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

Genotype-specific prevalence of human papillomavirus infection in asymptomatic Peruvian women: a community-based study

OBJECTIVE

To determine the general and genotype-specific prevalence of HPV and to identify potential risk factors for the infection in a population-based screening of Peruvian women.

RESULTS

A total of 524 samples were analyzed by PCR and a total of 100 HPV positive samples were found, of which 89 were high-risk, 19 were probably oncogenic, 9 were low-risk and 27 other HPV types. The 26-35 and 36-45 age groups showed the highest proportion of HPV positive samples with a total of 37% (37/100) and 30% (30/100), respectively. Moreover, high-risk HPV was found in 33.7% of both groups and probably oncogenic HPV in 52.6% and 31.6%, respectively. High-risk HPV were the most frequent types identified in the population studied, being HPV-52, HPV-31 and HPV-16 the most commonly detected with 17.6%, 15.7% y 12.9%, respectively. Demographic characteristics and habits were assessed in the studied population. A total of 62% high-risk HPV were detected in married/cohabiting women. Women with two children showed the highest proportion (33.8%) of high-risk HPV, followed by women with only one child (26.9%). Those women without history of abortion had a higher frequency of high-risk HPV (71.9%), followed by those with one abortion (25.8%).

Sex Worker Health Outcomes in High-Income Countries of Varied Regulatory Environments: A Systematic Review

There is significant debate regarding the regulation of the sex industry, with a complex range of cultural, political and social factors influencing regulatory models which vary considerably between and within countries. This systematic review examined the available evidence on the relationship between different approaches to sex industry regulation in high-income countries, and associated effects on sex worker health status. Objectives included identification of sex worker health outcomes, including sexual health, substance use and experience of stigma and violence. A search was performed electronically in eight scholarly databases which yielded 95 articles which met the criteria for inclusion. Findings suggested that sex workers in legalised and decriminalized countries demonstrated greater health outcomes, including awareness of health conditions and risk factors.

Prevalence and genotype distribution of genital human papillomavirus infection in female sex workers in the world: a systematic review and meta-analysis

BACKGROUND

Female sex workers (FSWs) are amongst the most susceptible groups to acquire human papillomavirus (HPV) infection and consequently, to develop cervical intraepithelial neoplasia and cervical cancer. This is the first systematic review and meta-analysis to provide estimates of the pooled prevalence of HPV infection and the distribution of HPV types among FSWs across the world.

METHODS

Five computerized databases were searched for relevant studies published since the inception date of databases to September 2019. The pooled HPV prevalence was calculated by the random effect model described by DerSimonian-Laird. Subgroup analysis was performed to identify the probable sources of heterogeneity. The meta-analysis was performed using the "Metaprop" function in the R package Meta.

RESULTS

Sixty-two studies involving 21,402 FSWs from 33 countries were included in this meta-analysis, and the pooled HPV prevalence was 42.6% (95% confidence interval (CI): 38.5-46.7%). HPV-16 (10.1, 95% CI: 8.2-12.5%), HPV-52 (7.9, 95% CI: 5.9-10.7%), and HPV-53 (6.0, 95% CI: 4.4-8.1%) were the most common high-risk HPV types identified among FSWs. The pooled estimated prevalence of HPV infection among FSWs before and after 2010 were slightly different, 43.6% (95% CI: 36.1-51.4%) and 41.9% (95% CI: 37.2-46.8%), respectively.

CONCLUSION

Due to the high prevalence of HPV infection, particularly with high-risk types, FSWs have a great susceptibility to the development of cervical and vaginal cancers. Furthermore, they can transmit their infection to their clients, which may result in a high prevalence of HPV and the incidence of HPV-associated malignancies among the general population.

Vaginal and anal human papillomavirus infection and seropositivity among female sex workers in Amsterdam, the Netherlands: Prevalence, concordance and risk factors

BACKGROUND

We studied prevalence, risk factors and concordance of vaginal and anal HPV infection and L1 seropositivity among female sex workers (FSW) in Amsterdam.

METHODS

In 2016, FSW aged ≥18 years having a sexually transmitted infections (STI) consultation were invited to participate. Participation entailed taking vaginal and anal self-swabs. Demographics and sexual behaviour data were collected. HPV DNA was analysed using the SPF10-PCR-DEIA-LiPA25-system-v1. Serum was tested for HPV L1 antibodies using multiplex serology assays. Determinants of vaginal and anal high risk HPV (hrHPV) infection and L1 seropositivity were assessed with logistic regression analyses.

RESULTS

We included 304 FSW; median age was 29 years (IQR 25-37). Vaginal and anal hrHPV prevalence were 46% and 55%, respectively. HrHPV L1 seropositivity was 37%. Vaginal-anal hrHPV concordance was strong, but no significant association between vaginal or anal hrHPV infection and seropositivity was found. Having had anal sexual contact was not associated with anal hrHPV infection (P = 0.119).

DISCUSSION

Vaginal and anal hrHPV prevalence is high among FSW in Amsterdam, the Netherlands. Promotion of HPV vaccination, preferably at the beginning of the sex (work) career, may be a useful prevention method against hrHPV infection and disease.

Prevalence of High-Risk Human Papillomavirus (HR-HPV) Genotypes and Multiple Infections in Cervical Abnormalities from Northern Xinjiang, China

Multiple human papillomavirus (HPV) genotypes often coexist within the cervical epithelia and are frequently detected together in various grades of the cervical neoplasia. To date, only a few reports exist on multiple HPV infections of HPV in Xinjiang Uygur Autonomous Region (XUAR). In the present study, we investigated the prevalence of High-Risk HPV (HR-HPV) genotypes and multiple infections. Cervical cytology samples were collected from 428 women who presented cervical abnormalities. Genotyping of HPV was performed by polymerase chain reaction–sequencing based typing (PCR-SBT) using consensus primers and specific primers. Of them, 166 samples were positive for HPV according to PCR results using the consensus primers. These samples contained cervical abnormalities enriched with inflammation (n = 107), cervical intraepithelial neoplasia (CIN) I (n = 19), CINII-III (n = 9) and cervical cancer (n = 31). Of the 166 HPV positive samples as determined by PCR analysis, 151 were further typed by PCR-SBT using 19 pairs of genotype-specific primers. Using this method, 17 different HR-HPV genotypes were identified. The most frequently observed HPV genotypes were HPV16 (44.0%, 73/166), 53 (28.9%, 48/166), 52 (25.3%, 42/166), 58 (22.3%, 37/166) and 35 (17.5%, 29/166). The proportions of single and multiple infections in the HPV-positive specimens were 34.9% and 65.1%, respectively. Multiple HPV types were most prevalent in the inflammatory state (63.0%), followed by cervical cancer (24.1%), CINI (11.1%), and CINII-III (1.9%). The results of our data analyses suggested that i) multiple HPV infection is not necessarily correlated with the severity of cervical abnormalities; and ii) among the multiple HPV infections, double infections combined with HPV16 is the most common. In addition, L1 full-length sequences of the top five high-risk HPV genotypes were amplified and sequenced. According to the L1 sequence of the epidemic genotypes that were amplified, we found that these genotypes contained the sequence point mutation, and that some of these genotypes further showed amino acid modifications. These results provide a basis for the construction of a polyvalent vaccine that is suitable for use in the XUAR, even in economically challenged communities located in China.

