The potential economic burden of Zika in the continental United States

Background: As the Zika virus epidemic continues to spread internationally, countries such as the United States must determine how much to invest in prevention, control, and response. Fundamental to these decisions is quantifying the potential economic burden of Zika under different scenarios. Methodology/Principle findings: To inform such decision making, our team developed a computational model to forecast the potential economic burden of Zika across six states in the US (Alabama, Florida, Georgia, Louisiana, Mississippi, and Texas) which are at greatest risk of Zika emergence, under a wide range of attack rates, scenarios and circumstances. In order to accommodate a wide range of possibilities, different scenarios explored the effects of varying the attack rate from 0.01% to 10%. Across the six states, an attack rate of 0.01% is estimated to cost $183.4 million to society ($117.1 million in direct medical costs and $66.3 million in productivity losses), 0.025% would result in $198.6 million ($119.4 million and $79.2 million), 0.10% would result in $274.6 million ($130.8 million and $143.8 million) and 1% would result in $1.2 billion ($268.0 million and $919.2 million). Conclusions: Our model and study show how direct medical costs, Medicaid costs, productivity losses, and total costs to society may vary with different attack rates across the six states and the circumstances at which they may exceed certain thresholds (e.g., Zika prevention and control funding allocations that are being debated by the US government). A Zika attack rate of 0.3% across the six states at greatest risk of Zika infection, would result in total costs that exceed $0.5 billion, an attack rate of 1% would exceed $1 billion, and an attack rate of 2% would exceed $2 billion. Author summary: Our work forecasts the cost and economic burden of the Zika virus across six states in the US which are at the greatest risk of Zika (Alabama, Florida, Georgia, Louisiana, Mississippi, and Texas). We evaluated the burden by varying attack rates, scenarios, and circumstances. All costs are reported in 2016 dollars. This is the first study to determine the potential economic impact of the Zika epidemic in the US across a wide range of possible scenarios (e.g., different scenarios explored the effects of varying attack rates from 0.01% to 10%). There has previously been debate regarding resource allocations to address the Zika epidemic. Our results are important for decision makers because they identify thresholds at which the economic impact of Zika on these six US states would exceed $0.5, $1.0, $1.5, and $2.0 billion. For example, a Zika attack rate of 1% across Alabama, Florida, Georgia, Louisiana, Mississippi, and Texas, the six states at greatest risk of Zika infection, would result in total costs that exceed $1 billion. Our study also reveals the primary determinants of Zika-associated costs, which can help guide future data collection and control efforts.