肠炎沙门菌引起的一起食物中毒事件的分子流行病学研究

目的对2012年深圳市龙岗区某酒楼发生的一起食物中毒事件的病原体进行分离鉴定和同源性分析。方法对2012年深圳市龙岗区某酒楼发生的食物中毒事件进行现场调查并采集患者肛拭子15份、厨工肛拭子3份和手拭子1份、可疑食品1份以及物表涂抹拭子2份。通过分离鉴定、生化试验和血清学分型确定菌型,再使用脉冲场电泳（PFGE）分型方法对同期患者中相同菌型的菌株进行同源性分析。食物中毒菌株使用K—B进行药敏分析。结果流行病学调查及实验室病原学检测证实本次事件是一起由肠炎沙门菌引起的食物中毒。共分离到16株肠炎沙门菌,其中患者、厨工及可疑食品分离出的肠炎沙门菌同源性达到95％以上,与同一时期散发临床患者分离的肠炎沙门菌同源性为89．4％,可判断为来自同一克隆株。结论此次事件是一起由肠炎沙门菌引起的食物中毒,分子流行病学的证据显示其可能的传播途径为厨工带菌者污染食品烧鸡,被患者进食后引起感染。     

中国首例猕猴α疱疹病毒1型感染病例的溯源和防控对策

目的:对中国首例猕猴α疱疹病毒1型感染病例的感染来源开展调查,探索其感染因素和防控策略。方法:运用现场流行病学调查方法收集病例信息,采集职业暴露人群、猕猴和环境样本,并应用实时荧光PCR方法进行猕猴α疱疹病毒1型核酸检测,分析可能的感染源。结果:采集共同暴露职业人员样本84件,猕猴生物样品89件,环境样本370件,经检...     

一起疑似食源性诺如病毒暴发的流行病学调查

目的调查广州市某小学出现多名急性胃肠炎病例的感染来源、传播途径和危险因素。方法按照病例定义开展病例搜索,采用描述性流行病学和病例对照研究方法进行分析;样本采用RT．PCR方法检测诺如病毒核酸。结果2013年3月28～31日,共发生诺如病毒感染性腹泻27例,罹患率为3．31％（27／816）。3月28日14：00—22：00时为发病高峰,病例有班级聚集性,病例对照结果显示饭前洗手（OR=0．13,95％CI：0．03—0．63）和每天洗手次数≥5次（OR=0．26,95％CI：0．10～0．72）为保护因素。采集患者、厨工肛拭子、剩余食物及环境涂抹样等85份标本,其中5份检出诺如病毒GII-4型。结论这是一起由诺如病毒GII-4型引起的急性胃肠炎暴发,暴发原因是带毒厨工污染部分食物所致,以食源性传播为主。     

北京市海淀区新型冠状病毒核酸检测实验室污染情况调查与处理

目的:调查海淀区新型冠状病毒（以下简称"新冠病毒"）核酸检测实验室污染情况,并规范出现污染后的处置措施。方法:对海淀区34家新冠病毒核酸检测实验室内物表进行涂抹采样,运用real time RT-PCR方法进行新冠病毒核酸检测。结果:海淀区34家新冠病毒核酸检测实验室采集的510件样本中,有1件新冠病毒核酸检测结果为阳...     

一起副溶血性弧菌食物中毒的现场流行病学调查分析

目的查明一起食物中毒事件的发生原因和可疑危险因素来源。方法通过流行病学曲线及回顾性队列研究查找可疑餐次,对可疑餐次食物开展病例对照研究,分析食用不同食物与食物中毒的关联性,并采集可疑食物和病例等标本进行实验室检测。结果共发现87例病例,症状主要为腹泻（96.5%）、腹痛（91.9%）、呕吐（44.8%）、发热（32.2%）。20日午餐（RR=21,95%CI=9.2~47）、晚餐（RR=4.9,95%CI=3.3~7.3）均是本次疑似食物中毒的暴露餐次。烧鸭（OR=26,95%CI=5.7~118）和白切鸡（OR=21;95%CI=2.5~180）是发病的危险因素。厨师在对白切鸡及烧鸭切块过程中发生交叉污染可能是此次食物中毒的感染环节。病例肛拭子检测为副溶血性弧菌阳性。结论食用被副溶血性弧菌污染的白切鸡和烧鸭是导致本次食物中毒的主要原因,建议加强对餐饮机构厨师的监督管理,提高其卫生安全意识,防止类似事件再次发生。     

