A combined cross-sectional analysis and case-control study evaluating tick-borne encephalitis vaccination coverage, disease and vaccine effectiveness in children and adolescents, Switzerland, 2005 to 2022.

BackgroundTick-borne encephalitis (TBE) is a severe, vaccine-preventable viral infection of the central nervous system. Symptoms are generally milder in children and adolescents than in adults, though severe disease does occur. A better understanding of the disease burden and duration of vaccine-mediated protection is important for vaccination recommendations.AimTo estimate TBE vaccination coverage, disease severity and vaccine effectiveness (VE) among individuals aged 0-17 years in Switzerland.MethodsVaccination coverage between 2005 and 2022 was estimated using the Swiss National Vaccination Coverage Survey (SNVCS), a nationwide, repeated cross-sectional study assessing vaccine uptake. Incidence and severity of TBE between 2005 and 2022 were determined using data from the Swiss disease surveillance system and VE was calculated using a case-control analysis, matching TBE cases with SNVCS controls.ResultsOver the study period, vaccination coverage increased substantially, from 4.8% (95% confidence interval (CI): 4.1-5.5%) to 50.1% (95% CI: 48.3-52.0%). Reported clinical symptoms in TBE cases were similar irrespective of age. Neurological involvement was less likely in incompletely (1-2 doses) and completely (≥ 3 doses) vaccinated cases compared with unvaccinated ones. For incomplete vaccination, VE was 66.2% (95% CI: 42.3-80.2), whereas VE for complete vaccination was 90.8% (95% CI: 87.7-96.4). Vaccine effectiveness remained high, 83.9% (95% CI: 69.0-91.7) up to 10 years since last vaccination.ConclusionsEven children younger than 5 years can experience severe TBE. Incomplete and complete vaccination protect against neurological manifestations of the disease. Complete vaccination offers durable protection up to 10 years against TBE.

Legionnaires' disease in Switzerland: rationale and study protocol of a prospective national case-control and molecular source attribution study (SwissLEGIO).

Switzerland has one of the highest annual Legionnaires' disease (LD) notification rates in Europe (7.8 cases/100,000 population in 2021). The main sources of infection and the cause for this high rate remain largely unknown. This hampers the implementation of targeted Legionella spp. control efforts. The SwissLEGIO national case-control and molecular source attribution study investigates risk factors and infection sources for community-acquired LD in Switzerland. Over the duration of one year, the study is recruiting 205 newly diagnosed LD patients through a network of 20 university and cantonal hospitals. Healthy controls matched for age, sex, and residence at district level are recruited from the general population. Risk factors for LD are assessed in questionnaire-based interviews. Clinical and environmental Legionella spp. isolates are compared using whole genome sequencing (WGS). Direct comparison of sero- and sequence types (ST), core genome multilocus sequencing types (cgMLST), and single nucleotide polymorphisms (SNPs) between clinical and environmental isolates are used to investigate the infection sources and the prevalence and virulence of different Legionella spp. strains detected across Switzerland. The SwissLEGIO study innovates in combining case-control and molecular typing approaches for source attribution on a national level outside an outbreak setting. The study provides a unique platform for national Legionellosis and Legionella research and is conducted in an inter- and transdisciplinary, co-production approach involving various national governmental and national research stakeholders.

Temporal trends in legionellosis national notification data and the effect of COVID-19, Switzerland, 2000-2020.

The notification rate of legionellosis in Switzerland and other European countries has markedly increased over the last 20 years. Here, we investigated the Swiss notification data on legionellosis from 2000 to 2020 in regards of overall time trend, content and data quality. We further explored the impact of the COVID-19 pandemic on the reported case numbers using an interrupted time series approach. Between 2000 and 2020, 5980 cases were included in our analysis. The annual crude notification rate for legionellosis cases increased from 1.1/100,000 population (CI: 0.9-1.4) in 2000 to 5.6/100,000 population (CI: 5.1-6.1) in 2020. In recent years, the summer peaks have been more pronounced and some shifted earlier in the year. The highest notification rate was recorded in 2018 with 6.7/100,000 population (CI: 6.2-7.3). The hospitalisation rate for notified cases remained high across all study years (89.9%), while the case fatality rate slightly decreased (from 7.7% to 3.6%). COVID-19 containment measures, such as travel restrictions and/or related behavioural changes, are associated with a temporary decline in cases of 35%. Overall, the quality of the notification data was good. Clinical data were more susceptible to interferences than data from laboratory reporting, which could be observed most clearly in the decline of clinical reports by 4.3 percentage points in 2020. As the case classification for Legionnaires' disease includes pneumonia symptoms, this decline could lead to an underestimation of Legionnaires' disease cases, yet the continuous reporting though the diagnostic laboratories suggested a robust surveillance system for legionellosis in Switzerland.

National and regional variations in timely adherence to recommended measles vaccination scheme in 2-years old in Switzerland, 2005-2019.

