Quantifying the effect of threshold-triggered interventions on hepatitis E virus outbreaks.

Area of Science:

• Epidemiology
• Public Health
• Mathematical Modeling

Background:

• Hepatitis E virus (HEV) poses a significant public health risk, particularly in resource-limited settings with poor sanitation.
• Existing interventions like water, sanitation, and hygiene (WASH) programs and vaccination face implementation challenges regarding timing and resource allocation.

Purpose of the Study:

• To quantify the impact of WASH programs and vaccination on HEV transmission dynamics.
• To evaluate the effectiveness of early versus delayed intervention deployment.

Main Methods:

• Development of a delay differential model simulating HEV transmission.
• Incorporation of clinical status, testing, and isolation delays into the model.
• Simulation of interventions triggered by case detection thresholds.

Main Results:

• Combined WASH and vaccination, deployed early, reduced overall and severe HEV infections by approximately 94%.
• Individual interventions showed modest reductions; WASH was more effective than vaccination alone for overall infections, while vaccination excelled in reducing severe cases.
• Delayed deployment of interventions led to significantly lower reductions in HEV infections.

Conclusions:

• Timely and integrated responses, especially combining WASH and vaccination, are critical for effective HEV outbreak control.
• WASH interventions play a vital role in reducing waterborne HEV transmission in vulnerable populations.
• Mathematical modeling provides valuable insights for optimizing public health intervention strategies.