Contigiani M S, de Basualdo M, Cámara A, Ramírez A, Díaz G, González D, Medeot S, Osuna D
Instituto de Virología Dr. J.M. Vanella, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Argentina.
Rev Argent Microbiol. 1993 Oct-Dec;25(4):212-20.
In Argentina, there is no record of human cases produced by Dengue virus (Flavivirus), but Paraguay and Brasil (neighbouring countries) have notified human outbreaks of Dengue Haemorrhagic Fever. In this report, we inform the serological results of a limited human outbreak of a Dengue-like acute illness that occurred in General Belgrano Island, Formosa, Argentina in April 1989. This island is 35 km far from Clorinda city of Paraguay river, with a human population of 150 inhabitants. The weather of this area is humid with abundant rainfall, favouring mosquitoes proliferation. Two samples of serum from 28 human notified cases were studied using hemagglutination inhibition test (HI), complement fixation (CF), and plaque reduction neutralization (NT) test in Vero cell cultures. All tested sera were negative to Dengue, St. Louis encephalitis, Yellow Fever, Bussuquara, Rocio, Eastern and Western Equine Encephalitis arboviruses as well as Influenza and Rubella viruses. By contrast, infection with Venezuelan equine encephalitis virus (VEE), subtype VI-AG80-663 strain was demonstrated (34.5% positive by HI, 39.1% by CF and 51.6% by NT). Seroconversion was detected by NT in six cases and only five were positive by CF. The 26.8% of the sera reacted also with VEE subtype I AB by NT. Considering that no cross reaction were detected in NT with these two subtypes, our results suggest that both viruses are concomitantly circulating in the studied area. Furthermore, the seroconversions detected with AG80-663 strain firmly indicate that during the outbreak this virus subtype was circulating in the island, although we could not assure that it was the causal agent of the acute disease.
在阿根廷，没有登革病毒（黄病毒属）导致人类病例的记录，但邻国巴拉圭和巴西已通报了登革出血热的人间疫情。在本报告中，我们通报了1989年4月在阿根廷福尔摩沙省贝尔格拉诺将军岛发生的一起有限的类登革急性疾病人间疫情的血清学检测结果。该岛距离巴拉圭河的克洛林达市35公里，有150名居民。该地区气候湿润，降雨充沛，有利于蚊子繁殖。对28例报告病例的两份血清样本进行了研究，采用了血凝抑制试验（HI）、补体结合试验（CF）以及在Vero细胞培养物中的蚀斑减少中和试验（NT）。所有检测血清对登革病毒、圣路易斯脑炎病毒、黄热病病毒、布苏夸拉病毒、罗西奥病毒、东部和西部马脑炎虫媒病毒以及流感病毒和风疹病毒均呈阴性。相比之下，检测到感染了委内瑞拉马脑炎病毒（VEE），VI - AG80 - 663株亚型（HI阳性率为34.5%，CF阳性率为39.1%，NT阳性率为51.6%）。通过NT检测到6例血清转化，CF检测仅5例呈阳性。26.8%的血清通过NT也与VEE I AB亚型发生反应。鉴于在NT检测中未发现这两种亚型之间有交叉反应，我们的结果表明这两种病毒在研究区域同时传播。此外，用AG80 - 663株检测到的血清转化有力地表明，在疫情期间该病毒亚型在该岛传播，尽管我们不能确定它就是急性疾病的病原体。
