Enteric fever—a more inclusive term for typhoid fever and paratyphoid fever—is a systemic infection caused by Salmonella enterica, including S enterica serotype Typhi

Introduction Enteric fever—a more inclusive term for typhoid fever and paratyphoid fever—is a systemic infection caused by Salmonella enterica, including S enterica serotype Typhi (S typhi) and serotype Paratyphi (S paratyphi). Enteric fever is a faecal–oral transmissible disease and therefore is primarily a disease where overcrowding, poor sanitation, and untreated water are the norm. Until the early 20th century, the disease had a worldwide distribution, including the USA and Europe. The number of typhoid cases in the USA fell from 35 994 in 1920 to an average of 500 cases annually in the 1990s, largely as a result of changes in sanitation and hygiene. Today, most enteric fever infections occur in less developed countries where sanitary conditions remain poor and water supplies are not treated. Human beings are the only known reservoir and transmission occurs through food and water contaminated by acutely ill or chronic carriers of the organism. Obtaining accurate data on disease burden in developing countries is difficult because the diagnosis of enteric fever is often a clinical one, without blood culture confirmation, and most patients are treated as outpatients. Public-health figures may therefore underestimate enteric fever levels compared with community-based studies. Annual incidence rates of up to 198 per 100 000 in the Mekong Lancet Infect Dis 2005; 5: 623–28