Typhoid infection

Most typhoid infections occur in developing countries where sanitary conditions remain poor and water supplies are not treated.

Humans are the only known reservoir, and transmission occurs through food and water contaminated by acutely ill or chronic carriers of the organism.

Seen in developed countries mainly among travelers returning from endemic countries.

Highest incidence is in the Indian subcontinent and among travelers returning from that area.

Prolonged febrile illness with normal white blood cell count in returnees from an endemic area should increase suspicion.

Definitive diagnosis is by blood culture.

Presumptive antibiotic treatment in the traveler should depend upon the country of origin.

The current vaccines available offer only moderate protection against Salmonella typhi and almost no protection against S paratyphi, which has become a more dominant pathogen.

With the current vaccine efficacy and the increase in multidrug-resistant and extensively drug-resistant strains, cases are expected to continue to increase and become ever more challenging to treat.

Typhoid infection is a fecal-oral transmissible disease caused by the bacterium Salmonella enterica, serotype S typhi. A similar clinical syndrome is caused by Salmonella enterica, serotype S paratyphi, and the terms "enteric fever" and typhoid infection are used to describe both diseases. Unless otherwise stated, the information presented here will relate to both diseases (S typhi and S paratyphi) described by the term typhoid infection.