Population-based screening in a municipality after a primary school outbreak of the SARSCoV-2 Alpha variant, the Netherlands, December 2020–February 2021

An outbreak of SARS-CoV-2 Alpha variant (Pango lineage B.1.1.7) was detected at a primary school (School X) in Lansingerland, the Netherlands, in December 2020. The outbreak was studied retrospectively, and population-based screening was used to assess the extent of virus circulation and decelerate transmission. Cases were SARS-CoV-2 laboratory confirmed and were residents of Lansingerland (November 16(th) 2020 until February 22(th) 2021), or had an epidemiological link with School X or neighbouring schools. The SARS-CoV-2 variant was determined using variant PCR or whole genome sequencing. A questionnaire primarily assessed clinical symptoms. A total of 77 Alpha variant cases were found with an epidemiological link to School X, 16 Alpha variant cases linked to the neighbouring schools, and 146 Alpha variant cases among residents of Lansingerland without a link to the schools. The mean number of self-reported symptoms was not significantly different among Alpha variant infected individuals compared to non-Alpha infected individuals. The secondary attack rate (SAR) among Alpha variant exposed individuals in households was 52% higher compared to non-Alpha variant exposed individuals (p = 0.010), with the mean household age, and mean number of children and adults per household as confounders. Sequence analysis of 60 Alpha variant sequences obtained from cases confirmed virus transmission between School X and neighbouring schools, and showed that multiple introductions of the Alpha variant had already taken place in Lansingerland at the time of the study. The alpha variant caused a large outbreak at both locations of School X, and subsequently spread to neighbouring schools, and households. Population-based screening (together with other public health measures) nearly stopped transmission of the outbreak strain, but did not prevent variant replacement in the Lansingerland municipality

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. Logistic regression was applied to estimate determinants of HPV prevalent infections. RESULTS: HPV prevalence was 54% among males and 72% among females. High-risk (HR) HPV was present in males and females, 40% and 58%, respectively. Independent risk factors for HR-HPV infection were female gender, number of lifetime sex partners and a history of chlamydia or gonorrhea. In addition, not having a casual partner and consistent condom use were protective factors in women, but not in men. For low-risk (LR) HPV, the odds were smaller. Multiple HR-HPV and sexual risk behavior showed a stronger association compared with a single HR-HPV infection. CONCLUSIONS: Prevalence of HR-HPV is high in both genders. Infection with multiple HR-HPV types was more associated with high-risk sexual behavior than infection with LR-HPV types or a single HR-HPV type

Impact of genital warts on emotional and sexual well-being differs by gender

To assess gender-specific impact of genital warts on health-related quality of life (HRQoL), and to explore to what extent sexual characteristics and clinical symptoms influenced the impact on emotional and sexual well-being of both sexes. We conducted a survey of sexual and clinical characteristics from persons diagnosed with genital warts at STI clinics. HRQoL was measured using two measurement tools: 1) the generic EQ-5D; and 2) the genital warts-specific CECA-10 including an emotional well-being and a sexual activity dimension. The EQ-5D scores were compared with scores of the general population. Descriptive analyses were used to explore characteristics associated with HRQoL scores stratified for gender. The HRQoL-measurement tools showed that genital warts have especially an emotional impact. The impact of genital warts on HRQoL was greater for women than for men. In addition, the CECA-10 showed that in women the impact of genital warts on sexual activity was influenced by age, relationship status and number of warts. No related factors were seen in men. Genital warts have a greater impact on women than on men. In women, sexual and clinical factors influenced the impact of genital warts on well-being, whereas in men no such factors were foun

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. We determined the genetic diversity of the L1 gene in HPV-16 and -18 viral strains circulating in the Netherlands at the start of vaccination in order to understand the baseline genetic diversity in the Dutch population. Methods DNA sequences of the L1 gene were determined in HPV-16 (n = 241) and HPV-18 (n = 108) positive anogenital samples collected in 2009 and 2011 among Dutch 16- to 24-year old female and male attendees of the sexually transmitted infection (STI) clinics. Phylogenetic analysis was performed and sequences were compared to reference sequences HPV-16 (AF536179) and HPV-18 (X05015) using BioNumerics 7.1. Results For HPV-16, ninety-five single nucleotide polymorphism (SNPs) were identified, twenty seven (28%) were non-synonymous variations. For HPV-18, seventy-one SNPs were identified, twenty-nine (41%) were non-synonymous. The majority of the non-silent variations were located in sequences encoding alpha helix, beta sheet or surface loops, in particular in the immunodominant FG loop, and may influence the protein secondary structure and immune recognition. Conclusions This study provides unique pre-vaccination/baseline data on the genetic L1 diversity of HPV- 16 and -18 viruses circulating in the Netherlands among adolescents and young adults

Correction: Genetic diversity in the major capsid L1 protein of HPV-16 and HPV-18 in the Netherlands

In the Data Availability statement and the Materials and Methods section, the GenBank accession number KU70477 appears incorrectly. The correct accession number should be KU707477

Repeated STI and HIV testing among HIV-negative men who have sex with men attending a large STI clinic in Amsterdam: a longitudinal study

In the Netherlands, men who have sex with men (MSM) are advised via informal guidelines to test for STI at least annually. We estimated the proportion of HIV-negative MSM testing repeatedly at 12-month or smaller intervals at a large STI clinic in the Netherlands. In addition, we explored whether repeated testing is related to risk behaviour. Longitudinal data of HIV-negative MSM visiting the Amsterdam STI clinic between 2009 and 2012 were analysed. To estimate the timing of repeated testing, Kaplan-Meier methods were used. Determinants for repeated testing (distinguishing testing at 12-month or smaller intervals and less than 12-monthly testing, with single testers as reference group) were identified using multivariate multinomial logistic regression analyses. In total, 19,479 consultations of 9174 HIV-negative MSM were identified. Of these MSM, 35% (95% CI 33% to 36%) were estimated to return to the STI clinic within 1 year following baseline consultation. Among 1767 men with at least two consultations and at least 2 years between baseline and last consultation, 43% tested repeatedly at 12-month or smaller intervals in those first 2 years. Repeated testers reported higher sexual risk behaviour (ie, only casual or both casual and steady sex partners, higher numbers of sex partners) at baseline compared with single testers. This effect tended to be slightly stronger for men testing repeatedly at 12-month or smaller intervals. The proportion of MSM testing for STI annually is low. MSM testing repeatedly had higher baseline levels of risk behaviour. Strategies to motivate MSM to test annually should be explore

Characteristics of study population.

<p>Characteristics of study population.</p

Maximum parsimony tree based on nucleotide sequences of L1 HPV-16 gene.

<p>Study sequences of 241 HPV-16 positive samples collected in 2009 and 2011 are shown in blue. Reference sequences of European/A lineages (GenBank reference AF536179 K02718 = NC001526, HQ644236, AF534061) are shown in green, African/B lineages (GenBank references AF472508, HQ644298 and AF536180) in brown. African-2/C lineage GenBank reference AF472509 is shown in pink. References sequences from lineage D are shown in purple HQ644257 (sublineage D1-North American), AY686579-(sublineage D2, Asian-American) AF402678 (sublineage D3, Asian-American). HPV-16 variant used in the vaccine (GenBank reference AF043286) is shown in red. The number given in each circle indicates the number of viral strains with the same sequence.</p