Prevalence, incidence and clearance of human papillomavirus infection among young primiparous pregnant women in Kampala, Uganda.

The proportion of women who have already been exposed to human papillomavirus (HPV) infection by the time they first become pregnant, and the influence of pregnancy and delivery on the course of HPV infection are unclear. In Kampala, Uganda, 987 young primiparous pregnant women aged <25 years had gynaecological examination and liquid-based cytology. In the follow-up, women acted as their own controls, i.e., 1st/2nd versus 3rd trimesters (105 women), and during pregnancy versus after delivery (289 women). HPV was assessed using highly sensitive PCR assays. Prevalence of HPV and HIV infections at baseline were 60.0% and 7.3%, respectively. HPV16 and 18 were detected in 8.4% and 5.8%, respectively, i.e., less frequently than HPV51 (8.7%) and 52 (12.1%). At follow-up new HPV infections were detected in 42.9% of women between the 1st/2nd and 3rd trimesters, and 38.1% between pregnancy and delivery, but 50.4% and 71.8% of HPV infections, respectively, cleared, leaving HPV prevalence unchanged in the different periods. Prevalence of cytological abnormalities diminished after delivery (from 21.2% to 12.4%). Presence of genital warts and sexually transmitted infections other than HPV were the strongest risk factors for prevalent or incident HPV infection. Clearance was lower among HIV-positive women. In conclusion, HPV prevalence was high in primiparous women in Uganda, but pregnancy did not seem to be a period of special vulnerability to the infection.

Increased risk for cervical disease progression of French women infected with the human papillomavirus type 16 E6-350G variant.

To test the significance of human papillomavirus (HPV) type 16 and HPV16 E6 variants as risk factors for viral persistence and progression to high-grade lesion, we did a nested case-control study within a cohort study of >15,000 Caucasian French women. Three groups infected with high-risk HPV were compared: (a) women with cleared infection (controls, n = 201), (b) women with persistent infection (cases, n = 87), and (c) women who progressed into high-grade lesion (cases, n = 58). Women with persistent HPV infection and those that progressed into high-grade lesions were likelier to harbor HPV16 than other high-risk HPV types [odds ratio (OR), 2.4; 95% confidence interval (95% CI), 1.3-4.3 and OR, 4.2; 95% CI, 2.2-8.1, respectively]. Notably, especially elevated ORs of persistence (3.0; 95% CI, 1.4-6.7) and progression (6.2; 95% CI, 2.7-14.3) were found among women who harbored the HPV16 350G variant. Thus, HPV type and HPV16 variant seem to be risk factors for viral persistence and progression of infections into high-grade cervical lesions.

Papillomavirus infection in the conjunctiva of individuals with and without AIDS: an autopsy series from Uganda.

HIV and genus beta human papillomavirus (HPV) types have been associated with squamous cell carcinoma of the conjunctiva (SCC). To determine whether conjunctival HPV infection is associated with AIDS, we analysed 136 lesion-free eye biopsies and tested for genera alpha, beta and gamma HPV types. Only infections with genera beta and gamma HPV types was found. After adjustment for age and gender, no excess of genera beta or gamma HPV infection was found in individuals who had died of or with AIDS compared to those who had died of other infectious diseases [relative risk (RR)=1.3; 95% confidence interval (CI): 0.4-4.8], or chronic diseases or trauma (RR=0.9; 95% CI: 0.3-2.9). Our findings suggest that infection with genera beta or gamma HPV types in lesion-free conjunctivas is common, but not greatly enhanced by the presence of AIDS.

HPV type infection in different anogenital sites among HIV-positive Brazilian women.

OBJECTIVES: To evaluate the prevalence of human papillomavirus (HPV) types, and risk factors for HPV positivity across cervix, vagina and anus, we conducted a study among 138 women with human immunodeficiency virus (HIV). GOAL: Compare the prevalence of different HPV types and the risk factors for HPV positivity in three sites. RESULTS: The most frequently detected HPV types in all sites were, in decreasing order, HPV16, 53, 18, 61 and 81. Agreement between the cervix and vagina was good (kappa 0.60 - 0.80) for HPV16 and 53 and excellent (Kappa > 0.80) for HPV18 and 61. HPV positivity was inversely associated with age for all combinations including the anal site. CONCLUSION: In HIV positive women, HPV18 is the most spread HPV type found in combinations of anal and genital sites. The relationship of anal to genital infection has implications for the development of anal malignancies. Thus, the efficacy of the current HPV vaccine may be considered not only for the cervix, but also for prevention of HPV18 anal infection among immunossuppressed individuals.

