Risk factors for HPV DNA detection in middle-aged women

Risk of cervical cancer associated with extending the interval between cervical-cancer screenings

BACKGROUND

Although contemporary guidelines suggest that the intervals between Papanicolaou tests can be extended to three years among low-risk women with previous negative tests, the excess risk of cervical cancer associated with less frequent than annual screening is uncertain.

METHODS

We determined the prevalence of biopsy-proven cervical neoplasia among 938,576 women younger than 65 years of age, stratified according to the number of previous consecutive negative Papanicolaou tests. Using a Markov model that estimates the rate at which dysplasia will progress to cancer, we estimated the risk of cancer within three years after one or more negative Papanicolaou tests, as well as the number of additional Papanicolaou tests and colposcopic examinations that would be required to avert one case of cancer given a particular interval between screenings.

RESULTS

Among 31,728 women 30 to 64 years of age who had had three or more consecutive negative tests, the prevalence of biopsy-proven cervical intraepithelial neoplasia of grade 2 was 0.028 percent and the prevalence of grade 3 neoplasia was 0.019 percent; none of the women had invasive cervical cancer. According to our model, the estimated risk of cancer with annual Papanicolaou tests for three years was 2 in 100,000 among women 30 to 44 years of age, 1 in 100,000 among women 45 to 59 years of age, and 1 in 100,000 among women 60 to 64 years of age; these risks would be 5 in 100,000, 2 in 100,000, and 1 in 100,000, respectively, if screening were performed once three years after the last negative test. To avert one additional case of cancer by screening 100,000 women annually for three years rather than once three years after the last negative test, an average of 69,665 additional Papanicolaou tests and 3861 colposcopic examinations would be needed in women 30 to 44 years of age and an average of 209,324 additional Papanicolaou tests and 11,502 colposcopic examinations in women 45 to 59 years of age.

CONCLUSIONS

As compared with annual screening for three years, screening performed once three years after the last negative test in women 30 to 64 years of age who have had three or more consecutive negative Papanicolaou tests is associated with an average excess risk of cervical cancer of approximately 3 in 100,000.

Psychosocial stress and cervical neoplasia risk

OBJECTIVE

We assessed the association between psychosocial stress and preinvasive cervical neoplasia development controlling for HR-HPV infection.

METHODS

This case-control study enrolled low-income women receiving family planning services at health department clinics. There were 59 cases with biopsy confirmed HSIL and 163 with low-grade SIL and 160 controls with normal cervical cytology. A modified SLE scale was used to measure stressful events and the perceived impact of the event in the prior 5 years. Unconditional logistic regression was used to assess SIL risk and stressful events scores and by subscales.

RESULTS

After adjusting for age, HR-HPV infection, and lifetime number of sex partners, the SLE count score was associated with an increased risk of SIL among white women (aOR = 1.20; 95% CI = 1.04, 1.38) yet not among African American women (aOR = 1.02; 95% CI = 0.87, 1.19). The relationship stress subscale (divorce, infidelity, an increase in the number of arguments, and psychological and physical partner violence) was the only one of four subscales (loss, violence, and financial stress) associated with SIL, again, only among white women (aOR = 1.54; 95% CI = 1.21, 1.96).

CONCLUSIONS

These data suggest that psychosocial stress may play a role in SIL development. Future studies are needed to confirm these findings, to explore racial difference in reporting stress, and to explore the mechanism through which psychosocial stress may affect cervical neoplasia risk.

Human papillomavirus infection among women in South and North Vietnam

The incidence rate of invasive cervical carcinoma (ICC) is 4-fold higher in Ho Chi Minh City, in the South of Vietnam, than in Hanoi, in the North. Thus, we explored the prevalence of and the risk factors for human papillomavirus (HPV) infection in these 2 areas. A population-based random sample of married women aged 15-69 years were interviewed and had a gynaecological examination in the urban district of Ho Chi Minh City and in a peri-urban district in Hanoi. HPV DNA detection was performed using a GP5+/6+ primer-mediated PCR enzyme immunoassay. A total of 922 women from Ho Chi Minh and 994 from Hanoi, for whom a Pap smear and HPV-status were available, were evaluated. HPV DNA was detected among 10.9% of women in Ho Chi Minh City and 2.0% in Hanoi (age standardized prevalence, world standard population: 10.6% and 2.3%, respectively). In the 2 areas combined, 30 different HPV types were found, the most common being HPV 16 (in 14 single and 18 multiple infections), followed by HPV 58, 18 and 56. A peak of HPV DNA detection in women younger than age 25 was found in Ho Chi Minh City (22.3%) but not in Hanoi. Major risk factors for HPV DNA detection were indicators of sexual habits, most notably the presence of HSV-2 antibodies, nulliparity and the current use of oral contraceptives. Women in Hanoi showed the lowest HPV prevalence ever reported so far, suggesting that HPV has not spread widely in this population. As expected, HPV prevalence in a population seemed to be closely correlated with ICC incidence rates.

