Trung Nam Tran

The Burden of Genital Warts: A Study of Nearly 70,000 Women from the General Female Population in the 4 Nordic Countries

OBJECTIVE To assess the burden and correlates of genital warts in women. METHODS We conducted a population-based cross-sectional study in 69,147 women (18-45 years of age) randomly chosen from the general population in Denmark, Iceland, Norway, and Sweden. Information on clinically diagnosed genital warts and lifestyle habits was collected using a questionnaire. RESULTS Overall, 10.6% reported ever having had clinically diagnosed genital warts. In addition, 1.3% reported having experienced genital warts within the past 12 months. The cumulative incidence for different birth cohorts, estimated on the basis of age at first diagnosis of genital warts, increased with each subsequent younger birth cohort (P<.01). The lifetime number of sex partners was strongly correlated with a history of genital warts (odds ratio for > or =15 partners vs. 1 partner, 9.45 [95% confidence interval, 7.89-11.30]). The likelihood of reporting genital warts also increased with a history of sexually transmitted disease, use of hormonal contraceptives, use of condoms, smoking, and higher education. CONCLUSIONS The data suggest that 1 in 10 women in the Nordic countries experience genital warts before the age of 45 years, with an increasing occurrence in younger birth cohorts. These data are important for developing and evaluating strategies (e.g., human papillomavirus [HPV] vaccination) to control and prevent HPV infection and disease in the population.

Attitudes to HPV vaccination among parents of children aged 12-15 years-a population-based survey in Sweden.

In this population‐based survey undertaken in Sweden in 2007, we investigated correlates of attitudes to human papillomavirus (HPV) vaccination among parents of children aged 12–15 years. We invited 16,000 parents of girls and 4,000 parents of boys, randomly selected from the Swedish population. Response rates were 70 and 69%, respectively. Multinomial logistic regression models were applied to investigate correlates of acceptability to HPV vaccination. Among studied parents, 76% were willing to vaccinate their child if the vaccine is for free and 63% were willing to vaccinate even if the vaccine comes with a cost. Having heard of HPV was associated with both willingness to vaccinate if the vaccine is free (odds ratio [OR]: 1.42; 95% confidence interval [CI]: 1.21–1.66) and willingness to vaccinate even if the vaccine is not free (OR: 1.96; 95% CI: 1.75–2.20) compared with those who never heard of HPV. Beliefs about vaccine safety and efficacy were also strong correlates of willingness to vaccinate. Parents born outside Europe and those with higher education were less willing to vaccinate if the vaccine is not free. In conclusion, the willingness to vaccinate was reasonably high and cost did not appear to be a major barrier. Information about vaccine safety and efficacy is important and parents need information about HPV and the HPV vaccine.

Long-term Effectiveness of Varicella Vaccine: A 14-Year, Prospective Cohort Study

BACKGROUND: Varicella vaccine was licensed in the United States in 1995 for individuals ≥12 months of age. A second dose was recommended in the United States in June 2006. Varicella incidence and vaccine effectiveness were assessed in a 14-year prospective study conducted at Kaiser Permanente Northern California. METHODS: A total of 7585 children vaccinated with varicella vaccine in their second year of life in 1995 were followed up prospectively for breakthrough varicella and herpes zoster (HZ) through 2009. A total of 2826 of these children received a second dose in 2006–2009. Incidences of varicella and HZ were estimated and compared with prevaccine era rates. RESULTS: In this cohort of vaccinated children, the average incidence of varicella was 15.9 per 1000 person-years, nine- to tenfold lower than in the prevaccine era. Vaccine effectiveness at the end of the study period was 90%, with no indication of waning over time. Most cases of varicella were mild and occurred early after vaccination. No child developed varicella after a second dose. HZ cases were mild, and rates were lower in the cohort of vaccinated children than in unvaccinated children during the prevaccine era (relative risk: 0.61 [95% confidence interval: 0.43–0.89]). CONCLUSIONS: This study confirmed that varicella vaccine is effective at preventing chicken pox, with no waning noted over a 14-year period. One dose provided excellent protection against moderate to severe disease, and most cases occurred shortly after the cohort was vaccinated. The study data also suggest that varicella vaccination may reduce the risks of HZ in vaccinated children.