Infection with human papillomavirus and HIV among young women in Kampala, Uganda.

BACKGROUND: Information on the prevalence of cervical infection with different human papillomavirus (HPV) types among young women is essential to support the introduction of HPV vaccine in Uganda. METHODS: Cross-sectional findings are presented from a cohort study of 1,275 sexually active women aged 12-24 years seeking health services at a clinic for teenagers in Kampala, Uganda. We assessed the presence of 39 HPV types by use of highly sensitive polymerase chain reaction assays. RESULTS: The prevalence of HPV infection was 74.6%, and the prevalence of human immunodeficiency virus infection was 8.6%. High-risk HPV types were found in 51.4% of women, and the most frequently detected high-risk types were, in decreasing order, HPV 52, 51, 18, and 16. A total of 71.8% of the women who were positive for HPV 16 and/or 18 were also infected with other high-risk HPV types. HIV-positive women had a higher prevalence of HPV infection (87.8% vs 73.2%) and of multiple-type infections (64.6% vs 37.3%), compared with HIV-negative women. Employment in the tertiary sector, lifetime number of sexual partners, concurrent pregnancy, and the presence of genital warts were significantly associated with HPV positivity. CONCLUSIONS: The prevalence of HPV infection is high among young women in Kampala, Uganda. Clinics for teenagers provide an opportunity to monitor the impact of HPV vaccines and, possibly, to catch up unvaccinated young women who have recently become sexually active.

Human papillomavirus infection in women in Shenzhen City, People's Republic of China, a population typical of recent Chinese urbanisation.

Select cancer registries report that cervical cancer is relatively rare in the People's Republic of China, but may not be representative of the entire country. We carried out a survey of human papillomavirus (HPV) prevalence in 3 samples of women, i.e., general population, factory workers, and tertiary sector workers, in Shenzhen City in 2004. All participants were interviewed and offered gynaecological examination. HPV detection in exfoliated cervical cells was performed using a GP5+/6+ PCR-based assay. Overall HPV prevalence was 18.4% among the general population (n = 534), 11.2% among factory workers (n = 269) and 18.8% among tertiary sector workers (n = 224). Corresponding prevalence for high-risk HPV types was 13.5%, 8.2% and 13.8%, respectively. The most commonly found HPV types were HPV16, 52, 58, 31 and 39. HPV prevalence significantly increased with age in the general population, whereas it was highest below age 25 years in tertiary sector workers. Associations of HPV prevalence with indicators of sexual behaviour were stronger among tertiary sector workers than in the other samples of women. High HPV prevalence in all age groups and the appearance of a 'western-type' peak in HPV prevalence among young women employed in the tertiary sector raise important questions concerning the real cervical cancer burden, and its control, in urban China.

Cervical infection with Chlamydia trachomatis and Neisseria gonorrhoeae in women from ten areas in four continents. A cross-sectional study.

OBJECTIVES: Better information on the prevalence of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection is needed in many world areas. STUDY DESIGN: Cross-sectional study of population-based samples of nonpregnant women aged 15 to 44 years in Nigeria, Colombia, Argentina, Vietnam (2 areas), China, Thailand (2 areas), Korea, and Spain. 5,328 consenting women aged 15 to 44 years participated. Exfoliated cervical cells were collected and testing for CT and NG and human papillomavirus (HPV) was done using PCR-based assays. RESULTS: Age-standardized CT prevalence ranged between 0.2% (95% confidence interval, CI: 0.0-0.7%) in Spain and 5.6% (95% CI: 3.4-7.8%) in Nigeria. NG ranged between 0% (with broad CIs) in several areas and 2.6% (95% CI: 1.0-4.2%) in Nigeria. Prevalence of CT in all areas combined was greater in women aged 15 to 24 (4.5; 95% CI: 3.4-5.8%) than 25 to 44 (2.6; 95% CI: 2.1-3.1%), whereas NG prevalence was similar in the 2 age groups (0.3%). The only significant risk factors were NG infection (for CT), CT infection (for NG) and infection with high-risk HPV types (for both). CONCLUSIONS: The prevalence of CT and, most notably, NG was relatively low in a variety of countries. Our findings, however, do not apply to subsets of high-risk women who are likely to be underrepresented in our population-based samples.

Maternal medication use and the risk of brain tumors in the offspring: the SEARCH international case-control study.

