克—雅二氏病研究进展

牛海绵状脑病与变种克－雅二氏病之间的关系是近年来研究的热点之一，本文引用最新发表的文献，从分子免疫学与流行病学角度阐明了引起这两个病的病原体（朊蛋白）是一致的，并对该病的分型，临床表现，诊断与鉴别诊断作了扼要介绍。     

牛海绵状脑病和变异的克雅氏病：背景、演变和目前关注的问题（二）

第一例vCJD的发病出现在1994年初。也就是第一例BSE在牛身上被认识将近10年后。假设最早的vCJD反映了最早的与BSE接触。这个潜伏期与接着发生于实验动物身上的外周感染的潜伏期以及人类医源性CJD的潜伏期相一致。到2000年11月底。在英国总共有87例确定的或可能的病例,法国有2例证实的和1例可能的病例。爱尔兰共和国有1例证实的病例。     

莱姆病研究进展

莱姆病是一种新发的蜱传自然疫源性疾病,其病原体是伯氏疏螺旋体(Borrelia brugdorferi)。人被携带病原体的蜱叮咬而感染,可引起皮肤、神经、心脏和关节等多器官、多系统的损害,严重者造成终生残疾,甚至死亡。在我国,自1986年首次报道发现莱姆病以来,血清流行病学调查表明至少在27个省(市、自治区)的人群存在伯氏疏螺旋体感染,病原学证实其中18个省(市、自治区)存在莱姆病自然疫源地,9种蜱携带伯氏疏螺旋体,牛、羊、狗、野兔和8种野鼠有自然感染。     

军团病研究进展

军团病是近20年新发生的感染性疾病，最早于1976年在美国一次退伍军人集会中发生，此后在世界各国均有病例报告。2000—2002年欧洲共报道10322例军团菌感染患者，其中189起系医院内感染。我国于1982年首次从1例肺炎患者中分离到嗜肺军团菌目。目前军团菌属已分离出42种，64个血清型，其中至少有19种与人类军团病相关，但与人类疾病关系最密切的是嗜肺军团菌，共有15个血清型，我国分离的嗜肺军团菌以1、5、6、8、10血清型为主，此外有米克戴德军团菌和高曼军团菌。军团菌广泛存在于水和土壤等环境中，污染的水和土壤以气溶胶形式被人体吸入可能是军团菌感染的主要途径，军团菌也可在医院、宾馆等单位的供水系统、温泉水、空调的冷却塔等检出，并可能是引起暴发流行的原因。     

MHC typing in variant Creutzfeldt-Jakob disease

Identification of factors that cause susceptibility to, and clinical expression of, variant Creutzfeldt-Jakob disease (vCJD) is essential for future management of the disease. We established MHC genotypes of 76 individuals with vCJD and 131 controls, and analysed MHC phenotypes in relation to age of onset of vCJD and its duration from presentation to death. There were no significant differences between vCJD and control populations in frequencies of any MHC types, nor were there associations between MHC type and age of onset or duration of vCJD disease. Our results do not support the idea of an association between MHC types and either susceptibility to, or expression of, vCJD.     

Prion infectivity in variant Creutzfeldt-Jakob disease rectum

BACKGROUND: Disease-related prion protein (PrP(Sc)) is readily detectable in lymphoreticular tissues in variant Creutzfeldt-Jakob disease (vCJD), but not in other forms of human prion disease. This distinctive pathogenesis, with the unknown population prevalence of asymptomatic vCJD infection, has led to significant concerns that secondary transmission of vCJD prions will occur through a wide range of surgical procedures. To date PrP(Sc):prion infectivity ratios have not been determined in vCJD, and it is unknown whether vCJD prions are similar to experimental rodent prions, where PrP(Sc) concentration typically reflects infectious prion titre. AIM: To investigate prion infectivity in vCJD tissue containing barely detectable levels of PrP(Sc). METHODS: Transgenic mice expressing only human PrP (Tg(HuPrP129M(+/+)Prnp(o/o))-35 and Tg(HuPrP129M(+/+)Prnp(o/o))-45 mice) were inoculated with brain or rectal tissue from a previously characterised patient with vCJD. These tissues contain the maximum and minimum levels of detectable PrP(Sc) that have been observed in vCJD. RESULTS: Efficient transmission of prion infection was observed in transgenic mice inoculated with vCJD rectal tissue containing PrP(Sc) at a concentration of 10(4.7)-fold lower than that in vCJD brain. CONCLUSIONS: These data confirm the potential risks for secondary transmission of vCJD prions via gastrointestinal procedures and support the use of PrP(Sc) as a quantitative marker of prion infectivity in vCJD tissues.     

Incidence of variant Creutzfeldt-Jakob disease in the UK

The number of deaths from variant CJD (vCJD) in the UK increased in the last quarter of 1998, although numbers were lower in subsequent quarters. We analysed the numbers of definite and probable (living and dead) vCJD cases since 1994 to assess trends in incidence. We estimated that the number of onsets increased by 23% per year for 1994-2000 (p=0.004), and that deaths increased by 33% for 1995-2000 (p=0.005). The absolute number of cases in the UK is still low, but such an increase should be a matter of concern.