Cook County Home To Nation's Highest Number Of Syphilis Cases (VIDEO)

According to new data released Thursday by the Centers for Disease Control, Cook County, Ill. ranks first among the U.S. counties documenting reported cases of syphilis.

According to the data, Chicago's Cook County -- home to 799 reported cases of syphilis in 2010 -- is trailed by Los Angeles County, New York County and San Francisco County respectively. Miami-Dade County, Fla., rounds out the top five.

Dr. Bechara Choucair, head of the Chicago Department of Public Health, told CBS Chicago that the city of Chicago has generally seen reported cases of syphilis on the decline in recent years, but that "we are seeing an uptick and that’s the concern we have right now."

(Scroll down to watch a video report on Cook County's alarming syphilis rates.)

Dr. Susan Gerber of the Cook County Department of Public Health also noted an increase in suburban Cook County in 2010 -- specifically, a 72 percent increase in primary and secondary cases.

And Gerber told CBS that number is likely "just the tip of the iceberg" as many individuals who are infected may not be getting tested.

The news arrives amid reports that, on a national scale, the overall rate of syphilis infection has fallen for the first time in a decade -- with infection rates decreasing by 1.6 percent in 2010 compared with the year before, according to Reuters. Syphilis rates reportedly fell 20 percent among women but increased 1.3 percent among men.

If left untreated, syphilis can lead to serious long-term health complications, including damage to the brain, heart and other organs. Click here for information on how and where to get tested and here [PDF] to learn more about symptoms of the infection.

WATCH a report on the newly released CDC data: