From the question on page 100

Immunoassay for Treponema pallidum antibodies (TPAb ELISA) and the rapid plasma reagin test (RPR) performed at presentation were positive at high titres (1:16 and 1:128, respectively). TPAb were also detected in the cerebrospinal fluid (titre 1:128). T pallidum DNA-PCR of lung biopsy was not performed because of the poor specimen available.

Following the clinical and serological diagnosis of secondary syphilis with involvement of the central nervous system, intravenous ceftriaxone (2 g/day) was administered for 2 weeks because the patient reported allergy to penicillin. An unexpected and …