Genetic differences in host infectivity affect disease spread and survival in epidemics

Area of Science:

• * Evolutionary biology
• * Genetics
• * Epidemiology

Background:

• * Host genetics significantly impacts survival during epidemics, influencing disease resistance, endurance, and infectivity.
• * Genetic variation in disease endurance is rarely studied, and genetic variation in host infectivity remains largely unexplored despite observed phenotypic variation.
• * Understanding genetic contributions to all three traits is crucial for predicting and managing epidemic dynamics.

Purpose of the Study:

• * To develop an experimental design and statistical models for estimating genetic diversity in host resistance, endurance, and infectivity.
• * To provide the first direct evidence for genetic variation in host infectivity.
• * To assess the contribution of genetic variation in these three traits to overall host survival during epidemics.

Main Methods:

• * Development of novel statistical models for estimating genetic parameters.
• * Utilizing an experimental infection model in fish populations.
• * Quantifying genetic variation in resistance, endurance, and infectivity.

Main Results:

• * Demonstrated significant genetic variation in host infectivity for the first time.
• * Confirmed genetic variation in disease resistance and endurance.
• * Showcased how genetic differences in resistance, endurance, and infectivity collectively influence host survival rates.

Conclusions:

• * Host infectivity exhibits significant genetic variation, a previously underappreciated factor in epidemic dynamics.
• * Genetic diversity in resistance, endurance, and infectivity allows for diverse host response types.
• * Findings have critical implications for understanding and controlling epidemics by considering the genetic architecture of host-pathogen interactions.