Infectious syphilis under two years duration

Infectious syphilis under two years’ duration is a surveillance classification encompassing primary, secondary and early latent syphilis ^[1]. The duration boundary is used for reporting and does not imply that the date of infection is known precisely in every case ^[1]. Syphilis is a bacterial sexually transmitted infection caused by Treponema pallidum ^[2][3].

Classification may incorporate compatible clinical findings, including a primary chancre or signs of secondary syphilis, together with specified laboratory evidence ^[1]. Laboratory pathways include recent seroconversion and qualifying changes in non-treponemal antibody titres with treponemal confirmation ^[1].

Infectious syphilis is widely recognized as a common sexually transmitted infection. Public health tracking consistently documents its sustained prevalence across diverse demographic groups. Standardized monitoring frameworks capture its ongoing distribution to support community-level intervention planning ^[4].

Syphilis can be transmitted through sexual contact with infectious lesions during vaginal, anal or oral sex, through blood transfusion, and from a pregnant woman to her fetus ^[2][3]. Transmission may occur through exposed lesions or body areas not covered by a condom ^[2].

Correct and consistent condom use reduces the likelihood of sexual transmission, although it does not eliminate risk when infectious lesions are outside the covered area ^[2][5]. People at higher risk should undergo regular testing, and pregnant women should be tested at the first prenatal care visit; people diagnosed with syphilis should notify sexual partners ^[2].

Confirmed and probable cases that meet the national definition are reportable ^[1]. Interpretation of trends should retain the applicable definition version, the confirmed-versus-probable scope, and jurisdictional notification practices ^[1].

1. 1Australian Government Department of Health and Aged Care. Syphilis (less than 2 years duration) – surveillance case definition [Internet]. cited 11 Aug 2026.Available from: https://www.health.gov.au/sites/default/files/documents/2022/06/syphilis-less-than-2-years-duration-surveillance-case-definition.pdf
2. 2World Health Organization. Syphilis [Internet]. cited 20 May 2026.Available from: https://www.who.int/news-room/fact-sheets/detail/syphilis
3. 3World Health Organization. Syphilis -- Global [Internet]. cited 20 May 2026.Available from: https://www.who.int/health-topics/syphilis
4. 4US Centers for Disease Control and Prevention. About Syphilis | Syphilis | CDC [Internet]. cited 3 Sept 2026.Available from: https://www.cdc.gov/syphilis/about/
5. 5Wikipedia contributors. Syphilis - Wikipedia [Internet]. Wikipedia. cited 20 May 2026.Available from: https://en.wikipedia.org/wiki/Syphilis
6. 6Chevalier FJ et al. Syphilis: A Review. JAMA. 2025 Dec 2. PMID: 41100079. doi: 10.1001/jama.2025.17362.PubMed: https://pubmed.ncbi.nlm.nih.gov/41100079/