Pham Thi Hoang Anh

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

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

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.

Reproductive Factors, Oral Contraceptive Use, and Human Papillomavirus Infection: Pooled Analysis of the IARC HPV Prevalence Surveys

High parity, early age at first full-term pregnancy (FTP), and long-term oral contraceptive (OC) use increase cervical cancer risk, but it is unclear whether these variables are also associated with increased risk of acquisition and persistence of human papillomavirus (HPV) infection, the main cause of cervical cancer. Information on reproductive and menstrual characteristics and OC use were collected from 14 areas worldwide, among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was done using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate the odds ratios (OR) of being HPV-positive according to reproductive and menstrual factors and corresponding 95% confidence intervals (CI). When more than two groups were compared, floating CIs (FCI) were estimated. A total of 15,145 women (mean age, 40.9 years) were analyzed. Women with ≥5 FTPs (OR, 0.90; 95% FCI, 0.76-1.06) showed a similar risk of being HPV-positive compared with women with only one FTP (OR, 1.00; 95% FCI, 0.86-1.16). However, nulliparous women showed an OR of 1.40 (95% CI, 1.16-1.69) compared with parous women. Early age at first FTP was not significantly related to HPV positivity. HPV positivity was similar for women who reported ≥10 years of use of OCs (OR, 1.16; 95% FCI, 0.85-1.58) and never users of OCs (OR, 1.00; 95% FCI, 0.90-1.12). Our study suggests, therefore, that high parity, early age at first FTP, and long-term OC use are not associated with HPV prevalence, but rather these factors might be involved in the transition from HPV infection to neoplastic cervical lesions. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2148–53)

Geographic variation in the prevalence of Kaposi sarcoma-associated herpesvirus and risk factors for transmission.

BACKGROUND The aim of the present study was to estimate the prevalence of Kaposi sarcoma-associated herpesvirus (KSHV) in the female general population, to define geographic variation in and heterosexual transmission of the virus. METHODS The study included 10,963 women from 9 countries for whom information on sociodemographic characteristics and reproductive, sexual, and smoking behaviors were available. Antibodies against KSHV that encoded lytic antigen K8.1 and latent antigen ORF73 were determined. RESULTS The range of prevalence of KSHV (defined as detection of any antigen) was 3.81%-46.02%, with significant geographic variation noted. In Nigeria, the prevalence was 46.02%; in Colombia, 13.32%; in Costa Rica, 9.81%; in Argentina, 6.40%; in Ho Chi Minh City, Vietnam, 15.50%; in Hanoi, Vietnam, 11.26%; in Songkla, Thailand, 10%; in Lampang, Thailand, 8.63%; in Korea, 4.93%; and in Spain, 3.65%. The prevalence of KSHV slightly increased with increasing age among subjects in geographic areas where the prevalence of KSHV was high, such as Nigeria and Colombia, and it significantly decreased with increases in the educational level attained by subjects in those areas. KSHV was not statistically associated with age at first sexual intercourse, number of sex partners, number of children, patterns of oral contraceptive use, presence of cervical human papillomavirus DNA, or smoking status. CONCLUSIONS The study provides comparable estimates of KSHV prevalence in diverse cultural settings across 4 continents and provides evidence that sexual transmission of KSHV is not a major source of infection in the general population.

Cancer in the population of Hanoi, Vietnam, 1988-1990.

The first results from the population-based cancer registry for the city of Hanoi, in northern Vietnam, are presented. In men, incidence rates are moderate-low with the most common cancers being lung, stomach and liver. Cancer of the penis, reportedly very common in early case series from Vietnam, is now rarely seen. In women, incidence rates are low with the most common cancer, breast cancer, having a recorded incidence similar to that in China. Cervix cancer incidence is very low, which contrasts strongly with hospital series from the south of Vietnam, and of 30 years earlier in Hanoi. The incidence of choriocarcinoma is high, and that of nasopharynx cancer (in both sexes) moderately so; both findings are typical of southeast Asian populations. The incidence rates are coherent with the results from recent studies of Vietnamese migrants in the USA and UK.

