ABSTRACT
Sudan is subject to repeated outbreaks, including Viral Hemorrhagic Fever [VHF], which is considered to be a very serious illness. Yellow Fever [YF] outbreaks in Sudan have been reported from the 1940[s] through 2005. In 2012, a new outbreak of YF occurred in the Darfur region. To identify the potential for an outbreak, to diagnose the disease and to be able to recognize its cause among the initial reported cases. >This is a descriptive and investigative field study that applies standard communicable disease outbreak investigation steps. The study involved clinical, serological, entomological and environmental surveys. The field investigation confirmed the outbreak and identified its cause to be YF. National surveillance systems should be strong enough to detect VHF[s] in a timely manner. Local health facilities should be prepared to promptly treat the initial cases because the case fatality ratios [CFRs] are usually very high among the index cases