A Prolonged Outbreak of Enteric Fever Associated With Illegal Miners in the City of Matlosana, South Africa, November 2020-September 2022

Phuti Sekwadi*, Anthony Marius Smith, Wellington Maruma, Gift Mongologa, Grace Tsele, Mimmy Ngomane, Nomsa Tau, Shannon Williams, Bolele Disenyeng, Mahlaku Sebiloane, Leigh Johnston, Linda Erasmus, Juno Thomas

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Background. In South Africa, the annual incidence of enteric fever averaged 0.1 per 100 000 persons between 2003 and 2018. During 2021 an increase in the number of enteric fever cases was observed. An outbreak investigation was conducted to determine the magnitude and source of the outbreak. Methods. We performed a cross-sectional descriptive study. Data were collected through telephonic or face-to-face interviews with cases or proxies via a standardized case investigation form. Whole genome sequencing was performed on all Salmonella Typhi isolates. Drinking water samples were collected, tested, and analyzed. Descriptive analysis was performed with Microsoft Excel. Results. Between January 2020 and September 2022, a cluster of 53 genetically highly related Salmonella Typhi isolates was identified from 5 provinces in South Africa. Isolates associated with the cluster showed ≤5 allelic differences, as determined following core genome multilocus sequence typing analysis. Most cases (60%, 32/53) were in the North West province. Males represented 68% (36/53). Of these, 72% (26/36) were aged 15 to 49 years, with a median age of 31 years. Where occupation was known within this age group, 78% (14/18) were illegal gold miners. Illegal miners reported illness onset while working underground. Five municipal tap water samples were tested and showed no evidence of fecal contamination. Conclusions. This outbreak predominantly affected illegal gold miners, likely due to the consumption of contaminated groundwater while working in a gold mine shaft. In addition, this investigation highlights the value of whole genome sequencing to detect clusters and support epidemiologic investigation of enteric fever outbreaks.

Original languageEnglish
Article numberofae118
JournalOpen Forum Infectious Diseases
Volume11
Issue number3
DOIs
Publication statusPublished - Mar 2024

Keywords

  • carrier
  • enteric fever
  • illegal miner
  • prolonged outbreak

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