The congenital syphilis rate in the United States increased between 2005 and 2008, after dropping over the previous 14 years, which reflects an increase in the rate of primary and secondary syphilis cases among women, based on a report from the Centers for Disease Control and Prevention.
In 2008, there were 431 cases of congenital syphilis (CS) reported to state and local health departments in the United States, according to the report, based on national surveillance data between 2003 and 2008 (MMWR 2010;14:413–7).
However, this was an increase from 339 cases reported in 2005. And the CS rate increased by 23% during this time, from 8.2 cases per 100,000 live births in 2005 to 10.1 cases per 100,000 live births in 2008. Most of this increase was attributed to trends in the South, where the rate increased from 9.6 to 15.7/100,000 live births between 2005 and 2008—a 64% increase. In the Northeast, the rate increased from 4.2 to 5.4/100,000 live births—a 29% increase.
Previously, the CS rates had dropped, from 10.6 cases per 100,000 live births in 2003, to 8.2 cases per 100,000 live births in 2005 (which continued the decline from 1995, when the rate was almost 50 cases per 100,000 live births). The number of CS cases dropped from 432 in 2003 to 339 in 2005.
The increase in CS cases between 2005 and 2008 was preceded by a 38% increase in the rate of primary and secondary (P&S) syphilis among females aged 10 and older from 2004 to 2007, which continued to increase in 2008, according to the report, which noted that this trend may have been associated with the use of crack cocaine and commercial sex work.
Between 2005 and 2008, most of the increase in CS was seen among infants born to black mothers. In this group, the CS rate increased from 26.6 to 34.6 per 100,000 live births between 2005 and 2008—a 30% increase. (There were 156 cases in 2005 and 215 cases in 2008). The percentage of infants with CS born to black mothers who lived in the South increased from 51% in 2005 to 75% in 2008.
Between 2005 and 2008, there was a 2% increase in the CS rate among infants born to Hispanic mothers (12.6 to 12.8 cases per 100,000 live births) and a 115% increase among infants born to white mothers (1.3 to 2.8 cases per 100,000 live births). But the report pointed out that the number of infants with CS born to white mothers was small: 31 cases in 2005 and 65 in 2008.
In 2008, infants of black mothers accounted for 50% of CS cases; infants of Hispanic mothers, 31%; infants of white mothers, 15%; and infants of Asian/Pacific Islander and American Indian/Alaskan Native mothers, 2% and 1%. The remaining 1% of infants had mothers of unknown race/ethnicity.
The CDC recommends that all pregnant women be tested for syphilis at the first prenatal visit, but the mothers of 125 (nearly 30%) of the 431 infants with CS reported in 2008 had not received prenatal care, and syphilis was detected at delivery. Of the 276 infants (64%) whose mothers had received prenatal care, the mothers of 75 infants (27%) were first screened for syphilis within 30 days of delivery; 67 (24%) mothers had a positive screen more than 30 days before delivery but had not been treated. For the remaining 30 infants, whether the mother had received prenatal care was not known.
Of the cases reported in 2008, 25 (6%) were stillborn and 3 (1%) died within 30 days of delivery, for a case fatality ratio of 6.5%.
“Reversing the upward trend in CS rates will require collaboration among health care providers, health departments, health insurers, policy makers, and the public to reduce syphilis among women and to increase early prenatal care access and syphilis screening during pregnancy,” the report said.
An editorial comment on the findings pointed out that the increase in the primary and secondary syphilis rate from 1.1/1,000 females in 2007 to 1.5/1,000 females in 2008 “might portend a larger increase” in the CS rate in 2009 and in the future.