Metropolitan Perth syphilis outbreak alert

Key points

• Infectious syphilis cases are increasing significantly in the Perth metropolitan area.
• More cases are being detected in vulnerable populations, including Aboriginal and non-Aboriginal people, culturally and linguistically diverse people, people that are experiencing homelessness and people who inject drugs.
• Of concern are the women of reproductive age because of the risk of congenital syphilis.

Testing

• GPs should test for syphilis in all persons attending for diagnosis and treatment of any STI, or where screening for STIs is indicated.
• GPs and other health services working with identified vulnerable populations should offer opportunistic screening for STIs, including syphilis.
• All pregnant women should be screened for syphilis at the booking appointment and women from vulnerable and higher risk groups should also be screened at 28 weeks, 36 weeks and at delivery.
• All women of childbearing age diagnosed with syphilis require a pregnancy test.
• Discussion with a sexual health specialist is recommended for pregnant patients, HIV co-infection, and tertiary syphilis.

Treatment

• Infectious syphilis (2 years duration) should be treated with benzathine benzylpenicillin (Bicillin® L-A) injection 2.4 million units (1.8 gm) IM stat, one 1.2-million-unit syringe into each buttock intramuscularly.
• Syphilis of longer or unknown duration should be treated once weekly for three weeks.
• Benzathine benzylpenicillin is available as a Doctor’s Bag (external site) item.
• Metropolitan Communicable Disease Control (MCDC) (Healthy WA) can assist with the provision of benzathine benzyl penicillin.
• Syphilis serology (including RPR) should be repeated at the time of treatment and then be checked at 3-, 6- and 12-months post-treatment.
• Your local sexual health clinic (external site) can provide advice on clinical management.

Detailed treatment information is available in the Silver book (WA STI/BBV management guidelines)

Public health management

• All cases should be notified  promptly to the Department of Health.
• Contact tracing should commence straight away. MCDC (Healthy WA) can assist with contact tracing.

Syphilis epidemiology

The number of women acquiring syphilis in metropolitan Perth is increasing. There has been a pronounced increase among vulnerable and high priority groups, including:

• young Aboriginal and non-Aboriginal people
• people who are experiencing homelessness
• culturally and linguistically diverse communities
• people who inject drugs.

Aboriginal people comprised 12% of notifications of infectious syphilis in the metro area in 2020, compared to less than 1% in 2015.

There have been 26 infectious syphilis notifications in people experiencing homelessness in the past 18 months, compared to 6 in the previous four years combined. Of individuals experiencing homelessness notified with infectious syphilis since 2017, half are Aboriginal people.

Notifications in women of childbearing age increased nearly 6-fold between 2015 and 2019. There have been eight notifications in pregnant women in the first half of 2020.

There have been two cases of congenital syphilis in Perth since 2018, including one stillbirth, both in women from vulnerable groups who contracted syphilis during pregnancy which was not diagnosed until the time of delivery.