The causes of biological false positive reagin (non-treponemal) tests are:
Acute (persisting less than 6 months): acute viral febrile illness (e.g. infectious mononucleosis, viral pneumonia, hepatitis); and pregnancy.
Chronic (persisting six months or more): intravenous drug abuse; autoimmune disease — positive serology may predate the disease (e.g. disseminated lupus erythematosis, rheumatoid arthritis, thyroiditis); malaria; and lepromatous leprosy.
The diagnosis of congenital syphilis is mainly dependent on serology.
Negative serology in the presence of Tpallidum infection may occur in: very early infection; and immunodeficiency following HIV infectioa CSF examination includes white cell count, total protein and VDRL or RPR. Raised lymphocyte count, raised total protein and positive reagin test in the CSF is indicative of neurosyphilis. CSF examination is indicated: where there are symptoms or signs of CNS disease in the presence of positive serological tests for syphilis;
before retreating a patient who has had relapse, treatment failure or reinfection after any form of treatment; in any patient who has been treated with non-penicillin regimens; where late or latent syphilis has been discovered and the period of latency cannot be determined or is in excess of 2 years; or before treatment with benzathine penicillin except in early disease.