BACKGROUND: Although monitoring of vaccination program performance is usually evaluated by measurement of vaccine coverage, timely uptake is rarely part of this assessment. This study aims to examine the timeliness of the administration of a measles-containing-vaccine (MCV) for 2-year-old children between 2005 and 2019. METHODS: We used data from the Swiss National Vaccination Coverage Survey 2005-2019 for the study. We defined timely vaccinated as a vaccination administered within the recommended age specified in the Swiss National Vaccination Schedule, with an added tolerance period of 30.4 days for both MCV 1 and 2 doses. The median delay time was estimated by Kaplan-Meier survival curve and examined using log-rank test. A Cox hazard ratio was used to identify factors associated with delay. RESULTS: 81% (95% CI:79-82%) of toddlers were timely vaccinated for MCV1 and 82% (95% CI:81-83%) for MCV2 in survey period 2017-2019. Between 2005 and 2019, the median age of vaccinated children ranged between 12.2 and 12.5 and 18.3-22.0 months for MCV1 and MCV2 with median delay of 44 and 38 days, respectively, at the national level. Children in the French-, Italian- and German-speaking regions were vaccinated earlier between 2005 and 2019 for MCV1 (vaccination coverage range before 10 months of age: 1.7-45.9%, 1.2-35.3% and 1.4-15.0%, respectively). Nationality, linguistic regions, and survey periods were the strongest predictive factors related to prolonged delay time. CONCLUSION: Overall adherence to recommendations has improved over time, as MCV coverage has significantly increased over the years with differences across linguistic regions. Vaccinations were administered earlier and with shorter delay time.

Risk factors for severe outcomes for COVID-19 patients hospitalised in Switzerland during the first pandemic wave, February to August 2020: prospective observational cohort study.

BACKGROUND: As clinical signs of COVID-19 differ widely among individuals, from mild to severe, the definition of risk groups has important consequences for recommendations to the public, control measures and patient management, and needs to be reviewed regularly. AIM: The aim of this study was to explore risk factors for in-hospital mortality and intensive care unit (ICU) admission for hospitalised COVID-19 patients during the first epidemic wave in Switzerland, as an example of a country that coped well during the first wave of the pandemic. METHODS: This study included all (n = 3590) adult polymerase chain reaction (PCR)-confirmed hospitalised patients in 17 hospitals from the hospital-based surveillance of COVID-19 (CH-Sur) by 1 September 2020. We calculated univariable and multivariable (adjusted) (1) proportional hazards (Fine and Gray) survival regression models and (2) logistic regression models for in-hospital mortality and admission to ICU, to evaluate the most common comorbidities as potential risk factors. RESULTS AND DISCUSSION: We found that old age was the strongest factor for in-hospital mortality after having adjusted for gender and the considered comorbidities (hazard ratio [HR] 2.46, 95% confidence interval [CI] 2.33−2.59 and HR 5.6 95% CI 5.23−6 for ages 65 and 80 years, respectively). In addition, male gender remained an important risk factor in the multivariable models (HR 1.47, 95% CI 1.41−1.53). Of all comorbidities, renal disease, oncological pathologies, chronic respiratory disease, cardiovascular disease (but not hypertension) and dementia were also risk factors for in-hospital mortality. With respect to ICU admission risk, the pattern was different, as patients with higher chances of survival might have been admitted more often to ICU. Male gender (OR 1.91, 95% CI 1.58−2.31), hypertension (OR  1.3, 95% CI 1.07−1.59) and age 55–79 years (OR 1.15, 95% CI 1.06−1.26) are risk factors for ICU admission. Patients aged 80+ years, as well as patients with dementia or with liver disease were admitted less often to ICU. CONCLUSION: We conclude that increasing age is the most important risk factor for in-hospital mortality of hospitalised COVID-19 patients in Switzerland, along with male gender and followed by the presence of comorbidities such as renal diseases, chronic respiratory or cardiovascular disease, oncological malignancies and dementia. Male gender, hypertension and age between 55 and 79 years are, however, risk factors for ICU admission. Mortality and ICU admission need to be considered as separate outcomes when investigating risk factors for pandemic control measures and for hospital resources planning.

Marked increase in measles vaccination coverage among young adults in Switzerland: a campaign or cohort effect?

OBJECTIVES: To evaluate the impact of the Swiss measles elimination strategy-including a mass media campaign-on vaccination coverage and awareness among young adults aged 20-29 years. METHODS: Comparison of the results of two cross-sectional population surveys in 2012 and 2015. RESULTS: Documented vaccination coverage increased from 77 to 88% for two doses of measles vaccine. Major determinants of complete vaccination were survey year, birth cohort, sex and the absence of prior measles disease. If birth cohort and prior history of measles disease are included as factors in a multivariate model, the difference between 2012 and 2015 vanishes. CONCLUSIONS: The marked increase in complete measles vaccination coverage is due to a cohort effect, owing to the introduction of the second dose of vaccine in 1996. Most of the vaccinations were administered before the national strategy was implemented and vaccination catch-ups did not increase during the campaign in young adults. Nevertheless, this study provides evidence of an improvement in the awareness of measles and measles vaccination in young adults, which may result in an impact on measles vaccination coverage in the near future.