Poor sensitivity of polymerase chain reaction assays of genital skin swabs and urine to detect HPV 6 and 11 DNA in men

BACKGROUND

A possible reason for the failure to detect human papillomavirus (HPV) DNA in asymptomatic men who are likely to be infected is the sensitivity of the detection methods.

GOAL

The goal of this study was to identify a method for sampling the anogenital skin of men that was simple and well tolerated and that would permit the detection of asymptomatic or subclinical HPV infection, which is thought to occur commonly in sexually active men.

STUDY DESIGN

Swabs of genital skin and urine from men at high and low risk of infection with types 6 and 11 were tested for HPV by polymerase chain reaction.

RESULTS

These specimens had a low sensitivity for HPV detection, often because inadequate material was collected on the swab.

CONCLUSION

Noninvasive sampling of genital skin to identify individuals with subclinical HPV infection remains a challenge. Future studies should involve the use of more abrasive sampling devices (such as cytobrushes), perhaps combined with some type of soap to dislodge more epithelial cells.

Prevalence of human papillomavirus infection in women in Busan, South Korea

To investigate the prevalence of and the risk factors for human papillomavirus (HPV) infection in South Korea, we interviewed and examined a randomly selected sample of 863 sexually active women (age range = 20-74 years, median 44) and 103 self-reported virgins from Busan. The presence of DNA of 34 different HPV types in cervical exfoliated cells was tested among sexually active women by means of a PCR-based assay. IgG antibodies against L1 virus-like particles (anti-VLPs) of HPV types 16, 18, 31, 33 and 58 were also evaluated by means of ELISA. The overall prevalence of HPV DNA was 10.4% (95% confidence interval, CI: 8.5-12.7%). The most often found HPV DNA types were HPV 70, HPV 16 and HPV 33; 19.8% (95% CI: 17.2-22.0) of sexually active women had antibodies against one or more HPV types. The most common anti-VLPs were against HPV 18, 31 and 16. Prevalences standardized by age on the basis of the world standard population were 13.0% for HPV DNA and 17.1% for anti-VLPs. The concordance between the 2 HPV markers at an individual level was modest, but the risk factors for detection of HPV DNA and anti-VLPs were similar: number of lifetime sexual partners (odds ratio, OR for >/= 4 vs. 1 = 3.5 and 5.4, respectively), seropositivity for herpes simplex virus-2 antibodies (OR = 2.6 and 2.5, respectively) and being single or divorced. HPV DNA, but not anti-VLPs, were elevated among women whose husbands were thought by their wives to have extra-marital affairs and those who had undergone vasectomy. Among 103 virgins, 4.9% had anti-VLPs (1/73 among those aged 24 years or less).

Can cervical cancer screening be stopped at 50? The prevalence of HPV in elderly women

Although the relation between cervical cancer and the human papillomavirus (HPV) has been established beyond doubt, the introduction of HPV detection in cervical cancer screening is halted, primarily by the high rate of false positivity in relation to morbidity, since the majority of women infected with HPV will not develop lesions. To counteract overconsumption of cervical cancer screening in elderly women, we wanted to test the hypothesis that women of 50 years or older who are HPV-negative and have a cytologically normal smear might be encouraged to refrain from further screening. As a first step, the prevalence of high-risk HPV in a population of 1,936 women of 50 years and older was investigated. After an initial decline, a slightly higher prevalence can be seen with increasing age. There is a decrease in the prevalence of multiple infections with age, paralleled by an increase in single infections, especially of HPV type 16 in the eldest-age group. However, neither the decrease in multiple infections nor the increase in single infections is statistically significant. The data obtained in this study show that, even in the presence of a slight increase in the HPV prevalence in elderly women, approximately 94% of the elderly women can be withdrawn from the cervical cancer screening. However, a follow-up study will be necessary to determine the frequency of (re)infection as well as the course of an HPV infection in elderly women.

