Epidemiology and clinical features of Hymenoptera stings in East Azerbaijan, northwestern Iran

BACKGROUND: Stings caused by Hymenoptera including honey bees, wasps, and hornets represent a growing global and national health concern with outcomes ranging from mild local reactions to severe systemic complications. Despite their significance, region-specific epidemiological data from Iran remain limited. This study aimed to investigate the demographic characteristics, anatomical distribution, seasonal patterns, clinical features, and hospitalization-related factors among Hymenoptera sting victims in northwestern Iran. METHODS: A retrospective descriptive-analytical study was conducted between 2021 and 2024 in East Azerbaijan Province, Iran, using medical records from hospitals affiliated with Tabriz University of Medical Sciences. A total of 225 eligible patients with confirmed or clinically suspected Hymenoptera stings were analyzed through a census-based approach. Demographic (including age, sex, and occupational status), epidemiological, and clinical variables were collected via structured forms. Descriptive statistics were applied. Chi-square or exact tests were used to assess associations between categorical variables, and multivariable logistic regression was performed to identify independent predictors of hospitalization. Statistical significance was set at p < 0.05. RESULTS: Among 225 cases, 71.6% were male, and the mean age was 30.99 ± 18.49 years, showing a bimodal distribution peaking in children aged <10 years and adults aged 30-49 years. A highly significant association was found between gender and occupation (p < 0.001); females were predominantly housewives, males were distributed mainly among self-employed individuals, students, farmers, and manual workers. Urban areas accounted for 53.3% of incidents, and summer was the peak season (52.4%). The head and neck were the most affected sites (44.9%), with a significant gender disparity: males were more frequently stung on the head/neck, whereas females were more frequently stung on the limbs (p < 0.001). Hospitalization was required in 28.0% of patients. In multivariable logistic regression, pain (OR = 40.43, 95% CI: 12.56-130.15), severe muscle pain (OR = 77.56, 95% CI: 12.97-463.89), and local swelling/redness (OR = 16.05, 95% CI: 3.96-65.06) were independently associated with hospitalization. Male gender showed a non-significant trend toward higher odds of hospitalization (OR = 3.06, p = 0.067). CONCLUSION: Hymenoptera stings in northwestern Iran are shaped by a complex interplay of ecological, occupational, and socio-cultural factors. The distinct anatomical sting patterns may be influenced by regional dress codes and gender-specific activities, suggest that preventive strategies should address both domestic and occupational exposure settings. Public health interventions should focus on habitat management in residential areas, awareness among households, and protective clothing for outdoor workers to reduce the burden of envenomation.