2012 West Nile Virus Outbreak: How Deadly Is It?

Centers For Disease Control and Prevention officials announced in August that the recent outbreak of West Nile was the largest ever seen in the United States. Now it is on track to be the deadliest.

READ: West Nile Virus: What You Need To Know

Carried by birds and mosquitoes, which have spread it across the entire country, the virus has sickened 30,000 people since it first showed up in the United States in 1999.