Joce R E, Murphy F, Robertson M H
Hertfordshire Health Agency, Welwyn Garden City, Herts.
Epidemiol Infect. 1995 Aug;115(1):31-8. doi: 10.1017/s095026880005809x.
during July 1991, a single laboratory reported an increased number of an unusual salmonella isolate. An outbreak control team was convened. A case was defined as an individual with diarrhoea from whose faecal sample Salmonella hadar was isolated after 1 July 1991. By 30 July, 90 isolates had been identified and 57 persons interviewed including 39 primary cases. Interviews failed to identify any common features among the cases. A review of the laboratory procedures revealed that the selenite enrichment medium was inoculated using the spoon from the stool collection kit after it was used to emulsify the faecal sample with saline for microscopy. Salmonella hadar was isolated from this saline. Once this practice was stopped, no further isolates of S. hadar were made. This pseudo-outbreak is a powerful reminder to verify the existence of an outbreak, especially when epidemiological data are inconsistent.
1991年7月期间，一个实验室报告称一种不寻常的沙门氏菌分离株数量增加。于是召集了一个疫情控制小组。病例定义为1991年7月1日后粪便样本中分离出哈达尔沙门氏菌的腹泻患者。到7月30日，已鉴定出90株分离株，并对57人进行了访谈，其中包括39例主要病例。访谈未能确定病例之间的任何共同特征。对实验室程序的审查发现，在使用粪便采集试剂盒中的勺子将粪便样本与盐水乳化以进行显微镜检查后，用该勺子接种了亚硒酸盐增菌培养基。从这种盐水中分离出了哈达尔沙门氏菌。一旦停止这种做法，就没有再分离出哈达尔沙门氏菌。这次假性疫情有力地提醒人们要核实疫情的存在，尤其是在流行病学数据不一致的时候。