Low grade squamous intra-epithelial lesions and human papillomavirus infection in Colombian women

Low grade squamous intra-epithelial lesions could be considered as a manifestation of human papillomavirus exposition, however the discrepancy between rates of infection with human papillomavirus and development of low grade squamous intra-epithelial lesions is notable. Here we report a cross-sectional three-armed case-control study in the Colombian population, to compare the risk factors of women with low grade squamous intra-epithelial lesions with that of human papillomavirus DNA-negative and positive women with normal cytology.

Prevalence and genotype distribution of cervical human papillomavirus infection: Comparison between pregnant women and non-pregnant controls

Controversies exist on the effect of pregnancy on human papillomavirus (HPV) infection. A cross-sectional section study was conducted to compare the prevalence and genotype distribution of cervical HPV infection between pregnant and non-pregnant women in Hong Kong. Cervical samples were collected from 308 pregnant women and from the same number of age-matched controls recruited from a cervical cancer screening center located at the same hospital. HPV was detected by the polymerase chain reaction, followed by genotype identification by restriction fragment length polymorphism and direct sequencing analyses. The prevalence of HPV for pregnant women was 10.1%, without significant variation with age, gestation, gravidity and parity. The prevalence of HPV for non-pregnant group was 11.4% and did not show significant difference when compared to the pregnant group either by overall or age-stratified subgroup analyses. When the analysis was stratified according to the risk-type of HPV infection, still no significant difference between pregnant and non-pregnant groups was observed (all types: 10.1 vs. 11.4%, P = 0.602; high-risk types: 5.8 vs. 7.8%, P = 0.338; low-risk types: 1.0 vs. 2.9%, P = 0.080; unknown-risk types: 3.2% vs. 1.3%, P = 0.105). The results of this study show no evidence for an influence of pregnancy on HPV prevalence, and a majority of HPV-infected pregnant women had normal cervical cytology. HPV positive results in pregnant women per se should be managed conservatively.

Cervicovaginal coinfections with human papillomavirus and Chlamydia trachomatis

Human papillomavirus (HPV) and Chlamydia trachomatis (CT) are the two most common sexually transmitted pathogens, and infection with either reportedly was associated with cervical intraepithelial neoplasia (CIN) in women. In view of their similar mode of transmission, CT infection was examined as a possible HPV cofactor in the etiology of CIN disease. In total, 129 women were included in the study, of whom 80 were negative (mean age 34.17 +/- 6.9) and 49 were positive (mean age 33.16 +/- 6.8) for HPV DNA (assessed by PCR). CT DNA was determined in endocervical and first-catch urine specimens by PCR. Whereas HPV-positive and HPV-negative women were similar with respect to age (p = 0.419) and pregnancy outcomes (p = 0.628), the number of smokers (p = 0.001), women with multiple male sex partners (p = 0.002) or with abnormal cytology (p < 0.001) was higher in the HPV-positive group. There was an increase in CT infection rate in HPV-positive (29/49) as compared to HPV-negative (10/80) women (p < 0.01). Within HPV-positive patients, there was no significant difference between CT-positive and CT-negative patients with regards to the risk factors studied. Collectively, this suggests that CT infection is a cofactor of HPV in CIN disease development, possibly by modulating the host's immunity and/or precipitation of chronic inflammation.

Prevalence and determinants of HPV infection among Colombian women with normal cytology

Human papillomavirus is the principal risk factor associated with cervical cancer, the most common malignancy among women in Colombia. We conducted a survey, aiming to report type specific prevalence and determinants of human papillomavirus infection in women with normal cytology. A total of 1859 women from Bogota, Colombia were interviewed and tested for human papillomavirus using a general primer GP5+/GP6+ mediated PCR-EIA. The overall HPV DNA prevalence was 14.8%; 9% of the women were infected by high risk types, 3.1% by low risk types, 2.3% by both high risk/low risk types and 0.4% by uncharacterized types (human papillomavirus X). Thirty-two different human papillomavirus types were detected, being human papillomavirus 16, 58, 56, 81(CP8304) and 18 the most common types. The human papillomavirus prevalence was 26.1% among women younger than 20 years, 2.3% in women aged 45-54 years, and 13.2% in women aged 55 years or more. For low risk types the highest peak of prevalence was observed in women aged 55 years or more. Compared to women aged 35-44 years, women aged less than 20 years had a 10-fold increased risk of having multiple infections. Besides age, there was a positive association between the risk of human papillomavirus infection and number of regular sexual partners and oral contraceptive use. In women aged below 25 years, high educational level and having had casual sexual partners predicted infection risk. In conclusion, there was a broad diversity of human papillomavirus infections with high risk types being the most common types detected. In this population multiplicity of sexual partners and, among young women, high educational level and casual sexual partners seem to determine risk.

