Correlation between viral load, multiplicity of infection, and persistence of HPV16 and HPV18 infection in a Dutch cohort of young women.

Background: Persistent high-risk human papillomavirus infection precedes the development of cervical cancer. Here we evaluated the contribution of HPV16/18 viral load and the presence of infections with multiple HPV types to persistence and clearance of HPV16/18 infections.

Methods: Vaginal self-swabs were obtained from young women (16-29 y) with one year interval.

Correction: Genetic Diversity in the Major Capsid L1 Protein of HPV-16 and HPV-18 in the Netherlands.

[This corrects the article DOI: 10.1371/journal.pone.

Genetic Diversity in the Major Capsid L1 Protein of HPV-16 and HPV-18 in the Netherlands.

Objectives: Intratypic molecular variants of human papillomavirus (HPV) type-16 and -18 exist. In the Netherlands, a bivalent vaccine, composed of recombinant L1 proteins from HPV-16 and -18, is used to prevent cervical cancer since 2009. Long-term vaccination could lead to changes in HPV-16 and -18 virus population, thereby hampering vaccination strategies.

Six-month incidence and persistence of oral HPV infection in HIV-negative and HIV-infected men who have sex with men.

Objectives: Our aim was to assess incidence and persistence of oral HPV infection in HIV-negative and HIV-infected men who have sex with men (MSM).

Methods: MSM aged ≥18 years were included in Amsterdam (the Netherlands) in 2010-2011, and followed up 6 months later. Participants completed risk factor questionnaires.

Varicella zoster virus infection occurs at a relatively young age in The Netherlands.

Introduction: To date, there is no universal varicella vaccination in the Netherlands. We studied the seroprevalence of varicella zoster virus (VZV) specific antibodies and determinants for seropositivity among participants of a serosurveillance study, conducted in 2006/2007 among Dutch inhabitants 0-79 years of age.

Materials And Methods: Serological testing of 6386 blood samples for VZV was performed with a fluorescent bead-based multiplex immunoassay.

Selective hepatitis B virus vaccination has reduced hepatitis B virus transmission in the Netherlands.

Background & Aims: In the Netherlands, a selective hepatitis B virus (HBV) vaccination programme started in 2002 for men having sex with men, drug users, commercial sex workers and heterosexuals with frequent partner changes. We assessed the programme's effectiveness to guide policy on HBV prevention.

Methods: We analysed reports of acute HBV infection in the Netherlands between 2004 and 2010 requesting serum from patients for HBV-genome S- and C-region sequencing.

Patterns of human papillomavirus DNA and antibody positivity in young males and females, suggesting a site-specific natural course of infection.

Background: To monitor the impact of human papillomavirus types 16 and 18 vaccine on HPV infection dynamics in the Netherlands, we started an ongoing study in sexually transmitted infection (STI) clinics in 2009. Here, we analyze baseline type-specific HPV DNA and HPV-specific antibody positivity rates.

Methods: We enrolled 3569 men and women, 16-24 years of age, from 14 STI clinics, and estimated genital and anal HPV DNA and antibody positivity rates of 7 main carcinogenic HPV types.

Changes in antibody seroprevalence of seven high-risk HPV types between nationwide surveillance studies from 1995-96 and 2006-07 in The Netherlands.

Objective: This study evaluates trends in antibody seroprevalences of seven high-risk human papillomavirus (hr-HPV) serotypes (HPV16, 18, 31, 33, 45, 52, and 58) between the 1995-96 and 2006-07 sero-surveys among the Dutch general population in the pre-vaccination era.

Methods: Serum samples of men and women (0-79 years of age) from two cross-sectional population-based serosurveillance studies performed in 1995-96 (n = 3303) and 2006-07 (n = 6384) were tested for HPV-specific antibodies in a VLP-based multiplex immunoassay.

Results: HPV16-specific antibody seroprevalence increased during adolescence and shifted to younger ages in the 2006-07 survey compared to the 1995-96 survey.

Seroprevalence of seven high-risk HPV types in The Netherlands.

Background: To obtain insight into the age-specific seroprevalence for seven high-risk human papillomavirus (hr-HPV) serotypes (HPV16, 18, 31, 33, 45, 52, and 58) among the general population in the pre-vaccination era in The Netherlands.

Methods: From a cross-sectional population-based study (ISRCTN 20164309) performed in 2006/2007 6384 sera of men, women and children were tested for seven hr-HPV specific antibodies using a fluorescent bead-based multiplex immunoassay with virus-like particles of the seven HPV serotypes.

Results: An increase in seroprevalence was observed in adolescents, especially for the most prevalent HPV type 16 (up to 11.

Global co-existence of two evolutionary lineages of parvovirus B19 1a, different in genome-wide synonymous positions.

Parvovirus B19 (B19V) can cause infection in humans. To date, three genotypes of B19V, with subtypes, are known, of which genotype 1a is the most prevalent genotype in the Western world. We sequenced the genome of B19V strains of 65 asymptomatic, recently infected Dutch blood donors, to investigate the spatio-temporal distribution of B19V strains, in the years 2003-2009.

Immunogenicity of a hexavalent vaccine co-administered with 7-valent pneumococcal conjugate vaccine. Findings from the National Immunisation Programme in The Netherlands.

