Clinical and serological outcomes in patients treated with oral doxycycline for early neurosyphilis
Nicolò Girometti, Muhammad Hyder Junejo, Diarmuid Nugent, Alan McOwan, Gary Whitlock, the 56 Dean Street Collaborative Group, Keerti Gedela, Sheel Patel, Tara Suchak, Victoria Tittle
Abstract
OBJECTIVES: Penicillin-based antibiotic treatment for syphilis infection with CNS involvement (early neurosyphilis) is not always a suitable treatment option. We compared outcomes of patients diagnosed with early neurosyphilis and treated with doxycycline or procaine G penicillin. METHODS: Serological and clinical outcomes were analysed in patients diagnosed with early neurosyphilis between January 2015 and October 2019 at 56 Dean Street, a combined sexual health and HIV service based in London, UK. Acute onset of CNS, ocular and/or otic symptomatology and a documented seroconverting syphilis serology or a >4-fold increase in rapid plasma reagin ('RPR)' test titre within the previous 12 months were criteria used to define a case. Mann-Whitney U-test and χ2 tests were used to test distributions between baseline characteristics and outcomes according to treatment administered. RESULTS: Eighty-seven patients were included: median age = 35 years (IQR = 31-45), 98% MSM, 79% white ethnicity, 53% HIV-1 positive and 40% previously diagnosed with syphilis at any stage. They were treated exclusively with either intramuscular (IM) procaine G penicillin (71%) or oral doxycycline (18%). Patients received doxycycline treatment over a penicillin-based regimen due to IM treatment declined (31%), inability to attend for IM injections (31%) or penicillin allergy (19%). Serological response was achieved by all patients; 91% reported full symptom resolution at 30 days from end of treatment. Similar rates of clinical and serological response and seroreversion were observed in the groups treated with procaine G penicillin versus doxycycline. CONCLUSIONS: The clinical and serological outcomes seen with penicillin-based versus doxycycline treatments were similar. A randomized controlled trial is needed to establish the effectiveness of doxycycline in the treatment of early neurosyphilis.