N-nitroso compounds (NOC) have been associated with carcinogenesis in a wide range of species, including humans. There is strong experimental data showing that nitrosamides (R(1)NNO.COR(2)), a type of NOC, are potent neuro-carcinogens when administered transplacentally. Some medications are a concentrated source of amides or amines, which in the presence of nitrites under normal acidic conditions of the stomach can form NOC. Therefore, these compounds, when ingested by women during pregnancy, may be important risk factors for tumors of the central nervous system in the offspring. The aim of the present study was to test the association between maternal use of medications that contain nitrosatable amines or amides and risk of primary childhood brain tumors (CBT). A case-control study was conducted, which included 1,218 cases and 2,223 population controls, recruited from 9 centers across North America, Europe and Australia. Analysis was conducted for all participants combined, by tumor type (astroglial, primitive neuroectodermal tumors and other glioma), and by age at diagnosis (< or =5 years; >5 years). There were no significant associations between maternal intake of medication containing nitrosatable amines or amides and CBT, for all participants combined and after stratification by age at diagnosis and histological subtype. This is the largest case-control study of CBT and maternal medications to date. Our data provide little support for an association between maternal use of medications that may form NOC and subsequent development of CBT in the offspring.

Variations in the age-specific curves of human papillomavirus prevalence in women worldwide.

An inverse relationship between age and human papillomavirus (HPV) prevalence has been reported in many developed countries, but information on this relationship is scarce in many other parts of the world. We carried out a cross-sectional study of sexually active women from the general population of 15 areas in 4 continents. Similar standardised protocols for women's enrolment, cervical specimen collection and PCR-based assays for HPV testing were used. HPV prevalence in different age groups was compared by study area. 18,498 women aged 15-74 years were included. Age-standardised HPV prevalence varied more than 10-fold between populations, as did the shape of age-specific curves. HPV prevalence peaked below age 25 or 35, and declined with age in Italy, the Netherlands, Spain, Argentina, Korea and in Lampang, Thailand and Ho Chi Minh, Vietnam. This was not the case in Songkla, Thailand nor Hanoi, Vietnam, where HPV prevalence was low in all age groups. In Chile, Colombia and Mexico, a second peak of HPV prevalence was detected among older women. In the poorest study areas in Asia (Shanxi, China and Dindigul, India), and in Nigeria, HPV prevalence was high across all age groups. The substantial differences observed in age-specific curves of HPV prevalence between populations may have a variety of explanations. These differences, however, underline that great caution should be used in inferring the natural history of HPV from age-specific prevalences.

Cervical carcinoma in Algiers, Algeria: human papillomavirus and lifestyle risk factors.

We conducted a hospital-based case-control study in Algiers, Algeria. A total of 198 cervical carcinoma (CC) cases (including 15 adeno- and adenosquamous carcinomas) and 202 age-matched control women were included. Human papillomavirus (HPV) DNA in cervical cells was evaluated using a PCR assay. Odds ratios and corresponding confidence intervals were computed by means of unconditional multiple logistic regression models. HPV infection was detected in 97.7% of CC cases and 12.4% of control women (OR = 635). Nineteen different HPV types were found. HPV 16 was the most common type in both CC cases and control women, followed by HPV 18 and 45. Twelve types (HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 66 and 73) were found as single infections in CC cases. Multiple HPV infections did not show a higher odds ratio for CC than single infections. In addition to HPV infection, husband's extramarital sexual relationships with other women (OR = 4.8) or prostitutes (OR = 3.2), residing in a rural environment for most of one's life (OR = 4.9) and indicators of poor sanitation or poor hygiene were the strongest risk factors for CC. Oral contraceptive use was unrelated to CC risk, while multiparity emerged as a significant risk factor after adjustment for sexual habits. Intrauterine device users showed a lower CC risk than nonusers. The role of major risk factors, except inside toilet, was confirmed in the analysis restricted to HPV-positive women. The distribution of HPV types in CC cases and control women in Algeria is more similar to the one found in Europe than the one in sub-Saharan Africa, where HPV 16 is less prevalent. A vaccine against HPV 16 and 18 may be effective in more than 3/4 of CCs in Algeria.

The natural course of Chlamydia trachomatis infection in asymptomatic Colombian women: a 5-year follow-up study.

