VISALIA -- Concerned health officials are investigating a recent spike in Tulare County residents who have contracted the sexually transmitted disease syphilis.
Local and state health officials say they don't know why 30 people got the disease here last year, while there has been no significant exposure to syphilis in the rest of the central San Joaquin Valley.
About half of the syphilis cases in the Valley -- Fresno, Tulare, Kings, Merced, Madera, Stanislaus and Kern counties -- come from Tulare County, according to preliminary 2007 data from the California Department of Public Health.
The increase in reported cases in Tulare County in 2007 comes after the county had 21 cases in 2006 and 14 in 2005, said county health officer Dr. Karen Haught.
"It is definitely something we're concerned about," she said. "We want to bring it down to zero."
Syphilis is considered a high priority for health officials who track sexually transmitted diseases because the bacteria can create severe health problems and even death if untreated.
Sores created by the bacteria also increase the chances of transmitting HIV, according to the Centers for Disease Control and Prevention.
Haught said most of those infected were methamphetamine users or had sexual contact with meth users. Those who abuse the drug, she said, are more likely to participate in risky behavior.
For every 100,000 people in Tulare County, 4.6 have syphilis. The Valley's rate is 1.2 for every 100,000 people, said Dr. Gail Bolan, chief of the state's STD control branch.
The trend seen in the county is considered significant, Bolan said, and state officials are helping Tulare County health officers manage their cases.
"The good news is the numbers are still relatively small," Bolan said, comparing the numbers to the rest of the state.
The Valley has not seen increases of the disease like the rest of the state has, Bolan said.
The syphilis rate across California has risen from 4.4 in 2005 to 5.4 per 100,000 people in 2007, according to preliminary state figures.
The number also grew nationally by 11.8% from 2005 to 2006, according to the Centers for Disease Control and Prevention.
Bolan said many places in California have seen the disease spread most among gay men who use meth.
But that's not the case in Tulare County, Haught said.
The number of men and women infected in the county were almost equal, according to preliminary statistics from the California Department of Public Health.
The increase of syphilis cases across the state has also caught the attention of Fresno County health officials. They had three cases in 2007 and seven cases in 2006, said David Luchini, division manager for communicable disease at the Fresno County Department of Public Health.
Luchini said Fresno County has kept its numbers low partly because of screenings and health education.
When the county saw a spike in the mid-1990s, Luchini said, the county used state and federal grants to help stem the spread of the disease. But now Luchini and other Valley health officials are hoping that increases seen in Tulare County and the rest of the state don't spread through the region.
"If there is starting to be an increase in Tulare County," Luchini said, "that's something we have to keep an eye on."