Population-based ultrasound prevalence and risk factors for cystic echinococcosis in endemic Kazakhstan

TL;DR

A study in Kazakhstan found that 0.34% of people in rural areas have a parasitic disease called cystic echinococcosis, with children being most affected, and identified dog ownership and poor hygiene as key risk factors.

Contribution

This study provides the first population-based ultrasound prevalence data and identifies specific risk factors for cystic echinococcosis in endemic regions of Kazakhstan.

Findings

The prevalence of cystic echinococcosis was 0.34%, with 82.1% of cases in young people aged 9–14 years.

Dog ownership, failure to deworm dogs, and feeding raw offal to dogs were significant risk factors for infection.

92.85% of detected cysts were active, indicating ongoing transmission in the studied communities.

Abstract

Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu lato, remains a significant public health concern in endemic areas of Kazakhstan. Despite global control efforts, CE persists due to insufficient deworming of dogs, the absence of control programs, and low public awareness.

A cross-sectional study was conducted between September 2023 and June 2024 in 51 remote villages across two endemic regions of Kazakhstan. Participants underwent abdominal ultrasound screening and completed a structured questionnaire to assess potential risk factors. Cyst staging was performed according to the WHO - Informal Working Group on Echinococcosis guidelines. Statistical analyses included both univariate and multivariate models to identify significant predictors of infection.

The prevalence of CE was 0.34%, with higher rates observed in young people (82.1%) than in adults (17.9%), particularly among those aged 9–14 years. Major potential risk factors included dog ownership (OR = 3.17, p = 0.012), failure to deworm dogs (OR = 11.12, p = 0.018), feeding raw offal to dogs (OR = 3.06, p = 0.012), and consumption of unwashed vegetables and fruits among women (OR = 5.25, p = 0.005). All identified CE cases were newly diagnosed. Of these, 92.85% were active cysts, predominantly found in young individuals, while inactive cysts accounted for 7.14%, distributed equally between adults and youths.

These findings underscore the urgent need for regular deworming programs for dogs, public education on hygiene practices, and stricter management of livestock offal. Further research is needed to investigate transmission through water and environmental contamination.

Cystic echinococcosis (CE) is a dog-transmitted parasitic disease common in rural communities where livestock farming is practiced. In Kazakhstan, this disease remains a major public health problem, yet its true burden has been poorly understood. We visited 51 villages, screened 8,296 residents with portable ultrasound machines, and interviewed community members about daily habits, dog care practices, and food hygiene to understand infection risks. We found that CE was present in 0.34% of the screened population. Strikingly, more than 80% of all detected cases were in children and adolescents, suggesting recent infections and showing that transmission is still active. Most of the cysts detected (93%), were in active stages. Through a questionnaire completed by more than 2,200 villagers, we learned that people were at much higher risk of infection if they owned dogs (3 times higher risk), did not deworm their dogs (11 times higher risk), or fed dogs raw organs from livestock (3 times higher risk). Eating unwashed vegetables and fruits also increased the risk of infection, especially among women. By combining ultrasound and questionnaire findings, our work shows where prevention efforts should focus. Improving dog deworming, managing slaughter waste safely, and encouraging simple hygiene practices could prevent cases and reduce the burden of this disease in endemic communities of Kazakhstan.

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