A Note on the Risk of Infections Invading Unaffected Regions

Area of Science:

• Epidemiology
• Mathematical Modeling
• Public Health

Background:

• Infectious disease outbreaks can emerge from international travel.
• Estimating the risk of disease introduction is crucial for public health preparedness.
• Previous models may not fully capture the complexities of disease transmission dynamics.

Purpose of the Study:

• To develop and apply probabilistic models for estimating infectious disease introduction risk.
• To analyze the risk of measles introduction into Italy and Zika virus into Rio de Janeiro.
• To provide quantitative insights into disease invasion potential via travelers.

Main Methods:

• Utilized a non-homogeneous birth process for directly transmitted infections (measles).
• Developed a novel model to assess vector-borne disease risk from infected travelers (Zika virus).
• Calculated invasion probabilities based on traveler infectivity and local transmission potential.

Main Results:

• Estimated a 93% risk of measles introduction into Italy in 2017.
• Calculated a 22% risk of Zika virus introduction into Rio de Janeiro.
• Demonstrated the utility of probabilistic modeling in assessing disease invasion risks.

Conclusions:

• Travelers pose a significant risk for introducing infectious diseases into new regions.
• Probabilistic models can effectively quantify invasion risks for both directly transmitted and vector-borne diseases.
• These findings highlight the importance of robust border health surveillance and control measures.