A dengue fever epidemic is sweeping Rio de Janeiro state and spreading to other Brazilian cities. Some 23 people have died and more than 50,000 have been diagnosed. Officials fear the actual number of cases may be four times those reported. The mosquito-borne disease is present is all areas of the state, in rich as well as poor neighborhoods. Symptoms are severe headaches, high fever, joint and muscle pain, nausea, vomiting and rash. There is no specific treatment or cure, but the disease usually runs its course in ten days. The only way to prevent the disease is to avoid mosquito bites. Wear clothing that covers the arms and legs and use insect repellent.