SACRAMENTO - Sacramento County experienced a small increase in the number of West Nile cases reported over the long weekend, newly released data show.
Since Friday, when the caseload hit 112, an additional four cases have been reported and confirmed by health officials.
The increase represents less than a 4 percent jump since Friday. That contrasts with previous reporting periods, when the number of local cases has jumped by 15 percent or more in just three days.
Dr. Glennah Trochet, Sacramento County health officer, said the relatively small increase does not necessarily mean the disease is on the wane.
Placer County reported an additional two cases on Tuesday, bringing its total to 22.
Statewide, the tally climbed from 500 human cases to 521, representing a 4 percent increase since Friday.
Only cases with laboratory-confirmed blood tests are included in the county and state totals.
Just 20 percent of all people who get infected will experience symptoms such as fever, body aches and rash, and only the most seriously ill will be tested for the virus. That means the caseload data are not a true reflection of the overall West Nile infection rate in California.
There is no known treatment for West Nile virus.