SALMONELLOSIS, INCLUDING TYPHOID-FEVER

Salmonella spp. are a major cause of human morbidity and mortality. The increased frequency of egg-associated Salmonella enteritidis outbreaks emphasizes the need for new prevention and control strategies. With the emergence of multidrug-resistant Salmonella strains, third-generation cephalosporins and quinolones are increasingly necessary to treat both complicated non-typhoidal Salmonella infections and typhoid fever. However, resistance is now being reported to both classes of antimicrobial agents, and there is unresolved concern about the use of quinolones in children aged less than 10 years. Recent studies of Salmonella pathogenesis and interactions with epithelial cells and macrophages have increased our understanding of Salmonella spp. infection. Interest also has been generated by the development of virulence-attenuated Salmonella typhi strains as new oral vaccines and as multivalent-vaccine vectors to express heterologous antigens to protect against a variety of infectious diseases.