Self-reported acute respiratory illness during the pre-ritual and post-return phases of Hajj among South African pilgrims in 2025: a retrospective cohort study.

OBJECTIVES

Respiratory illness is common during Hajj, but phase-specific data from sub-Saharan African pilgrims remain limited. We examined self-reported acute respiratory illness (ARI) among South African pilgrims during the pre-ritual period in Saudi Arabia and within 14 days after return and assessed associated factors.

METHODS

This retrospective observational cohort study included South African pilgrims accredited for the 2025 (1446H) Hajj. A structured electronic questionnaire was administered approximately 1 month after Hajj to capture symptoms retrospectively over two predefined recall periods. The primary outcome was modified syndromic ARI, defined as two or more self-reported symptoms from cough, subjective fever, sore throat, rhinorrhea, or nasal congestion during the relevant recall period. Logistic regression estimated unadjusted odds ratios and adjusted odds ratios (aORs) with 95% confidence intervals (CIs).

RESULTS

Of approximately 2500 accredited pilgrims, 541 (21.6%) completed the questionnaire. During the pre-ritual period, 234/541 reported modified syndromic ARI (43.3%; 95% CI 39.1-47.5). Pilgrims aged ≥60 years had lower adjusted odds of pre-ritual ARI than those aged 18-39 years (aOR 0.47; 95% CI 0.26-0.87). Seasonal influenza vaccination was associated with higher odds of pre-ritual ARI (aOR 1.57; 95% CI 1.10-2.26). Within 14 days after return, 257/541 reported ARI (47.5%; 95% CI 43.2-51.8). Pre-ritual ARI remained modestly associated with post-return ARI in exploratory adjusted analysis (aOR 1.46; 95% CI 1.03-2.07), while influenza vaccination was not associated with post-return ARI.

CONCLUSIONS

Modified syndromic ARI was common before the core Hajj rites and after return. Findings should not be interpreted as influenza-like illness, coronavirus disease 2019, pathogen-confirmed infection, or influenza vaccine effectiveness.