Prevalence of high-risk human papillomavirus and abnormal pap smears in female sex workers compared to the general population in Antwerp, Belgium

Background

Although female sex workers (FSWs) are a well-known high-risk group for Human Papillomavirus (HPV) infections, few tailored intervention programmes for HPV have been established worldwide. The lack of reliable data on the prevalence of HPV and related cervical lesions hampers the establishment of evidence-based intervention programmes.

The objectives of this study were to describe the prevalence of high-risk Human Papillomavirus (hrHPV) infections and abnormal pap smears in FSWs compared to a control group in Antwerp, Belgium.

Methods

HPV genotyping and cytology data were analysed from routine Pap smear tests that were collected from both FSWs and the general population (1334 samples for each group) between June 2006 and June 2010. Within the laboratory database, all FSWs were matched 1:1 for age and testing date to determine the ORs of hrHPV genotypes, DNA and cytology outcome.

Results

The prevalence of hrHPV DNA in FSWs was 41.7 % compared to 19.8 % in the age-matched controls with an overall OR of 2.8 (95 % CI: 2.3–3.4). Significant differences were observed in all age groups, and the most significant differences were observed in the cohort under 21 years of age (prevalence of 64.4 % in FSWs versus 14.8 % in controls; OR 10.3 (95 % CI: 5.0–21.2). Significantly more cervical lesions were observed in FSWs, particularly in the 17- to 21-year old age group (OR for LSIL or HSIL: 10.3 (95 % CI: 3.2–33.8). In both groups, HPV 16 was the most prevalent at 12.1 and 6.6 % in the FSW and control groups, respectively. HPV 18 was the 8^th and 7^th most frequent genotype at 5.0 and 2.5 % in the FSW and control groups, respectively.

Conclusions

FSWs have a significantly higher prevalence of hrHPV and more abnormal Pap smears than does the general population in Antwerp, Belgium. The hrHPV prevalence in FSWs is similar to that reported in the literature. The need for tailored intervention programmes should be investigated further.

Cervical Infection With Vaccine-Associated Human Papillomavirus (HPV) Genotypes as a Predictor of Acquisition and Clearance of Other HPV Infections

BACKGROUND

Recent birth cohorts vaccinated against human papillomavirus (HPV) may be protected against up to 4 genotypes (HPV-6, -11, -16, and -18). If natural competition exists between these and other HPV types, then the prevalence of other types may increase after vaccination.

METHODS

Cohort information from 3 studies was used to compare acquisition and clearance of 30 different HPV types (individually and grouped by species), according to infection status with vaccine-targeted types at baseline and the time of the index infection, respectively. Hazard ratios (HRs) were adjusted for predictors of multiple-type infection.

RESULTS

Among 3200 females across all studies, 857 were infected with HPV at baseline, and 994 acquired new infections during follow-up. Females infected with HPV-16 were at higher risk of acquiring other α-9 HPV types (HR, 1.9; 95% confidence interval [CI], 1.2-3.0) but at similar risk of clearing existing α-9 HPV infections (HR, 0.9; 95% CI, .7-1.3). Females infected with vaccine-targeted types were generally at higher risk of acquiring additional types (HRs, > 1.0) and at equal risk of clearing existing infections. Accounting for multiple comparisons, none of the HRs of < 1.0 or >1.0 were statistically significant in our analyses of acquisition or clearance.

CONCLUSIONS

Vaccine-targeted HPV types do not appear to compete with other types, suggesting that HPV type replacement is unlikely to occur.

Human papillomavirus prevalence in South African women and men according to age and human immunodeficiency virus status

BACKGROUND

Both cervical cancer and human immunodeficiency virus (HIV) are major public health problems in Sub-Saharan Africa. The objectives of the study were to investigate human papillomavirus (HPV) prevalence according to age, HIV status and gender.

METHODS

Participants were 208 HIV-negative women, 278 HIV-positive women, 325 HIV-negative men and 161 HIV-positive men between the ages of 18-66 years. HPV types were determined in cervical and penile cells by Roche Linear Array HPV genotyping assay.

RESULTS

HPV prevalence was 36.7 % (76/207; 95 % confidence intervals (CI): 30.4-43.4 %) in HIV-negative women, with the highest prevalence of 61.0 % (25/41; 95 % CI: 45.7-74.4 %) in women aged 18-25 years. HPV prevalence was 74.0 % (205/277; 95 % CI: 68.5-78.8 %) in HIV-positive women, with the highest prevalence of 86.4 % (38/44; 95 % CI: 72.9-94.0 %) in women aged 18-25 years. HPV prevalence was found to decrease with increasing age in HIV-negative women (P = 0.0007), but not in HIV-positive women (P = 0.898). HPV prevalence was 50.8 % (159/313; 95 % CI: 45.3-56.3 %) in HIV-negative men, with the highest prevalence of 77.0 % (27/35; 95 % CI: 60.7-88.2 %) in men aged 18-25 years. HPV prevalence was 76.6 % (121/158; 95 % CI: 69.2-82.9 %) in HIV-positive men, with the highest prevalence of 87.5 % (7/8; 95 % CI: 50.8-99.9 %) in men 18-25 years of age. HPV prevalence was found to decrease with increasing age in HIV-negative men (P = 0.004), but not in HIV-positive men (P = 0.385). HIV-positive women had a significantly higher prevalence of one or more HPV type(s) in the bivalent (HPV-16/18: 20 % 55/277, 9 % 12/207; P <0.001), quadrivalent (HPV-6/11/16/18: 26 % 71/277, 12 % 24/207; P = 0.001) and nonavalent vaccine (HPV-6/11/16/18/31/33/52/56/58: 65 % 181/277, 24 % 50/207; P <0.001) compared to HIV-negative women. Similar observation were observed in men for bivalent (20 % 32/158, 10 % 30/313; P = 0.001), quadrivalent (35 % 56/158, 13 % 41/313; P <0.001) and nonavalent vaccine (75 % 119/158, 28 % 87/313; P <0.001).

