In what is the second-worst year on record for the disease, the total number of cases of West Nile virus across the United States grew to 4,725, with 194 new cases reported, according to the Centers for Disease Control and Prevention.

Although the pace of new cases has slowed since the outbreak's peak in the late summer, new cases continue to be reported, particularly in states where warm temperatures persist. This year's outbreak has trailed only 2003 in total cases.

Just over half of the cases reported to the CDC this year have been of the severe neuroinvasive form of the disease, which can cause meningitis and encephalitis.

The death toll from West Nile is now the highest since 2003, when 264 deaths were reported. The highest number of deaths from West Nile was 284 in 2002.

CDC officials have said deaths often lag weeks to months from the time of infection because of lingering illness.

Almost 70 percent of the cases have been reported in eight states: Texas, California, Louisiana, Mississippi, Illinois, South Dakota, Michigan and Oklahoma.

More than a third of all cases have been reported in Texas, with Dallas-Fort Worth at the center of the outbreak.

The Texas Department of State Health Services has reported 1,683 cases and 77 deaths, including 915 cases and 36 deaths in the Dallas-Fort Worth area.

(Editing by Paul Thomasch and Vicki Allen)

• A Permanent Economic Emergency