Occurrence, risk factors, diagnosis and treatment of syphilis in the prospective observational Swiss HIV Cohort Study.
BACKGROUND
Annual syphilis testing was reintroduced in the Swiss HIV Cohort Study (SHCS) in 2004. We prospectively studied occurrence, risk factors, clinical manifestations, diagnostic approaches and treatment of syphilis.


METHODS
Over a period of 33 months, participants with positive test results for Treponema pallidum hemagglutination assay were studied using the SHCS database and an additional structured case report form.


RESULTS
Of 7244 cohort participants, 909 (12.5%) had positive syphilis serology. Among these, 633 had previously been treated and had no current signs or symptoms of syphilis at time of testing. Of 218 patients with newly detected untreated syphilis, 20% reported genitooral contacts as only risk behavior and 60% were asymptomatic. Newly detected syphilis was more frequent among men who have sex with men (MSM) [adjusted odds ratio (OR) 2.8, P < 0.001], in persons reporting casual sexual partners (adjusted OR 2.8, P < 0.001) and in MSM of younger age (P = 0.05). Only 35% of recommended cerebrospinal fluid (CFS) examinations were performed. Neurosyphilis was diagnosed in four neurologically asymptomatic patients; all of them had a Venereal Disease Research Laboratory (VDRL) titer of 1:>or=32. Ninety-one percent of the patients responded to treatment with at least a four-fold decline in VDRL titer.


CONCLUSIONS
Syphilis remains an important coinfection in the SHCS justifying reintroduction of routine screening. Genitooral contact is a significant way of transmission and young MSM are at high risk for syphilis. Current guidelines to rule out neurosyphilis by CSF analysis are inconsistently followed in clinical practice. Serologic treatment response is above 90% in the era of combination antiretroviral therapy.
Thurnheer
Maria Christine
MC
Clinic for Infectious Diseases, Bern University Hospital and University of Bern, Bern, Switzerland.
Weber
Rainer
R
Toutous-Trellu
Laurence
L
Cavassini
Matthias
M
Elzi
Luigia
L
Schmid
Patrick
P
Bernasconi
Enos
E
Christen
Anna B
AB
Zwahlen
Marcel
M
Furrer
Hansjakob
H
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D000328:Adult; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013557:Switzerland / Q000453:epidemiology; D013587:Syphilis / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D014210:Treponema pallidum / Q000302:isolation & purification*; D014481:United States / Q000453:epidemiology; D047568:Unsafe Sex