Editing Syphilis (section)

===Blood tests===
Blood tests are divided into [[Nontreponemal tests for syphilis|nontreponemal]] and treponemal tests.<ref name=Pri2008/>

Nontreponemal tests are used initially and include [[venereal disease research laboratory]] (VDRL) and [[rapid plasma reagin]] (RPR) tests. [[False positive#Type I error|False positives]] on the nontreponemal tests can occur with some viral infections, such as [[varicella]] (chickenpox) and [[measles]]. False positives can also occur with [[lymphoma]], [[tuberculosis]], [[malaria]], [[endocarditis]], [[connective tissue disease]], and [[pregnancy]].<ref name="RedBookSyphilis"/>

Because of the possibility of false positives with nontreponemal tests, confirmation is required with a treponemal test, such as [[Treponema pallidum particle agglutination assay|''Treponema pallidum'' particle agglutination assay]] (TPHA) or [[fluorescent treponemal antibody absorption test]] (FTA-Abs).<ref name="Kent08"/> Treponemal antibody tests usually become positive two to five weeks after the initial infection<ref name="Pri2008"/> and remain positive for many years.<ref>{{cite journal |last= Singh|first= Ameeta E.|author2=Barbara Romanowski|date=1 April 1999|title= Syphilis: Review with Emphasis on Clinical, Epidemiologic, and Some Biologic Features|journal= Clinical Microbiology Reviews|volume= 12|issue= 2|pages= 187–209 |pmid= 10194456 |pmc= 88914 |doi=10.1128/CMR.12.2.187}}</ref> Neurosyphilis is diagnosed by finding high numbers of [[leukocytes]] (predominately [[lymphocytes]]) and high protein levels in the [[cerebrospinal fluid]] in the setting of a known syphilis infection.<ref name="Kent08"/><ref name="RedBookSyphilis"/>