餐饮配送引起的一起学生集体食物中毒案例分析

目的分析一起由餐饮配送引起的较大级别学生集体食物中毒事件，为餐饮配送和学校集体用餐管理提供依据。方法通过流行病学调查、现场卫生学调查，结合病人临床症状以及实验室检测结果对事件原因进行分析判断。结果依据《葡萄球菌食物中毒诊断标准及处理原则》（WS／T80—1996），确认该事件为金黄色葡萄球菌食物中毒。配送食物受到金黄色葡萄球菌污染，在常温下存放时间过长，葡萄球菌繁殖并产生肠毒素是导致这起食物中毒事件的直接原因。结论餐饮配送已成为学校学生集体用餐的重要渠道之一，加强监督管理，提高餐饮配送单位自身管理水平和卫生意识对于预防学校集体食物中毒的发生具有重要意义。     

广州市2例人感染猪链球菌病的流行病学调查

目的查明广州市2例人感染猪链球菌病的感染来源、流行特征,为预防控制疫情提供依据。方法采用流行病学调查方法进行回顾性调查和现场调查,采集脑脊液标本进行细菌培养、分离,用PCR进行鉴定。结果患者均有明显的生猪接触史且首例患者手部有伤口,起病急,全身中毒症状明显,病程进展迅速,均为脑膜炎型。患者脑脊液分离培养出猪链球菌经生化和PCR检测结果为猪链球菌Ⅱ型,病人经及时治疗均痊愈出院。结论2例病例均为人感染猪链球菌病（Ⅱ型）实验室确诊病例,为散发疫情,相互间无流行病学关联,传播途径可能为接触被猪链球菌污染的生猪肉。     

河北省保定市一起水源性诺如病毒暴发疫情的流行特征及病原学研究

目的:对河北省保定市一起水源性诺如病毒感染性腹泻暴发疫情进行调查分析,了解其流行特征,确定致病原。方法:开展现场流行病学调查,采集患者呕吐物、肛拭子或粪便标本,居民末梢水以及污水井井水标本,采用荧光定量PCR（real-time PCR）检测诺如病毒核酸,对阳性标本进行扩增并测序分析。结果:该小区发现病例70例,罹患率...     

一起外运快餐引起爆发性食物中毒的调查报告

目的查明一起集体食物中毒事件发生的原因及影响因素。方法对食用该可疑食品的人员进行个案调查．对部分患者、从业人员肛拭采样以及抽检可疑食物、餐具进行细菌培养。结果共调查了539人，其中263人出现胃肠道症状，感染率为48．79％，确诊病例为82例。发病高峰集中在11月1日0-12时；临床症状以腹痛、腹泻为主。9例患者肛拭培养中检出致病性大肠埃希菌O127或腊样芽孢杆菌，1份卤水和4份餐具样品中亦检出致病菌。结论该起食物中毒是由混合性致病菌引起的，食品被污染的环节复杂多样。     

一起甲胺磷农药引起食物中毒的调查分析

目的通过对一起工地甲胺磷农药集体食物中毒事故的调查分析,探讨其预防方法以确诊是什么引起的食物中毒.方法采用流行病学调查,结合临床表现及实验室检验结果进行分析.结果所有患者均为在同一餐次、食用相同食物而发病,主要临床症状为头晕、头痛、恶心、呕吐、腹痛等;剩余食物甲胺磷阳性,定量检测均检出不同的甲胺磷含量,血液样本胆碱脂酶活力下降.结论这是一起典型的甲胺磷农药污染引起的食物中毒事件.     

