Rift Valley Fever and Crimean–Congo Hemorrhagic Fever: Arthropod-borne Zoonotic Diseases of Concern for Sudan

Abstract

Rift Valley fever (RVF) is a mosquito-borne virus of the family Bunyaviridae that periodically causes large severe disease outbreaks in livestock and humans in various areas of Africa, including Sudan. RVF in livestock is often characterized by sweeping abortion storms and high mortality disease, particularly in young animals. People get infected through exposure to the highly viremic infected livestock or by mosquito bite. RVF in humans can manifest as encephalitis, hepatitis and other severe complications with high case fatality among hospitalized patients. RVF outbreaks are often linked to unusually high rainfall or flooding, due to the floodwater Aedes sp. a mosquitoes serving as the primary virus vector. Crimean-Congo hemorrhagic fever (CCHF) virus is a tick-borne member of the family Bunyaviridae which is associated with severe HF in humans. Bite by infected ticks or exposure to viremic infected livestock are the main ways people acquire the infection. Unlike RVF virus, CCHF virus is not known to cause disease in infected livestock. The ecology, epidemiology and prevention of these viral diseases will be discussed.