‘Enteric fever’ is a potentially fatal, severe systemic disease, which is encountered worldwide. Traditionally, enteric fever refers to a bacteremic illness caused by members of certain Salmonella serotypes, notably: Salmonella typhi, a Gram-negative bacterium, and to a lesser extent, Salmonella paratyphi A, B and C. In addition, other non-salmonella organisms may produce a syndrome clinically indistinguishable from “enteric fever”. Brucella sp., Campylobacter sp., Edwardsiella tarda, Enterobacter Cloacae, Escherichia coli, Klebsiella pneumoniae, Providencia alcalifaciens, Pseudomonas sp., Serratia marcescens, Francisella sp. and Yersinia pp have been identified in enteric fever. This is, to the best of the authors’ knowledge, the first case of Citrobacter to be reported presenting as enteric fever in a normal host in Thailand.

Keywords: Enteric fever, Citrobacter sp.