Hemorrhagic fevers. This term conceals a group of tropical infections caused by a vast variety of viruses. Some fevers are transmitted by airborne droplets and the bites of mosquitoes, while the others directly through the blood, infected things or meat and milk of infected animals. All hemorrhagic fevers stand out by a high resistance of their carriers that are not destroyed in the environment. Symptoms during the first stage are similar: high fever, delirium, pain in the muscles and bones. After comes the physiological bleeding from different organs and the patients experience blood clotting problems. The fever frequently affects liver, heart and kidneys. Blood supply disorders may cause necrosis of the fingers and toes. Mortality is from 10-20% in the event of yellow fever which is the most secure kind of hemorrhagic fevers because an effective vaccine is invented to cure it. There is no vaccine to treat Marburg and Ebola fever, that’s why the mortality rate is up to 90%.