CDC: Gonorrhea rate down syphilis up

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CDC Gonorrhea rate down syphilis up

• Associated Press,
• November 8, 2005

http//www.cnn.com/2005/HEALTH/conditions/11/08/st
d.cases.ap/index.htm l
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Changes in prevalence

• ATLANTA, Georgia (AP) -- Gonorrhea has fallen to
  the lowest level on record in the United States,
  while the rates of other sexually transmitted
  diseases -- syphilis and chlamydia -- are on the
  rise, federal health officials said Tuesday.
• The seemingly paradoxical findings can be
  explained by the cyclical nature of syphilis
  outbreaks and a rise in risky sexual behavior
  among gay men, researchers said.

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Various Diseases

• The nation's gonorrhea rate fell to 113.5 cases
  per 100,000 people last year, the lowest level
  since the government started tracking cases in
  1941, according to the Centers for Disease
  Control and Prevention.
• At the same time, health official saw increases
  in syphilis, which is far more rare but has been
  increasing since 2000. The rate of reported
  early-stage syphilis was 2.7 cases per 100,000 in
  2004, up 29 percent since 2000.
• The chlamydia rate rose to 319.6 cases per
  100,000 in 2004, up about 6 percent from the year
  before. But researchers said it is not clear
  whether the rise represents a real increase in
  the prevalence of the disease, or simply reflects
  better awareness and detection.
• All three diseases are caused by sexually
  transmitted bacteria.

Cases per 100,000
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Epidemiology

• London researchers reported earlier this year
  that because of the life cycle of the syphilis
  bacteria, infections tend to peak at 8- to
  11-year intervals. Sexual behavior affects the
  overall number of people infected, but regular
  ups and downs are intrinsic to the disease, the
  researchers said. Gonorrhea does not follow the
  same pattern, they said, and rates have been
  gradually falling since the 1980s.
• Dr. Ronald Valdiserri, acting director of the
  CDC's National Center for HIV, STD and TB
  Prevention, said that may be part of the
  explanation for the rebound in syphilis, but a
  primary reason appears to be an increase in risky
  sexual behavior.
• In 2004, about 64 percent of reported early-stage
  syphilis infections occurred among men who had
  sex with men, up from 5 percent in 1999,
  according to the CDC.
• "It's very clear that for the last four years,
  when we've seen an increase it's primarily been
  in men and predominantly in men who have sex with
  men," Valdiserri said. "We know that's being
  fueled by increases in high-risk sexual behavior.
  We have good data to substantiate that."

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Reported and true numbers

• For chlamydia, a urine screening test is becoming
  more common, and health officials are working to
  make chlamydia screening routine in yearly
  gynecological exams for sexually active young
  adult women.
• Chlamydia is the most common of the three
  diseases. A total of 930,000 cases were reported
  last year. But health officials believe as many
  as 2.8 million new cases may actually be
  occurring each year.
• About 330,000 cases of gonorrhea were reported in
  2004. The CDC said there may really be as many as
  700,000 cases of that disease each year.
• Syphilis, a potentially deadly disease that first
  shows up as genital sores, has become relatively
  rare in the U.S., with about 8,000 cases reported
  in 2004. Detection is believed to be much better
  for syphilis, and the total number of annual
  cases is probably no more than 10,000.

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Chlamydia Rates by county United States, 2004
Source http//www.cdc.gov/std/stats/slides.htm
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Economics
Sexual Encounters

• Simple supply and demand analysis.
• Reduction in the price (related to possibility
  of disease, or ease of treatment) ? more activity.

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Encounters STDs