African Schistosomiasis: A Framework of Indicators Assessing the Transmission Risk and Intervention Effectiveness

Area of Science:

• Parasitology
• Public Health
• Environmental Health

Background:

• Schistosomiasis is a complex parasitic disease transmitted via snails, influenced by biological, environmental, behavioral, and socioeconomic factors.
• Effective control requires understanding transmission dynamics and prioritizing interventions for specific species like Schistosoma mansoni and S. haematobium.

Purpose of the Study:

• To systematically investigate the importance and feasibility of indicators influencing schistosomiasis transmission.
• To prioritize intervention measures for Schistosoma mansoni and S. haematobium infections in Zimbabwe.

Main Methods:

• A literature review and Delphi method group discussions were used to design a framework questionnaire.
• 27 schistosomiasis experts rated indicator importance and feasibility over two Delphi consultation rounds.
• The Delphi-entropy method assessed indicator weights, achieving a high average authority coefficient (0.88).

Main Results:

• A consensus framework was reached, including 2 primary, 6 secondary, and 39 tertiary indicators.
• Key factors influencing transmission: hazardous water exposure, safe drinking water access, sanitation facilities, and water contamination from open defecation.
• Prioritized interventions: improved diagnostics, health education, preventive chemotherapy, national control plans, and Water, Sanitation, and Hygiene (WASH) strategies.

Conclusions:

• While transmission factors are known, their detailed importance ranking aids control efforts.
• Prioritization of indicators and interventions can optimize resource allocation for schistosomiasis control.
• The study provides a framework for targeted schistosomiasis control in Zimbabwe, focusing on S. mansoni and S. haematobium.