The natural course of Chlamydia trachomatis infection and its risk factors were studied in Colombian women with normal cytological results, during a 5-year period. Eighty-two women who were found to be positive for C. trachomatis at the start of the study were studied at 6-month intervals. At each visit, a cervical scrape sample was obtained for detection of C. trachomatis by use of C. trachomatis endogenous-plasmid polymerase chain reaction (PCR)-enzyme immunoassay and VD2-PCR-reverse line blot assay. Of the women studied, 67% had a single-serovar infection, 10% had a mixed-serovar infection, and 23% had an infection with an unidentified type. An inversed rate of clearance of C. trachomatis infection was observed with oral contraceptive use (hazard ratio [HR], 1.7 [95% confidence interval {CI}, 1.1-2.7]) and first sexual intercourse at >/=20 years of age (HR, 4.3 [95% CI, 2.3-8.0]). Serovars of group B (B, D, and E) and C (H, I, J, and K) had a decreased rate of clearance (rate ratio, 0.4 [95% CI, 0.1-0.9]), compared with that for serovars of the intermediate group (F and G). At 4 years of follow-up, 94% of the women had cleared their infections.

Occupational risk factors for low grade and high grade glioma: results from an international case control study of adult brain tumours.

The majority of suspected occupational risk factors for adult brain tumours have yet to be confirmed as etiologically relevant. Within an international case-control study on brain tumours, lifelong occupational histories and information on exposures to specific substances were obtained by direct interviews to further investigate occupational risk factors for glioma. This is one of the largest studies of brain tumours in adults, including 1,178 cases and 1987 population controls from 8 collaborating study centres matched for age, gender and centre. All occupational information, was aggregated into 16 occupational categories. In a pooled analysis, odds ratios (OR), adjusted for education, were estimated separately for men and women and for high-grade glioma (HGG) and low-grade glioma (LGG), focusing especially on 6 categories defined a priori: agricultural, chemical, construction, metal, electrical/electronic and transport. For men, an elevated OR of glioma associated with the category "metal" (OR = 1.24, 95% CI 0.96-1.62) was seen, which appeared to be largely accounted for by LGG (OR = 1.59, 95% CI 1.00-2.52). For the other 5 occupational categories, no elevated risks for glioma were observed. For women the only noteworthy observation for the 6 a priori categories was an inverse association with the "agriculture" category (OR = 0.60, 95% CI 0.36-0.99). Apart from the 6 major categories, women working in food production or food processing (category "food") showed an increased OR of 1.95 (95% CI 1.04-3.68). None of the 20 substance groups was positively associated with glioma risk. Although some other point estimates were elevated, they lacked statistical significance. The results do not provide evidence of a strong association between occupational exposures and glioma development.

Determinants of clearance of human papillomavirus infections in Colombian women with normal cytology: a population-based, 5-year follow-up study.

Little is known about the factors that influence clearance of human papillomavirus (HPV), the primary cause of cervical carcinoma. A total of 227 women cytologically normal and HPV positive at baseline were identified from a population-based cohort of 1,995 Bogota, Colombia, women aged 13-85 years followed between 1993 and 2000 (mean follow-up, 5.3 years). HPV DNA detection and viral load determination were based on a GP5+/GP6+ polymerase chain reaction enzyme immunoassay. Rate ratio estimates for HPV clearance were calculated by using methods for interval-censored survival time data. Analyses were based on 316 type-specific HPV infections. HPV 16 had a significantly lower clearance rate than infections with low-risk types (rate ratio (RR) = 0.47, 95% confidence interval (CI): 0.32, 0.72), HPV types related to HPV 16 (types 31, 33, 35, 52, 58) had intermediate clearance rates (RR = 0.62, 95% CI: 0.47, 0.94), and other high-risk types did not show evidence of slower clearance compared with low-risk types. Infections with single and multiple HPV types had similar clearance rates. There was no evidence of a dose-response relation between clearance and viral load. Observed was slower clearance in parous women (RR = 0.64, 95% CI: 0.47, 0.89) and faster clearance in ever users of oral contraceptives (RR = 1.38, 95% CI: 1.07, 1.77).

Relation of childhood brain tumors to exposure of parents and children to tobacco smoke: the SEARCH international case-control study. Surveillance of Environmental Aspects Related to Cancer in Humans.

The etiology of childhood brain tumors (CBTs) remains unknown. Tobacco smoke contains several known carcinogens and can induce DNA adducts in human placenta and hemoglobin adducts in fetuses. We present the results of an international case-control study to evaluate the association between CBTs and exposure of parents and children to cigarette smoke. The study was undertaken as part of the SEARCH program of the IARC. Nine centers in 7 countries were involved. The studies mainly covered the 1980s and early 1990s. Cases (1,218, ages 0-19 years) were children newly diagnosed with a primary brain tumor; there were 2,223 population-based controls. Most mothers who agreed to participate were interviewed in person at home. Odds ratios (ORs) were calculated by unconditional logistic regression, adjusted for age, sex and center, for all types of CBT combined, 4 CBT histotypes, 5 age groups and each center. There was no association between the risk of brain tumors in the child and parental smoking prior to pregnancy, maternal smoking or regular exposure to others' cigarette smoke during pregnancy at home or at work, or passive smoking by the child during the first year of life. These results did not change considering the child's age at diagnosis, the histologic type of tumor or center.

