| outbreak of shigella sonnei infection traced to imported iceberg lettuce. | in the period from may through june 1994, an increase in the number of domestic cases of shigella sonnei infection was detected in several european countries, including norway, sweden, and the united kingdom. in all three countries epidemiological evidence incriminated imported iceberg lettuce of spanish origin as the vehicle of transmission. the outbreaks shared a number of common features: a predominance of adults among the case patients, the presence of double infections with other enteropath ... | 1995 | 7751364 |