Genetic Analysis of Viruses Associated with Emergence of Rift Valley Fever in Saudi Arabia and Yemen, 2000-01

摘要

The first confirmed Rift Valley fever outbreak outside Africa was reported in September 2000, in the Ara-bian Peninsula. As of February 2001, a total of 884 hospitalized patients were identified in Saudi Arabia,with 124 deaths. In Yemen, 1,087 cases were estimated to have occurred, with 121 deaths. Laboratorydiagnosis of Rift Valley fever virus (RVFV) infections included virus genetic detection and characterizationof clinical specimens by reverse transcription-polymerase chain reaction, in addition to serologic tests andvirus isolation. Genetic analysis of selected regions of virus S, M, and L RNA genome segments indicatedlittle genetic variation among the viruses associated with disease. The Saudi Arabia and Yemen viruseswere almost identical to those associated with earlier RVF epidemics in East Africa. Analysis of S, M, andL R NA genome segment sequence differences showed similar phylogenetic relationships among theseviruses, indicating that genetic reassortment did not play an important role in the emergence of this virus inthe Arabian Peninsula. These results are consistent with the recent introduction of RVFV into the ArabianPeninsula from East Africa