The hexavalent vaccine Infanrix hexa was introduced into the national childhood vaccination schedule in the Netherlands in 2006. It is offered, concomitantly with pneumococcal vaccine (Prevenar), to children at increased risk of hepatitis B, administered in a 4-dose schedule at 2, 3, 4 and 11 months of age. We assessed the immunogenicity of the HBV component of Infanrix hexa co-administered with Prevenar, and compared pertussis and Hib components in Infanrix hexa with the standard Infanrix-IPV+Hib vaccine.

Hepatitis C virus seroprevalence in the Netherlands.

A population-based anti-hepatitis C virus (HCV) prevalence is important for surveillance purposes and it provides an insight into the burden of disease. In The Netherlands, a recent HCV seroprevalence estimate is not available. This national population-based cross-sectional serosurvey (PIENTER-2) resulted in a weighted national HCV seroprevalence of 0.

Mumps vaccine effectiveness in primary schools and households, the Netherlands, 2008.

To estimate the mumps vaccine effectiveness (VE) during a large genotype D mumps outbreak, we conducted a cross-sectional study in eight primary schools and associated households in the Netherlands. Questionnaires were used to collect information on the occurrence of mumps. Multivariate analyses were used to estimate VE.

Prevention of perinatal hepatitis B virus transmission in the Netherlands, 2003-2007: children of Chinese mothers are at increased risk of breakthrough infection.

Background: In the Netherlands, different hepatitis B vaccination schedules have been used for children born to HBV-infected mothers. All schedules included a birth dose of hepatitis B immunoglobuline (HBIg). We assessed determinants of perinatal HBV transmission and determinants of anti-HBs titers in infants born to HBsAg positive mothers.

Type-specific human papillomavirus infections among young heterosexual male and female STI clinic attendees.

Background: Baseline genotype-specific human papillomavirus (HPV) prevalence rates and associated risk factors per gender enable future assessment of the impact of vaccination on HPV dynamics.

Methods: Before the start of national HPV vaccination for girls, data were collected cross-sectionally in nationwide Dutch sexually transmitted infections (STI) clinics among heterosexual males (n = 430) and females (n = 1136) aged 16 to 24 years. Self-collected vaginal or penile swabs were analyzed by a sensitive polymerase chain reaction (SPF10) and genotyped with line probe assay.

Transmission of mumps virus from mumps-vaccinated individuals to close contacts.

During a recent mumps epidemic in the Netherlands caused by a genotype D mumps virus strain, we investigated the potential of vaccinated people to spread mumps disease to close contacts. We compared mumps viral titers of oral fluid specimens obtained by quantitative PCR from vaccinated (n=60) and unvaccinated (n=111) mumps patients. We also investigated the occurrence of mumps infection among the household contacts of vaccinated mumps patients.

Assessment of serological evidence for mumps virus infection in vaccinated children.

It is estimated that at least one-third of mumps virus infections in non-vaccinated individuals are asymptomatic. Little information is available whether this proportion is the same among those vaccinated. We validated a commercial oral fluid mumps IgG-specific Enzyme Immunoassays (EIA) with vaccinated control groups to identify symptomatic and asymptomatic mumps virus infections in vaccinated individuals during a mumps outbreak in The Netherlands.

Assessing the potential effects and cost-effectiveness of programmatic herpes zoster vaccination of elderly in the Netherlands.

Background: Herpes zoster (HZ) is a painful disease affecting a considerable part of the elderly. Programmatic HZ vaccination of elderly people may considerably reduce HZ morbidity and its related costs, but the extent of these effects is unknown. In this article, the potential effects and cost-effectiveness of programmatic HZ vaccination of elderly in the Netherlands have been assessed according to a framework that was developed to support evidence-based decision making regarding inclusion of new vaccines in the Dutch National Immunization Program.

Age-specific HPV seroprevalence among young females in The Netherlands.

Objectives: To obtain insight into the age-specific seroprevalence for human papillomavirus (HPV) 6, 11, 16 and 18 among females before introduction of HPV vaccination in The Netherlands.

Methods: In a population-based study in The Netherlands, 637 sera of 11-26-year-old females were tested for HPV6/11/16/18 antibodies. Sera were tested using a competitive Luminex assay with neutralising monoclonal antibodies specific for each serotype.

[Management and treatment of pregnant women with hepatitis B].

Every year about 800 chronic hepatitis B infections are identified in the Netherlands as result of the nationwide pregnancy screening. About one-third of these are newly discovered infections. In recent years there has been a marked increase in treatment options for chronic hepatitis B infection using antiviral drugs.

Molecular sequence data of hepatitis B virus and genetic diversity after vaccination.

The effect of vaccination programs on transmission of infectious disease is usually assessed by monitoring programs that rely on notifications of symptomatic illness. For monitoring of infectious diseases with a high proportion of asymptomatic cases or a low reporting rate, molecular sequence data combined with modern coalescent-based techniques offer a complementary tool to assess transmission. Here, the authors investigate the added value of using viral sequence data to monitor a vaccination program that was started in 1998 and was targeted against hepatitis B virus in men who have sex with men in Amsterdam, the Netherlands.

Acute hepatitis B in a healthcare worker: a case report of genuine vaccination failure.

Background: Individuals who reach the antibody threshold level of 10IU/l against the surface protein of the hepatitis B virus (HBV) after completion of a series of hepatitis B vaccination are considered to be long-term protected against a clinically manifest HBV infection.

Case Report: Here we describe an acute hepatitis B infection in a patient who received five hepatitis B vaccinations. Although his initial response to vaccination was moderate, he finally reached an excellent hepatitis B surface antibody level (anti-HBs) titres of more than 1000 IU/l in response to a booster vaccination with a recombinant DNA vaccine.