Consumption Of Raspberries Research Articles

An Outbreak of Cyclosporiasis in 1996 Associated with Consumption of Fresh Berries - Ontario

A large foodborne outbreak of cyclosporiasis occurred in North America in 1996. An index cluster of cases associated with a catered event on May 11, 1996, in Ontario sparked the recognition of this outbreak in Canada. To describe the Ontario experience with the North American outbreak of cyclosporiasis in 1996. Public health units investigated the index and subsequent event-associated clusters. Investigations included retrospective cohort studies of clusters, traceback of suspect foods and a case-control study of sporadic cases. These activities, coordinated with those in the United States, were part of an international investigation. In Ontario, 232 cases of cyclosporiasis (20 laboratory-confirmed and 72 clinically defined cases associated with seven events plus 140 additional laboratory-confirmed sporadic cases) were identified between May 1 and July 30, 1996. For the index cluster, a strawberry flan with raspberries and blueberries was the only significant exposure (relative risk 2.16, P=0.02). Fresh berries were served at all seven events associated with clusters of cases. Raspberries were definitely served at three events, possibly served at three events, and not served at one event. Only imported berries were available in Ontario in May 1996, when initial clusters and sporadic cases were identified. The raspberries served at the two events with well documented traceback data came from Guatemala. Univariate analyses of the matched case-control study demonstrated that illness was associated with consumption of raspberries (matched odds ratio 21.0, 95% CI 3.48 to 448) and strawberries (matched odds ratio 28.5, 95% CI 4.02 to 478). Further evidence amassed by the international investigation compellingly implicated Guatemalan raspberries as the vehicle of the outbreak. Cyclosporiasis may be acquired domestically from the consumption of contaminated produce. The scope and vehicle of this international foodborne outbreak were recognized through a coordinated public health response.

Cyclosporiasis associated with imported raspberries, Florida, 1996.

Until 1995, infection with Cyclospora cayetanenis, a parasite that causes gastroenteritis, was diagnosed in the US primarily in overseas travelers; its modes of transmission were largely unknown. In 1995, 45 cases of cyclosporiasis were diagnosed in Florida residents who had no history of recent foreign travel, but an investigation could not pinpoint a source for the parasite. In 1996, a North American outbreak of cyclosporiasis resulted in more than 1400 cases, 180 of them in Florida. The authors investigated the 1996 Florida outbreak to identify the vehicle of transmission. The authors conducted a matched case-control study in which each of 86 laboratory-confirmed sporadic cases was matched with up to four controls. They also investigated nine clusters of cases associated with common meals and attempted to trace implicated foods to their countries of origin. In the case control study, eating raspberries was strongly associated with cyclosporiasis (matched odds ratio = 31.9; 95% confidence interval [CI] 7.4, 138.2). In the cluster investigation, raspberries were the only food common to all nine clusters of cases; a summary analysis showed a strong association between consumption of raspberries and confirmed or probable cyclosporiasis (risk ratio = 17.6; 95% CI 1.9, 188.8). Guatemala was the sole country of origin for raspberries served at six of nine events. Guatemalan raspberries were the vehicle for the 1996 Florida cyclosporiasis outbreak. Cyclospora is a foodborne pathogen that may play a growing role in the etiology of enteric disease in this country as food markets become increasingly international.

The return of Cyclospora in 1997: another outbreak of cyclosporiasis in North America associated with imported raspberries. Cyclospora Working Group.

In the spring of 1996, an outbreak of cyclosporiasis associated with fresh Guatemalan raspberries occurred in the United States and Canada. Another multistate outbreak of cyclosporiasis occurred in North America in the spring of 1997. To identify the vehicle of the outbreak that occurred in the spring of 1997. Retrospective cohort studies of clusters of cases associated with events (such as banquets) and traceback investigations of sources of implicated produce. United States and Canada. Persons who attended events associated with clusters of cases of cyclosporiasis. Identification of clinically defined or laboratory-confirmed cases of cyclosporiasis and risk factors for infection. 41 clusters of cases were reported in association with events held from 1 April through 26 May in 13 U.S. states, the District of Columbia, and 1 Canadian province. The clusters comprised 762 cases of cyclosporiasis, 192 (25.2%) of which were laboratory confirmed. In addition, 250 laboratory-confirmed sporadic cases were reported in persons who developed gastrointestinal symptoms from April through 15 June, for a total of 1012 cases. Fresh raspberries were the only food common to all 41 events and were the only type of berry served at 9 events (22.0%). Statistically significant associations between consumption of raspberry-containing items and cyclosporiasis were documented for 15 events (40.5% of 37). For 31 of the 33 events with well-documented traceback data, the raspberries either definitely came from Guatemala (8 events) or could have come from Guatemala (23 events). The mode of contamination of the raspberries remains unknown. The outbreak ended shortly after the exportation of fresh raspberries from Guatemala was voluntarily suspended at the end of May 1997. Similar multistate, multicluster outbreaks of cyclosporiasis associated with consumption of Guatemalan raspberries have occurred in consecutive years. These outbreaks highlight the need for better understanding of the biology and epidemiology of Cyclospora cayetanensis and for stronger prevention and control measures to ensure the safety of produce eaten raw.

An outbreak of cyclosporiasis in Florida in 1995: a harbinger of multistate outbreaks in 1996 and 1997.

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.