Identification of subgroups in the Danish population for targeted human papillomavirus vaccination efforts.

BACKGROUND: In the Danish childhood vaccination program, the human papillomavirus (HPV) vaccination coverage is lower than for other vaccines. To tailor a targeted HPV vaccination effort, we aimed to identify girls in Denmark with lower first dose HPV vaccination coverage than girls in general. METHODS: A population-based retrospective cohort study was performed of girls born in 2001-2004, residing in Denmark in September 2019 (N = 128,351). Data from the Danish Vaccination Register was linked to sociodemographic data from the Danish Civil Registration System and Statistics Denmark. Cox's proportional hazard regression models were used to compare vaccination uptake rates between subgroups of girls. RESULTS: HPV vaccination coverage at 14 years of age varied widely by municipality (53.4-80.6%). Girls living with neither of their parents had a lower chance of being vaccinated compared to girls living with both their parents (HR 0.43; 95% CI 0.41-0.46), likewise for girls attending special need education compared with girls attending public schools (HR 0.50; 95% CI 0.42-0.59). The vaccination uptake among immigrants was lower compared to Danish-born girls (HR 0.51; 95% CI 0.49-0.54), especially among immigrant girls whose parents had not passed any Danish exams. Finally, girls who were DTaP-IPV revaccinated had a 50% greater chance of being HPV vaccinated compared to girls who were not (HR 1.61; 95% CI 1.58-1.64). CONCLUSION: To increase the HPV vaccination uptake, we recommend vaccination efforts targeting girls living without any of their parents, girls attending special need education, immigrants, and girls who are not DTaP-IPV revaccinated. When targeting immigrants, the effort should focus on disseminating sufficient and understandable information about the Danish childhood vaccination program to the parents.

Risk of sequelae after invasive meningococcal disease.

BACKGROUND: Invasive meningococcal disease (IMD) is a rare but severe bacterial infection, of which a high proportion of survivors are affected by sequelae. In Denmark, IMD is a notifiable disease and data collection on sequelae information has been automated, enabling studies of sequelae due to IMD diagnosed after discharge. The aim of this study was to examine possible determinants for sequelae after IMD and to describe the distribution of sequelae by age, serogroup and clinical presentation, for all cases in Denmark from 2005-2020. METHODS: Data from The National Database for Notifiable Infectious Diseases was linked to data from The Danish National Patient Register and the Civil Registration System. Logistic regression models were used to study whether age, serogroup and/or clinical presentation were associated with sequelae. A descriptive analysis of the proportion of different types of sequelae across age groups, serogroups and clinical presentations was performed. RESULTS: In total, 25% of IMD survivors experienced one or more sequelae. We found no significant association between sequelae and age. The five most common sequelae in decreasing order of incidence were hearing loss, epilepsy, learning disabilities, headache and visual defects/loss of vision, with rates ranging from 8.2 to 2.8% of IMD survivors. The proportion of survivors with hearing loss and visual defects/loss of vision was not significantly different between clinical presentations. CONCLUSIONS: We suggest revising IMD treatment guidelines, to include routine referral to hearing and vision tests, irrespective of clinical presentation. Furthermore, it is important to increase the awareness among parents of children who have had IMD of possible future learning disabilities to make sure that necessary measures are taken in a timely manner.

Recent increased incidence of invasive serogroup W meningococcal disease: A retrospective observational study.

OBJECTIVES: Neisseria meningitidis serogroup W incidence has increased. Mortality associated with serogroup W has been higher than for other serogroups. Here we report epidemiological characteristics and risks of poor outcomes associated with invasive meningococcal disease in Denmark since 1980. METHODS: All cases of invasive meningococcal disease reported from 1980-2018 were analyzed. Incidence rates by age, sex, manifestation, and serogroup were calculated. Poisson regression was used to analyze the rise in serogroup W, and multivariate logistic analysis was used to analyze risk factors for mortality. RESULTS: A total of 5825 cases were analyzed. Risk of serogroup W infection increased after 2015 compared with all previous periods. Younger (<20 years) and older age (≥60 years) was associated with an increased risk of serogroup W infection compared with being aged 20-39. Crude case fatality was 12.0%, 11.9%, 9.2%, and 7.9% for serogroups W, Y, C, and B, respectively. After adjustment for age, sex, and manifestation, 30-day mortality was comparable for serogroups. Older age and manifestation with sepsis independently predicted risk of death. CONCLUSIONS: Invasive meningococcal disease caused by serogroup W has increased, but serogroup per se was not associated with an increased risk of 30-day mortality.

Underreporting of the 5-year tetanus, diphtheria, pertussis and polio booster vaccination in the Danish Vaccination Register.

BACKGROUND: In Denmark, vaccination coverage is measured using the Danish Vaccination Register (DDV). In general, the vaccination coverage is high, but for some vaccinations, the coverage is suboptimal with geographical variation. This study aims to validate the vaccination coverage of the 5-year booster and identify overall reasons for non-vaccination in Copenhagen. METHODS: We validated the coverage of the 5-year tetanus, diphtheria, pertussis and polio booster for children born in 2010 and living in Copenhagen municipality in 2018, an area with low coverage (current estimate: 89%). We identified all children born in 2010 in the Civil Registration System and sent an electronic questionnaire to parents of children without a record of the 5-year booster in the DDV. RESULTS: Parents of 692 children were contacted and 49% participated. Of those, 186 (55%) reported that the child was vaccinated: 61% by their general practitioner and 34% abroad. The most common reason for non-vaccination was forgetfulness (31%), 26% did not want their child vaccinated and 17% had migrated from abroad and were not aware of the vaccination schedule. Considering only children with documentation for the vaccination, the corrected vaccination coverage was 91%. CONCLUSIONS: We conclude that the coverage of the 5-year booster in Copenhagen is currently underestimated and should be adjusted by 2%. We recommend increased awareness from general practitioners and tailored communication about the vaccination programme targeting immigrants in Denmark.

Extreme concentrations of endogenous sex hormones, ischemic heart disease, and death in women.

OBJECTIVE: Sex hormones may be critical determinants of ischemic heart disease and death in women, but results from previous studies are conflicting. To clarify this, we tested the hypothesis that extreme plasma concentrations of endogenous estradiol and testosterone are associated with risk of ischemic heart disease and death in women. APPROACH AND RESULTS: In a nested prospective cohort study, we measured plasma estradiol in 4600 and total testosterone in 4716 women not receiving oral contraceptives or hormonal replacement therapy from the 1981 to 1983 examination of the Copenhagen City Heart Study. During ≤30 years of follow-up, 1013 women developed ischemic heart disease and 2716 died. In women with a plasma estradiol below the fifth percentile compared with between the 10th and 89th percentiles, multifactorially adjusted risk of ischemic heart disease was 44% (95% confidence interval, 14%-81%) higher; however, plasma estradiol concentrations did not associate with death. Also, in women with a plasma testosterone concentration at or above the 95th percentile compared with between the 10th and 89th percentiles, multifactorially adjusted risk was 68% (34%-210%) higher for ischemic heart disease, 36% (18%-58%) higher for any death, and 38% (15%-65%) higher for death from other causes than cardiovascular disease and cancer. These results were similar for postmenopausal women alone. CONCLUSIONS: In women, extreme low concentrations of endogenous estradiol were associated with high risk of ischemic heart disease, and extreme high concentrations of endogenous testosterone were associated with high risk of ischemic heart disease and death.