1. Syphilis Epidemiology Thad Zajdowicz, MD, MPH Medical Director, STD/HIV Program Chicago Dept of Public Health

3. Why a lecture on syphilis? Although syphilis is an eminently treatable disease, its continuing occurrence illustrates that our control efforts still need to be improved. The disease remains elusive clinically even today, and unless thought of and sought for can silently cause disease as it has for centuries. Further, control of syphilis is vital because of its interactions with HIV. This lecture will focus on syphilis epidemiology; following lectures will explore the clinical manifestations of this most protean of diseases.

4. Objectives To understand the prior and current impact of syphilisTo understand the prior and current impact of syphilis To define current trends of syphilis in the U.S.To define current trends of syphilis in the U.S. To understand how syphilis and HIV interactTo understand how syphilis and HIV interact

5. Etiology and Course Syphilis is a chronic, systemic infection caused by a spirochete, Treponema pallidum. The primary mode of transmission is via sexual contact. Untreated, syphilis progresses through a primary and secondary stage before becoming latent. Up to 1/3 of people with untreated syphilis develop tertiary disease late in life, primarily cardiovascular and neurologic. Syphilis is also transmitted congenitally from an infected mother to her infant.

6. Historical Issues Emergence of syphilis in Europe in 1490sEmergence of syphilis in Europe in 1490s ? Imported from the Americas (Columbian theory) or ? Emergence in Europe from other treponematoses? Imported from the Americas (Columbian theory) or ? Emergence in Europe from other treponematoses Severe disease (called The Great Pox to distinguish it from smallpox)Severe disease (called The Great Pox to distinguish it from smallpox)

7. Pre-Penicillin Era Highly prevalent in many countries/societies in pre-penicillin eraHighly prevalent in many countries/societies in pre-penicillin era Estimates of 10% of U.S. population infected in early 20 th CenturyEstimates of 10% of U.S. population infected in early 20 th Century –Higher rates in socially disadvantaged populations, e.g. rural African-Americans in the South Dramatic drop in incidence/prevalence after introduction of penicillin in mid- 1940sDramatic drop in incidence/prevalence after introduction of penicillin in mid- 1940s

8. Syphilis Worldwide WHO estimates 12 million new cases of syphilis worldwide (http://www.who.int/docstore/hiv/ GRSTI/pdf/figure09.pdf)WHO estimates 12 million new cases of syphilis worldwide (http://www.who.int/docstore/hiv/ GRSTI/pdf/figure09.pdf)http://www.who.int/docstore/hiv/ GRSTI/pdf/figure09.pdfhttp://www.who.int/docstore/hiv/ GRSTI/pdf/figure09.pdf Greatest burden in adolescents and young adultsGreatest burden in adolescents and young adults Greatest numbers of new cases in South and Southeast Asia, followed by sub-Saharan AfricaGreatest numbers of new cases in South and Southeast Asia, followed by sub-Saharan Africa

9. Syphilis in the U.S. http://www.cdc.gov/std/stats/2002pdf/Syphilis.pdf

10. Current U.S. Syphilis Epidemiology Rates of primary and secondary (P&S) syphilis declined every year from 1990-2000Rates of primary and secondary (P&S) syphilis declined every year from 1990-2000 In 2001, rates of P&S syphilis began rising againIn 2001, rates of P&S syphilis began rising again –However, rise in new cases is seen in men who have sex with men (MSM) –Male:female ratio of cases rose from ~ 1:1 to ~3.5:1 in past 8 years

11. Primary and Secondary Syphilis --- United States, 2002 Primary and Secondary Syphilis --- United States, 2002

12. P&S Syphilis Cases by Region Primary and Secondary Syphilis --- United States, 2002 Primary and Secondary Syphilis --- United States, 2002

13. Race & Ethnicity In 2001-2002, P&S syphilis rates increased 71.4% among non-Hispanic white men and 28.6% among Hispanic menIn 2001-2002, P&S syphilis rates increased 71.4% among non-Hispanic white men and 28.6% among Hispanic men –No changes in rates in females of same groups Among non-Hispanic blacks, P&S syphilis rates decreased 10.9%Among non-Hispanic blacks, P&S syphilis rates decreased 10.9% –2.2% for men, 22.6% for women There were significant rate changes in both Asian/Pacific Islanders and American Indians/Alaska NativesThere were significant rate changes in both Asian/Pacific Islanders and American Indians/Alaska Natives –However, very few cases in both groups overall

14. P&S Syphilis among MSM, Chicago, 2000-2002 by Month of Treatment 2000 20022001 CP

15. P&S Syphilis, by Gender and Sexual Orientation, 1998-2003*, Chicago N=338 N=282 N=292 N=317N=353N=161

16. Congenital Syphilis Syphilis is transmissible from mother to infantSyphilis is transmissible from mother to infant Transmission usually occurs during early stages, but may occur at any stage in an untreated motherTransmission usually occurs during early stages, but may occur at any stage in an untreated mother Incidence of infection rose in U.S. in late 1980s-early 1990s with rise in heterosexual casesIncidence of infection rose in U.S. in late 1980s-early 1990s with rise in heterosexual cases

17. Congenital Syphilis Rates of congenital syphilis in U.S. continue to decline as new cases of P&S syphilis decline in heterosexualsRates of congenital syphilis in U.S. continue to decline as new cases of P&S syphilis decline in heterosexuals http://www.cdc.gov/std/stats/tablessyph. htmhttp://www.cdc.gov/std/stats/tablessyph. htmhttp://www.cdc.gov/std/stats/tablessyph. htmhttp://www.cdc.gov/std/stats/tablessyph. htm http://www.cdc.gov/epo/mmwr/preview/ mmwrhtml/mm4834a3.htmhttp://www.cdc.gov/epo/mmwr/preview/ mmwrhtml/mm4834a3.htmhttp://www.cdc.gov/epo/mmwr/preview/ mmwrhtml/mm4834a3.htmhttp://www.cdc.gov/epo/mmwr/preview/ mmwrhtml/mm4834a3.htm

18. Epidemiological Synergy HIV and syphilis co-facilitate transmission of each otherHIV and syphilis co-facilitate transmission of each other Biological plausible because:Biological plausible because: –STDs facilitate HIV shedding –Cellular recruitment of HIV susceptible cells occurs –Mucosal barriers are breached –Immunosuppression

19. Behavioral Risk Behaviors that are risky for transmission of syphilis are also risky for transmission of HIVBehaviors that are risky for transmission of syphilis are also risky for transmission of HIV This has been demonstrated in studies in various areas of the worldThis has been demonstrated in studies in various areas of the world http://www.pubmedcentral.gov/articl erender.fcgi?tool=gateway&pubmedid =14585109http://www.pubmedcentral.gov/articl erender.fcgi?tool=gateway&pubmedid =14585109http://www.pubmedcentral.gov/articl erender.fcgi?tool=gateway&pubmedid =14585109http://www.pubmedcentral.gov/articl erender.fcgi?tool=gateway&pubmedid =14585109

20. Sources of Information The following sites are useful if more information on syphilis epidemiology is sought: information on syphilis epidemiology is sought: www.cdc.govwww.cdc.govCenters for Disease Control www.cdc.gov www.who.intwww.who.intWorld Health Organization www.who.int www.ashastd.orgwww.ashastd.org American Social Hygiene Assoc www.ashastd.org www.vnh.orgwww.vnh.orgVirtual Naval Hospital www.vnh.org