More babies are being born with syphilis, study finds

Data just published online shows a worrying increase in infectious syphilis cases in women living in Australia aged 15–44 (referred to as "reproductive age") and a subsequent rise in transmission from pregnant parent to child. This is called congenital syphilis.

Congenital syphilis is easily prevented through timely testing and treatment of syphilis during pregnancy. Left untreated, congenital syphilis can have devastating outcomes in more than 50% of cases including miscarriage, stillbirth, neonatal death and permanent disability.

We reviewed all cases of congenital syphilis in Australia between 2011 and 2021 and found tragically 25% were stillborn. For the birthing parent of babies with congenital syphilis, we found less than 40% were tested for syphilis in pregnancy. Nearly half had no record of receiving any antenatal care.

Experts have been aware of the resurgence of syphilis in Australia for some time. But ours is the first analysis that reveals significant gaps in antenatal care, leading to devastating outcomes.

Related: Syphilis cases soaring in the US, rising to highest peak since the 1950s

Syphilis cases have been rising for a decade

Between 2011 and 2021, the rate of infectious syphilis rose by more than 500% in women aged 15–44 years, from 141 in 2011 to 902 in 2021. This reflects an increase more broadly among young people.

Prior to 2011, infectious syphilis was rare. When cases began to rise, it was initially in men with male sexual partners in metropolitan areas, and young heterosexual people in remote Aboriginal and Torres Strait Islander communities. Health departments increased testing and initiated public health campaigns to decrease transmission.