The West Nile virus outbreak in 1999 demonstrated the country's capacity to meet an emerging public health threat. However, while the tracking and monitoring efforts that were put into place by 2000 were impressive, the response to the West Nile virus underscores a fundamental deficiency in the capacity of public health regarding the nation's environmental health efforts. Chronic diseases such as asthma, neurological diseases, and birth defects and their potential links to environmental factors are not being adequately tracked and monitored. New public health infrastructure resources are required.