RESUMO
Interest in coinfection with multiple types of human papillomavirus (HPV) has increased in response to the possibility of vaccination and the discovery that the host immune response appears to be mainly type specific. This study attempts to document the occurrence of coinfection with multiple HPV types and to determine whether these coinfections predicted acquisition or persistence of other HPV types in a prospective cohort of women in Brazil. Multiple HPV types were detected at the same visit in one-fifth of all women who tested positive for HPV at any time. Acquisition of an HPV infection was more likely among women with any HPV type detected on study entry. Persistence of HPV infection, the true precursor of cervical abnormalities, was independent of coinfection with other HPV types. Given the increasing prominence of HPV vaccination as a potential preventive approach, it is imperative that additional insights on cross-type protection be obtained from longer-term longitudinal investigations.
Assuntos
Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/virologia , Infecções Tumorais por Vírus/virologia , Doenças do Colo do Útero/virologia , Neoplasias do Colo do Útero/virologia , Adolescente , Adulto , Brasil/epidemiologia , Estudos de Coortes , DNA Viral/análise , Feminino , Humanos , Pessoa de Meia-Idade , Papillomaviridae/crescimento & desenvolvimento , Infecções por Papillomavirus/epidemiologia , Valor Preditivo dos Testes , Prevalência , Estudos Prospectivos , Infecções Tumorais por Vírus/epidemiologia , Doenças do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/epidemiologiaRESUMO
Acquisition and clearance of cervical human papillomavirus (HPV) infection were analyzed among 1425 low-income women attending a maternal and child health program in São Paulo, Brazil. Specimens collected every 4 months were tested by a polymerase chain reaction protocol (MY09/11). In all, 357 subjects were positive at least once. There were 1.3% new infections per month, with 38% cumulative positivity after 18 months. Of 177 positive subjects at enrollment, only 35% remained infected after 12 months. The monthly clearance rate was higher for nononcogenic types (12.2%; 95% confidence interval [CI], 9.6-15.4) than for oncogenic HPV infections (9.5%; 95% CI, 7.5-11.9). Median retention times were 8.1 months (95% CI, 7.8-8.3) for oncogenic types and 4.8 months (95% CI, 3.9-5.6) for nononcogenic HPV infections. The mean infection durations were 8.2 and 13.5 months for nononcogenic and oncogenic types, respectively. Although a woman's age did not affect mean duration for oncogenic types (13-14 months), nononcogenic-type infections lasted longer (10. 2 months) among younger (<35 years old) than in older women (5.6 months).
Assuntos
Colo do Útero/virologia , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/epidemiologia , Infecções Tumorais por Vírus/epidemiologia , Doenças do Colo do Útero/epidemiologia , Adulto , Distribuição por Idade , Brasil/epidemiologia , Estudos de Coortes , Feminino , Humanos , Incidência , Pessoa de Meia-Idade , Papillomaviridae/classificação , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Prevalência , Fatores de Risco , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia , Doenças do Colo do Útero/imunologia , Doenças do Colo do Útero/virologia , Neoplasias do Colo do Útero/etiologia , Neoplasias do Colo do Útero/virologiaRESUMO
We studied the relationship between risk factor information and breast cancer mortality by means of a case control study, nested within the population of the National Breast Screening Study of Canada (NBSS). The characteristics of women aged 40-59 years, identified at the initial screen, who subsequently died of breast cancer up to 7 years from the initial screen, were compared with those of controls drawn from the same population. Among the factors evaluated in this study, number of live births and presence of symptoms in the breast revealed on direct questioning were found to be significantly related to breast cancer mortality. The results suggest a decrease in risk of dying of breast cancer associated with one or more live births (OR: 0.79, 95% CI: 0.68, 0.93), and an increase in risk of dying of breast cancer associated with symptoms in the breast revealed on direct questioning at the initial screen (OR: 2.01, 95% CI: 1.20, 3.37).