Model-Based Projection of Zika Infection Risk with Temperature Effect: A Case Study in Southeast Asia

Area of Science:

• Epidemiology
• Mathematical Biology
• Public Health

Background:

• Zika virus (ZIKV) reemerged in the Americas, causing public health concerns due to birth defects and complex transmission.
• Limited data exists on ZIKV transmission potential in Southeast Asia, a region significantly affected by the virus.

Purpose of the Study:

• To develop and validate a dynamic mathematical model for ZIKV transmission incorporating human-mosquito interactions and temperature effects.
• To assess the risk of ZIKV outbreaks in Southeast Asia and the impact of control strategies.

Main Methods:

• A process-based mathematical model was developed, integrating human sexual transmissibility and mosquito biting transmissibility.
• The model was validated using data from the 2016 ZIKV outbreak in Singapore through Markov chain Monte Carlo simulation.
• Temperature-dependent effects on mosquito ecology and ZIKV transmission were analyzed.

Main Results:

• The estimated infection reproduction number (R0) in Singapore decreased from 6.93 to 0.24 after control measures, with sexual transmission contributing significantly (0.89 initially).
• Optimal temperatures for ZIKV infection and adult mosquito reproduction were estimated at 28°C and 25°C, respectively.
• R0 values in Southeast Asia were projected between 3 and 7, exhibiting an inverted-U pattern annually, indicating high transmission potential.

Conclusions:

• Mathematical modeling confirms a high risk of ZIKV outbreaks in Southeast Asia due to favorable transmission dynamics.
• Temperature plays a crucial role in ZIKV transmission potential, with specific optimal ranges identified.
• Effective control strategies are vital for mitigating ZIKV spread, particularly considering the contribution of sexual transmission.