Is use of hormone replacement therapy associated with increased detection of human papillomavirus and potential risk of HPV-related genital cancers?

Oral contraceptives (OC) are a risk factor for female genital cancers and in vivo studies have shown that progestins stimulate human papillomavirus (HPV) gene expression. A similar role for hormone replacement therapy (HRT) has received little evaluation. Cervical/vaginal specimens were obtained to detect HPV from postmenopausal women (n = 429) seeking annual gynaecologic care. HPV was detected in 14% of women and 4.4% had high-risk, oncogenic types. HPV prevalence was similar across current, past and never HRT users. After adjustment for HPV-related risk factors, current and past user status showed no increased viral detection compared with never users. HRT duration also did not elevate risk among current users. However, longer duration (adj. OR 1.5/year, 95% CI 1.0-2.3) and longer latency (adj. OR 1.2/year, 95% CI 0.9-1.7) among past users of oestrogen/progestin regimens were associated with greater risk. Overall use of HRTs was not associated with HPV detection or disease. However, past users of combination HRTs had significantly greater risk of HPV detection with longer HRT duration and latency, similar to OC-HPV findings. The recommendation that postmenopausal women continue HRTs long term may lead to an increased development of HPV-related diseases, of particular concern among those who discontinue HRTs and subsequent gynaecologic care for early cancer detection.

The causal relation between human papillomavirus and cervical cancer

The causal role of human papillomavirus infections in cervical cancer has been documented beyond reasonable doubt. The association is present in virtually all cervical cancer cases worldwide. It is the right time for medical societies and public health regulators to consider this evidence and to define its preventive and clinical implications. A comprehensive review of key studies and results is presented.

The diagnostics and prevalence of genital human papillomavirus (HPV) infection in Hungary

OBJECTIVE

To show the prevalence and determine the type of human papillomavirus (HPV) in healthy women of reproductive age in Hungary.

STUDY DESIGN

We determined HPV nucleic acid using the Digene Hybrid Capture HPV-DNA assay from endocervical swabs of 1121 volunteer women of reproductive age. With the help of the hybridization antibody capture test we determined 14 HPV types (low risk, intermediate and high risk).

RESULTS

HPV prevalence was 17.5% considering the whole material. At the Szeged center 27.6% of the women screened were HPV positive, whereas at the three centers in Budapest, HPV prevalence did not exceed 15% in either of them. With a cytological examination out of 1100 cases, 117 (10.6%) were found to be HPV infected. The virus infection could be shown out of 1018 non-malignant cytologies in 60 (5.9%) cases and from 82 epithelial lesions 57 (69.5%) were infected. The cytological and molecular HPV diagnoses showed a significant relation to each other (P<0.001). The cytological method showed HPV infections with a low degree of efficiency (sensitivity: 23.8%). On the other hand, the specificity (92.2%) is an acceptable method for the real negativity of the light microscopic HPV infection.

CONCLUSIONS

These facts mean regarding the detection of HPV-DNA genoms that HPV positive cytological reports are false negative and in dysplasias are false positive. Since in HPV infected women the development of CIN is a great risk, it is advisable to carry out the HPV determination and typing in the so-called "endangered" groups.

Using a new HPV detection system in epidemiological research: change of views on cervical dyskaryosis?

The prevalence of human papillomavirus (HPV) rises with increasing histological severity of neoplasia, more cigarettes smoked per day and higher lifetime number of sexual partners in women with cervical dyskaryosis. Recently, the highly sensitive SPF10 primers and Inno-LiPA (line probe assay) HPV prototype research assay became available for the detection and typing of HPV.

BACKGROUND

using this system, we challenged the previously reported findings.

STUDY DESIGN

the study group comprised 304 women referred because of abnormal pap smears in whom a histological diagnosis was made. Data on the lifetime number of sexual partners and smoking behaviour were obtained by questionnaire. HPV analysis was performed on cervical scrapes obtained at the enrollment visit.

RESULTS

oncogenic HPV was found in 288 (95%) women. A total of 86 (30%) out of these 288 women disclosed multiple types. HPV 16 occurred significantly less often in multiple infections than was expected on the basis of chance alone. The grade of neoplasia was significantly associated with the presence of oncogenic HPV, and this association depended on the presence of HPV type 16. No association was found between grade of neoplasia and the presence of multiple HPV types. Neither the lifetime number of sexual partners nor smoking were associated with oncogenic HPV, the five most frequent HPV types separately or the presence of multiple types.

