The Pan American Health Organization says inadequate sewage disposal and water supply issues in residential areas are part of the reason Brazil has a heightened dengue risk . Brazil has reported the most cases of dengue fever in South America over last 30 years . High-risk cities are Recife , Fortaleza and Natal , studies say . Comment: Hepatitis A and B , yellow fever , typhoid and malaria are also concerns during World Cup .
Brazil has reported the most cases of dengue fever in South America over last 30 years . High-risk cities are Recife , Fortaleza and Natal , studies say . Comment: Hepatitis A and B , yellow fever , typhoid and malaria are also concerns during World Cup .