Testing for human papilloma virus is helping to detect cancer-causing infections sooner than the previous Pap smear testing program, Melbourne researchers say.

A major paradigm shift in cervical screening tests is resulting in earlier detection of potentially cancer-causing infections, researchers say.

A test for the human papillomavirus (HPV) replaced Pap smear testing in December 2017, under the national cervical screening program.

A study found more than three times as many referrals for a colposcopy, a procedure to examine the cervix for signs of disease, based on HPV tests than referrals based on Pap smears.

The researchers said the referral rate based on the HPV sample results for women of recommended screening age (2.6 per cent) was considerably higher than that based on historical cytology (Pap) results from a laboratory (0.8 per cent).

"The higher rate is broadly consistent with clinical trial data and predictions from modelling," said the researchers, who are led by Dr Dorothy Machalek from the Centre for Women's Infectious Diseases at Royal Women's Hospital in Melbourne.

The study, published on Monday by the Medical Journal of Australia, said the national program was performing as expected during the initial HPV screening round.

The program distinguishes between primary screening and non-screening tests from women regarded as being at higher risk because of symptoms or signs of a prior cervical abnormality.

About eight per cent of tests for women in the primary screening program were positive for oncogenic HPV, the types associated with cervical cancer.

More than a third of those women also had abnormal cells.

Cancer-causing HPV was detected in 21 per cent of the non-screening tests, said the researchers, who reviewed 195,600 samples from a single laboratory during the first six months after the change in testing.

The study noted primary HPV testing is expected to have substantial advantages over cytology-based screening, including reduced incidence and mortality of cervical cancer and major cost savings.

"While the predicted long-term benefits are substantial, timely monitoring of the transitional phase is critical for ensuring the program performs as expected and community confidence in the policy is maintained," the researchers said.

The new screening program involves HPV testing every five years for women aged 25 to 74, replacing biennial Pap tests for those aged 18 to 69.