CONCLUSION

we conclude that the association between the detection of HPV and the epidemiological risk factors, as found with the GP5/6 PCR in the past, could not be confirmed when using SPF10 PCR primers and LiPA HPV genotyping. We suggest that the number of sexual partners and smoking may be determinants of high HPV viral load rather than determinants of the presence of HPV per se.

Human papillomavirus infection in Danish female sex workers. Decreasing prevalence with age despite continuously high sexual activity

BACKGROUND

The prevalence of the human papillomavirus (HPV) has been found to decrease with age, but whether this applies to all populations is not clear. Knowledge about the generalizability of this age dependency is important to understand the natural history of the infection, but may also have implications in relation to the use of HPV testing in cervical cancer screening.

GOAL

To study the prevalence and risk factors for HPV infection in a selected population of female sex workers and to compare the results with persons with different sexual habits from two other populations in the same geographic area.

STUDY DESIGN

A case-control study among 188 female sex workers from Copenhagen. Data were obtained by personal interviews. Cervical material was collected by a self-administered lavage kit, and HPV testing was done by means of GP5+/6+ primers based on HPV, polymerase chain reaction, enzyme immunoassay.

RESULTS

Among sex workers, age was the most important risk factor for HPV infection. Number of private sex partners in the last 4 months was also a significant risk factor, and a protective effect of condom use was indicated.

CONCLUSION

The HPV prevalence is declining in sex workers with age despite continuously high sexual activity, most likely indicating that an immune response is acquired over time.

Epidemiology of sexually transmitted infections and human immunodeficiency virus in Europe

Sexually transmitted infections and HIV in Europe present considerable social and medical problems and are not always adequately controlled. The recent trends for sexually transmitted infections and HIV in Western and Eastern Europe are reviewed.

[Human papillomavirus and human immunodeficiency virus infections as risk factors for cervix cancer in women prisoners]

BACKGROUND

The identification of high risk groups for genital human papillomavirus (HPV) infection may contribute to cervical cancer prevention. The study was designed to estimate the prevalence of HPV infection and the related risk of cervical cancer among imprisoned women.

PATIENTS AND METHODS

157 women were visited at the Medical Office of a prison in Barcelona, Spain. Women underwent a structured interview, determination of HIV serostatus and detection of HPV cervical infection by means of PCR.

RESULTS

The prevalence of HPV infection was 46%. Prostitution was reported by 38.2% and intravenous drug use by 64.3%. HIV infection was detected in 56.1%. Cervical cytology revealed 19 women with ASCUS and 28 with squamous intraepithelial lesions (SIL) (all grades). HPV infection was associated with an increased risk of intravenous drug use for more than 10 years (prevalence odds ratio [POR] = 2.9) and seropositivity to HIV (POR = 4.7). The increase in risk for SIL related to HIV was explained by the presence of HPV. HIV positive women with low CD4 counts may increase the risk for SIL independently of HPV.

CONCLUSION

HIV positive women are at high risk for HPV infection and as a consequence, for developing SIL. HIV positive women should be closely monitored for cervical cancer.

Human tumor growth is inhibited by a vaccinia virus carrying the E2 gene of bovine papillomavirus

BACKGROUND

Papillomavirus is the etiologic agent associated with cervical carcinoma. The papilloma E2 protein is able to regulate negatively the expression of E6 and E7 papilloma oncoproteins. Therefore, a new, highly attenuated vaccinia virus known as modified vaccinia virus Ankara (MVA), which carries the papillomavirus E2 gene, was used for the treatment of tumors associated with human papillomavirus.

METHODS

Analysis of expression of the E2 gene from the recombinant vaccinia virus was performed by reverse transcription-polymerase chain reaction of RNA isolated from infected cells. Detection of the E2 protein was done by immunoprecipitation from proteins labeled with [(35)S]-methionine, isolated from infected cells. The therapeutic effect of the MVA E2 recombinant virus over human tumors was tested in nude mice bearing tumors generated by inoculation of HeLa cells. Series of 10 nude mice with tumors of different sizes were injected with MVA, MVA E2, or phosphate-buffered saline. Tumor size was monitored every week to assess growth.

