Five-year descriptive epidemiology of measles in Punjab, Pakistan, 2022–2026: trends, age distribution, and geographic burden; a retrospective surveillance study

Measles resurgences following the COVID-19 pandemic have placed millions of unvaccinated children at risk across South Asia. Punjab, Pakistan’s most populous province with approximately 125 million residents, experienced a sustained measles epidemic from 2022 to 2024. This study describes the five-year epidemiology of measles in Punjab using individual-level surveillance data from the provincial Expanded Program on Immunization (EPI) surveillance system. We conducted a retrospective descriptive analysis of 72,565 suspected measles case records from the Punjab EPI VPD surveillance line-list, epidemiological week 1 of 2022 through epidemiological week 23 of 2026. Variables analyzed included case counts, incidence rates per 100,000 population, age at illness onset, sex, vaccination status, case outcomes, and district-level geographic distribution. District-level population denominators adjusted for annual growth were applied to calculate incidence rates. Statistical analysis used the Cochran-Armitage trend test, Wilson 95% confidence intervals, and Spearman rank correlation. Reported measles cases escalated from 6,613 in 2022 to a peak of 23,623 in 2024 (incidence 18.92 per 100,000 population), before declining to 19,913 in 2025 and 9,898 through week 23 of 2026. Overall, 184 deaths were recorded (case fatality ratio [CFR] 0.25%). Male cases predominated (57–58% annually; M:F ratio 1.40:1). The proportion of infants under 12 months rose from 37.3% (95% CI 36.2–38.5%) in 2022 to 47.9% (95% CI 46.9–48.9%) in 2026 (Cochran-Armitage z = 12.77, p < 0.0001), with median age at infection declining from 18 months (IQR 8–42) to 12 months (IQR 7–36). Zero-dose cases peaked at 49.6% (95% CI 49.0–50.2%) in 2024 (z = 3.37, p = 0.0008). Chiniot (62.95 per 100,000) and Jhang (59.98 per 100,000) bore the highest district incidence in 2024. Reported first-dose measles-containing vaccine (MCV1) coverage was paradoxically positively correlated with district measles incidence (Spearman rho = + 0.370, p = 0.027), consistent with surveillance activity bias. Punjab experienced a measles epidemic peaking in 2024, with 72,565 reported suspected cases and 184 deaths across 2022 to 2026, driven by accumulation of unvaccinated children within districts reporting nominally high MCV1 coverage. The progressive shift in disease burden toward infants under 12 months demands renewed focus on vaccination system quality, zero-dose outreach, and surveillance sensitivity. These findings are relevant to other high-burden EMRO settings facing similar immunization system challenges.