SACRAMENTO — California's number of West Nile cases topped 800 on Friday, with Sacramento County still leading all counties in the state with a total of 170 cases.

Even as the numbers continue to climb, state officials confirmed that the pace of the disease is slowing.

‘‘It appears the peak transmission season was the end of August, as West Nile activity is tapering off,'' said Dr. Vicki Kramer, chief of the vector-borne disease section of the state Department of Health Services.

As it did last year, California has led the nation this season in West Nile cases, with 801.

Only two other states have had more than 100 cases this season: South Dakota, with 208 and Illinois, with 172.

The federal Centers for Disease Control and Prevention this week reported a total of 1,804 human cases of West Nile virus in 2005, more than the total of 1,784 reported in all of 2004.

So far this year, 52 people have died from West Nile in the United States, 16 of them in California.