RESULTS

The MVA E2 recombinant virus efficiently expressed the E2 protein in BS-C-1 cells. This protein was able to repress, in vivo, the papillomavirus P105 promoter, which controls the expression of the E6 and E7 oncoproteins. In nude mice the MVA E2 virus reduced tumor growth very efficiently. In contrast, tumors continued to grow in mice treated with MVA or PBS. The life expectancy of MVA E2-treated mice was also increased three- to fourfold compared with that of animals that received MVA or PBS.

CONCLUSIONS

The growth of human tumors was efficiently inhibited by the MVA E2 recombinant vaccinia virus. The absence of side effects in treated animals suggested that the MVA E2 virus is a safe biologic agent that could in the future be used in humans for the treatment of cervical carcinoma.

Population-based study of human papillomavirus infection and cervical neoplasia in rural Costa Rica

BACKGROUND

Human papillomavirus (HPV) is the main cause of cervical neoplasia. Because few population-based studies have investigated the prevalence of type-specific infection in relation to cervical disease, we studied a high-risk population, estimating the prevalence of HPV infection and the risk associated with various HPV types.

METHODS

We screened 9175 women in Guanacaste, Costa Rica, to obtain a referent standard final diagnosis, and tested 3024 women for more than 40 types of HPV with a polymerase chain reaction-based system.

RESULTS

Among women with normal cytology, HPV infections peaked first in women younger than 25 years, and they peaked again at age 55 years or older with predominantly non-cancer-associated types of HPV and uncharacterized HPV types. Low-grade squamous intraepithelial lesions (LSILs) (n = 189) decreased consistently with age. The prevalence of high-grade squamous intraepithelial lesions (HSILs) (n = 128) peaked first around age 30 years and again at age 65 years or older. Seventy-three percent of LSILs were HPV positive, with HPV16 being the predominant type (16% of positive subjects). HPV was found in 89% of HSILs and 88% of cancers, with HPV16 being strongly predominant (51% and 53% of positive subjects). Virtually all HSILs and cancers had cancer-associated HPV types, with high odds ratios (ORs) and attributable fractions around 80%. Risk for HPV16 was particularly high (OR for HSILs = 320, 95% confidence interval [CI] = 97-1000; OR for cancer = 710, 95% CI = 110-4500).

CONCLUSIONS

We confirm the early decline of HPV infection with age but note increased prevalence after menopause, which could be related to a second peak of HSILs, an observation that warrants further investigation. At least 80% of HPVs involved in cervical carcinogenesis in this population have been characterized. Polyvalent vaccines including the main cancer-associated HPV types may be able to prevent most cases of cervical disease in this region.

Determinants of low-risk and high-risk cervical human papillomavirus infections in Montreal University students

BACKGROUND

Previous studies have been inconsistent about the degree of sexual transmissibility of cervical human papillomavirus (HPV) infection. The authors hypothesize that risk factors for HPV infection vary according to HPV type.

GOAL

To estimate the prevalence of HPV infection in asymptomatic women and to identify risk factors for overall HPV infection and HPV infection by oncogenic and nononcogenic type.

STUDY DESIGN

A cross-sectional survey was conducted at the McGill University clinic in Montreal. Cervical specimens were collected from 489 female students presenting at the clinic for a routine Papanicolaou test. Data on potential risk factors was obtained by questionnaire. Human papillomavirus DNA was detected by the polymerase chain reaction using consensus primers (MY09/11) followed by hybridization with generic and type-specific probes using Southern blot and dot blot techniques.

RESULTS

The overall HPV prevalence was 21.8%. A low-risk HPV infection was found in 6.2% of the women, 11.8% had a high-risk HPV infection (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58), 7.1% had an unknown HPV type, and 2.7% had a multiple type infection. Two profiles emerged for sexual activity and risk of HPV infection according to oncogenic risk after multivariate analysis. Lifetime frequency of sexual intercourse and lifetime number of oral sex partners was associated with high-oncogenic-risk HPV infections; however, HPV infection with low-oncogenic-risk types was invariant with respect to markers of sexual activity.

CONCLUSION

These results suggest that there are differences in epidemiologic correlates of transmission between low-risk and high-oncogenic-risk HPV types based on oncogenicity. This finding has important implications for primary prevention of HPV infection and cervical cancer precursors.

Risk factors for human papillomavirus and cervical precancerous lesions, and the role of concurrent HIV-1 infection

OBJECTIVES

To identify risk factors for human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) of the cervix, and to measure the impact of concurrent HIV-1 infection.

