Scorpion sting stratification in Iran: A systematic review of epidemiological patterns, determinants, and climate change impacts
Clinical Snapshot
PICO Framework
| P — Population | Human populations residing in Iran, particularly in arid and semi-arid regions, exposed to scorpion envenomation |
| I — Intervention | Exposure to scorpion stings (envenomation events), with particular focus on species from genera Hemiscorpius and Androctonus |
| C — Comparator | Comparisons across geographic regions (provinces), time periods, climatic zones, and demographic subgroups within Iran; no formal control group |
| O — Outcomes | Primary: pooled incidence rate of scorpion stings per 100,000 population per year; Secondary: spatial and temporal distribution patterns, ecological and climatic determinants, climate change impacts on habitat suitability and human-scorpion conflict |
Bottom Line
This PRISMA 2020-compliant systematic review and meta-analysis provides the most comprehensive synthesis to date of scorpion envenomation epidemiology in Iran, confirming a substantial national burden with a pooled incidence of 92.7 per 100,000 per year. Hyperendemic levels are concentrated in southwestern and western provinces, with Hemiscorpius and Androctonus species posing the greatest clinical threat. However, the extreme statistical heterogeneity (I² = 98.9%) means the pooled estimate should be interpreted cautiously — it reflects a wide range of regional realities rather than a uniform national risk. The review's value lies primarily in its public health and surveillance implications: it identifies climatic variables, unplanned urbanisation, and occupational exposure as key modifiable determinants, and presents emerging evidence that climate change is expanding scorpion habitats and prolonging envenomation seasons. For clinicians, the review reinforces the importance of geographic risk stratification when managing envenomation cases. For health systems, it makes a compelling case for climate-adaptive surveillance and antivenom resource allocation. The absence of clinical outcome data, formal risk of bias assessment, and GRADE certainty ratings limits its direct influence on clinical management guidelines. Overall, this is a valuable epidemiological resource with moderate methodological rigour.
Key Findings
P Value: Not reported in abstract
Effect Size: 92.7 per 100,000 population per year
Primary Outcome: Pooled national incidence rate of scorpion stings in Iran
Nnt Or Sensitivity: I² = 98.9% (extreme heterogeneity); hyperendemic burden confirmed in southwestern and western provinces; Hemiscorpius and Androctonus identified as highest-severity genera; climate change modelling indicates expanding suitable habitat and prolonged active seasons — no NNT applicable (epidemiological/public health review)
Confidence Interval: 95% CI: 68.4–117.0 per 100,000 population per year
Clinical Application
Findings support targeted public health interventions including enhanced surveillance systems, community education programmes, antivenom stockpiling in hyperendemic provinces, and integration of climate-adaptive risk modelling into provincial health planning. Clinical application is primarily at the public health and health systems level rather than individual patient management. Direct clinical applicability to Australia is limited, as the scorpion species implicated (Hemiscorpius, Androctonus) are not endemic to Australia. However, the methodological framework for scorpion envenomation surveillance is relevant to Australian toxinology practice. The Australian context for scorpion envenomation involves primarily Urodacus species, which carry lower medical severity. The TGA does not list a specific scorpion antivenom for Australian species. RACGP and ACEM guidelines for envenomation management should be consulted for domestic cases. The climate change modelling methodology has indirect relevance to Australian vector and venomous species distribution planning. For clinicians managing returned travellers from Iran or the Middle East presenting with scorpion envenomation, awareness of Hemiscorpius and Androctonus toxidromes is clinically important. Populations in arid and semi-arid regions of Iran, particularly southwestern provinces (e.g., Khuzestan) and western provinces; occupationally exposed individuals (agricultural workers, outdoor labourers); travellers to endemic regions
Abstract
This systematic review provides a comprehensive synthesis of the epidemiology of scorpion sting stratification across Iran's geography, a critical public health concern in its arid and semi-arid regions. Conducted in accordance with PRISMA 2020 guidelines, the review analyzes the spatial and temporal patterns of envenomations, identifies key ecological, climatic, and anthropogenic determinants, and evaluates the growing evidence for climate change as a driver of increased risk. The study confirms hyperendemic levels of scorpion stings in the southwestern and western provinces, with species from the genera Hemiscorpius and Androctonus presenting the most severe medical threat. A meta-analysis of national data yields a pooled incidence rate of 92.7 per 100,000 population per year (95% CI: 68.4-117.0), with extreme heterogeneity (I² = 98.9%) reflecting stark regional disparities. The primary determinants of scorpion distribution and human-scorpion conflicts include climatic variables (temperature, precipitation, and humidity), land-use practices, unplanned urbanization, and occupational exposure. Recent evidence from species distribution modeling strongly suggests that climate change is expanding suitable habitats for scorpions, prolonging their active seasons, and increasing human-scorpion conflicts. This review highlights the critical need for improved surveillance, predictive spatial risk models, and climate-adaptive public health strategies to address this growing threat.
References
- 1.Nasirian, H. (2026). Scorpion sting stratification in Iran: A systematic review of epidemiological patterns, determinants, and climate change impacts. International Journal of Biometeorology. https://doi.org/10.1088/2515-7620/ae3fef
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