience UV index 10 to 11 during summer. Cloud cover reduces UV radiation by only 20 to 30 percent. UV exposure occurs during outdoor activities, beach time, and rainforest excursions.