Hutin Y J, Pool V, Cramer E H, Nainan O V, Weth J, Williams I T, Goldstein S T, Gensheimer K F, Bell B P, Shapiro C N, Alter M J, Margolis H S
Hepatitis Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
N Engl J Med. 1999 Feb 25;340(8):595-602. doi: 10.1056/NEJM199902253400802.
We investigated a large, foodborne outbreak of hepatitis A that occurred in February and March 1997 in Michigan and then extended the investigation to determine whether it was related to sporadic cases reported in other states among persons who had consumed frozen strawberries, the food suspected of causing the outbreak.
The cases of hepatitis A were serologically confirmed. Epidemiologic studies were conducted in the two states with sufficient numbers of cases, Michigan and Maine. Hepatitis A virus RNA detected in clinical specimens was sequenced to determine the relatedness of the virus from outbreak-related cases and other cases.
A total of 213 cases of hepatitis A were reported from 23 schools in Michigan and 29 cases from 13 schools in Maine, with the median rate of attack ranging from 0.2 to 14 percent. Hepatitis A was associated with the consumption of frozen strawberries in a case-control study (odds ratio for the disease, 8.3; 95 percent confidence interval, 2.1 to 33) and a cohort study (relative risk of infection, 7.5; 95 percent confidence interval, 1.1 to 53) in Michigan and in a case-control study in Maine (odds ratio for infection, 3.4; 95 percent confidence interval, 1.0 to 14). The genetic sequences of viruses from 126 patients in Michigan and Maine were identical to one another and to those from 5 patients in Wisconsin and 7 patients in Arizona, all of whom attended schools where frozen strawberries from the same processor had been served, and to those in 2 patients from Louisiana, both of whom had consumed commercially prepared products containing frozen strawberries from the same processor.
We describe a large outbreak of hepatitis A in Michigan that was associated with the consumption of frozen strawberries. We found apparently sporadic cases in other states that could be linked to the same source by viral genetic analysis.
我们调查了1997年2月和3月在密歇根州发生的一起大规模食源性甲型肝炎暴发事件，随后扩大调查范围，以确定该事件是否与其他州报告的散发病例有关，这些散发病例的患者均食用过被怀疑导致此次暴发的冷冻草莓。
甲型肝炎病例经血清学确诊。在病例数量充足的密歇根州和缅因州开展了流行病学研究。对临床标本中检测到的甲型肝炎病毒RNA进行测序，以确定与暴发相关病例及其他病例的病毒相关性。
密歇根州23所学校共报告了213例甲型肝炎病例，缅因州13所学校报告了29例，攻击率中位数在0.2%至14%之间。在密歇根州的一项病例对照研究（疾病比值比为8.3；95%置信区间为2.1至33）和队列研究（感染相对风险为7.5；95%置信区间为1.1至53）以及缅因州的一项病例对照研究（感染比值比为3.4；95%置信区间为1.0至14）中，甲型肝炎均与食用冷冻草莓有关。密歇根州和缅因州126名患者的病毒基因序列彼此相同，与威斯康星州5名患者及亚利桑那州7名患者的病毒基因序列相同，这些患者所在学校均供应了来自同一加工商的冷冻草莓，还与路易斯安那州2名患者的病毒基因序列相同，这两名患者均食用了含有来自同一加工商的冷冻草莓的商业制备产品。
我们描述了密歇根州一起与食用冷冻草莓相关的大规模甲型肝炎暴发事件。我们通过病毒基因分析发现，其他州的一些明显散发病例可能与同一来源有关。
