一起由食物引起的流行性出血热爆发

<正> 流行性出血热(EHF,以下简称出血热),自1978年李镐汪等从疫区黑线姬鼠分离到朝鲜出血热病毒,在病原学上有了重大突破以来,在流行病学上的研究也有了进一步的发展。有关其传播途径问题,长期以来国内外虽有各种假说,但均缺乏确凿的病原学或流行病学证据。因此,对传播途径的深入研究,实为有效防制本病的关键问题。 1982年10—12月,在西安××学院内发生了一起流行性出血热的爆发,通过流行病学调查分析,试图对本病的传播途径问题加以研究。

A-Food-Borne Outbreak of Epidemic Hemorrhagic Fever(EHF)

From October to December 1982, a food-borne outbreak of EHF occurred in a college in the suburbs of Xi'an. There was a total of 40 cases in this outbreak. According to clinical typing, 33.3％ of patients were severe. The positive rate of serum immunofluorescent antibody was 86.1％, but in 97 intimate contacts these antibodies were all nagative. Apodemus agrarius was a predominant rodent (76.5％) in the studied area. The positive rate of immunofluorescent antigen in the Iung of A agrarius was 10.4％. The time and place of distribution of EHF showed a high degree of concentration: all 40 cases occurred within 41 days and 38 of them occurred in the students' residential quarters, 38 patients but two being students. Epidemiological studies suggested that 38 cases were associated with a dining room. Data of investigations supported the hypothesis that this outbreak was transmitted by food. Meantime, part of students had some experiments with rats, the morbidity rate of EHF in students who had got toach with rats were significantly higher than in those who had not. The experimental animals were examined for EHF antigen in the lung, and the positive rate was 9.2％. For this reason, there was a great confusion to draw a conclusion. Afterwards, the confounding factors were excluded by dichotomy and retrospective case-control studies, and the charateristic of this outbreak was identified undoubtedly.