【摘要】 1965年新疆巴楚县阿克沙克马拉勒地区发生出血热患者11例,死亡10例。1966年同一地区发病8例,死亡6例。两年中共发生病人19例,死亡16例,病死率84.2%。1966年4~6月在这一地区进行了流行病学的调查研究。对1966年经临床观察和病原学或血清学确诊的5例患者和1965年有较完整病历或流行病学调查记录的6例,共11例病人流行病学调查资料进行分析的结果,发现所有病例均出现在4月下旬至6月上旬的50天时间内,具有明显的春夏季节性。除1例患者为乡村兽医外,其余都是牧羊人。7例患者发病前的活动范围为阿克沙克马拉勒以北,东西约70km的荒漠牧场中。病人之间没有联系,呈高度散发状态,其中3例有近期蜱咬史。另4例患者属于同一个家庭,首发病例是居住在牧场中放牧的家庭主妇,患病期间在前来参加护理和帮助家务的子女和儿媳中有3人相继被感染发病,是一起家庭内的暴发流行。首发病例有近期蜱咬史。用补体结合试验方法对当地居民进行了血清流行病学调查,共检查农牧民728人,其中抗体阳性者71人,阳性率10.2%,在有放牧史的156人中血清学阳性者30人,阳性率19.25%;没有放牧史的572人中血清阳性者44人,阳性率7.7%,二者之间差异显著(χ2=17.98,P<0.001)。在没有本病发生的阿图什县和疏附县农村居民89人作为对照的血清中没有检出抗体。当地的荒漠牧场是叶尔羌河南岸南北纵深约20km的以胡杨和红柳为主的荒漠林景观,已被充分利用作为牧场。附近农区的羊群在其中放牧。牧人居住在简陋的牧棚中,生活条件极为简单。几乎所有的牧羊人都有蜱咬史。调查中共发现硬蜱4属9种。亚洲璃眼蜱为优势种,其次为银盾革蜱。成蜱的活动季节在4~6月份,5月中旬数量达高峰。在4~5月份牛体上的蜱指数为130.67,羊体上蜱指数为97.87。在适宜的生境中(常有家畜放牧的胡杨-红柳混交林)亚洲璃眼蜱游离成蜱的数量很大,每人每小时可捕捉500只以上。在40批亚洲璃眼蜱标本中(每批50只)分离到巴楚出血热病毒4株。野生动物的初步调查发现塔里木兔、大耳猬、子午沙鼠和短耳沙鼠,这些动物体外均发现有幼蜱和稚蜱寄生,但未做进一步研究。当地家畜中数量最多的是绵羊,也是亚洲璃眼蜱成蜱的主要寄主。对18只绵羊血清标本进行补体结合试验的结果10只为阳性,阳性率为55.5%,而且抗体滴度较高。通过流行病学和生态学的初步研究,作者的结论如下:巴楚出血热是存在于当地以胡杨-红柳林型为主的荒漠林景观中的一种自然疫源性疾病。通过硬蜱的叮咬传播,亚洲璃眼蜱是主要媒介。通过与病人的密切接触,可因病人血液的污染而被感染并可造成家庭内的暴发流行。绵羊是硬蜱主要的血源动物,在维持硬蜱的密度及支持其数量的增长上起重要作用。在实验感染中发现绵羊经病毒攻击后呈不显性感染,但病毒血症可持续6天以上,通过绵羊后,病毒滴度显著增高的结果提示绵羊可能是本病重要的储存宿主和传染源。作者讨论了本病的预防措施和在流行病学及生态学方面需要进一步研究的问题。更多还原

【Abstract】 There were 11 cases with hemorrhagic fever occurred in Aksakmaral area of Bachu County in 1965, in which 10 cases died. In the same area 8 cases were found in 1966 and 6 were dead. Thus all of 19 cases occurred within two years, 16 were dead with the fatality rate of 84.2%. An epidemiological survey was carried out in this area from April-May, 1966. The epidemiological analysis showed that all of 11 cases with detailed epidemiological records occurred within 50 days from the first decade of April to the second decade of May. Except one veterinarian all of the remains were herdsman. Seven cases moved in the pastureland in a range about 70 kilometers before being ill. there was no relationship among these cases. The distribution was scattered. Three of them had a history of tick bitten before taken ill. Another 4 cases belonged to the same family, the initial case was home-maker and subsequently a son, a daughter and a daughter-in-law onset one after another within 9 days due to intimate contact when nursing their mother. It was a home-outbreak. The initial case had a history of tick bitten. In a sero-epidemiological survey the sera of 728 residents were examined with complement fixation test, 71 were positive (10.2%). In 156 persons who had the history of grazing sheep 30 were positive with the antibody positive rate of 19.25%. In 572 people without the grazing history, 44 were positive with the positive rate of 7.7%, and no positive antibody was found in 89 control sera from villagers in Atushi and Shufu Counties. The pastureland near Aksakmaral is a desert-forest (Tugai forest) landscape consisted mainly of populus diversifolia and Tamariska, located on the southern bank of Yerkan river, and fully be utilized as natural (grazing) farm. The living condition of the herdsman resided there at the rough sheds were very simple. Almost all the herdsman had tick bitten history. There were 9 species of ticks belonging to 6 genera found, the predominant species was Hyalomma asiticum, the next Dermacenter niveus. April and June were active seasons of the adult tick of Hyalomma, the peak of tick density in the middle of May. During April and May the tick index of cattle was 130.67 and 97.87 of sheep. The number of free adult Hyalomma asiaticum was very high in the suitable biotope, one could catch it over 500 within 1 hour. Four strains of Bachu hemorrhagic fever virus were isolated from 40 batches (50/patch) of Hyalomma asiaticum. The wild amimals were captured in this area including Lepus yarkendensis, Hemiechinus auritus, Meriones meridianus and Brachiones przewalskii. The larva and nymph of ticks were found on these animals. Sheep was the most numerous animal in livestocks. It played the role of blood source for ticks. In the sera of 18 local sheep tested with CF the antibody-positive rate was 55.5%(10/18) with higher titre. The authors concluded through the preliminary investigation that Bachu hemorrhagic fever was a natural focal infectious disease existed in the local desert-forest landscape. It was transmitted by tick bitten and Hyalomma asiaticum was the main vector. The intimate contact with patients could result in infection. Sheep was the major blood source for ticks and might play an important role in sustaining the tick density and supporting the extension of tick population. In view of that the sheep appeared asymptomatic infection after challenge with Bachu hemorrhagic fever virus, the viraemia could sustained over 6 days and the virus titer increased. It indicated the sheep possibly as the important reservoir of this virus. The authors discussed the preventive measures and the problems in epidemiology and ecology of this disease that needed further study.更多还原