Epidemiological Trends and Demographic Determinants of Malaria in Chabahar and Suburbs, Southeastern Iran: Insights from a Six-Year Study (2019 - 2024)

Abstract

Background: Malaria remains a critical public health challenge in southeastern Iran, where Chabahar’s tropical climate and cross-border migration from endemic regions exacerbate transmission. Objectives: This six-year study (2019 - 2024) investigates malaria trends, climatic drivers, and demographic risks to inform targeted control strategies. Methods: A retrospective analysis of 3,393 confirmed malaria cases was conducted using blood smears, rapid diagnostic tests, and demographic questionnaires. Meteorological data were integrated to assess the impacts of temperature, humidity, and precipitation. Statistical analyses (SPSS version 26) included ANOVA, Spearman’s correlation, and chi-square tests. Results: Malaria incidence peaked in 2023 (1,272 cases), with Plasmodium vivax dominating (98.7% in 2023; 85.8% in 2024), while P. falciparum prevailed in 2021 (84.9%). Temperature strongly correlated with transmission, particularly for mixed infections (mean: 33.6°C; P < 0.001), whereas humidity and precipitation showed no significant effect. Males constituted 72.9% to 81.6% of cases, and international travel was linked to higher P. vivax incidence (35.8% of travel-related infections). Afghan nationals exhibited the highest P. vivax burden (83%), underscoring cross-border transmission risks. Conclusions: Temperature-driven transmission and migration dynamics necessitate climate-informed strategies in Chabahar. Prioritizing male populations, travelers, and cross-border collaboration, alongside enhanced surveillance for relapsing P. vivax, is critical for elimination. Integrating temperature-based predictive models and addressing regional genetic factors (e.g., G6PD deficiency) could optimize interventions in this high-risk zone.