CONCLUSIONS

This study demonstrated high HPV prevalence among HIV-positive women and men in all age groups. The high prevalence of HPV types found in bivalent, quadrivalent and nonavalent vaccines in South African HIV-positive and HIV-negative women and men demonstrate that this population will greatly benefit from current HPV vaccines.

Human papillomavirus infection and cervical dysplasia in female sex workers in Northeast China: an observational study

Background

Women having multiple sex partners are reportedly at an increased risk of HPV infection. However, the prevalence and risk factors of HPV infection in female sex workers (FSWs) vary considerably across racial/ethnic, socioeconomic, and geographic groups. This study aimed to determine the prevalence and risk factors of HPV infection in FSWs in Northeast China.

Methods

A total of 309 FSWs identified and approached through a local police office and 1000 healthy subjects from a single factor undergoing annual gynecological examinations in Shenyang were recruited. A liquid-based ThinPrep Pap test and the Hybrid Capture II-based high-risk HPV DNA test, with or without a colposcopic examination, were performed on both FSWs and control subjects. Data on HPV infection and histological and cytological lesions of the cervix were obtained and analyzed. A questionnaire survey was administered to all 309 FSWs with their socio-demographic and behavioral information collected. The association of various socio-demographic and behavioral variables with HPV infection was assessed.

Results

HPV was significantly more prevalent in FSWs (61.90 %) than in healthy control subjects (21.00 %) (P < 0.01), so were cervical lesions (P < 0.01). HPV prevalence in our sample of FSWs fell in the upper range of reported values in FSWs across different countries, and was similar to that for FSWs in the southeast Chinese city of Huzhou but higher than that for FSWs in southwest China, Guangxi, as compared with data from other studies within China. HPV infection in FSWs was significantly associated with the age at first sexual intercourse (OR 0.699, 95 % CI 0.492–0.992) and post-menopause (OR 2.928, 95 % CI 1.099–7.800) (P < 0.05).

Conclusions

FSWs are at a substantially high risk of HPV infection and cervical dysplasia development as compared with healthy control subjects in Shenyang, China. Age of first sexual intercourse and post-menopause are two independent risk factors for HPV infection in this special group of population. Intensified and coordinated efforts from government, public health sector, communities and families are needed to reduce the risk of HPV infection in this specific group of population.

Cervical HPV Infection in Female Sex Workers: A Global Perspective

Introduction:

Approximately 291 million women worldwide are HPV DNA carriers. Studies have indicated that having multiple sexual partners may lead to higher HPV transmission. Thus female sex workers (FSWs) may be at greater risk of infection compared to the general population. Herein we review publications with data on FSW cervical HPV test results. We also examine variations of HPV prevalence and risk behaviors by region. Knowledge of prevalent HPV types in FSWs may lead to improved prevention measures and assist in understanding vaccination in high-risk groups.

Methods:

We conducted a review of the literature by searching PUBMED using the terms “prostitution” or “female sex workers”, “human papillomavirus” or “HPV”, and “prevalence” or “PCR” to find articles. We excluded studies without HPV testing or HPV type specific results, or unconventional HPV testing.

Results:

A total of 35 peer-reviewed publications were included in our review. High risk HPV types 16 and 18 ranged from 1.1-38.9‰ in prevalence. In addition to high-risk HPV types, newer studies reported non-carcinogenic HPV types also of high prevalence. The most prevalent HPV types reported among FSWs included HPV 6 (11.5%), 16 (38.9%), 18 (23.1%), 31 (28.4%), 52 (32.7%), and 58 (26.0%).

Conclusions:

Female sex workers have an overall high prevalence of HPV infection of high-risk types as evident through various testing methods. FSWs are thought to be at increased risk of cervical cancer because of high HPV exposure. This highlights the need for HPV and cervical prevention campaigns tailored to FSWs.

Human papillomavirus infections among Hungarian female sex workers

The purpose of this study was to assess the human papillomavirus (HPV) prevalence in cervical, oropharyngeal and anal samples of the high-risk population of Hungarian female sex workers (FSWs). HPV testing of swab specimens from FSWs (n = 34) using polymerase chain reaction (PCR) methodology was performed. Results were compared with control group (n = 52) matched for age. Questionnaires were used to obtain data regarding participants' sexual behaviour. Data were analysed using SPSS. HPV DNA was detected in at least one location in a great majority of FSWs (82.4%), compared with 46.2% of the general female population (P < 0.05). Both the cervical and the anal samples of sex workers showed higher infection rates than those of controls (64.7% vs. 34.6% and 50.0% vs. 15.4%, respectively, P < 0.05). High-risk HPV prevalence was also significantly higher in sex workers (55.9% vs. 25.0%, P < 0.05). A significantly higher proportion of FSWs had a history of genital warts (26.5% vs. 3.8%, P < 0.05). The results suggest that condom use may not result in adequate protection from HPV infection. The high infection rates among FSWs should be viewed as a priority group for HPV and cervical cancer prevention programmes since they are sources of HPV infection for the general population.

Prevalence and determinants of high-risk human papillomavirus infection in women from a sub-Saharan African community

BACKGROUND

Human papillomavirus infection with high-risk types (HR-HPV) is a necessary cause of cervical cancer, the most common malignancy among sub-Saharan African women. Little is known about prevalence of cervical HR-HPV infection in this region.

METHODS

A cross-sectional study of 1528 women examined the determinants of HR-HPV infection among women in Kinshasa, Democratic Republic of Congo. Information was collected on sociodemographic, reproductive, lifestyle characteristics, and health-seeking behaviors. Cervical samples were tested for HPV-DNA by Hybrid Capture 2. Unconditional logistic regression identified predictors of HPV positivity.

RESULTS

HR-HPV prevalence was 12.5% in all women and 8.7% in women with normal cytology. Prevalence was highest (18.3%) in individuals <35 years of age and gradually decreased with age. Excess HR-HPV infection risk was observed in women who were smokers (odds ratio [OR] = 1.60; 95% confidence interval [CI]: 1.11-2.31), divorced/separated (OR = 1.60; 95% CI: 1.11-2.32), in polygamous marriages (OR = 1.28; 95% CI: 0.90-1.82), using medical contraceptives (OR = 2.40; 95% CI: 1.20-4.80), and who preferred male physicians (OR = 1.90; 95% CI: 1.20-3.05). A statistically marginal increase was found in women whose partners had sex with prostitutes (OR = 2.40; 95% CI: 0.72-8.01). A higher standard of living was associated with reduced risk.

