Is acute uncomplicated urinary tract infection a foodborne illness, and are animals the source?

Acute uncomplicated cystitis and pyelo-nephritis, most episodes of which are caused by uropathogenic strains of Esch-erichia coli, are very common infections affecting otherwise healthy women. Uro-pathogenic E. coli strains, compared with fecal strains, are more likely to possess the potential for enhanced extraintestinal vir-ulence, which enables the organisms to overcome local host defenses and cause urinary tract infection (UTI) [1]. In general , uropathogens are thought to initially colonize the gastrointestinal tract, and their movement into the vagina and bladder with subsequent UTI is facilitated mainly by sexual intercourse [2]. It is not known, however, where uropathogens originate, when they appear, or how long they persist in the intestines or vaginas of healthy women before onset of UTI. Given our understanding of the environmental reservoir of E. coli, their distribution among animals, water, and types of food, and the fact that the main vehicle for colonization and infection with these and other enteric organisms is contaminated food and water, it is not a far-fetched assumption that uropathogenic E. coli most likely originate from contaminated food or water. Uropathogenic E. coli might contaminate food or water via many routes, including sewage, wild or domesticated animals, or food handlers, but no clear linkage has been made between in-gestion of contaminated food or water or direct animal contact and human UTI [3]. Colonization of the gastrointestinal tract with antibiotic-resistant E. coli strains has been demonstrated following travel to areas with a high prevalence of antibiotic resistance, presumably via ingestion of contaminated food or water [4], and recent travel outside the United States has been shown to be a risk factor for UTI caused by trimethoprim-sulfamethoxazole (TMP-SMZ)–resistant E. coli [5]. Human-to-human transmission, presumably via the fecal-oral route, is suggested by the observations that transmission of E. coli among children at day care centers and from such children to household members are common [6]. There is also evidence that uropathogenic strains may occasionally be shared between sex partners, but the direction of transmission has not been determined [2]. Sporadic, nonrecurrent, community-acquired UTIs are generally considered to be unrelated events, although community outbreaks of UTIs caused by multidrug-resistant strains of E. coli have been reported [7]. UTI clustering is also suggested by recent investigations demonstrating that a high proportion of TMP-SMZ–re-sistant strains causing acute uncomplicated UTI in different geographic areas of the United States were caused by clonal group A (CgA) [5, 7]. These observations suggest …