Human papillomavirus vaccine uptake in adolescence and adherence to cervical cancer screening in Switzerland: a national cross-sectional survey.

OBJECTIVES: The objectives were to measure uptake of and factors associated with human papillomavirus (HPV) vaccination initiation and to determine whether HPV vaccination reduced the uptake of cervical cancer screening. METHODS: We conducted a cross-sectional survey in a random sample of Swiss women aged 18-49 years in 2014 (N = 3588). RESULTS: Vaccination initiation was 69.3% and full coverage (three doses) 54.1% for 18-20-year olds, respectively, 42.4% and 33.9% for 21-24-year olds. Women with ≥ 10 lifetime sexual partners were less likely to have received any HPV vaccination than women with ≤ 2 partners (18-20 years OR 0.2, 21-24 years OR 0.5). Amongst 1000 unvaccinated women (18-24 years), reasons for not having initiated vaccination were lack of information (22.5%) and fear of vaccine side effects (18.1%). Vaccination status was not associated with adherence to cervical cancer screening recommendations (OR 1.3). 95.4% of all vaccinated participants knew about the continued need for screening. CONCLUSIONS: Our data suggest that HPV vaccination is not associated with reduced uptake of cervical cancer screening. This study provides information that can be used to improve HPV vaccination uptake in Switzerland.

Prospective pertussis surveillance in Switzerland, 1991-2006.

Pertussis has been monitored in Switzerland since 1991 by the nationwide Swiss Sentinel Surveillance Network (SSSN), consisting of approximately 200 general practitioners, internists and pediatricians representing about 3% of the total primary care physicians of these specialities. SSSN members report patients with cough ≥ 14 days plus either an epidemiological link or characteristic symptoms (paroxysms, whoop, post-tussive vomiting) on a weekly basis to the Federal Office of Public Health. Confirmatory PCR from nasopharyngeal specimens is offered for free. A total of 4992 cases have been reported until 2006. Yearly incidence has dropped from 70 cases per 100,000 inhabitants in 1992 to 40 in 2006, with a single epidemic in 1994-1995 with 280-370 cases/100,000. On average 80% of reported cases were tested by PCR, 24% of these were confirmed as Bordetella pertussis infections. For 2.6% of patients complications were reported, most commonly pneumonia, asthma bronchiale, otitis media, bronchitis and rib fractures. On average, 1.5% of patients were hospitalized. Disease in vaccinated patients was mitigated with less frequent complications (unvaccinated: 5.1%; 3 doses: 3.0%; ≥ 4 doses: 1.7%), hospitalizations (unvaccinated: 3.6%; ≥ 1 dose: 1.1%) and various clinical symptoms compared to unvaccinated patients. Comparing the periods 1991-1996, 1997-2001 and 2002-2006, a shift of pertussis from age group 1-9 years to 10-19 and ≥ 40 years was observed among patients cared for by general practitioners and internists. The benefits of further booster doses in adolescents and/or adults need to be considered.

Gastrointestinal parasite egg excretion in young calves in periurban livestock production in Mali.

To acquire the information needed to improve parasite control in periurban cattle production in Mali, repeated sampling of faeces of 694 calves kept around Bamako was done in 2003/2004. The effects of season, age, breed, management type, parasite control and presence of sheep on egg and oocyst counts were determined. A Bayesian model was used with a negative binomial distribution and herd and individual effects, to account for the clustering of calves in herds and the repeated sampling. Interviews were conducted to report the current control strategies. We found eggs of Strongyloides papillosus (Age class 0-1 month: prevalence 39%, 2-3 months: 59%, 5-6 months: 42%), strongyles (14%, 24%, 36%), coccidian oocysts (37%, 68%, 64%) and at low prevalence eggs of Toxocara vitulorum, Moniezia sp., Trichuris sp. and Paramphistomum sp. Season and age effects occurred. Reported utilisation of parasite control was high (92%) but monthly recorded use was significantly lower (61%).

Species diversity and acquisition of gastrointestinal parasites in calves aged 0-13 months in periurban livestock production in Mali.

Post-mortem inspections on 51 calves were conducted to investigate acquisition and spectrum of gastrointestinal parasites in young calves in periurban livestock production in Mali. Generalized linear models with herd as a repeated effect were used to test the influence of management, age and season of birth on parasite numbers and diversity. Parasite number and burden increased with age. In the age class 4-13 months animals carried already up to eight different gastrointestinal parasite species. Parasite spectrum found included 11 nematodes, 3 cestodes and 1 protozoan parasite. The most frequent parasite species found were Haemonchus placei (age class 0-1 month: 7%, 1-4 months: 38%, 4-13 months: 69%), Cooperia pectinata (0%, 33% and 44%) and C. punctata (0%, 33% and 38%). Calves born during the rainy season had higher parasite burden and species diversity than calves born during the dry season. Calves kept under modernised management excreted more Strongyloides papillosus eggs than calves kept under traditional management. Calves acquired most of the parasites occurring in adult bovines in West Africa within their first year of life.