Health
Increasing syphilis rates may be caused by bacterial factors
NEWS IN BRIEF — Posted Feb. 14, 2005
Syphilis outbreaks could be caused by a 10-year cycle of increasing then waning immunity to the bacteria rather than changes in human behavior, according to a paper published in the Jan. 27 issue of Nature.
Public health officials long have been concerned about increasing syphilis rates for fear that they could be an indicator of increasing unsafe sex, which could, in turn, lead to increasing HIV incidence.
But researchers at the Imperial College London analyzed data from 68 U.S. cities since the 1940s and found that syphilis rates escalated every 10 years. Authors of the paper suspect that as immunity to syphilis in the population falls, the number of cases increases. Immediately after an epidemic, when immunity is at its highest, the numbers wane.
Authors suggested that this knowledge could lead to elimination of the disease.
"It may be possible to use these findings to help doctors and sexual health workers predict and prepare for future outbreaks of the disease," said Dr. Nicholas Grassly, lead author and professor of infectious disease epidemiology. "Troughs in the number of cases offer an unprecedented opportunity for eradication of the disease. However, when this opportunity is missed, an epidemic is likely to follow."
The paper also included data about gonorrhea but did not find the same cyclic pattern as syphilis. Authors suggest that this sexually transmitted disease might be a better marker of changes in behavior.
Note: This item originally appeared at http://www.ama-assn.org/amednews/2005/02/14/hlbf0214.htm.
