Age Patterns of Persons with Campylobacteriosis, England and Wales, 1990–2007

C infection remains a major public health problem worldwide. The infection is unpleasant, although generally self-limiting, and most patients experience acute enteritis for 7 to 10 days (1). Approximately one tenth of patients with laboratory-confi rmed cases require hospital treatment as a result of their illness (2), and a range of gastrointestinal, arthritic, and neurologic sequelae add to disease effects (3). Although food is likely the main source of transmission to humans, most human infections cannot be explained by recognized risk factors. In the late 1970s, when the role of Campylobacter spp. in human gastrointestinal disease had been newly appreciated, the number of laboratory-confi rmed infections in England and Wales began to rise; 8,956 cases were reported in 1980 and 33,234 in 1989 (Health Protection Agency, unpub. data). This increase was largely artifactual, refl ecting increased scientifi c interest in, and testing for, Campylobacter spp. and improvements in media and methods for isolating them (4,5). The incidence continued to rise throughout the 1990s and peaked in 2000 at 58,236 cases. The reasons for this increase are unknown; further methodologic improvements or increased surveillance activity in that decade cannot fully explain it. Incidence rapidly decreased between 2000 and 2004 (from 57,674 to 44,294 cases; 24% decrease; Health Protection Agency, unpub. data), after which incidence increased for 3 consecutive years; provisional total was 51,758 cases in 2007 (Health Protection Agency, unpub. data). The reasons for these recent changes in incidence are again unknown. To explore hypotheses for changes in incidence related to age, we analyzed electronic laboratory data for Campylobacter infections reported in England and Wales from 1990 through 2007.