WP 27 Reporting Only Primary and Secondary Syphilis Grossly Underestimates Infectious Syphilis Burden; New York City, Philadelphia, North Carolina, Florida, and Maricopa County Arizona, 2013-2015

Wednesday, September 21, 2016
Galleria Exhibit Hall
Julie Schillinger, MD, MSc, Bureau of Sexually Transmitted Disease Control, NYC Department of Health & Mental Hygiene, Division of Sexually Transmitted Disease Prevention, Centers for Disease Control and Prevention, Long Island City, NY, Ebiere Okah, BA, School of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, Felicia Lewis, MD, Division of STD Prevention, Centers for Disease Control and Prevention and Philadelphia Department of Public Health, Philadelphia, PA, Greta Anschuetz, MPH, STD Control Program, Philadelphia Department of Public Health, Philadelphia, PA, Anna Cope, PhD MPH, North Carolina Communicable Disease Branch, Division of STD Prevention, Centers for Disease Control and Prevention, Raleigh, NC, James Matthias, MPH, Epidemiology and Statistics Branch, Division of STD Prevention, Centers for Disease Control and Prevention, Tallahassee, FL, Melanie Taylor, MD, MPH, DIVISION OF STD PREVENTION, CENTERS FOR DISEASE CONTROL, Phoenix, AZ and Thomas Peterman, MD, MSc, Epidemiology and Statistics Branch, Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA

Background:  Primary and secondary syphilis infections represent recently acquired infections and are often the focus of epidemiologic reports of disease burden and trends. Latent syphilis infections may also be recently acquired, but may be classified as late latent (LL) infection when proof of acquisition in the past year cannot be documented.

Methods:  Primary, secondary, early latent (EL), and LL syphilis cases reported to STD surveillance programs in New York City, Philadelphia, North Carolina,  Florida, and Maricopa County, Arizona were examined in aggregate, stratified by patient sex, age group, syphilis stage, diagnosing titer (<1:4, 1:8, 1:16, 1:32,  >1:64). Data were from a recent period during 2013-2015, when individual jurisdictions used consistent criteria for field investigation of reactive syphilis serologies, and syphilis case-patient interview.

Results: There were 2,201 primary (2,085 male, 116 female), 5,726 secondary (5,163 male, 563 female), 7,698 EL (6,784 male, 914 female) and 8,803 LL (6,685 male, 2,118 female) syphilis cases reported from the combined jurisdictions. The diagnostic titer was >1:64 in 49% (3,744/7,698) of EL (50% males, 38% females), and 31% (2,732/8,803) of LL cases (37% males, 14% females). Among LL cases, case-patients aged 10-19 (39%, 108/276) and 20-24 years (35%, 419/1,182) had the highest proportion titers >1:64; the proportion was higher among males (10-19: 45%, 74/165, and 20-24: 40%, 345/854) than females (10-19: 31%, 34/111, and 20-24: 23%, 74/328). Examined by jurisdiction, there was some variation in the age groups with highest proportion titers >1:64.

Conclusions:  P&S represented about one third of syphilis cases and less than half infections acquired within the past year.  A substantial proportion of EL and LL cases have high titers suggesting very recent acquisition, and ongoing risk for transmission, especially among males, and teens/young adults. Measures of disease burden focusing solely on P&S syphilis will grossly underestimate infectious burden.