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( GBMSM ); female sexual partner ( s ) of GBMSM ; and sex workers . 13
Recommendations for antenatal screening frequency vary based on local guidelines . All pregnant individuals should have a syphilis test at their first antenatal visit and , if at higher risk of infection , repeat testing in the third trimester and at six weeks postpartum . 26
Box 2 outlines the groups of pregnant women who are considered higher risk and may warrant repeat testing .
Diagnosis
Syphilis is primarily diagnosed by serology and , if any lesions are present , PCR of these lesions . 22 Serology is tested for syphilis antibodies . The assays used vary by laboratory , but in Australia , they commonly include screening with enzyme immunoassay ( EIA ) or chemiluminescence immunoassay ( CLIA ), with further testing using
Box 2 . Pregnant women at higher risk of syphilis are those who 26
• Have a current or recent STI
• Have previously had syphilis in pregnancy
• Live ( or their partner lives ) in an area of high syphilis prevalence or a declared outbreak
• Inject drugs during pregnancy
• Are a sexual contact of a person with infectious syphilis
• Have unprotected vaginal , oral or anal sex with a male partner at high risk of having syphilis ( eg , MSM )
• Have a partner / partners who has / have sexual partners from high-prevalence countries
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rapid plasma regain ( RPR ) and T . pallidum particle agglutination assay ( TPPA ). 22
Any genital , anal or oral ulcers or lumps of otherwise unknown cause warrant a swab from the base of the ulcer or papule and testing for syphilis and HSV PCR — and if in remote Australia , donovanosis PCR . Syphilis PCR may be positive with negative serology in primary infection . 22
Patients who have been treated for syphilis infection previously will usually have positive antibody ( EIA , CLIA or TPPA ) tests for life . If the RPR titre is initially raised , it should fall after treatment . In reinfection , there will be a significant rise in RPR . 22
Some states and territories have syphilis registers that record previous serology results and treatments . 27
Notification
Syphilis is a nationally notifiable disease , which means notification to your jurisdictional authority is required . If there is a syphilis register in your jurisdiction , clinical
27 , 28 details should also be promptly reported .
Management
Treatment is with IM long-acting benzathine benzylpenicillin ( benzathine penicillin G ) 2.4 MU ( 1.8g ) given as two injections , containing 1.2 MU ( 0.9 g ) each . 22 Early syphilis ( less than two years ’ duration ) is treated with a single dose . Late syphilis ( more than two years ’ duration ) or syphilis of unknown duration is treated with weekly doses for three weeks . 22
Benzathine benzylpenicillin is different from short-acting formulations ( such as benzylpenicillin ), which are ineffective against T . pallidum . 22
Benzathine benzylpenicillin is available
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on the PBS general schedule and as part of the PBS prescriber ’ s bag . 22
Repeat RPR serology on the day treatment starts to establish a baseline for monitoring treatment response . 22 Patients should be warned about the common Jarisch – Herxheimer reaction , which can occur 6-12 hours after treatment . This involves several hours of fever , malaise , headaches , rigors and joint pains and is managed with rest and simple analgesia . 22
It is important to advise patients to have no sexual contact for seven days after treatment . Additionally , request testing for other STIs and discuss contact tracing and partner notification . The Let Them Know website can assist with anonymous partner notification . 29 Sexual contacts of individuals with syphilis should have an STI screen — including syphilis serology — and if any suspicious lesions are present , these should be swabbed for syphilis PCR . 30 Contacts from the past three months should receive a single dose of benzathine benzylpenicillin without awaiting serology results as these are likely to be negative in the weeks following exposure . 30
For infection in pregnancy , prompt treatment of ongoing sexual contacts is a high priority to prevent reinfection during pregnancy . 22
When to seek help
Seek specialist advice for patients who
have penicillin allergy and urgent specialist advice for any syphilis diagnosis in a child or in pregnancy . Patients with acute neurological symptoms or suspected tertiary disease should be referred to a sexual health or infectious diseases clinic . 22
Follow-up
Repeat RPR serology is recommended six
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months after treatment completion . Adequate treatment response is indicated by a fourfold drop in RPR — for example , 1:64 to 1:16 ). 22 Where RPR titres are low to begin with , a fourfold drop may not be seen . 31 Syphilis infection does not confer immunity to further infections ; therefore , if sexual risk occurs , repeat screening should be undertaken . 13
Conclusion
With cases of syphilis rising and reports of congenital and neurosyphilis increasing , it is vital for doctors to be vigilant and consider testing for those with potential symptoms of this great mimicker , as well as for those in populations at higher risk .
References on request from kate . kelso @ adg . com . au
Online resources
• Guidelines — Australian STI Management
Guidelines for Use in Primary Care : sti . guidelines . org . au — The ASHM syphilis decisionmaking Tool : bit . ly / 3L37MH4
• Antenatal screening guidelines — Department of Health ’ s Clinical Practice Guidelines : Pregnancy Care : bit . ly / 3UOxoe7 — ASHM Bloodborne Viruses and Sexually Transmissible Infections in Antenatal Care : bit . ly / 40dqosm
• Patient fact sheet — StaySTIFree : staystifree . org . au
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Treponema pallidum . |