High risk of Mycobacterium tuberculosis infection during the Hajj pilgrimage

Annelies Wilder-Smith, Winnie Foo, Arul Earnest, Nicholas I. Paton

Research output: Contribution to journalArticleResearchpeer-review

69 Citations (Scopus)


INTRODUCTION: Annually more than 2 million pilgrims from all over the world attend the Hajj in Saudi Arabia. Overcrowding during this pilgrimage leads to a high risk of transmission of airborne infectious diseases. Tuberculosis (TB) is common among hospitalized pilgrims, but the overall risk of acquiring Mycobacterium tuberculosis infection during this pilgrimage is not known. We conducted a prospective study to assess the risk of M. tuberculosis infection among Hajj pilgrims. METHODS: We measured the immune response to TB antigens using a whole-blood assay (QuantiFERON TB assay) prior to departure and 3 months after return from the Hajj pilgrimage. RESULTS: Of 357 paired assays, 149 pilgrims were negative prior to the Hajj and 15 (10%) of these had a significant rise in immune response to TB antigens. CONCLUSIONS: Pilgrims may be at high risk of acquiring M. tuberculosis infection during the Hajj. This has significant public health implications for TB control in countries with large Muslim populations.

Original languageEnglish
Pages (from-to)336-339
Number of pages4
JournalTropical Medicine and International Health
Issue number4
Publication statusPublished - 1 Apr 2005
Externally publishedYes


  • Cell-mediated gamma-interferon response to tuberculosis antigens
  • Hajj pilgrims
  • Latent tuberculosis infection
  • QuantiFERON TB assay

Cite this