Payment P, Franco E, Fout G S
Institut Armand-Frappier, Université du Québec, Laval, Canada.
Can J Microbiol. 1994 Oct;40(10):805-9. doi: 10.1139/m94-128.
To determine the seroprevalence of Norwalk virus and whether Norwalk virus contributed to an observed increase in illness in tap water drinkers participating in a prospective epidemiological study, sera collected during the study were examined for changes in Norwalk virus antibody titer, using a specific enzyme immunoassay. Antibodies to Norwalk virus were measured in sera collected in March, June and September 1988 and in June 1989, and antibodies were found in 79% of the individuals. Seroprevalence increased with age, being 55% (ages 9-19), 79% (20-39), 87% (40-49), 84% (50-59), and 100% (60 and older). Norwalk infections occurred in 33% of the individuals during the course of the study. The highest rate of infection (expressed as a monthly rate) was observed during the summer of 1988. These results confirm that a large number of infections owing to Norwalk viruses occur throughout the year. A previous seroconversion or a high serum titer were not always protective. Finally, there was no detectable difference in infection rate between consumers of tap water and consumers of water treated by reverse-osmosis units, suggesting that Norwalk virus infections were not responsible for the excess of gastrointestinal illness observed in tap water drinkers during this epidemiological study.
为确定诺沃克病毒的血清流行率，以及诺沃克病毒是否导致了参与一项前瞻性流行病学研究的自来水饮用者中观察到的疾病增加，使用特定的酶免疫测定法检测了研究期间收集的血清中诺沃克病毒抗体滴度的变化。在1988年3月、6月、9月以及1989年6月收集的血清中检测了诺沃克病毒抗体，发现79%的个体体内存在抗体。血清流行率随年龄增长而升高，9至19岁为55%，20至39岁为79%，40至49岁为87%，50至59岁为84%，60岁及以上为100%。在研究过程中，33%的个体发生了诺沃克病毒感染。感染率最高（按月感染率计算）出现在1988年夏季。这些结果证实，全年都有大量由诺沃克病毒引起的感染发生。先前的血清转化或高血清滴度并不总是具有保护作用。最后，自来水饮用者和使用反渗透装置处理水的饮用者之间的感染率没有可检测到的差异，这表明在这项流行病学研究中，诺沃克病毒感染并非自来水饮用者中观察到的胃肠道疾病过量的原因。
