Abstract:
In June 2022, a gastroenteritis outbreak occurred in a town in Northern Italy, possibly associated with the ingestion of norovirus from public drinking water. Noroviruses are highly infectious RNA viruses, with high stability in the environment. They are the primary cause of non-bacterial gastroenteritis worldwide, and despite the fact that the disease is mainly self-limiting, norovirus infection can lead to severe illness in the immunocompromised, the elderly and children. Immediately after the notification of the suspected norovirus outbreak, faecal specimens were collected from hospitalised patients, and water samples were collected from public drinking fountains in the affected area, to confirm the presence of norovirus. Norovirus was detected in 80 % (95 % CI 0.58-0.91) of the faecal specimens, and in 50 % (95 % CI 0.28-0.72) of the water samples using RT (reverse transcription) Real-time PCR. The identification of GII genotype in all samples confirmed public drinking water as the source of norovirus contamination. In addition, in one faeces and one water sample, the co-presence of genotypes GI and GII was detected. The strains were typed by sequencing, with most of them belonging to the genotype GII.3. Immediately after the confirmation of norovirus contamination in public drinking water, the local competent authorities applied safety measures, resulting in a decline in number of cases. Moreover, after the application of disinfection protocols in the water plant, the sampling was repeated with negative results for norovirus in the affected area. However, positive samples were found in the neighbouring area (prevalence 10.00 %, 95 % CI 0.02-0.40) and in the water spring (prevalence 50.00 %, 95 % CI 0.21-0.78), suggesting norovirus persistence and spread from the water source. The prompt identification of the source of contamination, and collaboration with the local authorities guided the implementation of proper procedures to control viral spread, resulting in the successful control of the outbreak.
摘要:
2022年6月,意大利北部的一个城镇发生肠胃炎疫情,可能与从公共饮用水中摄入诺如病毒有关。诺罗病毒是高度传染性的RNA病毒,在环境中具有很高的稳定性。它们是全球非细菌性胃肠炎的主要原因,尽管这种疾病主要是自限性的,诺如病毒感染可导致免疫功能低下的严重疾病,老人和孩子。在接获怀疑诺如病毒爆发的通知后,粪便标本是从住院患者收集的,水样是从受影响地区的公共饮水机收集的,确认诺如病毒的存在。在80%(95%CI0.58-0.91)的粪便标本中检测到诺如病毒,并使用RT(逆转录)实时PCR在50%(95%CI0.28-0.72)的水样中。所有样品中GII基因型的鉴定证实公共饮用水是诺如病毒污染的来源。此外,在一个粪便和一个水样中,检测到基因型GI和GII的共存。通过测序对菌株进行分型,其中大多数属于基因型GII.3。在确认公众饮用水中诺如病毒污染后,当地主管部门采取了安全措施,导致案件数量下降。此外,在水厂应用消毒方案后,在受影响地区,诺如病毒的结果为阴性。然而,在邻近地区发现阳性样本(患病率10.00%,95%CI0.02-0.40)和水泉(患病率50.00%,95%CI0.21-0.78),表明诺如病毒持续存在并从水源传播。及时识别污染源,与地方当局的合作指导了控制病毒传播的适当程序的实施,导致疫情的成功控制。