Reconstructing long-term dengue virus immunity in French Polynesia

Area of Science:

• Epidemiology
• Mathematical Modeling
• Infectious Disease Dynamics

Background:

• Dengue virus infection risk is complicated by serotype-specific histories and age.
• Quantifying severe dengue risk based on these factors is rarely done.
• Island communities with single-serotype outbreaks offer a simplified model for analysis.

Purpose of the Study:

• To disentangle the roles of serotype, age, and surveillance changes in dengue disease risk.
• To estimate serotype-specific infection histories and reporting probabilities.
• To model dengue transmission over 35 years in French Polynesia.

Main Methods:

• Developed mathematical models to analyze 35 years of dengue surveillance and seroprevalence data.
• Estimated annual force of infection, serotype-specific reporting probabilities, and surveillance capability changes.
• Utilized age and serotype-specific distribution of dengue cases.

Main Results:

• Observed eight dengue epidemics between 1979-2014, with increasing reporting probabilities for DENV-1.
• Secondary DENV-1 infections had a 3.6x higher reporting probability than primary infections.
• Reporting probabilities declined with age, varied by serotype (DENV-3 highest), and increased overall surveillance over time.

Conclusions:

• Characterized factors influencing dengue dissemination and reporting in a simplified epidemiological setting.
• Provided key estimates for understanding dengue in more complex, multi-serotype circulation environments.
• Demonstrated a sharp increase in epidemic probability with the fraction of susceptible children.