METHODS

Women were studied at a family planning clinic in Nairobi, Kenya. Demographic and historical information was obtained using a semi-structured questionnaire and specimens were collected for sexually transmitted diseases (STDs), HPV, cervical cytology, and HIV-1 testing.

RESULTS

HPV was detected in 87 of 513 women (17%), including 81 (93%) oncogenic types (16, 18, 31, 33 and others) and six (7%) non-oncogenic types (6 and 11). HIV-1 prevalence was 10%. HPV detection was associated with HIV-1 infection [adjusted odds ratio (aOR) 3.9, 95% confidence interval (CI), 2.0-7.7], sexual behavior indicators including the number of sex partners and inflammatory STDs, as well as the number of pregnancies (0 or 1 vs. > or = 3, aOR 0.4; 95% CI, 0.2-0.9). SIL was detected in 61 women (11.9%), including 28 (46%) with low-grade lesions (LSIL) and 33 (54%) with high-grade lesions (HSIL). HPV infection was strongly associated with HSIL (OR 14.9; 95% CI, 6.8-32.8). In a multivariate model predictors of HSIL included HIV-1 serpositivity (aOR 4.8; 95% CI, 1.8-12.4), the number of lifetime sex partners (0-1 vs. > or = 4; aOR 3.8; 95% CI, 1.1-13.5), and older age (< 26 vs. > 30; OR 3.9; 95% CI, 1.1-13.6). An analysis stratified by HIV-1 showed a stronger association between HPV and HSIL in HIV-1 negative women (OR 17.0; 95% CI, 6.4-46.3) then in HIV-1 positive women (OR 4.5; 95% CI, 0.8-27.4).

CONCLUSION

Our results indicate that HSIL and even invasive cancer are highly prevalent in this setting of women on reproductive age considered to be at low risk for STDs, suggesting that routine Pap smear screening may save lives.

High risk genital papillomavirus infections are not spread vertically

The Medline-indexed literature on risk factors for HPV infection and HPV transmission is critically reviewed. Principles for assay validation and interpretation, reliability of different study designs and principles for interpretation of conflicting reports are discussed. The conclusions arrived at can be summarised as: (1) There is overwhelming epidemiological evidence that the only quantitatively important mode of transmission of infection with oncogenic genital HPV types is sexual. (2) There is also evidence that benign genital HPV types can be transmitted sexually, but the epidemiological data on the benign virus types are less extensive and less clear. (3) Perinatal HPV transmission is unequivocally demonstrated only for the rare disease juvenile respiratory papillomatosis.

Human papillomavirus cervical infection and associated risk factors in a region of Argentina with a high incidence of cervical carcinoma

OBJECTIVE

To assess the prevalence and potential risk factors associated with human papillomavirus (HPV) cervical infection among women residing in a region of northeastern Argentina with a high incidence of cervical cancer.

METHODS

A case-control study of 330 women participating in a cervical cytological screening program conducted in Posadas city, Misiones, Argentina, from February 1997 to November 1998 was carried out. Standardized questionnaires were administered, and clinical examination including colposcopy was performed. Fresh endocervical specimens for HPV DNA detection by generic polymerase chain reaction were collected and the products typed by dot-blot hybridization.

RESULTS

Human papillomavirus DNA was found in 61% of samples analyzed (185/301). Samples with normal cytology had a 43% infection rate (85/199), while those classified as low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, and invasive cervical carcinoma had an infection rate of 96% (53/55), 100% (29/29), and 100% (18/18), respectively. Human papillomavirus typing showed a 64% (118/185) prevalence of type 16 among all the infected population analyzed; type 16 was detected among 49% (42/85) of infected samples with normal cytology and in an average of 74% (74/100) with abnormal cytology. Sexual behavior, residence in southern Paraguay, and history of a previous sexually transmitted diseases were the main risk factors associated with high-grade cervical lesions.

CONCLUSIONS

An elevated prevalence of HPV infection was detected in this population, which also has a high incidence of cervical cancer. The broad distribution of high-risk HPV type 16 in women with normal cytology and colposcopy suggests that viral infection is an important determinant of regional cancer incidence.

Detection of Chlamydia trachomatis DNA in cervical samples with regard to infection by human papillomavirus

OBJECTIVE

The correlation between human papillomavirus (HPV) and Chlamydia, trachomatis infections was evaluated in 144 patients with normal cytology or with atypical squamous cells of undetermined significance (ASCUS).

