The potential economic burden of Zika in the continental United States

Abstract

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.

Fig 1. Model structure.

The flow diagram above illustrates each of the paths an individual in the model can take in the event of a Zika virus outbreak, given different probabilities at each node. The model includes all individuals in the six selected states considered at risk for Zika virus infection in the US.

Fig 2. Total costs for all states combined.

Medicaid costs, direct medical costs, productivity losses, and total costs for all six states combined. Illustrated here is the base case scenario (solid line) as well as the range from the more conservative to the less conservative scenario (shaded region).

Fig 3. Direct medical costs per state.

Direct medical costs by state and attack rate. Illustrated here is the base case scenario (solid line) as well as the range from the more conservative to the less conservative scenario (shaded region).

Fig 4. Medicaid costs per state.

Medicaid costs by state and attack rate. Illustrated here is the base case scenario (solid line) as well as the range from the more conservative to the less conservative scenario (shaded region).

Fig 5. Productivity losses per state.

Total productivity losses by state and attack rate. Illustrated here is the base case scenario (solid line) as well as the range from the more conservative to the less conservative scenario (shaded region).

Fig 6. Total costs per state.

Total costs (direct medical and productivity losses) by state and attack rate. Illustrated here is the base case scenario (solid line) as well as the range from the more conservative to the less conservative scenario (shaded region).