Molecular epidemiological investigation of a typhoid fever outbreak in South Africa, 2005: the relationship to a previous epidemic in 1993

Epidemiol Infect. 2011 Aug;139(8):1239-45. doi: 10.1017/S0950268810002207. Epub 2010 Sep 28.


In 2005, over 600 clinically diagnosed typhoid fever cases occurred in South Africa, where an outbreak had been previously described in 1993. Case-control and molecular investigations, including Salmonella enterica serovar Typhi (S. Typhi) isolates from that area from 1993, 2005 and later, were undertaken. Controls were significantly older than cases (P=0·003), possibly due to immunity from previous infection, and a significantly larger proportion had attended a gathering (P=0·035). Exposure to commercial food outlets and person-to-person transmission was not significant. Pulsed-field gel electrophoresis and multi-locus tandem repeat analysis revealed common clusters of S. Typhi strains identified in 1993 and 2005 as well as in 2007 and 2009. This outbreak probably occurred in a non-immune population due to faecally contaminated water. S. Typhi strains appeared to be related to strains from 1993; failure to address unsafe water may lead to further outbreaks in the area if the current population immunity wanes or is lost.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Child
  • Child, Preschool
  • Disease Outbreaks*
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Humans
  • Male
  • Middle Aged
  • Molecular Epidemiology
  • Molecular Typing
  • Salmonella typhi / classification*
  • Salmonella typhi / genetics*
  • Salmonella typhi / isolation & purification
  • South Africa / epidemiology
  • Typhoid Fever / epidemiology*
  • Young Adult