METHODS

Cervical samples were analysed using polymerase chain reaction (PCR) and non-radioactive Southern blot analysis. Specificity and sensitivity of two C. trachomatis PCR systems: major outer membrane protein (MOMP)-PCR and plasmid-PCR were determined. Southern blot hybridization of the PCR amplicons was done using 5' and 3' biotinylated oligonucleotide probes.

RESULTS

All cervical samples were tested by the plasmid-PCR due to a 10 times higher sensitivity compared to the MOMP-PCR. To determine the specificity of our C. trachomatis primer sets different bacteria and viruses which can cause urogenital infections were analysed. Comparison of the probes revealed an increased sensitivity of the 5' and 3' double-biotinylated probe vs. the 5' biotinylated probe. The infection rate of C. trachomatis in cervical samples of HPV-positive patients was 10.3% (three out of 29) vs. 1.7% (two out of 115; P< or =0.05) in HPV-negative patients. In patients HPV-X (unsequenced HPV-types) positive the rate was 14.3% (one out of seven) vs. 2.9% (four out of 137: P = 0.2) in HPV-X negative patients. In high risk (HR) HPV-positive cervical samples the infection rate was 9.1% (two out of 22) vs. 2.5% (three out of 122; P = 0.14) in HR HPV-negative samples. Chlamydia trachomatis frequency of patients with cytological changes (ASCUS) was 27.3% (three out of 11) vs. 1.5% (two out of 1 33) in patients with normal cytology (P = 0.003). The highest prevalence rate of C. trachomatis-positive cervical samples (50%; one out of two) was found in HR HPV-positive patients with cytological changes (ASCUS) vs. 5% (one out of 20) in HR HPV-positive patients with normal cytology (P = 0.17). Patients negative for HPV and positive for ASCIIS have a C. trachomatis rate of 22.2% (two out of nine) vs. HPV-negative patients with normal cytology (none out of 106; P = 0.006) and vs. HR HPV-negative patients with normal cytology (0.9%; one out of 113; P = 0.014).

CONCLUSIONS

There appears to be a correlation between cervical HPV and cervical C. trachomatis infections. The prevalence rate of C. trachomatis was significantly higher in patients with abnormal cytology (ASCUS) vs. normal cytology.

Race and clinical outcome in patients with carcinoma of the uterine cervix treated with radiation therapy

OBJECTIVES

The aim of this study was to examine factors underlying differences in outcome between African-American (AA) and Caucasian (C) patients undergoing radiation therapy (RT).

METHODS

Patient, tumor, treatment characteristics, and the outcome of 316 AA and 94 C cervical cancer patients who underwent RT were compared. Median follow-up was 72.4 months.

RESULTS

AA patients had a trend to a poorer 8-year cause-specific survival (47.9 vs 60.6%) (P = 0.10) compared to C patients with a significant difference seen in stage IIB-IVA disease (34.3 vs 59.5%) (P = 0.04). Several factors correlated with poor outcome were present in the AA group including lower mean hemoglobin levels during RT (P = 0.001), lower median income (P = 0.001), and less frequent intracavitary RT (P = 0.09). In addition, while uncommon in C patients, health problems were major reasons for treatment protraction and inability to undergo intracavitary RT in the AA patients. Multivariate analysis demonstrated that race was not an independent prognostic factor after controlling for difference in patient, tumor, and treatment factors.

CONCLUSIONS

AA cervical cancer patients possess multiple factors that adversely impact upon the efficacy of RT. These findings may add further insight into the observed differences in outcome of cervical cancer patients based on race.

Detection and identification of human papilloma viral DNA, types 16, 18, and 33, by a combination of polymerase chain reaction and a colorimetric solid phase capture hybridisation assay

A colorimetric microplate hybridization assay was developed previously to simplify detection procedures of DNA fragments resulting from polymerase chain reactions (PCR). This format has now been adapted for the simultaneous detection and identification of three human papillomavirus (HPV), types 16, 18 and 33, associated frequently with cervical cancer. This post-PCR detection system uses three type-specific capture oligonucleotides linked covalently to a single microplate well and three type-specific multibiotinylated oligonucleotidic probes for detection. It therefore offers a double specificity; the first is conferred by pairs of primers, specific of each type of virus tested, and the second, by the sets of capture and detection probes which are complementary to internal regions of the amplified DNA fragments. The detection format outperformed agarose gel electrophoresis of amplified DNA products in sensitivity and specificity. The rapidity and simplicity of this hybridisation system would justify its use in routine diagnostic examination of cervical specimens (smears and biopsies).