An epizootic of Rift Valley fever in Egypt in 1997
An epizootic of Rift Valley fever in Egypt in 1997
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DOI：
10.20506/rst.18.3.1195
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发表时间：
1999-12-01
期刊：
影响因子：
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通讯作者：
Hussein, M
中科院分区：
文献类型：
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作者：
Abd El-Rahim, IHA;Abd El-Hakim, U;Hussein, M
1997年4月至8月间，埃及发生了裂谷热流行病。感染牛和羊的症状是高热、黄疸、血性腹泻和流产。在上埃及的阿斯旺和艾斯尤特省收集流产羊胎和受影响牛群的血清，进行病毒学和血清学检查。接种胎肝和胎脾混悬液后48 h，在Vero细胞培养物中检测到细胞病变效应。相同的悬浮液在小鼠脑内注射后2至3天引起麻痹和死亡。采用琼脂凝胶沉淀试验（AGPT）和直接荧光抗体技术对分离的病毒进行鉴定。血清学检查结果表明，所有被测羊（57）和牛（93）的血清学试验，使用补体结合（CF），血清中和（SN）和间接免疫荧光试验的阳性结果;而只有48（84.2%）的57只羊血清和69（74.2%）的93头牛血清使用AG PT阳性结果。血清样品的滴定表明SN比CF更敏感。受感染的反刍动物的进口，特别是来自苏丹的骆驼，是感染的主要来源。阿斯旺是埃及与苏丹相邻的省份，是埃及裂谷热病毒感染的重点地区。由于昆虫数量多，裂谷热的动物流行病通常发生在埃及的夏季。不时出现的动物流行病表明埃及实施的裂谷热疫苗接种计划失败。
An epizootic of Rift Valley fever (RVF) occurred in Egypt between April and August 1997. The signs among infected cattle and sheep were high fever, icterus, bloody diarrhoea and abortion. Aborted sheep foetuses a nd sera from the affected herds were collected in the Aswan and Assiut Provinces, Upper Egypt, for virological and serological examination. A cytopathic effect was detected in Vero cell cultures 48 h after inoculation with the foetal liver and spleen suspensions. The same suspensions caused paralysis and mortalities two to three days post intra cerebral injection in mice. The isolated virus was identified using an agar gel precipitation test (AGPT) and a direct fluorescent antibody technique. Serological examination revealed that all tested sheep (57) and cattle (93) gave positive results to serological tests, using a complement fixation (CF), serum neutralisation (SN) and indirect immunofluorescence assay; while only 48 (84.2%) out of 57 sheep sera and 69 (74.2%) out of 93 cattle sera gave positive results using an AG PT. Titration of the serum samples indicated that SN is more sensitive than CF. Importation of infected ruminants, especially camels from the Sudan, is the principal source of infection. Aswan, the nea rest Egyptian province to the Sudan, is the focus of RVF virus infection in Egypt. As a result of high insect populations, the epizootics of RVF have usually occurred during the summer in Egypt. Reoccurrence of epizootics from time to time indicates failure of the applied RVF vaccination programme in Egypt.