Rio de Janeiro has had to open military field hospitals to cope with the influx of patients streaming into the public health care system with dengue fever. Meanwhile, troops are busy eradicating mosquitoes that spread dengue fever. So far 54 people have died from dengue in Rio reports Reuters, though other news agency report 67 people have fallen victim to the disease. Dengue fever can be a mild disease, but if it becomes the more complicated dengue hemorrhagic fever, it is deadly.