CONCLUSION

HR-HPV positivity was associated with behavioral and sexual characteristics thought to affect risk of new infections and immune function. However, HPV prevalence did not correlate with numbers of sex partners, possibly because of a high HPV infection rate per sexual contact or because subjects were older than 30 years. Our study should assist in designing strategies for control of cervical cancer in this low-resource, high cervical cancer risk setting in sub-Saharan Africa.

Human papillomavirus prevalence, cervical abnormalities and risk factors among female sex workers in Lima, Peru

Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infection. Questionnaires were administered to 200 FSWs aged 18-26 years in Lima, Peru, to gather risk behaviours, and cervical swab samples were collected for Pap smears and HPV DNA testing as part of a longitudinal study. Participants reported a median of 120 clients in the past month, and 99.2% reported using condoms with clients. The prevalence of any HPV in cervical samples was 66.8%; 34 (17.1%) participants had prevalent HPV 16 or 18, and 92 (46.2%) had one or more oncogenic types. Fifteen women had abnormal Pap smears, 13 of which were HPV DNA positive. Fewer years since first sex was associated with oncogenic HPV prevalence in a model adjusted for previous sexually transmitted infection (STI) status and condom use with partners (prevalence ratio = 0.77, 95% confidence interval [CI] = 0.60-0.97). Our data confirm the high rates of HPV transmission among FSWs in Peru, highlighting the need for early and effective strategies to prevent cervical cancer.

Prevalence and genotype distribution of human papillomavirus infection among female sex workers in Guangxi, China: implications for interventions

Human papillomavirus (HPV) infection is a major public health concern in women, but information on HPV among female sex workers in China is limited. The aim of the study was to estimate the prevalence and genotype distribution of HPV infection among female sex workers in two cities in Guangxi, China. A total of 811 female sex workers were recruited from venues between July and September of 2009. Data on socio-demographic and behavior characteristics were collected, and cervical swabs were collected to determine HPV infection and genotype distribution. The overall prevalence of infection with any HPV type was 38.9%. HPV type 52 was the most prevalent type with prevalence of 11%, followed by HPV types 16, 58, 53, and CP8304, with prevalences of 6.5%, 5.7%, 5.6%, and 4.8%, respectively. HPV 16 or 18 accounted for 23.2% of all HPV positive cases. Age group <20 years was significantly associated with infection of the high-risk and multiple types of HPV infection. A higher prevalence of multiple HPV infection was observed among female sex workers from the outdoor venues (14.0%; 95%CI, 10.6%-17.3%). These findings have important implications for developing HPV prevention programs including HPV vaccination in female sex workers.

Epidemiology and burden of HPV infection and related diseases: implications for prevention strategies

Human papillomavirus (HPV) infection is a necessary, although not sufficient cause of cervical cancer. Globally, HPV infection accounts for an estimated 530,000 cervical cancer cases (~270,000 deaths) annually, with the majority (86% of cases, 88% of deaths) occurring in developing countries. Approximately 90% of anal cancers and a smaller subset (<50%) of other cancers (oropharyngeal, penile, vaginal, vulvar) are also attributed to HPV. In total, HPV accounts for 5.2% of the worldwide cancer burden. HPVs 16 and 18 are responsible for 70% of cervical cancer cases and, especially HPV 16, for a large proportion of other cancers. Prophylactic vaccination targeting these genotypes is therefore expected to have a major impact on the burden of cervical cancer as well as that of other HPV-related cancers. Over the past 50 years, organized or opportunistic screening with Papanicolaou (Pap) cytology has led to major reductions in cervical cancer in most developed countries. However, due to lack of resources or inadequate infrastructure, many countries have failed to reduce cervical cancer mortality through screening. HPV DNA testing recently emerged as a likely candidate to replace Pap cytology for primary screening. It is less prone to human error and more sensitive than Pap in detecting high-grade cervical lesions. For countries with national vaccination programs, HPV testing may also serve as a low cost strategy to monitor long term vaccine efficacy. Introduction of well organized vaccination and screening programs should be a priority for all countries. Increased support from donors is needed to support this cause.

Prevalence of human papillomavirus infection among female sex workers in Bulgaria

The present study estimates the prevalence and risk factors of human papillomavirus (HPV) infection among female sex workers (FSWs) in Bulgaria. HPV DNA was detected by polymerase chain reaction (PCR) in 43.4% of FSWs. HPV16 was the most common type, found in 17.0% of samples, followed by HPV31 (9.4%). Age and smoking were associated with a significantly greater risk of being infected. The results of this study indicate that FSWs in Bulgaria are at increased risk for cervical cancer and represent an important source of HPV infection for the general population in the country. They should be considered as a priority group in cervical cancer control programmes.

Oncogenic HPV among HIV infected female population in West Bengal, India

BACKGROUND

Prevalence of both cervical cancer and Human Immunodeficiency Virus (HIV) infection are very high in India. Natural history of Human Papilloma Virus (HPV) infection is known to be altered in HIV positive women and there is an increased possibility of persistence of HPV infections in this population. Therefore, this study was conducted to understand the epidemiology and circulating genotypes of oncogenic HPV among HIV positive and negative female population in West Bengal, India.

METHODS

In this hospital-based cross-sectional study, 93 known HIV positive females attending a pre-ART registration clinic and 1106 HIV negative females attending a Reproductive and Child Health Care Clinic were subjected to study. Cervical cell samples collected from the study population were tested for the presence of HPV 16, 18 using specific primers. Roche PCR assay was used to detect other specific HPV genotypes in the cervical cells specimens of HIV positive cases only.

RESULTS

Prevalence of HPV 16, 18 among HIV positive females (32.2%; n = 30) was higher than HIV negative females (9.1%; n = 101). About 53% (23/43) of cases with oncogenic HPV were infected with genotypes other than 16, 18 either as single/multiple infections. HPV 18 and HPV 16 were the predominant genotypes among HIV positive and HIV negative subjects respectively. Oncogenic HPV was not found to be associated with age and duration of sexual exposure. But the presence of HIV was found to a statistically significant predictor oncogenic HPV.

CONCLUSION

The currently available HPV vaccines offer protection only against HPV 16 and 18 and some cross- protection to few associated genotypes. These vaccines are therefore less likely to offer protection against cervical cancer in HIV positive women a high percentage of who were infected with non-16 and non-18 oncogenic HPV genotypes. Additionally, there is a lack of sufficient evidence of immunogenicity in HIV infected individuals. Therefore, prevention of cervical cancer in HIV positive women must be focused towards early detection of oncogenic HPV & cervical cytological abnormality followed by an appropriate treatment.

