A51.1Primary anal syphilis
Code usage status
Primary diagnosis
May be used as the primary diagnosis
Apply only when it matches the confirmed diagnosis and the documented clinical record.
Specificity
Complete code in the classification
Use when the diagnosis matches and no exclusion applies.
- Official Vietnamese name
- Bệnh giang mai hậu môn sơ nhiễm
Related A51 codes
A51
Early syphilis
A51.0
Primary diagnosis candidate
Primary genital syphilis
A51.2
Primary diagnosis candidate
Primary syphilis of other sites
A51.3
Primary diagnosis candidate
Secondary syphilis of skin and mucous membranes
A51.4
Primary diagnosis candidate
Other secondary syphilis
A51.5
Primary diagnosis candidate
Early syphilis, latent
A51.9
Primary diagnosis candidate
Early syphilis, unspecified
Clinical record checklist
View coding guide →- Confirm that the code matches the final documented diagnosis.
- Use one primary-diagnosis code and record only relevant additional conditions.
- Review Ministry indicators, inclusions, exclusions and notes.
- Do not infer a diagnosis beyond the clinical record.
2026 regulatory basis
Indicators are taken from columns 24–29 of the classification accompanying Circular 06/2026/TT-BYT, cross-referenced with Decision 1849/QĐ-BYT and Official Dispatch 4059/BYT-BH.
