Koumans E H, Katz D J, Malecki J M, Kumar S, Wahlquist S P, Arrowood M J, Hightower A W, Herwaldt B L
Division of Parasitic Diseases, National Center for Infectious Diseases, and Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia 30341-3724, USA.
Am J Trop Med Hyg. 1998 Aug;59(2):235-42. doi: 10.4269/ajtmh.1998.59.235.
Before 1995, only one outbreak of cyclosporiasis had been reported in the United States. To identify risk factors for Cyclospora infection acquired in Florida in 1995, we conducted a matched case-control study (24 sporadic cases and 69 controls) and retrospective cohort studies of clusters of cases associated with two May social events (attack rates = 15.4% [8 of 52] and 54.5% [6 of 11]). In univariate analysis of data from the case-control study, consumption of fresh raspberries (odds ratio [OR] = 6.0, 95% confidence interval [CI] = 1.1-31.7) and bare-handed contact with soil (OR = 5.4, 95% CI = 1.4-20.7) were associated with infection; soil contact was also implicated in multivariate analysis. For the events, mixed-fruit items that had only fresh raspberries and strawberries in common had elevated relative risks (3.7 and 4.2), but the confidence intervals overlapped 1.0. The raspberries eaten at the events and by sporadic case-patients were imported. Given the cumulative evidence of the three studies and the occurrence in 1996 and 1997 of outbreaks in North America associated with consumption of Guatemalan raspberries, food-borne transmission of Cyclospora was likely in 1995 in Florida as well.
1995年以前，美国仅报告过一次环孢子虫病暴发。为确定1995年在佛罗里达州感染环孢子虫的危险因素，我们开展了一项配对病例对照研究（24例散发病例和69名对照），并对与5月两次社交活动相关的病例集群进行了回顾性队列研究（罹患率分别为15.4%[52人中的8人]和54.5%[11人中的6人]）。在病例对照研究数据的单变量分析中，食用新鲜树莓（比值比[OR]=6.0，95%置信区间[CI]=1.1 - 31.7）和徒手接触土壤（OR = 5.4，95% CI = 1.4 - 20.7）与感染相关；在多变量分析中也涉及土壤接触。对于这些活动，仅含新鲜树莓和草莓的混合水果食品有较高的相对风险（3.7和4.2），但置信区间与1.0重叠。在这些活动中以及散发病例患者食用的树莓是进口的。鉴于这三项研究的累积证据以及1996年和1997年北美发生的与食用危地马拉树莓相关的暴发，1995年在佛罗里达州通过食物传播环孢子虫也很可能发生。