Prevalence of human papillomavirus infection and genotype distribution among high-risk Korean women for prospecting the strategy of vaccine development

We investigated the prevalence of human papillomavirus (HPV) infection and the distribution of high-risk HPV genotypes among 2,308 high-risk Korean women to predict how much the current prophylactic HPV vaccines might affect the prevention of cervical cancer in Korea. HPV DNA was detected in 939 women (40.7%) but only one-third of women were positive for HPV-16 and/or HPV-18, the genotypes used for developing the HPV vaccines. Thus, the development of area-specific HPV vaccines based on dominant HPV genotypes in our country is needed for preventing HPV infection and the development of premalignant lesions in the cervix of Korean women.

Human papillomavirus infection and risk factors in a cohort of Tuscan women aged 18-24: results at recruitment

Background

There is conclusive evidence that human papillomavirus (HPV) infections of the cervix are a necessary cause of cervical cancer. In Italy there are consistent data of HPV prevalence in women aged 25 - 64 years, but there is limited data for younger women. The objective of this on-going 3-year prospective cohort study is to investigate the prevalence, acquisition, clearance and persistence of HPV infections in young Tuscan women and the risk factors correlated with such events.

Methods

One thousand and sixty-six women aged between 18 and 24 years were enrolled and received an initial HPV test. They were asked to return to the clinic over the study period for further tests every 12 months, if their HPV HR result was negative, or every 6 months, if positive. Additionally, women with an HPV positive result were given a cytological examination and if the cytological diagnosis was ASC-US or more severe, only women with HPV HR, were referred for colposcopy.

Results

We present here data for the enrolment phase of the study. At baseline, within the study sample, just under 30% of women were infected by HPV and 19.3% of women were infected with oncogenic types. A relationship was highlighted between HPV infection, number of sexual partners (in particularly in the last 3 years) and the lifetime number of partner's partners. Condom use showed a slight protective effect in univariate analysis but these data were not statistically significant in multivariate analysis. The association between HPV infection and demographic and behavioural variables were tested by crude odds ratio (OR). Multivariate logistic regression was applied to compute the adjusted odds ratios.

Conclusions

The prevalence of oncogenic HPV types was high in young Tuscan women. The 3-year follow-up of this cohort may provide a better understanding of the processes of acquisition, clearance and persistence of infection and the correlated risk factors.

Prevalence and risk factors of high-risk human papillomavirus in female sex workers in Spain: differences by geographical origin

OBJECTIVE

To study the influence of socioeconomic variables, lifestyles, and sexual behaviors on the prevalence of high-risk human papillomavirus (HR-HPV) infection in female sex worker (FSW) according to their geographic origin in Alicante, Spain.

METHODS

This is a cross-sectional study of 549 FSW attending an AIDS information and prevention center from May 2003 to December 2004. Face-to-face interviews were carried out. HR-HPV was determined through Digene HR-HPV Test. Hybrid Capture II-positive samples (Digene Corp., Gaithersburg, MD) for PCR were directly sequenced. Data were analyzed using multiple logistic regression.

RESULTS

HR-HPV prevalence was 28% in Spaniards, 32% in Latin Americans, 32% in Eastern Europeans, 16% in sub-Saharan Africans, and 65% in North Africans (p=0.04). Lower HR-HPV prevalence was associated with higher age, higher education, and higher body mass index (BMI) (p values for trend<0.05). In multivariate analyses, the effects of geographical origin, age, and education were maintained, together with time in sex work; women engaged for >1 year had a lower HR-HPV prevalence (OR 0.57, 95% CI 0.36-0.91) compared with those engaged <1 year. HR-HPV-16 was the most common type (n=23, 24%), followed by HR-HPV-18 and HR-HPV-31, (n=11, 11%), respectively.

CONCLUSIONS

HR-HPV prevalence is very high in FSW and varies by geographic origin. Women of younger age and lower education level and those engaged in sex work for <1 year showed the highest prevalence, making them a priority group for cervical cancer prevention programs.

[How did I contract human Papillomavirus (HPV)?]

More than 120 genotypes have been identified among the Papillomavirus (HPV) family. These viruses are ubiquitary with skin or mucous membrane tropism and cause various pathologies from wart to neoplasia. HPV family is classified according to their tropism. Genital HPV infection is considered as the most frequent sexually transmitted disease in the world. Seventy-five percent of women will be in contact with HPV at least one time in their life. HPV is usually transmitted through direct skin-to-skin contact, more often during penetrative genital contact. Other types of genital contact in the absence of penetration can lead to HPV infection, but those routes of transmission are much less common than sexual intercourse. However, virgins (<2 % of cases) and young children can present HPV infection, suggesting other routes of transmission than sexual intercourse. HPV infection could occur during delivery; vaginal deliveries appear to promote this transmission in comparison with cesarean section. But cesarean section do not completely protect against contamination risk. In utero, vertical transmission has been suggested by different studies but with lack of evidence. HPV infection can be detected on inanimate objects, such as clothing or environmental surfaces. However, transmission is not known to occur by this route. More detailed knowledges of the transmission route of HPV infection will enable to get prevention more effective.

Exposure to high-risk genital human papillomavirus and its association with risky sexual practices and laboratory-confirmed chlamydia among African-American women

BACKGROUND

Genital human papillomavirus (HPV) is the most common sexually transmitted infection (STI) in the United States and African-American women have the highest prevalence of high-risk HPV. This study examined exposure to high-risk HPV in African-American women and its relation to risky sexual practices and laboratory-confirmed chlamydia.

METHODS

A sample of 665 African-American women between 18 and 29 years old, recruited from October 2002 to March 2006 in Atlanta, Georgia, completed an Audio Computer-Assisted Survey Interview assessing sociodemographics, health practices, and risky sexual practices. Participants also provided vaginal swab specimens assayed for STIs and high-risk HPV.

RESULTS

The overall prevalence of high-risk HPV was 38.9%. Among women 18 to 24 years old, it was 42.4%; it was 31% among women 25 to 29 years old. Age-stratified logistic regression analyses indicated that women between the ages of 18 and 29 and 18 and 24 who had multiple male sexual partners did not use a condom during their last casual sexual encounter and tested positive for chlamydia were significantly more likely to test positive for high-risk HPV. Women 18 to 24 years old who reported having a casual or risky sexual partner were significantly more likely to test positive for high-risk HPV. No significant correlates were identified among women 25 to 29 years old.

