[Prevalence of genital HPV infection among women screened for cervical cancer]

OBJECTIVE

To assess the prevalence of high-risk genital human papillomavirus (HPV) infection by age group and risk factors associated.

METHODS

Cross-sectional study in a sample of 2,300 women (15-65 years old) who self-referred to cervical cancer screening in Sao Paulo and Campinas, Southeastern Brazil, between February 2002 and March 2003. An epidemiological questionnaire was applied and cervical specimens were obtained for cytology and hybrid capture II test (HCII) for HPV detection. Statistical analysis included Pearson Chi-square and unconditional multiple logistic regression model (forward likelihood ratio).

RESULTS

High-risk genital HPV infection prevalence in this sample was 17.8% and age distribution was as follows: 27.1% (<25 years), 21.3% (25-34 years), 12.1% (35-44 years), 12.0% (45-54 years) and 13.9% (55-65 years). Subjects with the highest number of lifetime sexual partners had the highest rates of genital HPV infection. To be living with a partner, aged 35 to 44 years, and former smokers were protective factors. High-risk genital HPV infection was 14.3% in normal cytology, 77.8% in high grade squamous intraepithelial lesions and in the two cases (100%) of cervical cancer.

CONCLUSIONS

High-risk HPV prevalence was high in the sample studied. The highest prevalence of HPV infection was seen in women under 25 years old and then a new increase was seen over the age of 55 and the highest rates were found among those with many sexual partners during their lifetime.

Cost-effectiveness analysis of introducing universal human papillomavirus vaccination of girls aged 11 years into the National Immunization Program in Brazil

OBJECTIVES

To evaluate the impact and cost-effectiveness of introducing universal human papillomavirus (HPV) vaccination into the National Immunization Program (NIP) in Brazil.

METHODS

The Excel-based CERVIVAC decision support model was used to compare two strategies: (1) status quo (with current screening program) and (2) vaccination of a cohort of 11-year-old girls. National parameters for the epidemiology and costs of cervical cancer were estimated in depth. The estimates were based on data from the health information systems of the public health system, the PNAD 2008 national household survey, and relevant scientific literature on Brazil. Costs are expressed in 2008 United States dollars (US$), and a 5% discount rate is applied to both future costs and future health benefits.

RESULTS

Introducing the HPV vaccine would reduce the burden of disease. The model estimated there would be 229 deaths avoided and 6677 disability-adjusted life years (DALYs) averted in the vaccinated cohort. The incremental cost-effectiveness ratios (ICERs) per DALY averted from the perspectives of the government (US$ 7663), health system (US$ 7412), and society (US$ 7298) would be considered cost-effective, according to the parameters adopted by the World Health Organization. In the sensitivity analysis, the ICERs were most sensitive to variations in discount rate, disease burden, vaccine efficacy, and proportion of cervical cancer caused by types 16 and 18. However, universal HPV vaccination remained a cost-effective strategy in most variations of the key estimates.

CONCLUSIONS

Vaccine introduction could contribute additional benefits in controlling cervical cancer, but it requires large investments by the NIP. Among the essential conditions for attaining the expected favorable results are immunization program sustainability, equity in a population perspective, improvement of the screening program, and development of a surveillance system.

[Serological detection of anti HPV 16/18 and its association with pap smear in adolescents and young women]

OBJECTIVE

Verify the relation between HPV 16/18 antibodies and the association with cervical cytology findings in adolescents and young women.

METHODS

A cross sectional study with 541 healthy and sexually active women from 15 to 25 years of age was carried on from September to November 2000. At gynecological examination, a cervical sample on liquid-base for cytology-testing and a blood sample for ELISA identification of HPV 16 and 18 antibodies were collected and sent to a reference laboratory in Belgium. Statistical analysis estimated the prevalence and prevalence ratio with a 95% confidence interval.

RESULTS

Of these young women, 150 (27.7%) were seropositive: 79 (14.6%) to HPV 16 antibody; 35 (6.4%) to HPV 18 antibody and 36 (6.6%) to both HPV 16/18 antibodies. Cytological abnormalities were detected in 107 cases (20.5%): 63 presented with atypical squamous cells of undetermined significance (ASCUS), 41 were suggestive of low grade squamous intra-epithelial lesion (LGSIL) and 3 of high grade squamous intra-epithelial lesion (HGSIL). Prevalence of abnormal cytology with a positive serology was only 1.75 times that of prevalence of abnormal cytology with a negative serology. Detection of abnormal cytology was not correlated with positive serology.

CONCLUSION

Results of this study indicate a high prevalence of HPV 16 and 18 in young healthy women which showed no relation to the abnormal findings of cytology smears.

Annual national direct and indirect cost estimates of the prevention and treatment of cervical cancer in Brazil

OBJECTIVE

To estimate the annual direct and indirect costs of the prevention and treatment of cervical cancer in Brazil.

METHODS

This cost description study used a "gross-costing" methodology and adopted the health system and societal perspectives. The estimates were grouped into sets of procedures performed in phases of cervical cancer care: the screening, diagnosis and treatment of precancerous lesions and the treatment of cervical cancer. The costs were estimated for the public and private health systems, using data from national health information systems, population surveys, and literature reviews. The cost estimates are presented in 2006 USD.

RESULTS

From the societal perspective, the estimated total costs of the prevention and treatment of cervical cancer amounted to USD $1,321,683,034, which was categorized as follows: procedures (USD $213,199,490), visits (USD $325,509,842), transportation (USD $106,521,537) and productivity losses (USD $676,452,166). Indirect costs represented 51% of the total costs, followed by direct medical costs (visits and procedures) at 41% and direct non-medical costs (transportation) at 8%. The public system represented 46% of the total costs, and the private system represented 54%.

