P034 Primary syphilis presentation characteristics and serological response, is there still more to learn?

Abstract

<h3>Background</h3> Rates of infectious syphilis has significantly increased in men who have sex with men (MSM). Recent data has shown that primary syphilis does not always present with painless genital lesions. Our aim was to describe the clinical characteristics, serological response and management of primary syphilis in HIV-positive and negative MSM. <h3>Methods</h3> We reviewed the microbiological and demographic data of MSM presenting with primary syphilis between January 2016 – March 2020 in our clinic-based population in Brighton, UK. <h3>Results</h3> There were 111 cases of primary syphilis in MSM, the median age was 46 years (IQR=37–53 years) and 40 (36%) were living with HIV. 56/111 (50%) of MSM presented with painful lesions and 14% with extra-genital lesions. Extra-genital lesions were significantly more likely to be painful than genital lesions (OR 4.72; 95%, CI1.25–17.83,p=0.02). Overall, serology had a sensitivity of 80% (57/71) compared with Treponema pallidum PCR. Serology was more sensitive in MSM with no previous syphilis (OR= 3.38, 95%CI1.002– 11.43, p&lt; 0.05). There were no differences in the characteristics, serological response or management between HIV positive and negative MSM. <h3>Conclusion</h3> Fifty percent of MSM with primary syphilis presented with painful lesions; extra-genital lesions are more likely to be painful than genital lesions and serology is sensitive in 80% of MSM, and there were no differences between HIV positive and negative MSM. Understanding the characteristics of primary syphilis will underpin public health campaigns.