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BACKGROUND: The national Human Papillomavirus (HPV) Immunisation Programme in New Zealand was introduced in 2008, and involves routine vaccination of girls 12-13 years with a catch-up for females aged up to 19 years. The aims of this study were to measure the pre-vaccination prevalence of oncogenic HPV infection in women aged 20-69 years who were participating in the New Zealand National Cervical Screening Programme (NZ-NCSP) and who were: (1) referred with high grade cytology with a subsequent histologically-confirmed high grade cervical intraepithelial neoplasia (CIN2/3) or adenocarcinoma in situ (AIS); or (2) were in the wider group of women who had a cytological prediction of high grade squamous disease or glandular abnormality (ASC-H/ HSIL+/AGC/AIS). METHODS: Women aged 20-69 years appearing on the NZ-NCSP register between August 2009-February 2011 with a cytology record of ASC-H/HSIL+/AGC/AIS were invited to participate in the study. Liquid-based cytology specimens were tested for 37 HPV types using Linear Array genotyping. The prevalence of type-specific HPV infection was reported within women with histologically-confirmed CIN 2/3 and within the wider group with ASC-H/HSIL+/AGC/AIS cytology. Age-specific trends for the relative proportion of HPV 16/18 vs. other oncogenic types in CIN2/3 were assessed. RESULTS: A total of 594 women with ASC-H/HSIL+/AGC/AIS cytology and a valid HPV test were recruited; of these 356 (60%) had confirmed CIN2/3 and 6 (1%) had confirmed AIS or glandular dysplasia. Positivity rates for any oncogenic HPV infection and for HPV16 and/or 18 within confirmed CIN2/3-AIS were 95% (95%CI: 92-97%) and 60% (54-65%) respectively; in all women with ASC-H/HSIL+/AGC/AIS cytology it was 87% (84-89%) and 53% (49-57%), respectively. The most common reported HPV types in women with CIN 2/3 were 16 (51%), 52 (19%), 31 (17%), 33 (13%) and 18 (12%). A trend for higher rates of HPV 16/18 infection compared to other oncogenic types was observed in younger women (p=0.0006). CONCLUSIONS: The prevalence of HPV 16/18 in confirmed high grade disease in New Zealand is comparable to that observed in Australia and European countries. Test positivity rates for type 52 appear higher than in comparable studies in other developed countries. A greater proportion of high grade lesions in younger women appear to be associated with HPV 16/18 infection

Background New Zealand initiated HPV vaccination in 2008, and has attained 3-dose coverage of ~50 % in 12–13 year old girls. Due to the success of program initiatives in Māori girls, higher coverage rates of ~60 % have been achieved in this group. We have previously reported a benchmark overall pre-vaccination prevalence of oncogenic HPV infection in high grade cervical lesions in New Zealand. The current extended analysis provides separate pre-vaccination benchmark prevalence for Māori and non-Māori women. Methods The National Cervical Screening Programme Register (NCSP-R) was used to identify any woman aged 20–69 years of age with an index high grade cytology report from 2009–2011. Extended recruitment was performed until 2012 in clinics with a high proportion of Māori women. Ethnicity status was based on self-reported information by participating women through phone contact supplemented by recordings on the study questionnaire (the NCSP-R was not used to extract ethnicity status). A total of 730 women consented to participate and had a valid HPV test result; 418 of these had histologically-confirmed cervical intraepithelial neoplasia (CIN) 2/3 lesions (149 Māori, 269 non-Māori). The prevalence of any cervical oncogenic HPV infection, HPV16, and HPV18 was calculated in women with CIN2/3. Results In confirmed CIN2/3, the prevalence of any oncogenic HPV, HPV16 and HPV18 was 96 % (95 % CI:91–99 %), 54 % (95 % CI:46–63 %), 11 % (95 % CI:7–18 %) in Māori and 96 % (95 % CI:93–98 %), 54 % (95 % CI:48–60 %), 11 % (95 % CI:7–15 %) in non-Māori women, respectively. Age-specific patterns of infection for HPV16/18 in confirmed CIN2/3 differed between the two groups (Pinteraction = 0.02), with a lower prevalence in younger vs. older Māori women (57 % in 20–29 years vs 75 % in 40–69 years) but a higher prevalence in younger vs. older non-Māori women (70 % in 20–29 years vs 49 % in 40–69 years); the difference in the age-specific patterns of infection for HPV16/18 was not significant either when considering confirmed CIN2 alone (p = 0.09) or CIN3 alone (p = 0.22). Conclusions The overall prevalence of vaccine-included types in CIN2/3 was similar in Māori and non-Māori women, implying that the long-term effects of vaccination will be similar in the two groups. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-1034-5) contains supplementary material, which is available to authorized users.