EPIDEMIOLOGICAL PATTERNS, CYCLICITY, AND SEASONAL TRANSFORMATION OF MEASLES INCIDENCE IN THE JALAL-ABAD REGION (2014–2025)

Abstract

The aim of this study was to investigate the dynamics, seasonal variability, and epidemiological features of measles incidence among the rural population and at the regional level in the Jalal-Abad region of the Kyrgyz Republic. A retrospective analysis of official statistical data for 2014–2025 was conducted using comparative and analytical methods. It was established that the measles epidemic process has a pronounced cyclical pattern with peaks occurring every 3–4 years. During periods of epidemic intensification, incidence rates reached 244.5 per 100,000 population at the regional level and 206.9 among the rural population (2015), and in 2023 — 138.7 and 110.2, respectively. In 2024–2025, a decline in incidence intensity was observed to 106.4–40.8 at the regional level and 97.4–35.2 in rural areas. It was found that regional indicators consistently exceed rural values by 1.1–1.6 times. The incidence among children under 14 years of age is 2–4 times higher than in the general population, reaching 482.3 per 100,000 population during epidemic peaks. Seasonal dynamics are characterized by variability: from a pronounced autumn-winter peak (October–November 2023, up to 46.8 per 100,000 population) to a shift of activity to the winter-spring period (2024) and a smoother pattern without a pronounced seasonal rise (2025). The identified features are due to external and independent vaccination coverage, the presence of “immune gaps” and fluctuations in the level of herd immunity. The obtained results highlight the need to strengthen immunization programs and epidemiological surveillance.