Synergy between Cigarette Smoking and Human Papillomavirus Type 16 in Cervical Cancer In situ Development

Background: A majority of studies have implicated the involvement of cigarette smoking in cervical cancer development, although its mechanism of action remains unclear. We conducted a large population-based case-control study to address the potential interaction between smoking and human papillomavirus type 16 (HPV-16) in development of cervical cancer in situ (CIS). Methods: Information on risk factors for CIS was collected via interview, and archival cervical smears were tested for HPV-16 DNA presence in cases (n = 375) and controls (n = 363). Adjusted odds ratios (OR) for the effects of smoking, HPV-16 presence/absence, and load at first smear (taken, on average, 9 years before diagnosis) were calculated. Results: The risk for CIS among current smokers who were HPV-16 positive at time of first smear was >14-fold [adjusted OR, 14.4; confidence interval (95% CI), 5.6-36.8] compared with HPV-16-negative current smokers. In contrast, the risk for CIS among HPV-16-positive nonsmokers was only 6-fold (adjusted OR, 5.6; 95% CI, 2.7-11.5), compared with HPV-16-negative nonsmokers. HPV-16-positive smokers with high viral load at time of first smear exhibited a high risk for CIS (adjusted OR, 27.0; 95% CI, 6.5-114.2) compared with HPV-16-negative smokers. Within nonsmokers, however, high HPV-16 load contributed only a 6-fold increased risk compared with HPV-16-negative nonsmokers (adjusted OR, 5.9; 95% CI, 2.4-14.6). Interaction was observed (P = 0.03) between duration of smoking and HPV-16 presence in CIS development. Conclusion: Results suggest a synergistic effect between smoking and both HPV-16 status and HPV-16 viral load, which may occur almost a decade before CIS detection. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2141–7)

Risk of cancer after blood transfusion from donors with subclinical cancer: a retrospective cohort study

BACKGROUND Although mechanisms for detection of short-term complications after blood transfusions are well developed, complications with delayed onset, notably transmission of chronic diseases such as cancer, have been difficult to assess. Our aim was to investigate the possible risk of cancer transmission from blood donors to recipients through blood transfusion. METHODS We did a register-based retrospective cohort study of cancer incidence among patients who received blood from donors deemed to have a subclinical cancer at the time of donation. These precancerous donors were diagnosed with a cancer within 5 years of the donation. Data from all computerised blood bank registers in Sweden and Denmark gathered between 1968 and 2002 were merged into a common database. Demographic and medical data, including mortality and cancer incidence, were ascertained through linkages with nationwide, and essentially complete, population and health-care registers. The risk of cancer in exposed recipients relative to that in recipients who received blood from non-cancerous donors was estimated with multivariate Poisson regression, adjusting for potential confounding factors. FINDINGS Of the 354 094 transfusion recipients eligible for this analysis, 12,012 (3%) were exposed to blood products from precancerous donors. There was no excess risk of cancer overall (adjusted relative risk 1.00, 95% CI 0.94-1.07) or in crude anatomical subsites among recipients of blood from precancerous donors compared with recipients of blood from non-cancerous donors. INTERPRETATION Our data provide no evidence that blood transfusions from precancerous blood donors are associated with increased risk of cancer among recipients compared with transfusions from non-cancerous donors.

A population-based binational register for monitoring long-term outcome and possible disease concordance among blood donors and recipients

Background and Objectives  Even with appropriate donor deferrals and advanced screening tests, the risk of disease transmission through blood transfusion cannot be completely disregarded. Efficient monitoring of possible disease transmission between blood donors and recipients should be an important component of a comprehensive haemovigilance system.

Acceptability of HPV vaccination among young adults aged 18–30 years–a population based survey in Sweden

Acceptability of human papillomavirus (HPV) vaccination seems to be high in the Western world but fewer data are available for men than for women. There are also concerns that HPV vaccination might lead young people to change their healthcare-related behaviours. We investigated these issues in a population-based survey performed in Sweden during January-May, 2007, just after HPV vaccination had been licensed. A total of 10567 men and women aged 18 to 30 years participated. The intention to accept HPV vaccination among these young adults was relatively high but could likely be improved with higher awareness of HPV-related diseases as well as of the safety and efficacy of vaccines in general. Also, the cost of the vaccine needs to be affordable. Even though few young adults stated their healthcare-related behaviours would change after HPV vaccination, a significant number were uncertain, suggesting a need for continued educational efforts when HPV-vaccinating this group.

