Pan American Health Organization · 1st edition, 2024 · 60 pages
One Health guidance for endemic countries to eliminate fascioliasis through preventive chemotherapy, animal treatment, and environmental management
- Issuer
- Pan American Health Organization
- Edition
- 1st edition, 2024
- Audience
- National programme managers, epidemiologists, public health officials, veterinary public health professionals, clinicians in endemic areas
- Evidence
- Expert consensus based on regional consultation, field experience from Bolivia and Peru, and WHO Collaborating Center on fascioliasis; acknowledges knowledge gaps
- Reviewed
- 17 Oct 2026 · GMJ
What this guideline says
GMJ summary
These operational guidelines establish a comprehensive One Health approach to eliminate human fascioliasis as a public health problem in the Americas by 2030, defined as achieving sustained prevalence ≤5% by coprology without high-intensity infections (≥400 eggs per gram of faeces). The guidelines integrate interventions across human health, veterinary medicine, food safety, sanitation, and environmental management, recognising that while animal fasciolosis is widespread, human disease is concentrated in specific rural communities with particular socioeconomic and environmental risk factors.
The core intervention is preventive chemotherapy with triclabendazole (10 mg/kg single dose) for populations in endemic areas with >5% prevalence, combined with strategic treatment of livestock, management of intermediate host snails (Lymnaeidae family), improved sanitation and safe water access, and community education on food safety. The guidelines detail thresholds for mass drug administration versus selective chemotherapy, monitoring through sentinel surveillance every 1–2 years and impact surveys every 5 years, and emphasise achieving ≥75% coverage for effectiveness.
Developed through consultation with endemic countries (Bolivia and Peru) and regional experts, the guidelines acknowledge knowledge gaps and provide practical adaptations for small-scale family farming contexts that characterise affected communities. Success requires multisectoral coordination through national One Health committees, political commitment, and sustained implementation of complementary measures beyond chemotherapy alone.
Key points
For clinicians — doses and thresholds as stated in the guideline
- Elimination target: sustained prevalence ≤5% by coprology without high-intensity infections (≥400 eggs per gram of faeces) by 2030
- Preventive chemotherapy with triclabendazole 10 mg/kg single dose when prevalence >5%; eligible population aged 5–65 years (or 4–65 if national evidence supports)
- Mass drug administration or targeted chemotherapy annually until impact survey shows ≤5% prevalence after 5 years; then one round of targeted/selective chemotherapy at 2 years
- Treatment coverage must reach ≥75% of target population to achieve expected impact on prevalence and infection intensity
- Infection intensity classification: low 1–99 eggs/g, moderate 100–399 eggs/g, high ≥400 eggs/g (Kato-Katz method)
- Baseline survey required in at-risk populations (presence of intermediate host snails, socioeconomic risk factors, and coprological evidence of endemicity)
- Sentinel site surveillance every 1–2 years (50–100 children aged 5–14 per school); impact assessment surveys every 5 years using representative probabilistic sampling
- Animal treatment should follow locally-developed strategic schedules based on epidemiology; triclabendazole use in animals should be avoided when possible to preserve efficacy for human treatment
Infection intensity based on eggs per gram (epg) of faeces
Table extracted from the guideline
| Intensity category | Eggs per gram of faeces |
|---|---|
| Low | 1–99 epg |
| Moderate | 100–399 epg |
| High | ≥400 epg |
Source: Pan American Health Organization, Operational guidelines for the elimination of human fascioliasis as a public health problem in the Americas. Reproduced in summary form.
From the guideline
Verbatim
“The objective of the Pan American Health Organization with regard to human fascioliasis is, by 2030, to eliminate human fascioliasis as a public health problem, defined as a sustained prevalence ≤5%, by coprology, without high-intensity infections (≥400 eggs per gram of feces).”
Editor’s perspective
Why this matters for Georgia and the region
Prof. Giorgi Pkhakadze, MD, MPH, PhD
Editor-in-Chief, Georgian Medical Journal · Chair, Public Health Institute of Georgia · WHO consultant, health and migration
As Chair of the Public Health Institute of Georgia and former WHO consultant, I find these guidelines particularly valuable because they operationalise a genuine One Health approach for a complex zoonotic disease, moving beyond rhetoric to concrete intersectoral coordination mechanisms. While Georgia is not currently endemic for human fascioliasis, we have documented animal fasciolosis in livestock, and our experience with the national hepatitis C elimination programme since 2015 demonstrates that elimination targets are achievable when political commitment meets operational clarity. The emphasis I would stress to Georgian colleagues is the importance of baseline epidemiological assessment before launching any intervention—these guidelines rightly insist on confirming human endemicity through coprological surveys rather than assuming it from animal disease data, a distinction critical for efficient resource allocation. The realistic caveat is that the recommended ≥75% coverage threshold for preventive chemotherapy and the requirement for sustained surveillance over 5–7 years demand health system capacity and financing that may be challenging in rural mountain communities where such diseases would most likely occur, requiring careful adaptation of the monitoring framework to local primary healthcare infrastructure.
