Enteric fever

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(Redirected from Typhoid fever)

Background

Microbiology

  • Caused by Salmonella enterica subspecies enterica serotypes Typhi and Paratyphi
  • Virulence is related to Vi antigen and invasin protein

Epidemiology

  • Fecal-oral transmission acquired from contaminated food, milk, or water
  • Less than 5% of infected people become chronic carriers, with bacteria remaining in the gallbladder despite adequate antibiotic treatment

Pathophysiology

  • Induction of pH-shock proteins and other adaptions allow ingested bacteria to pass through the stomach and into the small intestine
  • There, they penetrate the intestinal mucosa followed by mononuclear cells, which transport them to lymph nodes
  • They multiple within the reticuloendothelial system during the incubation period
  • After a threshold is reached, they disseminate to blood

Clinical Manifestations

Diagnosis

  • Blood cultures (large volume, like x4), stool cultures, bone marrow
  • Biopsy (most sensitive)

Management

  • Treatment with third-generation cephalosporins like ceftriaxone, stepped down to oral when improving and susceptibility data are available
  • Duration 10 to 14 days
    • Can take 4 to 6 days to defervesce, even with treatment
  • Monitor for relapse 2 to 3 weeks after treatment ends