Active syphilis among men who have sex with men

Export Indicator

Percentage of men who have sex with men with active syphilis
What it measures

Progress in decreasing high-risk sexual behaviour and intervention efforts to control syphilis among men who have sex with men

Rationale

Testing of syphilis among men who have sex with men is important for their health and for second-generation surveillance purposes.

Numerator

Number of men who have sex with men testing positive for active syphilis

Denominator

Number of men who have sex with men tested for active syphilis

Calculation

Numerator/denominator

Method of measurement
Measurement tools. Routine health information systems, sentinel surveillance or special surveys.
 
How to measure. The traditional approach to determining seroprevalence has been to screen with a non-treponemal test that measures reaginic antibody (such as VDRL or RPR) and confirm positive results with a treponemal test that measures treponemal antibody (such as TPHA, TPPA, enzyme immunoassay or rapid treponemal test). Newer, rapid treponemal tests are comparatively easy to use, which encourages the use of these tests for screening, ideally paired with a non-treponemal test that detects reaginic antibody. Whichever approach is used, the proposed indicator requires both a positive non-treponemal test and a positive treponemal test to give a proxy for active infection.
 
Just a non-treponemal test, or just a treponemal test, although useful in some situations for therapeutic purposes, is not sufficiently specific for surveillance of men who have sex with men. The requirement for both a positive non-treponemal test and a positive treponemal test among men who have sex with men differs from the indicator on syphilis testing among antenatal care attendees because men who have sex with men are more likely to have a history of previous infection. A positive treponemal test measures lifetime exposure, whereas the non- treponemal test better indicates active infection.
Disaggregation

None

Strengths and weaknesses
Strengths. Requiring testing using both tests enhances the specificity of the reported numbers of positive tests. In addition, requiring testing using both tests increases the likelihood of identifying active disease.
 
Weaknesses. Requiring testing using both tests increases the difficulty of acquiring data for this indicator.
Further information
Quality assurance. Quality assurance and quality control should be an integral part of syphilis testing to ensure reliable results.
 
Use of the data. Look at trends in comparable groups over time. Compare with data on trends in syphilis and HIV if these are available.
 
Quality control of data and notes for the reporting tool. Do not count multiple tests run on the same person: if a person has been tested more than once in the past 12 months, they should not be counted more than once. Please describe the setting in which the data were collected in the comments field.