A radioimmunoassay for parathymosin

A slide latex agglutination (SLA) assay was developed for rapid screening for Clostridium perfringens type A enterotoxin (CPE). SLA specifically detected CPE added to buffer or normal feces (sensitivity limit of 1 μg CPE/g feces). Using clinical fecal samples from C. perfringens food poisoning cases, a strong correlation was shown between (1) SLA results and results from other CPE assays and (2) between SLA results and illness status.     

Development and preliminary evaluation of a slide latex agglutination assay for detection of Clostridium perfringens type A enterotoxin

A slide latex agglutination (SLA) assay was developed for rapid screening for Clostridium perfringens type A enterotoxin (CPE). SLA specifically detected CPE added to buffer or normal feces (sensitivity limit of 1 μg CPE/g feces). Using clinical fecal samples from C. perfringens food poisoning cases, a strong correlation was shown between (1) SLA results and results from other CPE assays and (2) between SLA results and illness status.     

PCR identification of the plasmid-borne enterotoxin gene (cpe) in Clostridium perfringens strains isolated from food poisoning outbreaks

It is generally accepted that Clostridium perfringens strains associated with food poisoning carry their enterotoxin gene, cpe, on the chromosome, while C. perfringens strains isolated from non-food-borne diseases, such as antibiotic-associated diarrhea and sporadic diarrhea, carry cpe on the plasmid. However, we recently encountered a food poisoning outbreak caused by C. perfringens bearing a plasmid cpe. We therefore investigated a total of 31 clinical and non-clinical C. perfringens strains to locate the cpe gene by PCR. The cpe of nine heat-sensitive (100 degrees C for 10min) strains isolated from three outbreaks of food poisoning were located on the plasmid, while those of six heat-resistant strains from other food poisoning outbreaks were located on the chromosome. Moreover, the cpe of 5 heat-sensitive strains isolated from healthy human feces and those of 11 heat-sensitive soil strains were also located on the plasmid. These findings indicate that heat-sensitive, cpe-plasmid-borne C. perfringens strains should not be disregarded as causative agents of food poisoning.     

Acute lead poisoning with eosinophilic meningoencephalitis in calves on a farm receiving land application of sewage sludge

A total of 3 cases of acute lead poisoning in calves was confirmed by atomic absorption spectrophotometric analysis of biological samples, presence of an acute lead exposure source, clinical signs of impaired vision in one case and eosinophilic meningoencephalitis in another case. One of two other calves which died approximately 2 months earlier had nervous signs and it is likely that they also had lead poisoning. Dams of two of the cases did not have elevated lead levels. Municipal sewage sludge had been applied to most fields on the farm during the preceding 5 year period. There had been approximately a doubling of the lead content in the soil; however, the foodstuffs produced on the farm had low lead concentrations. The extremely high lead levels in the abomasal contents and feces of calves eliminated sludge as the source of the lead in this acute poisoning episode. The contents of oil filters, accessible to calves but not to adult cattle, had lead levels as high as 26,922 micrograms/g and was the most likely lead source responsible for this lead intoxication. It appears that the manifestation of eosinophilic meningoencephalitis in lead poisoning cases may occur in young calves as well as in cows and in acute as well as in chronic intoxications.     