CONCLUSIONS

Programs should aim to educate, decrease risky sexual practices, and increase screening and treatment for STIs among women with high-risk HPV infections. HPV vaccination recommendations for young adult African-American women warrant special consideration.

Prevalence and predictors of high-risk human papillomavirus infection in a population-based sample of women in rural Uganda

High-risk genital human papillomavirus (HPV) infection is aetiologically linked to cervical cancer; however, data on the prevalence and determinants of high-risk HPV infection in Uganda are limited. We conducted a population-based cross-sectional survey among 18-49-year-old women in rural Southwest Uganda. The primary outcome was presence or absence of high-risk HPV DNA (for genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 or 68) in the genital secretions as determined by HPV DNA Hybrid Capture 2 assay (Digene Corp, Beltsville, MD, USA). In 314 women who participated, the prevalence of high-risk HPV was 17.2% (54/314; 95% confidence interval [CI]: 13-21). Older women had a lower proportion of high-risk HPV infection; with a 9% decrease in the odds ratio (OR) of high-risk HPV infection per year increase in age (OR = 0.91; 95% CI: 0.86, 0.96). The odds of detecting high-risk HPV infection was higher among women who were previously tested positive for HIV (OR = 12.1; 95% CI: 2.8, 52.3). In this population of rural Ugandan women, the prevalence of high-risk cervical HPV infection was high. Information on predictors of high-risk HPV infection and intention to receive a vaccine can guide future immunization initiatives for young sexually active women.

Oncogenic human papilloma virus and cervical pre-cancerous lesions in brothel-based sex workers in India

A community-based cross-sectional study was conducted in brothel-based sex workers of West Bengal, Eastern India, to determine their oncogenic human papillomavirus (HPV) status and the presence of pre-cancerous lesions. A total of 229 sex workers from three districts of West Bengal participated in the study. All the study participants were interviewed with the aid of a pre-tested questionnaire to determine their sociodemographics, risk behaviour and risk perceptions after obtaining informed verbal consent. The interview was followed by collection of cervical cells from all participants using a disposable vaginal speculum and cervical cytobrush. Oncogenic HPV DNA was detected by real-time polymerase chain reaction (PCR). A simultaneous Papanicolaou test ('Pap smear') was performed to detect cervical cytological abnormalities. Overall, the prevalence of oncogenic HPV was found to be 25% (58/229) among the studied population. A subset (n=112) of the sample was tested separately to determine the existence and magnitude of HPV genotypes 16 and 18. The results showed that genotype 16 was prevalent in 10% (11/112), genotype 18 in 7% (8/112) and both genotype 16 and 18 in 7% (8/112). The HPV prevalence rate showed a decreasing trend with age, being 71.4% in the 10-19 years age group, 32.3% in the 20-29 years age group, 18.3% in the 30-39 years age group and 2.5% in the >or=40 years age group (statistically significant differences, P1 year, respectively. This difference was found to be statistically significant both by univariate and multivariate analysis. In this study, it was observed that sex workers with an average number of daily clients of six or more had an HPV prevalence of 67% (n=6), those with four to five clients had a prevalence of 45% (n=9), those with two to three clients had a prevalence of 30% (n=34) and those with one or less clients had a prevalence of 10% (n=9) (statistically significant differences, P=0.00003). Multivariate analysis showed a statistical association only with a duration of sex work of or=101 (OR=2.5; 95% CI 1.3-5). Regarding pre-cancerous lesions, 2 of 229 sex workers showed the presence of a low-grade squamous intraepithelial lesion along with high-risk HPV. Thus, 1% of the studied population suffer from a pre-cancerous lesion caused by high-risk HPV. This study concludes that young sex workers are particularly vulnerable to high-risk HPV, similar to human immunodeficiency virus (HIV). The observation of older sex workers relatively free from HPV supports the view of acquired immunity against HPV, which needs to be studied in-depth further. There is a need for a suitable community-based intervention programme targeted towards sex workers, with special reference to younger sex workers, for control and prevention of HPV and cervical cancer. Vaccination against HPV for newly entrant sex workers may be an important component for a successful intervention programme.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

[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.

Human papillomavirus infection in women attended at a cervical cancer screening service in Natal, Brazil

We analyzed cervical specimens of 202 women, aged 15 to 64 years, attended at Luis Antonio Hospital, Natal, Brazil, to determine the prevalence of HPV and identify the more frequent genotypes and risk factors for HPV infection in women attended at a cervical cancer screening service. Two specimens were collected from each patient: one for cytological examination and the other to detect HPV DNA by PCR, and typing by dot blot hybridization. A total of 54.5% of the sample had normal cytology and 45.5% had cytological alterations. HPV was detected in 24.5% of the cytologically normal women and in 59.8% of those with altered cytology. Both single and double HPV infection increased the likelihood of cytological alterations. Thirteen types of HPV were identified, most of which were high risk. HPV 16 was the most prevalent single-type infection, followed by HPV 58. The most frequent double infection was the association between HPV 56 and 57. The prevalence of HPV in cytologically normal women was greater than that reported for countries on all the continents except Africa. The inverse was observed in women with cytological alterations. The distribution of HPV types was similar to that described for the Americas, with some differences. Multiple sexual partners was the only risk factor showing an association with the presence of HPV infection.

Sexually transmissible infections among female sex workers: an international review with an emphasis on hard-to-access populations

Background: Women who work commercially in sex work (female sex workers [FSW]) are considered a high-risk group for sexually transmissible infections (STI), yet the level of reported pathogens varies in studies around the world. This study reviewed STI rates reported in 42 studies of FSW around the world published between 1995 and 2006 and analysed the trends and types of populations surveyed, emphasising difficult to access FSW populations. Methods:Studies were retrieved by PUBMED and other search engines and were included if two or more pathogens were studied and valid laboratory methods were reported. Results: The five most commonly assessed pathogens were Neisseria gonorrhea (prevalence 0.5–41.3), Chlamydia trachomatis (0.61–46.2), Treponema pallidum (syphilis; 1.5–60.5), HIV (0–76.6), and Trichomonas vaginalis (trichmoniasis; 0.11–51.0). Neisseria gonorrhea and C. trachomatis were the most commonly tested pathogens and high prevalence levels were found in diverse areas of the world. HIV was highly prevalent mostly in African countries. Although human papillomavirus infection was surveyed in few studies, prevalence rates were very high and its aetiological role in cervical cancer warrant its inclusion in future FSW monitoring. Hard-to-access FSW groups tended to have higher rates of STI. Conclusions: The five most commonly detected pathogens correspond to those that are highly prevalent in the general population, however there is an urgent need to develop rapid testing diagnostics for all five pathogens to increase prevention and treatment, especially in outreach programs to the most vulnerable groups among FSW.

