Rates of gonorrhoea, chlamydia and syphilis in New Zealand decreased in 2025, according to the latest national surveillance data published by the New Zealand Institute for Public Health and Forensic Science (PHF Science).
Compared with 2024, infectious syphilis rates fell by 27 percent, gonorrhoea by 17 percent and chlamydia by 13 percent. Rates were the lowest recorded for infectious syphilis since 2022, gonorrhoea since 2018 and chlamydia since before 2015.
The largest reductions in syphilis and gonorrhoea were seen among men who have sex with men (MSM), likely due to improvements in STI prevention, testing, treatment and contact management. Increased use of doxycycline post-exposure prophylaxis (doxy-PEP) among MSM may have also contributed.
Despite the positive trend, inequities persist. Māori and Pacific peoples, young people and MSM continue to experience disproportionately high rates of infection. Māori and Pacific peoples were also inequitably affected by antenatal and congenital syphilis. Four cases of congenital syphilis were reported in 2025. Two of the four cases reported in 2025 involved no or late antenatal care, highlighting the importance of equitable access to antenatal and sexual healthcare.
Surveillance also identified a continuing threat from antimicrobial resistance. New Zealand reported its first extensively drug-resistant Neisseria gonorrhoeae isolate in 2025, which was resistant to ceftriaxone and highly resistant to azithromycin. The proportion of isolates showing signs of acquired resistance to azithromycin also increased, reaching 8.4 percent in 2025.
2025 STI Annual Report at glance:
- STI rates fell in 2025: Gonorrhoea decreased 17%, infectious syphilis 27% and chlamydia 13% compared with 2024.
- Marked reductions in infectious syphilis and gonorrhoea were seen among men who have sex with men (MSM), particularly European/Other MSM. Infectious syphilis rates among MSM fell 35%, while gonorrhoea fell 22%.
- Declines were widespread: Rates fell across all ethnic groups and regions for all three STIs, except infectious syphilis in the South Island, which remained stable. Rates also fell across most age groups.
- Prevention may be making a difference: Improvements in STI prevention, testing, treatment and contact management are likely to have contributed. Increased use of doxycycline post-exposure prophylaxis (doxy-PEP) among MSM may also have played a role.
- Inequities remain: Māori and Pacific peoples, young people and MSM continue to experience disproportionately high STI rates. In 2025, infectious syphilis rates were around twice as high among Māori and Pacific peoples as European/Other people, while gonorrhoea and chlamydia rates were several times higher.
- Congenital syphilis remains a concern: Four cases were reported in 2025, down from six in 2024, but New Zealand's elimination target is zero cases for this preventable infection. Since 2017, 87% of congenital syphilis cases have been among Māori or Pacific infants.
- Antimicrobial resistance remains an emerging threat: New Zealand reported its first extensively drug-resistant (XDR) Neisseria gonorrhoeae isolate in 2025, resistant to ceftriaxone and highly resistant to azithromycin. While this infection was acquired overseas and there was no transmission in New Zealand, its detection highlights the need to ensure surveillance for antimicrobial resistant gonorrhoea is sensitive and timely.
- The proportion of Neisseria gonorrhoeae isolates with signs of acquired azithromycin resistance increased to 8.4% in 2025, highlighting the need to review the role of azithromycin in gonorrhoea treatment.