Goller J L, Dimitriadis A, Tan A, Kelly H, Marshall J A
Victorian Infectious Diseases Reference Laboratory, 10 Wreckyn Street, North Melbourne, Victoria 3051, Australia.
J Hosp Infect. 2004 Dec;58(4):286-91. doi: 10.1016/j.jhin.2004.07.001.
Noroviruses are important pathogens in both sporadic cases and outbreaks of gastroenteritis in humans. Noroviruses can affect individuals of all ages in a variety of settings, but are a particularly important cause of gastroenteritis in aged-care facilities. The relationship between clinical symptoms and norovirus excretion and the possible role of asymptomatic carriage of norovirus in the elderly are poorly understood. This study examined symptoms and norovirus excretion in elderly individuals associated with a norovirus outbreak in an aged-care facility. Ten individuals aged 79-94 years were recruited for the study. Nine were symptomatic and one was an asymptomatic contact who subsequently developed gastroenteritis. The 10 participants were interviewed regarding their clinical symptoms between two and six times over a three-week study period. One or more sequential faecal samples were collected from all participants over the same period and tested by reverse transcription-polymerase chain reaction for the presence of norovirus. Norovirus was detected in faecal samples from all 10 study participants and was commonly detected in formed stools. In the nine symptomatic participants, acute symptoms such as diarrhoea and vomiting had largely resolved by the third or fourth day of illness, but non-specific symptoms such as headache, thirst and vertigo could persist for as long as 19 days. Both acute and non-specific symptoms appeared to resolve and recur in some participants. The median excretion time for norovirus was 8.6 days (range 2-15 days) in symptomatic participants (N=5). There was no general relationship between the duration of norovirus excretion and the duration of either acute or non-specific symptoms. A faecal sample collected from the asymptomatic contact the day before gastroenteritis symptoms began was positive for norovirus, demonstrating prodromal excretion of norovirus. The results of this study indicate that infection control guidelines should consider both long-term excretion and prodromal excretion of norovirus, and the possibility that formed stools can contain norovirus. Furthermore, the care of elderly individuals recovering from a norovirus infection should take long-term non-specific clinical symptoms into account.
诺如病毒是人类散发性胃肠炎病例和暴发疫情中的重要病原体。诺如病毒可在各种环境中感染所有年龄段的个体，但在老年护理机构中，它是胃肠炎的一个特别重要病因。临床症状与诺如病毒排泄之间的关系以及诺如病毒无症状携带在老年人中的可能作用尚不清楚。本研究调查了一家老年护理机构中与诺如病毒暴发相关的老年人的症状和诺如病毒排泄情况。招募了10名年龄在79至94岁之间的个体参与研究。9人有症状，1人是无症状接触者，随后出现了胃肠炎。在为期三周的研究期间，对这10名参与者进行了两至六次关于其临床症状的访谈。在同一时期从所有参与者那里采集了一份或多份连续的粪便样本，并通过逆转录聚合酶链反应检测是否存在诺如病毒。在所有10名研究参与者的粪便样本中均检测到了诺如病毒，且在成形粪便中也普遍检测到。在9名有症状的参与者中，腹泻和呕吐等急性症状在发病后的第三天或第四天基本缓解，但头痛、口渴和眩晕等非特异性症状可能持续长达19天。一些参与者的急性和非特异性症状似乎会缓解并复发。有症状参与者（N = 5）中诺如病毒的中位排泄时间为8.6天（范围为2至15天）。诺如病毒排泄持续时间与急性或非特异性症状持续时间之间没有普遍关系。在胃肠炎症状开始前一天从无症状接触者采集的粪便样本中诺如病毒呈阳性，表明诺如病毒有前驱排泄。本研究结果表明，感染控制指南应考虑诺如病毒的长期排泄和前驱排泄，以及成形粪便可能含有诺如病毒的可能性。此外，对从诺如病毒感染中康复的老年人的护理应考虑到长期的非特异性临床症状。