Cytologic diagnosis of atypical squamous cells of undetermined significance in perimenopausal and postmenopausal women

BACKGROUND

The authors have noted that in cervical cytology specimens from perimenopausal and postmenopausal women, the diagnosis of atypical squamous cells of undetermined significance (ASC-US), as defined in the Bethesda system, is often not associated with a clinically evident lesion on follow-up. Reflex human papillomavirus (HPV) testing provides an opportunity to distinguish cytologic features of significance from those within the spectrum of benign cellular change in this age group.

METHODS

Liquid-based preparations that were diagnosed as ASC-US between January 2003 and July 2005 at Emory University Hospital were identified from the computer files. The results of HPV-DNA testing were recorded. Two hundred four Papanicolaou tests from perimenopausal women (n = 81, 40-49 years) and postmenopausal women (n = 123, >50 years) were reviewed in a blinded fashion.

RESULTS

HPV-DNA results were available for 903 of 1044 patients diagnosed as ASC-US. Overall, 323 results (35.8%) were positive, 510 results (56.6%) were negative, and 70 results (7.8%) were indeterminate. In addition, 73% of ASC-US specimens in patients aged > or =40 years were negative for HPV DNA. The HPV-DNA detection rate dropped from 60% in the group ages 10 to 19 years to approximately 18% in the group aged >50 years. A review of HPV-negative cases in the group aged >40 years showed squamous cells with random nuclear enlargement and slight hyperchromasia that likely were interpreted as ASC-US (based on the cells that were dotted by the original reviewer). Nuclear grooves were frequent in these nuclei; and cytoplasmic halos, when present, usually were perinuclear.

CONCLUSIONS

HPV-DNA detection in cervical cytology specimens has an inverse relation to patient age. A diagnosis of ASC-US in perimenopausal and postmenopausal women is likely to result in a negative HPV-DNA test in a significant proportion of patients. Enlarged nuclei with nuclear grooves and slight hyperchromasia are possibly the cause of ASC-US overdiagnosis in this age group.

Human papillomavirus status and cervical abnormalities in women from public and private health care in Rio de Janeiro State, Brazil

This article reports the HPV status and cervical cytological abnormalities in patients attended at public and private gynecological services from Rio de Janeiro State. It also comments the performance of each HPV DNA tests used. A set of 454 women from private health clinics was tested by routine Capture Hybrid II HPV DNA assay. Among these, 58.4% presented HPV and nearly 90% of them were infected by high risk HPV types. However, this group presented few premalignant cervical lesions and no invasive cervical cancer was registered. We also studied 220 women from low income class attended at public health system. They were HPV tested by polymerase chain reaction using My09/11 primers followed by HPV typing with E6 specific primers. The overall HPV prevalence was 77.3%. They also showed a high percentage of high squamous intraepithelial lesion-HSIL (26.3%), and invasive cervical carcinoma (16.3%). HPV infection was found in 93.1% and 94.4% of them, respectively. The mean ages in both groups were 31.5 and 38 years, respectively. In series 1, HPV prevalence declined with age, data consistent with viral transient infection. In series 2, HPV prevalence did not decline, independent of age interval, supporting not only the idea of viral persistence into this group, but also regional epidemiological variations in the same geographic area. Significant cytological differences were seen between both groups. Normal and benign cases were the most prevalent cytological findings in series 1 while pre-malignant lesions were the most common diagnosis in the series 2. HPV prevalence in normal cases were statistically higher than those from series 1 (p<0.001), indicating a higher exposure to HPV infection. Women from both samples were referred for previous abnormal cytology. However, socio-demographic evidence shows that women from series 1 have access to treatment more easily and faster than women from series 2 before the development of pre-malignant lesions. These data provides baseline support for the role of social inequalities linked to high risk HPV infection leading to cervical cancer. Broadly screening programs and the development of safe and effective vaccines against HPV would diminish the toll of this disease that affect mainly poor women.

Infectious Agents

There is substantial evidence that infectious agents play a causal role in a variety of human malignancies. These cancers include the liver, cervix, stomach, nasopharynx, bladder, and bile duct as well as Kaposi sarcoma (KS) and several lymphomas. This chapter summarizes the biological and epidemiologic features of each of the major oncogenic infections, beginning with the viruses, followed by H. pylori, and with a brief summary of the relevant parasites.

The epidemiology of genital human papillomavirus infection

Clinical and subclinical human papillomavirus (HPV) infections are the most common sexually transmitted infections in the world, and most sexually-active individuals are likely to be exposed to HPV infection during their lifetimes. More than 40 genotypes of HPV infect the epithelial lining of the anogenital tract and other mucosal areas of the body; of these, 13-18 types are considered to be high-oncogenic risk HPV types (HR-HPV). Persistent infection with HR-HPVs is now unequivocally established as a necessary cause of cervical cancer and is likely to be responsible for a substantial proportion of other anogenital neoplasms and upper aero-digestive tract cancers. Low oncogenic risk HPV types (LR-HPV) are also responsible for considerable morbidity as the cause of genital warts. Youth and certain sexual characteristics are key risk factors for HPV acquisition and persistence of HPV infection, but other mediating factors include smoking, oral contraceptive (OC) use, other STIs (e.g. chlamydia, herpes simplex virus), chronic inflammation, immunosuppressive conditions including HIV infection, parity, dietary factors, and polymorphisms in the human leukocyte antigen system. Not surprisingly, these factors are also established or candidate cofactors identified in epidemiologic studies of cervical cancer. HPV transmissibility and molecular events in HPV-induced carcinogenesis have been the focus of recent multidisciplinary epidemiologic studies. This shift in research focus coincides with a shift in cancer prevention techniques towards immunization with HPV vaccines and HPV testing of precancerous lesions.

Condom use and the risk of genital human papillomavirus infection in young women

BACKGROUND

To evaluate whether the use of male condoms reduces the risk of male-to-female transmission of human papillomavirus (HPV) infection, longitudinal studies explicitly designed to evaluate the temporal relationship between condom use and HPV infection are needed.