Farm-related exposures and childhood brain tumours in seven countries: results from the SEARCH International Brain Tumour Study.

A total of 1218 cases of childhood brain tumours (CBT) and 2223 control subjects from the general population were included in a population-based case-control study conducted in nine centres in seven countries. Mothers were asked about farm- or agriculture-related exposures. Significantly elevated odds ratios (OR) for CBT were associated with children's personal and maternal prenatal exposure while living on a farm with pigs (child OR = 1.7, mother OR = 2.3), horses (child OR = 1.6, mother OR = 1.8), dogs (child OR = 1.5, mother OR = 1.5) and cats (child OR = 1.5, mother OR = 1.7). Children who were exposed to pigs, horses and cats combined, while living on a farm, had a threefold elevated OR for CBT. Increased ORs for primitive neuroectodermal tumours (PNET) were associated with children's farm exposure to dogs (OR = 1.9) and cats (OR = 2.2), and maternal farm exposure to pigs (OR = 4.2). The OR for CBT was elevated (OR = 2.3) for children of mothers who had preconception/prenatal farm- or agriculture-related employment involving potential contact with animals, relative to no farm- or agriculture-related employment. In particular, increased ORs for CBT were observed for children of mothers who were employed as general farmers (OR = 4.1) or general farm workers (OR = 3.8). During the 5 years preceding the index child's birth, maternal exposures were related to CBT, relative to no maternal exposure to agricultural chemicals or animal products: fertilisers (OR = 1.8), pesticides (OR = 2.0), animal manure (OR = 2.0) and unprocessed wool (OR = 3.0). Our findings suggest that various farm-related exposures are positively associated with CBT and warrant further investigation into the public health importance of these associations.

Historia natural de la infección por el virus del papiloma humano: un estudio de cinco años de seguimiento / Natural history of the infection by papillomavirus

Introducción: El virus del papiloma humano es el principal factor de riesgo asociado con el desarrollo de cáncer cervical, uno de los cánceres más comunes en mujeres colombianas. En Colombia, donde las tasas de incidencia de cáncer cervical son altas, se tiene poca información acerca de la prevalencia de la infección y no se tienen datos de seguimiento sobre la persistencia o eliminación de la infección y los factores de riesgo asociados. En este reporte se presentan los resultados de la prevalencia de la infección por HPV y los factores de riesgo asociados en mujeres que tuvieron una citología normal al comienzo del estudio así como el seguimiento de 227 mujeres positivas para la infección por HPV durante un periodo de cinco años, en la ciudad de Bogotá, Colombia

Infecciones por Chlamydia trachomatis y su asociación con el virus del papiloma humano: un estudio de seguimiento / Chlamydia trachomatis infections and their association with the human papilloma virus {HPV} in a cohort study

Objetivo: estudiar el curso natural de las infecciones por Chlamydia trachomatis (C.trachomatis) y su asociación con el virus del papiloma humano (VPH) en mujeres bogotanas con citología normal, durante un periodo de cinco años. Metodología: se analizaron 82 mujeres positivas para C. trachomatis a itervalos de ses meses. En cada visita se realizó un cepillado cervical para hacer la detección del plásmido endógeno de C.trachomatis con el uso de los indicadores específicos Bio PL6.1/PL6.2 y, para la detección de VPH, con los iniciadores Bio GP5+/GP6+, mediante el desarrollo de un PCR-EIA. De estas mujeres, 18 (21,9 porciento)fueron positivas para VPH genérico, 13(15,8 por ciento) de las cuales tuvieron VPH de alto riesgo y 5 (6,1por ciento) VPH de bajo riesgo. Resultados: durante el seguimiento, el VPH genérico no se asoció con la eliminación o persistencia de la infección por C. trachomatis. después de cuatro años de seguimiento, 6 por ciento de las mujeres infectadas por C. trachomatis aún no habían superado la infección. Conclusión: en este estudio se observó un bajo porcentaje de infecciones persistentes por C. trachomatis después de cuatro años de seguimiento, y el VPH no fue un factor de riesgo para la persistencia o eliminación de las infecciones por este germen.