Cholera is still present in 58 countries as of 2001 where 185,000 cases were reported to the World Health Organization (WHO). Ingesting contaminated water or food can put you at risk for contracting cholera.
Travelers to Brazil who follow the usual tourist itineraries and follow food safety recommendations should have low risk of contracting cholera. It is important to avoid drinking or eating in untreated water or uncooked or raw food. Travelers are not required to have vaccinations against cholera anymore.
Yellow fever is caused by mosquitoes and is a viral illness. The symptoms can vary and may resemble the flu. Yellow fever is common in sub-Saharan Africa and South America. Cases of yellow fever have been noted in young men exposed through occupation to the vector population in Brazil.
Malaria is caused by a parasite and can be fatal. Malaria is passed to humans from a bite of an infected mosquito. You can prevent malaria by seeing your health care provider while planning your trip to Brazil. Your provider will give you a vaccination and antimalaria medication. Prevent mosquito bites by bringing along a deet containing insect repellant, a mosquito bed netting and clothes that have long sleeves and long pants.
Dengue is a viral infection transmitted to humans by mosquitos. Mosquitos are most active during the day, so take precautions to prevent being bitten by mosquitoes while they are active. The risk is usually higher in urban areas but can occur in rural areas as well.
Lymphatic filariasis is caused by the adult worm and once infected live in the lymphatic vessels of the host. Infected mosquitoes transmit the disease from one person to another. 120 million individuals are infected with lymphatic filariasis in tropical areas such as sub-Saharan Africa, Egypt, Southern Asia, the western Pacific islands, and the northeastern coasts of South and Central American and also the Caribbean islands. There is no vaccine for lymphatic filariasis. The best thing anyone can do visiting Brazil is to avoid being bitten by mosquitoes by using personal protective clothing and using insect repellent.
Another tropical disease common to Brazil is leishmaniasis. Leishmaniasis is a parasitic disease caused by the bite of the sand flies. This disease is found more often in rural areas, so one preventative may be to avoid the rural areas of Brazil. Dusk and dawn are the two times to be especially careful of sand flies, but usually bite more often at nighttime. Prevent being bitten by wearing clothing that covers much of the body as possible and using insect repellent. Clothing should be treated with permethrin. Bed netting should be used for sleeping. Permethrin aerosol can be sprayed on bed netting, and window screens.
River blindness is also prevalent in Brazil and is a disease transmitted by the bite of a female black fly. They bite during the day and are found by rivers and streams in Brazil. Risk of infection is greater if you live or work near fly habitats. There are no vaccines for either river blindness or chemoprophylaxis applications so protective measures must be taken. Avoid areas known to have black flies and wear protective clothing.