Seroprevalence of Antibodies against Human Papillomavirus (HPV) Types 16 and 18 in Four Continents: the International Agency for Research on Cancer HPV Prevalence Surveys

Background: Few human papillomavirus (HPV) seroprevalence studies have been carried out in women from low-resource countries. Methods: Seroprevalence of antibodies against HPV16 and HPV18 was assessed in 7,074 women ≥15 years of age (median 44 years) from eight world areas. Serum antibodies against HPV16 and HPV18 were tested for using enzyme-linked immunosorbent assay. HPV DNA was assessed using a general primer GP5+/6+–mediated PCR. Results: HPV16 and HPV18 seroprevalence both ranged from <1% (Hanoi, Vietnam) to ≥25% (Nigeria). Of women who were HPV16 or HPV18 DNA-positive, seropositivity for the same type was 39.8% and 23.2%, respectively. Seropositivity for either type was directly associated with markers of sexual behavior. HPV16 and/or 18 (HPV16/18)–seropositive women had an increased risk of having cytologic abnormalities only if they were also HPV DNA-positive. A high international correlation was found between HPV16/18 seroprevalence and overall HPV DNA prevalence (r = 0.81; P = 0.022). However, HPV16/18 seroprevalence was substantially higher than the corresponding DNA prevalence in all study areas (although to different extents) and, contrary to DNA, tended to increase from young to middle age, and then decline or remain fairly constant. In all study areas, the vast majority of the information on the burden of exposure to HPV16/18 derived from serology. Conclusions: The correlation between HPV DNA and HPV serology was not very good at an individual woman level, but high at a population level. Impact: HPV serology is a poor marker of current infection or related lesions, but it can contribute, together with DNA, in evaluating the variations in the burden of HPV infection worldwide. Cancer Epidemiol Biomarkers Prev; 19(9); 2379–88. ©2010 AACR.

Cervical Infection With Chlamydia trachomatis and Neisseria gonorrhoeae in Women From Ten Areas in Four Continents A Cross-Sectional Study

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

Duration of Signs and Survival in Premenopausal Women with Breast Cancer

AbstractCondensed. Among 550 women reporting a lump as the first sign of breast cancer, those with this sign for 6–29 months compared to those with 1–6 months, had bigger tumors and more frequent axillary node involvement. Overall survival, however, was not significantly different in these two groups. Background. The relationship of delay in diagnosis of breast cancer to survival is uncertain. Methods. We evaluated the relationship of patient-reported duration of signs of breast cancer to survival in participants in a clinical trial of adjuvant hormonal therapy in Vietnam and China. Results. Among 550 women reporting a lump as the first sign of breast cancer and information on when this appeared, the median duration of this sign before diagnosis was 6 months. Comparing two groups of patients with durations of lumps 1–6 months and 6–29 months, the group with longer duration of lumps had larger tumors clinically and pathologically (p= 0.0006, and p= 0.004), more frequent axillary node involvement (p= 0.008), and shorter but not statistically different disease-free and overall survival from the time of diagnosis (p= 0.09 and 0.35, respectively). Conclusions. Breast cancer evolves slowly in the detectable period of its natural history. The impact of delays in diagnosis of less than 6 months is likely to be very limited; delays more than 6 months appear to have some, but marginal impact on survival.

Hepatitis C virus seroprevalence in the general female population from 8 countries

BACKGROUND Hepatitis C virus (HCV) infection is a significant global health issue because it is widespread and persistent and can cause serious liver diseases. OBJECTIVES The aim of this study is to estimate HCV prevalence in women from the general population in different geographical areas worldwide and to assess the potential role of sexual behaviour in the virus transmission. STUDY DESIGN Each participating centre recruited a random sample of women from the general population aged from less than 20 to more than 75 years. The study included 8130 women from 8 countries with information on sociodemographic factors, reproductive and sexual behaviour, smoking habit and HPV DNA through individual interviews. A blood sample was also collected to perform serological tests. We estimated the prevalence ratios associated to HCV to evaluate the effect of sexual behaviour in viral transmission. RESULTS Women were reactive to a minimum of two HCV antigens, including at least one non structural protein were considered as positive (33% of the samples were classified as positive, 40% as negative, and 27% as indeterminate (N=402), that were considered as not positive). The age-adjusted HCV seroprevalence varied significantly by regions (0.3% in Argentina to 21.1% in Nigeria). We found no association between HCV prevalence and age, educational level, smoking habit and any of the available variables for sexual behaviour and reproductive history. CONCLUSIONS This large study showed heterogeneous distribution of HCV seroprevalence in female and provides evidence of the null impact of sexual behaviour in HCV transmission.