CD4 and syphilis: Multivariate analysis identified young age (age <33 years versus age >40, adjusted HR 4.0, 95%CI 2.22–7.18, p<0.001; age 33–40 versus age >40, adjusted HR 2.9, 95%CI 1.61–5.10, p<0.001), history of syphilis infection (adjusted HR 3.0, 95%CI 2.03–4.47, p<0.001), positive baseline anti-Eh (adjusted HR 1.8, 95%CI 1.17–2.68, p = 0.006), and higher baseline CD4 count (CD4 ≥350 /μL versus CD4 <200 /μL, HR 1.6, 95%CI 1.00–2.53, p = 0.050) as independent risk factors for incident syphilis (Table 3).