Worst of West Nile may be over in U.S.

Health officials said on Wednesday that the worst of the U.S. West Nile virus outbreak may be over but that cases will continue to add up to the nation's highest yearly total.

During a media briefing, Lyle Peterson, the director of the Division of Vector-Borne Diseases at the CDC, said that signs are present that the activity for the virus has peaked. Illness and death reports are lagging indicators of the virus and the CDC expects that there will be a high volume of reports until October, CIDRAP News reports.

In total, there have been 2,636 cases of West Nile virus so far in the U.S. this year, a growth of 643 cases from the previous week. The number of total neuroinvasive disease cases jumped 336 to 1,405 and the number of deaths rose by 31 to 118 overall.

Two-thirds of the cases have been reported by six states, including Michigan, Louisiana, Oklahoma, Mississippi, South Dakota and Texas. Approximately 40 percent of the cases have been in Texas, mostly concentrated in the Dallas County area. Texas has experienced 1,150 infections, 564 neuroinvasive disease cases and 50 deaths, according to CIDRAP News.

While the number of overall cases lags behind the pace for 2003, Peterson said that this outbreak has been the most serious one reported.