Prevalence of ocular allergy among children in Africa: a systematic review and meta-analysis
Abstract
Ocular allergy ranges from seasonal and perennial allergic conjunctivitis to chronic, potentially sight-threatening vernal keratoconjunctivitis (VKC). African prevalence studies use heterogeneous terminology and case-ascertainment methods, and their estimates have not previously been synthesized. To synthesise published prevalence estimates of ocular allergy among African children, quantify uncertainty around summary estimates, and describe between-study variation. PubMed/MEDLINE, Google Scholar, African Journals Online and African Index Medicus were searched for observational studies published from 1 January 2010 to 31 December 2025. Disease-specific terms were supplemented with broader ocular-morbidity terminology, reference-list screening and citation verification to identify studies reporting ocular allergy as a secondary outcome. Eligible studies enrolled African children and provided an extractable numerator and denominator. Logit-transformed proportions were pooled using a random-effects restricted maximum-likelihood (REML) model in Stata 17. Heterogeneity, 95% prediction intervals, diagnostic and setting subgroups, and sensitivity analyses were reported. Fourteen studies from five countries included 18,681 children, of whom 1,911 had ocular allergy, allergic conjunctivitis or VKC/vernal disease. The pooled prevalence was 9.4% (95% confidence interval [CI] 5.4%–15.6%), with extreme heterogeneity (τ2 = 1.23; I2 = 99.19%; Q(13) = 1844.38, p < 0.001) and a 95% prediction interval of 0.8%–55.9%. The pooled estimate was 14.5% (95% CI 5.5%–33.0%; k = 6) for allergic conjunctivitis and 6.6% (95% CI 3.8%–11.2%; k = 8) for VKC/vernal disease; the subgroup difference was not statistically significant (Q β (1) = 1.99, p = 0.158). School/community studies yielded 8.9% (95% CI 5.0%–15.4%; k = 13), whereas the single clinic study reported 17.6% (95% CI 15.8%–19.6%). Substituting a narrower VKC case definition gave 8.4% (95% CI 4.9%–14.2%), and leave-one-out estimates ranged from 8.0% to 10.2%. Published studies consistently report ocular allergy among African children, although the available evidence is too heterogeneous to support a reliable continental prevalence estimate. Variation in case definition and ascertainment is a plausible and likely substantial contributor, but could not be quantified formally. The findings support consideration of ocular allergy within school eye-health and primary eye-care programmes while underscoring the need for standardised diagnostic and reporting methods.
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BibTeX
@article{ismail2026prevalence,
title = {{Prevalence of ocular allergy among children in Africa: a systematic review and meta-analysis}},
author = {Mohamed Farah Ismail and Intisar Khalafalla and Ahmed Saed Dirie and Chalachew Muche Alemayehu and Charity Zalwango and Sowda Abdikarim Sheikh Isse and Fathi Abdi Farah and Zakaria Omar Sheck and Amina Mohamed Mire and Abdirashid Dahir Herow and Amina Aden Ahmed and Farah Dubad Abdi and Ibrahim Abdirahman Mohamed and Mohamed Jayte and Bahja Ahmed Mumin and Theoneste Hakizimana},
journal = {Scientific Reports},
year = {2026},
month = oct,
doi = {10.1038/s41598-026-71277-9},
url = {https://www.nature.com/articles/s41598-026-71277-9},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Prevalence of ocular allergy among children in Africa: a systematic review and meta-analysis
AU - Mohamed Farah Ismail
AU - Intisar Khalafalla
AU - Ahmed Saed Dirie
AU - Chalachew Muche Alemayehu
AU - Charity Zalwango
AU - Sowda Abdikarim Sheikh Isse
AU - Fathi Abdi Farah
AU - Zakaria Omar Sheck
AU - Amina Mohamed Mire
AU - Abdirashid Dahir Herow
AU - Amina Aden Ahmed
AU - Farah Dubad Abdi
AU - Ibrahim Abdirahman Mohamed
AU - Mohamed Jayte
AU - Bahja Ahmed Mumin
AU - Theoneste Hakizimana
PY - 2026
DA - 2026/10/01
JO - Scientific Reports
DO - 10.1038/s41598-026-71277-9
UR - https://www.nature.com/articles/s41598-026-71277-9
AB - Ocular allergy ranges from seasonal and perennial allergic conjunctivitis to chronic, potentially sight-threatening vernal keratoconjunctivitis (VKC). African prevalence studies use heterogeneous terminology and case-ascertainment methods, and their estimates have not previously been synthesized. To synthesise published prevalence estimates of ocular allergy among African children, quantify uncertainty around summary estimates, and describe between-study variation. PubMed/MEDLINE, Google Scholar, African Journals Online and African Index Medicus were searched for observational studies published from 1 January 2010 to 31 December 2025. Disease-specific terms were supplemented with broader ocular-morbidity terminology, reference-list screening and citation verification to identify studies reporting ocular allergy as a secondary outcome. Eligible studies enrolled African children and provided an extractable numerator and denominator. Logit-transformed proportions were pooled using a random-effects restricted maximum-likelihood (REML) model in Stata 17. Heterogeneity, 95% prediction intervals, diagnostic and setting subgroups, and sensitivity analyses were reported. Fourteen studies from five countries included 18,681 children, of whom 1,911 had ocular allergy, allergic conjunctivitis or VKC/vernal disease. The pooled prevalence was 9.4% (95% confidence interval [CI] 5.4%–15.6%), with extreme heterogeneity (τ2 = 1.23; I2 = 99.19%; Q(13) = 1844.38, p < 0.001) and a 95% prediction interval of 0.8%–55.9%. The pooled estimate was 14.5% (95% CI 5.5%–33.0%; k = 6) for allergic conjunctivitis and 6.6% (95% CI 3.8%–11.2%; k = 8) for VKC/vernal disease; the subgroup difference was not statistically significant (Q β (1) = 1.99, p = 0.158). School/community studies yielded 8.9% (95% CI 5.0%–15.4%; k = 13), whereas the single clinic study reported 17.6% (95% CI 15.8%–19.6%). Substituting a narrower VKC case definition gave 8.4% (95% CI 4.9%–14.2%), and leave-one-out estimates ranged from 8.0% to 10.2%. Published studies consistently report ocular allergy among African children, although the available evidence is too heterogeneous to support a reliable continental prevalence estimate. Variation in case definition and ascertainment is a plausible and likely substantial contributor, but could not be quantified formally. The findings support consideration of ocular allergy within school eye-health and primary eye-care programmes while underscoring the need for standardised diagnostic and reporting methods.
SN - 2045-2322
ER -