Public health acting director Mark Veitch said there had been 1014 cases of chlamydia reported in the state this year and a noted reduction in genital warts.

Notifications of chlamydia in the state peaked in 2010 with more than 2000 cases reported.

By 2012, the number had dropped to 1787.

Mr Veitch said the infection could be hard to detect.

``Chlamydia infection is very common and often there are no symptoms, yet it can cause serious long-term problems if not treated, including pelvic inflammatory disease or infertility.''

Mr Veitch said the introduction of an HPV vaccine for girls and young women explained the decrease in genital warts.

``The expansion of the school-based HPV vaccination program to include boys this year is expected to result in further reductions in genital warts among vaccinated men and women in the future,'' Mr Veitch said.

Mr Veitch advised people to use condoms when entering new relationships until there was certainty both people were infection-free.

``It is vitally important for sexually active people to have regular sexual health screens, especially if they have unprotected sex, a new sexual partner, or sex while travelling or with a traveller,'' Mr Veitch said.

Sexual health checks are provided by GPs, Family Planning Tasmania and the Sexual Health Service.