Miami Herald: While the world continues to be on alert for a potential swine flu pandemic, South Americans have been suffering for months from one of the worst viral epidemics on record. Hundreds of thousands of people have been sickened by dengue fever this year; more than 70 have died. ”This is the largest epidemic in many years,” said Dr. Eddy Martinez, the director of epidemiology for Bolivia’s Ministry of Health in the capital city of La Paz. By mid-April, he said, there had …