CONCLUSION

Our national cost estimates of cervical cancer prevention and treatment, indicating the economic importance of cervical cancer screening and care, will be useful in monitoring the effect of the HPV vaccine introduction and are of interest in research and health care management.

Rastreamento anterior para câncer de colo uterino em mulheres com alterações citológicas ou histológicas

OBJETIVO: Analisar a história de rastreamento citológico anterior em mulheres que apresentaram alterações citológicas e confirmação histológica para câncer cervical. MÉTODOS: Estudo transversal com 5.485 mulheres (15-65 anos) que se submeteram a rastreamento para o câncer cervical entre fevereiro de 2002 a março de 2003, em São Paulo e Campinas, SP. Aplicou-se questionário comportamental e foi feita a coleta da citologia oncológica convencional ou em base líquida. Para as participantes com alterações citológicas indicou-se colposcopia e, nos casos anormais, procedeu-se à biópsia cervical. Para investigar a associação entre as variáveis qualitativas e o resultado da citologia, utilizou-se o teste de qui-quadrado de Pearson com nível de significância de 5%. RESULTADOS: Dentre os resultados citológicos, 354 (6,4%) foram anormais, detectando-se 41 lesões intra-epitelial escamosa de alto grau e três carcinomas; em 92,6% revelaram-se normais. De 289 colposcopias realizadas, 145 (50,2%) apresentaram alterações. Dentre as biópsias cervicais foram encontrados 14 casos de neoplasia intra-epitelial cervical grau 3 e quatro carcinomas. Referiram ter realizado exame citológico prévio: 100% das mulheres com citologia compatível com carcinoma, 97,6% das que apresentaram lesões intra-epiteliais de alto grau, 100% daquelas com confirmação histológica de carcinoma cervical, e 92,9% das mulheres com neoplasia intra-epitelial cervical grau 3. A realização de citologia anterior em período inferior a três anos foi referida, respectivamente, por 86,5% e 92,8% dessas participantes com alterações citológicas e histológicas. CONCLUSÕES: Entre as mulheres que apresentaram confirmação histológica de neoplasia intra-epitelial cervical grau 3 ou carcinoma e aquelas que não apresentaram alterações histológicas não houve diferença estatisticamente significante do número de exames citológicos realizados, bem como o tempo do último exame citológico anterior.

Opportunity for catch-up HPV vaccination in young women after first delivery

BACKGROUND

Early age at first delivery has been identified as a risk factor for high-risk HPV-type infection and cervical cancer development.

METHODS

A cross-sectional study was carried out in a large public maternity hospital in São Paulo, Brazil. During June 2006 to February 2007, 301 women aged 15-24 years who gave birth to their first child were recruited between 43 and 60 days after delivery. Detection of HPV DNA in cervical specimens was performed using a standardised PCR protocol with PGMY09/11 primers. The association of selected factors with HPV infection was assessed by using a Generalised Linear Model.

RESULTS

HPV DNA was detected in 58.5% (95% CI 52.7% to 64.0%) of the enrolled young women. The most common types of HPV found were: HPV16, HPV51, HPV52, HPV58 and HPV71. The overall prevalence of HPV types targeted by the HPV prophylactic vaccines was: HPV 16-12.0%, HPV 18- 2.3% and HPV 6 and 11 4.3%. In the multivariate analysis, only age (inversely, p for trend=0.02) and smoking habits were independently associated with HPV infection.

CONCLUSIONS

The findings show that these young primiparous women had high cervical HPV prevalence, suggesting that this is a high-risk group for cervical cancer development. Nevertheless, 17.3% were positive for any of the four HPV types included in HPV vaccines (HPV6, 11, 16 or 18), with 13.3% positive for HPV 16 or 18 and only 1.0% having both vaccine related-oncogenic HPV types. Thus, young primiparous women could benefit from catch-up HPV vaccination programmes.

Seroprevalence of human papillomavirus 6, 11, 16, and 18 in young primiparous women in Sao Paulo, Brazil

INTRODUCTION

Data on epidemiology of HPV infection are needed for the development of human papillomavirus (HPV) vaccine recommendations, especially in countries where HPV vaccination is not yet included in public vaccination programs. The aim of this study was to determine the prevalence of serum antibodies to HPV types 6, 11, 16, and 18 and associated factors among young women after birth of the first child.

METHODS

This cross-sectional study was carried out in a large public maternity hospital in Sao Paulo, Brazil. Three hundred one women aged 15 to 24 years who gave birth to their first child were recruited between 43 and 60 days after delivery. Seroprevalence was performed using a type-specific enzyme-linked immunosorbent assay based on HPV Late protein 1 viruslike particles. The association of seroreactivity with these 4 HPV types with selected demographic and behavioral factors was assessed by Generalized Linear Model analysis.

RESULTS

Fifty-eight (19.3%) women (95% confidence interval, 15.0%-24.2%) had antibodies to any of the 4 viruslike particles tested. The overall seroprevalence rates of the HPV types were: HPV16, 9.0%; HPV18, 7.0%; and HPV 6+11, 7.7%, which are targeted by the HPV prophylactic vaccines. In the multivariate analysis, only age (inversely, P = 0.044 for trend) and previous sexually transmitted disease (P = 0.008) were 2 factors independently associated with HPV seropositivity.

CONCLUSIONS

These data offer additional information on the epidemiology of HPV in a group of young Brazilian women after first delivery and contribute to establish a baseline of HPV seroprevalence against which post-HPV vaccine era seroprevalence can be compared.