# Long‐Term Epidemiological Insights Into Human Cystic Echinococcosis in Northeastern Iran: A 17‐Year Retrospective Analysis

## TL;DR

A 17-year study in northeastern Iran shows cystic echinococcosis remains a public health issue, with the liver being the most affected organ and a need for continued control efforts.

## Contribution

The study provides a long-term epidemiological analysis of human cystic echinococcosis in northeastern Iran using 17 years of surgical data.

## Key findings

- The liver was the most commonly affected organ (81.5%) in CE cases.
- A nonsignificant declining trend in CE incidence was observed over the 17-year period.
- Urban residents and females were disproportionately affected by CE.

## Abstract

Cystic echinococcosis (CE) remains an important public health challenge in endemic regions of Iran, especially in areas with intensive livestock farming and close human–animal contact. Long‐term epidemiological analyses are essential for identifying patterns, informing control strategies, and evaluating intervention outcomes.

A 17‐year cross‐sectional study design based on retrospective data (2006–2022) was conducted on surgically confirmed human CE cases from two referral hospitals in Razavi Khorasan Province, northeastern Iran. Demographic, clinical, and spatial data from patients residing in Torbat‐e Heydariyeh, Zaveh, Mahvelat, and Roshtkhar were reviewed. Descriptive and inferential statistical analyses were performed using SPSS v.25, including chi‐square, Mann–Whitney U, and one‐way ANOVA tests (α = 0.05). Temporal trends were assessed using Poisson regression, and case distribution was visualized via GIS‐based heatmapping (ArcGIS Pro 3.2).

A total of 232 CE surgical cases were recorded during a 17‐year period, corresponding to an average annual incidence of 13.6 and a surgical incidence rate of 3/100,000 population. The liver was the most affected organ (81.5%), and abdominal pain was the most frequent presenting symptom (73.7%). Two age peaks were observed at 21–40 and ≥ 61 years. Females (57.8%) and urban residents (64.7%) comprised the majority of patients. Regression analysis indicated a nonsignificant declining trend over time (β = −0.95, 95% CI: −2.71–0.81, p = 0.26). A statistically significant association was found between residency and organ involvement in patients with CE (χ
2 = 5.78, df = 1, p = 0.016).

This 17‐year analysis reveals persistent CE burden in northeastern Iran despite a modest decline in recent years. Sustained One Health surveillance, public education, and strengthened veterinary–human collaboration are required to mitigate disease transmission and improve control outcomes.