The Epidemiology of Herpes Zoster in Patients with Newly Diagnosed Cancer

Background: Given the limited literature, we conducted a study to examine the epidemiology of herpes zoster (HZ) among newly diagnosed cancer patients. Methods: We identified adult health plan members of Kaiser Permanente Northern California diagnosed with invasive cancer from 2001 to 2005. Electronic health records with inpatient and outpatient diagnoses, laboratory tests, and antiviral medications were used to identify HZ diagnoses from 2001 to 2006. HZ diagnoses and associated complications were confirmed by medical chart review. Treatment with chemotherapy and corticosteroids was used to classify patients by immunosuppression level. Results: Among 14,670 cancer patients, 424 were diagnosed with HZ during follow-up (median 22 months). The incidence of HZ was 31/1,000 person-year (PY) in patients with hematologic malignancies and 12/1,000 PY in patients with solid tumors. The corresponding 2-year cumulative incidence of HZ was approximately 6% and 2%, respectively. Compared with incidence rates of HZ reported in a general US population, the age- and sex-standardized rates of HZ were 4.8 times higher [95% confidence interval (CI), 4.0–5.6] in patients with hematologic malignancies and 1.9 times higher (95% CI, 1.7–2.1) in those with solid tumors. HZ risk increased with increasing level of immunosuppression. Among HZ cases, 19% with hematologic malignancies and 14% with solid tumors had HZ-associated pain for at least 30 days. The corresponding numbers for nonpain-related complications were 30% and 18%, respectively. Conclusions: Cancer patients are at substantially increased risk of HZ and among those with HZ, complications are relatively common. Impact: Better HZ prevention and treatment options for cancer patients are needed. Cancer Epidemiol Biomarkers Prev; 22(1); 82–90. ©2012 AACR.

Measles, mumps, and rubella virus vaccine (M–M–R™II): A review of 32 years of clinical and postmarketing experience

M-M-R™II (measles, mumps, and rubella virus vaccine live; Merck, Sharp, & Dohme Corp.) is indicated for simultaneous vaccination against measles, mumps, and rubella in individuals ≥ 12 months of age. Before the vaccine era, these viruses infected most exposed individuals, with subsequent morbidity and mortality. One of the greatest achievements of public health has been to eliminate these 3 diseases in large geographic areas. The safety profile of M-M-R™II is described using data from routine global postmarketing surveillance. Postmarketing surveillance has limitations (including incomplete reporting of case data), but allows collection of real-world information on large numbers of individuals, who may have concurrent medical problems excluding them from clinical trials. It can also identify rare adverse experiences (AEs). Over its 32-year history, ≈ 575 million doses of M-M-R™II have been distributed worldwide, with 17,536 AEs voluntarily reported for an overall rate of 30.5 AEs/1,000,000 doses distributed. This review provides evidence that the vaccine is safe and well-tolerated.

Life time suicidal thoughts in an urban community in Hanoi, Vietnam

BackgroundSuicidal thought is a risk factor and a stage in the suicidal process from planning to attempting and dying by suicide. To date, studies on suicidal thought in the general population, especially in Asian communities, have been limited.MethodThe WHO SUPRE-MISS (the multisite intervention study on suicidal behaviours) community survey questionnaire was filled in for 2,280 randomly selected residents of the DongDa district of Hanoi, Vietnam by means of face-to-face interviews. This multi-factor questionnaire includes such variables as sociodemographic information, suicidal thought and history of suicide attempts, physical health, alcohol consumption and medication.ResultsPrevalence rates for life time suicidal thoughts, suicide plans and suicide attempts were 8.9%, 1.1% and 0.4% respectively. Suicidal thoughts are associated with multiple characteristics, such as female gender, single/widowed/separated/divorced marital status, low income, lifestyle (use of alcohol, sedatives and pain relief medication), but not with low education or employment status. Having no religion and being a Buddhist appear to be protective factors for suicidal thought.The ratio of suicidal thoughts, suicide plans and suicide attempts on a lifetime basis is 22.3:2.8:1.ConclusionIn Vietnam, as in Western and other Asian countries, suicidal thoughts are associated with similar negative psychosocial risk factors, lifestyle and emotional problems, which implies that suicide preventive measure developed elsewhere can be adjusted to Vietnamese condition. Understanding the unique and common risks in a culture may assist in prediction and control.