METHODS

We followed 82 female university students who reported their first intercourse with a male partner either during the study period or within two weeks before enrollment. Cervical and vulvovaginal samples for HPV DNA testing and Papanicolaou testing were collected at gynecologic examinations every four months. Every two weeks, women used electronic diaries to record information about their daily sexual behavior. Cox proportional-hazards models were used to evaluate risk factors for HPV infection.

RESULTS

The incidence of genital HPV infection was 37.8 per 100 patient-years at risk among women whose partners used condoms for all instances of intercourse during the eight months before testing, as compared with 89.3 per 100 patient-years at risk in women whose partners used condoms less than 5 percent of the time (adjusted hazard ratio, 0.3; 95 percent confidence interval, 0.1 to 0.6, adjusted for the number of new partners and the number of previous partners of the male partner). Similar associations were observed when the analysis was restricted to high-risk and low-risk types of HPV and HPV types 6, 11, 16, and 18. In women reporting 100 percent condom use by their partners, no cervical squamous intraepithelial lesions were detected in 32 patient-years at risk, whereas 14 incident lesions were detected during 97 patient-years at risk among women whose partners did not use condoms or used them less consistently.

CONCLUSIONS

Among newly sexually active women, consistent condom use by their partners appears to reduce the risk of cervical and vulvovaginal HPV infection.

Primary prevention of human papillomavirus-dependent neoplasia: No condom, no sex

Cervix cancer is one of several neoplastic disorders that arise following transfer of human papillomavirus (HPV) during unprotected sexual intercourse, and like most other sexually transmitted diseases (STDs), is largely preventable by consistent condom use. This primary prevention strategy has received little support, however, when compared with massive secondary prevention initiatives involving cervical screening. The reasons for this anomalous situation are complex, and include: (i) the asymptomatic nature of most primary HPV infections; (ii) widespread ignorance concerning the venereal aetiology of HPV-related cancers; (iii) the common but incorrect belief that condom use does not reduce HPV transmission; (iv) the perceived irrelevance of safe sex campaigns based on reducing transmission of human immunodeficiency virus (HIV) in high-HPV but low-HIV countries such as the Philippines; (v) the promotion of oral contraception by the medical and pharmaceutical sectors as the sexual prophylaxis of choice; and (vi) the assumption that HPV vaccines will solve the problem. Here it is proposed that the high prevalence of non-HIV STDs, including distressing disorders such as genital warts and herpes simplex, can be exploited with greater efficacy as a public health deterrent to unsafe sex and HPV transmission. Targeting a "mutually assured infection" campaign at vulnerable subgroups such as teenagers and oral contraceptive users could help reverse the global expansion of HPV-related cancers.

Human papillomavirus infection: biology, epidemiology, and prevention

Over the past several decades, knowledge of the biology and epidemiology of human papillomavirus (HPV) infection has increased tremendously. However, there are still many unanswered questions concerning the interaction of the virus with its host. The virus has been identified as a necessary causal agent for cervical squamous neoplasia and has been linked to the development of neoplasia in several other mucosal sites. The viral oncogenes E6 and E7 are the major players in the virus' scheme to evade the immune system and use the host cell replication machinery to survive. Many risk factors for infection with HPV have been identified; however, the focus now centers on identifying risk factors for persistence of the infection as it is likely that transient infections play a very small role in the overall development of clinical disease. Prevention measures to date have centered around screening programs, mostly for cervical cancer, including the perfection of screening techniques and inclusion of molecular testing for HPV into screening regimens. The development of prophylactic and therapeutic vaccines has also increased as primary prevention measures appear to have the best hope for long-term effects on cancer incidence.

Female sex street workers and sexually transmitted infections: their knowledge and behaviour in Italy

OBJECTIVE

This study assessed knowledge and sexual behaviour regarding sexually transmitted infections (STIs) among female sex street workers in the area of Milan, Italy.

METHODS

A questionnaire was administered covering socio-demographic characteristics; knowledge about STIs; sexual behaviour.

RESULTS

A total of 241 female sex street workers were interviewed. A vast majority knew AIDS and syphilis, whereas the knowledge about other STIs was unsatisfactory. Only 11.7% knew that STIs are transmitted by sexual intercourse with HIV seropositive partners, by unprotected sexual intercourse, and that kissing was not a mode of transmission. This knowledge was significantly higher in female sex street workers with a higher number of years in sex work and among those who received information from physicians and associations about STIs. The mean score of fear for contracting STIs was 7.5 and being younger, practicing prostitution for shorter period of time, and requiring more information about STIs were significantly associated with this fear. 'Ever condom use' was 100% during anal intercourse with clients; whereas only one woman reported vaginal and oral intercourse without condom. Only 15.2, 16.7, and 30% of those engaged in vaginal, oral, and anal intercourse with a non-paying sexual partner used condoms all the times. Overall, 83.5% of female sex street workers used a condom every time with clients or non-paying partners and those with fewer clients and partners routinely were more likely to use it.

CONCLUSION

Interventions for preventing STIs and for improving the level of knowledge of STIs among female sex street workers are strongly needed.

Influence of age and geographical origin in the prevalence of high risk human papillomavirus in migrant female sex workers in Spain

OBJECTIVES

To estimate the prevalence and risk factors of high risk human papillomavirus (HPV) infection in migrant female sex workers (FSW) according to age and geographical origin.

METHODS

Cross sectional study of migrant FSW attending a sexually transmitted infection (STI) clinic in Madrid during 2002. Information on sociodemographic characteristics, reproductive and sexual health, smoking, time in commercial sex work, history of STIs, HIV, hepatitis B, hepatitis C, syphilis, and genitourinary infections was collected. High risk HPV Infection was determined through the Digene HPV Test, Hybrid Capture II. Data were analysed through multiple logistic regression.

RESULTS

734 women were studied. Overall HPV prevalence was 39%; 61% in eastern Europeans, 42% in Ecuadorians, 39% in Colombians, 29% in sub-Saharan Africans, and 24% in Caribbeans (p = 0.057). HPV prevalence showed a decreasing trend by age; 49% under 20 years, 35% in 21-25 years,14% over 36 years% (p<0.005). In multivariate analyses, area of origin (p = 0.07), hormonal contraception in women not using condoms (OR 19.45 95% CI: 2.45 to 154.27), smoking, age, and an interaction between these last two variables (p = 0.039) had statistically significant associations with HPV prevalence. STI prevalence was 11% and was not related to age or geographical origin.

CONCLUSIONS

High risk HPV prevalence in migrant FSW is elevated and related to age, area of origin, and use of oral contraceptives in women not using condoms. These data support the role of acquired immunity in the epidemiology of HPV infection and identifies migrant FSW as a priority group for sexual health promotion.