A yellow fever vaccination is recommended for those travelling to rural areas and parts of Sao Paulo and Parana. Those travelling from infected areas require a yellow fever certificate. Typhoid and Hepatitis A immunisation is also recommended. Mosquito-borne diseases like dengue fever and malaria are prevalent and insect protection is strongly advised. Malaria exists below 2,953ft (900m) in most rural areas. Chagas disease, caused by a parasite, is widespread in rural areas of Brazil. Until recently infection was believed to be from insect bites only, but an outbreak in March 2005 that has caused three deaths in Santa Catarina was traced to the ingestion of sugar cane juice contaminated with the faeces of vector insects, and in the north east further cases were linked to the ingestion of juice from the acai fruit; visitors are advised to seek medical advice urgently if any of the symptoms occur (fever, nausea, muscle aches and pains and/or swelling at the site of the insect bite). Tap water is heavily treated resulting in a strong chemical taste; bottled water is, however, freely available for drinking purposes. Milk in rural areas is not pasteurised. Travellers are advised to take along medication for travellers’ diarhhoea. Hospitals in the major cities are fairly good, but medical costs are high and medical insurance is strongly recommended.