ORCID 0000-0001-7609-4515 · Perspective written for the GMJ Guidelines Library, 17 Oct 2026
Applicability
Georgia and the South Caucasus
While Georgia and the South Caucasus are not considered endemic for human fascioliasis, animal fasciolosis caused by Fasciola hepatica is present in livestock across Eastern Europe and the Caucasus region. For Georgia, these guidelines offer a framework should human cases be detected in rural livestock-rearing communities, particularly given the country’s experience with other neglected parasitic diseases and integrated One Health approaches. National surveillance systems would need to assess whether environmental conditions (presence of Lymnaeidae snail vectors, consumption of wild aquatic plants, small-scale farming with inadequate sanitation) create transmission potential. The emphasis on multisectoral coordination aligns with Georgia’s established One Health platform for zoonotic disease control, and the veterinary public health components could integrate with existing livestock disease programmes. Any future programme would require baseline malacological surveys to identify intermediate host snail species and distribution, and epidemiological assessment in high-risk populations before adopting the chemotherapy thresholds and monitoring frameworks detailed here.
Questions this guideline answers
Quick answers
When should preventive chemotherapy be started in a community?
When a baseline survey using coprological tests shows prevalence >5% in a community where intermediate host snails (Lymnaeidae family) are present and socioeconomic risk factors exist (e.g., consumption of watercress or wild aquatic plants). If prevalence is ≤5%, treat individual cases only.
What is the treatment regimen for fascioliasis?
For individual treatment, WHO recommends triclabendazole 10 mg/kg as a single oral dose. If therapeutic failure occurs or the clinician considers necessary, two doses of 10 mg/kg can be given 12–24 hours apart (total 20 mg/kg). For preventive chemotherapy programmes, a single 10 mg/kg dose is used. The drug should be taken with high-fat food to increase absorption.
How do you monitor if a control programme is working?
Through sentinel site surveillance every 1–2 years (50–100 children aged 5–14 per selected school using Kato-Katz method) and impact assessment surveys every 5 years using representative population sampling. Surveys should be conducted at least 9 months after the last treatment. Coverage monitoring should confirm ≥75% of the target population received treatment.
Who should not receive triclabendazole in mass drug administration campaigns?
Exclude severely ill people, those with acute gastrointestinal symptoms (vomiting, diarrhoea, abdominal pain), pregnant or breastfeeding women, people with liver dysfunction, children under 4 years of age, and people who recently received treatment for fascioliasis. These groups can be treated individually under medical supervision if infected.
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- Issuer
- Pan American Health Organization
- Type
- Procedures, manuals, guidelines
- Edition
- 1st edition, 2024
- Status
- Current
- Published
- 2024-01-01
- Languages
- English, Spanish
- Scope
- Endemic countries in the Americas with human fascioliasis; adaptable framework for elimination programmes
- Audience
- National programme managers, epidemiologists, public health officials, veterinary public health professionals, clinicians in endemic areas
- Pages
- 60
- Licence
- CC BY-NC-SA 3.0 IGO
- ISBN
- 978-92-75-12808-4 (PDF)
- Evidence
- Expert consensus based on regional consultation, field experience from Bolivia and Peru, and WHO Collaborating Center on fascioliasis; acknowledges knowledge gaps
- Record history
- Created 17 Oct 2026 · updated 17 Oct 2026 · next check Apr 2027
Pan American Health Organization. Operational guidelines for the elimination of human fascioliasis as a public health problem in the Americas. Washington, D.C.: PAHO; 2024. Available from: https://doi.org/10.37774/9789275128084GMJ Guidelines Library records are original summaries written by the GMJ editorial team from the issuer’s published document and reviewed by a physician. They do not replace the full guideline. The document is the copyright of its issuer and is linked, not hosted. Spotted an error or a newer edition? Tell the Guidelines Desk.
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