Torque teno virus in fecal samples of patients with gastroenteritis: prevalence, genogroups distribution, and viral load

Torque teno virus (TTV, genus Alphatorquevirus, family Anelloviridae) is a DNA virus, highly prevalent in populations from around the world. TTV isolates have been classified into five main phylogenetic groups (1-5) showing a large genetic distance between them. The presence of TTV has been detected in feces. However, whether all five TTV genogroups are excreted in feces and the frequency of these events are presently unknown. The presence of TTV DNA was assessed in feces from 135 Brazilian (0-90 years old) patients with gastroenteritis by using three PCR methods, including real-time PCR. One hundred twenty one (91.1%) samples were positive with at least one method. Using a genogroup-specific assay, it was shown that all genogroups were present. Thirty-seven (27.4%), 27 (20.0%), 57 (42.2%), 29 (21.5%), and 33 (24.4%) fecal samples contained TTV isolates belonging to genogroups 1-5, respectively. Coinfections with two, three, four, and five TTV genogroups were found in 23 (17.0%), 15 (11.1%), 7 (5.2%), and 7 (5.2%) fecal samples, respectively. Thus, 52 (38.5%) samples contained more than one TTV genogroup. Viral loads ranged from 2.6 to 6.5 log genome equivalents per gram of feces. However, only moderate variations of viral load were noted depending on genogroup and number of coinfecting TTV genogroups. These results show a high prevalence and a diversity of TTV isolates in feces.     

急性毒鼠强中毒的脑电图分析

目的:探讨急性毒鼠强中毒时脑电图的变化及与临床的关系。方法:对13例急性毒鼠强中毒的脑电图进行回顾性分析及随访。结果:13例患者中正常范围内脑电图1例,轻度异常脑电图2例,均为轻度中毒患者。这2例患者的脑电图在一周后复查时恢复正常范围。5例中度异常脑电图均为中度中毒患者,在一周后复查时4例脑波恢复α波,但仍有较多量的θ波,复型慢波及阵发性尖波消失。另1例为6-7Hz的θ波,并仍有少量的复型慢波及阵发性尖波。5例重度异常脑电图其中4例为重度中毒患者,1例为中度中毒患者。第一次复查时脑波虽有改善但仍可见复型慢波及阵发性高幅尖波。这10例中一重度异常脑电图的患者在3月后第二次复查时,其中8例脑电图恢复正常范围,另2例脑波虽恢复到8-9Hz的α波,但仍有较多量的θ波及少量的复型慢波,阵发性尖波消失。结论:毒鼠强中毒患者脑电图的异常程度与中毒程度及临床症状相一致。其动态变化可反映病情的转归。提示脑电图检查可反映脑损害的程度,可为临床诊断,预后,评估提供依据。     

Diagnosing tick-borne encephalitis: a re-evaluation of notified cases

We set out to investigate the serological response of TBE virus (TBEV)-specific IgM and IgG antibodies in stored serum and cerebrospinal fluid (CSF) in notified TBE patients, in order to confirm or reject the diagnosis. We applied the ELISA methods used in clinical practice, Enzygnost and Immunozym, and assessed RT-PCR as a diagnostic tool. A total of 173 TBE cases were notified to the Public Health Agency. Samples from 129 patients were eligible for the study. Stored serum samples were found for 111 patients and CSF samples for 88 patients. All serum samples were analyzed with both Enzygnost and Immunozym, as well as an additional 140 control samples. CSF samples, including samples from ten controls, were analyzed with Immunozym. RT-PCR for TBEV was performed on 126 serum, two whole blood, 96 CSF, two feces and four nasopharynx samples. Only two of 111 notified patients lacked detectable TBEV IgM in serum, from whom one sample was RT-PCR positive. According to the ECDC definition, 117/129 (90.7%) of the reported TBE cases were confirmed. Positive RT-PCR results were obtained in eight patients, one from whole blood and eight from serum samples. Four out of eight of the RT-PCR positive patients were TBEV-IgM positive and none had detectable TBEV-specific IgG. All of the tested CSF, feces and nasopharynx samples were RT-PCR-negative. TBEV-specific IgG was detected in 88.4% and IgM in 31.6% of the CSF samples. RT-PCR on serum samples and CSF IgG antibodies can be used as complementary methods in TBE diagnostics, not least early in the disease course.