# A systematic review and meta-analysis of incidence and spatiotemporal trends of snakebites in Iran

## TL;DR

Snakebites in Iran are a growing public health issue, with significant regional and gender disparities, requiring targeted prevention and improved medical resources.

## Contribution

This is the first comprehensive meta-analysis providing reliable nationwide snakebite incidence estimates and spatiotemporal trends in Iran.

## Key findings

- The national snakebite incidence is approximately 32 cases per 100,000 people annually.
- Southeastern and southwestern provinces have the highest snakebite rates, over 100 times higher than northern regions.
- Snakebite incidence has increased over time, with men being significantly more affected than women.

## Abstract

Snakebites are a neglected public health concern, particularly in tropical regions, causing significant morbidity and mortality. Despite Iran’s high snakebite burden, epidemiological data remain inconsistent. This systematic review and meta-analysis aim to provide estimates of snakebite incidence and geographical distribution across Iranian provinces.

A comprehensive search was conducted in PubMed/MEDLINE, Scopus, Web of Science, Embase, Google Scholar, and Persian databases (Magiran, SID) up to February 2025. Observational studies reporting snakebite incidence in Iran were included. Two independent reviewers screened studies, extracted data, and assessed bias using the Newcastle-Ottawa Scale (NOS). A random-effects meta-analysis was performed, with heterogeneity evaluated via I². Meta-regression analyzed temporal trends.

Of 618 initially identified studies, 8 met the inclusion criteria. This meta-analysis found Iran’s overall snakebite incidence to be 31.89 cases per 100,000 population (95% CI: 16.58-47.20), with extreme regional variation (0.14-295.45). Males showed a significantly higher incidence (108.34) than females (66.79). Geographic analysis revealed the highest rates in southeastern (109.68) and southwestern (116.04) regions, and the lowest in northwestern (4.30) and northern (4.05) areas. Meta-regression indicated a significant temporal increase in incidence (β = 0.035, p < 0.001). High heterogeneity (I² ≥ 99.8%) suggests additional underlying factors influence snakebite distribution.

Snakebite incidence in Iran exhibits marked geographical and gender disparities, with an upward temporal trend. These findings highlight the need for targeted prevention strategies, improved antivenom access, and enhanced surveillance in high-risk provinces.

Snakebites are a serious but often overlooked health problem, especially in countries like Iran. However, getting a clear picture of how many people are bitten and where it happens most has been difficult due to inconsistent data. This study aimed to provide the first reliable nationwide estimates of snakebite incidence across Iran to help guide public health efforts.

We combined and analyzed the results of all relevant published studies on snakebites in Iran. Our key findings were:

The national snakebite incidence is approximately 32 cases per 100,000 people each year.

The risk is not evenly distributed. The southeastern and southwestern provinces (like Sistan-Baluchestan and Khuzestan) have alarmingly high rates, over 100 times greater than in northern provinces.

Men are bitten at a significantly higher rate than women.

The data shows that snakebites have been increasing over time across the country.

These results reveal a critical and growing health disparity within Iran. The high incidence in specific regions calls for urgent, targeted action. Public health officials should focus prevention programs, ensure adequate antivenom supplies, and strengthen medical training in the high-risk provinces we identified.