DEEP DIVE / TESTING, RESISTANCE & FOLLOW-UP
Screening and contact assessment are different
CDC and Australian guidance do not recommend routine testing for people without symptoms. Testing still makes sense for symptoms such as persistent urethritis or cervicitis, or selected pelvic or rectal symptoms, and for ongoing partners of someone with a confirmed result. [01][02]
In Denmark, the published recommendations differ. National guidance from Statens Serum Institut (updated 8 December 2025) names symptoms, or contact with someone known to be infected, as reasons to test, discourages routine screening without symptoms, and does not explicitly exclude protected contacts. Capital Region clinical guidance (updated 3 March 2026) is narrower: people without symptoms are not tested unless they are a regular partner of someone with Mgen, which would not automatically include a one-time protected contact without symptoms. Each guideline is contact-based, so someone who only shares a partner, with no direct contact, decides from their own contacts, any direct partner's diagnosis and their own symptoms.
A repeat positive is a question, not a diagnosis of the source
| Possible explanation | What helps distinguish it |
|---|---|
Reinfection | Contacts after treatment; whether relevant partners were tested or treated |
Persistent infection / resistance | Original regimen, adherence, resistance results and timing of test of cure |
Site or sampling issue | Which tissue was tested; assay and specimen collection |
Testing too early or other assay limitations | Date relative to treatment and exposure; clinician review |
Several earlier negative results are useful information, but they cannot show whether a current infection is residual, new, or from a particular person. Mgen is also not a harmless organism that simply "overgrows" in everyone. [01][02][06]
Treatment is not just "another antibiotic"
Mgen has no cell wall: penicillins and cephalosporins are ineffective against it. Treatment requires an active antibiotic regimen selected for drug resistance, contraindications, side effects and local access. A staged course is common; adding or repeating azithromycin without the appropriate plan can select resistance. Specialist advice is appropriate after treatment failure. [01][02]
Follow-up is jurisdiction- and regimen-specific
CDC does not require a routine test of cure for someone without symptoms who received a recommended regimen; alternative regimens or ongoing symptoms can call for one. Australian guidance uses a test of cure depending on circumstances, no earlier than 14-21 days after finishing. A test taken too soon may not answer whether infection remains, so the clinic's plan is the one to follow. [01][02]
What the prevalence data do - and do not - establish
The Swedish club study is a relevant direct sample, not a universal ceiling. The US clinic study supports higher selected-population scenarios, not an automatic assignment to everyone in a sexual community. Asymptomatic infections detected by study testing are already counted; multiplying prevalence again by an asymptomatic fraction double-counts them. [04][05][06]