mRNA vaccine effectiveness against hospitalisation due to severe acute respiratory infection (SARI) COVID-19 during Omicron variant predominance estimated from real-world surveillance data, Slovenia, February to March 2022.

For the period of predominance of SARS-CoV-2 Omicron variant in Slovenia, February to March 2022, we estimated mRNA vaccine effectiveness (VE) against severe acute respiratory infection (SARI) COVID-19 using surveillance data. In the most vulnerable age group comprising individuals aged 65 years and more, VE against SARI COVID-19 was 95% (95% CI: 95-96%) for those vaccinated with three doses, in comparison to 82% (95% CI: 79-84%) for those vaccinated with two doses. Such levels of protection were maintained for at least 6 months.

Vaccine effectiveness against severe acute respiratory infections (SARI) COVID-19 hospitalisations estimated from real-world surveillance data, Slovenia, October 2021.

We estimated vaccine effectiveness (VE) against severe COVID-19 during October 2021, using Slovenian surveillance data. For people fully vaccinated with any vaccine in age groups 18-49, 50-64, ≥ 65 years, VE was 86% (95% CI: 79-90), 89% (85-91), and 77% (74-81). Among ≥ 65 year-olds fully vaccinated with mRNA vaccines, VE decreased from 93% (95% CI: 88-96) in those vaccinated ≤ 3 months ago to 43% (95% CI: 30-54) in those vaccinated ≥ 6 months ago, suggesting the need for early boosters.

Enhanced national surveillance of severe acute respiratory infections (SARI) within COVID-19 surveillance, Slovenia, weeks 13 to 37 2021.

We monitored trends of severe COVID-19 morbidity in Slovenia during weeks 13 to 37 2021. National weekly rates of severe acute respiratory infections (SARI) cases testing positive for SARS-CoV-2 at admission in all hospitals varied between 0.2 and 16.3 cases per 100,000 population. Of those without previous COVID-19 diagnosis, SARI COVID-19 admission rates ranged between 0.3 and 17.5 per 100,000 unvaccinated, and 0.0 and 7.3 per 100,000 fully vaccinated individuals. National SARI COVID-19 surveillance is essential in informing COVID-19 response.

Initial assessment of the COVID-19 vaccination's impact on case numbers, hospitalisations and deaths in people aged 80 years and older, 15 EU/EEA countries, December 2020 to May 2021.

Prioritisation of elderly people in COVID-19 vaccination campaigns aimed at reducing severe outcomes in this group. Using EU/EEA surveillance and vaccination uptake, we estimated the risk ratio of case, hospitalisation and death notifications in people 80 years and older compared with 25-59-year-olds. Highest impact was observed for full vaccination uptake 80% or higher with reductions in notification rates of cases up to 65% (IRR: 0.35; 95% CI: 0.13-0.99), hospitalisations up to 78% (IRR: 0.22; 95% CI: 0.13-0.37) and deaths up to 84% (IRR: 0.16; 95% CI: 0.13-0.20).

Estimating the annual burden of tick-borne encephalitis to inform vaccination policy, Slovenia, 2009 to 2013.

With an annual incidence between 8 and 15 per 100,000 population in the period from 2009 to 2013, Slovenia has one of the highest notified incidences of tick-borne encephalitis (TBE) in Europe. TBE vaccination coverage remains at about 7.3%. To inform vaccination policy, we used surveillance data from 2009 to 2013 to calculate the overall and age- and sex-specific mean annual TBE incidence. We estimated disability-adjusted life years (DALYs) with 95% uncertainty intervals (UI), using the Burden of Communicable Diseases in Europe approach from the European Centre for Disease Prevention and Control. The mean annual incidence was 11.6 per 100,000 population, peaking in older age groups (50-74 years: 18.5/100,000) while relatively lower among children (5-14 years: 10.2/100,000). We estimated an overall 10.95 DALYs per 100,000 population per year (95% UI: 10.25-11.65). In contrast to the TBE incidence, the disease burden in children aged 5-14 years was higher than in adults aged 50-74 years: 17.31 (95% UI: 14.58-20.08) and 11.58 (95% UI: 10.25-12.91) DALYs per 100,000 stratum-specific population, respectively. In a limited resource setting where prioritisation of TBE vaccination strategies is required, vaccination programmes targeting children may have a higher impact on disease burden.

Adverse events following school-based vaccination of girls with quadrivalent human papillomavirus vaccine in Slovenia, 2009 to 2013.

Adverse events following immunisation (AEFIs) with qHPV reported to the Slovenian AEFI Registry for the first four school years of the vaccination programme were analysed. We calculated annual reporting rates for 11-14 year-old vaccinees with AEFIs, using the number of qHPV doses distributed within the school-based vaccination programme as the denominator. Between September 2009 and August 2013, 211 AEFIs that occurred in 89 vaccinees were reported, a rate of 149.5 vaccinees with AEFI per 100,000 qHPV doses distributed. For five vaccinees, serious AEFIs (8.4 per 100,000 doses distributed) were reported. The highest reporting rates were for fatigue, headache, and fever (≥ 38.0°) (53.8, 40.3, and 35.3 per 100,000 qHPV doses distributed, respectively). As no AEFI resulted in permanent sequelae and they all were categorised as serious only due to the criterion of a minimum of one day of hospitalisation, this provides reassurance for the safety of our school-based HPV vaccination programme. Further AEFI surveillance is warranted to provide data for HPV vaccination programme monitoring and evaluation of its safety.

Pre-vaccination prevalence of infections with 25 non-high-risk human papillomavirus types among 1,000 Slovenian women in cervical cancer screening.

Cervical infections with non-high-risk human papillomavirus (non-HR-HPV) types have been associated with genital warts and a fraction of atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions. The pre-vaccination prevalence of cervical infections with 25 non-HR-HPV types has been estimated, regardless of and without the coexistence of infection with HR-HPV types among Slovenian women 20-64 years old in cervical cancer screening, overall and according to age and cytology result. One thousand cervical specimens selected randomly from 4,455 specimens collected in 2010 in the Slovenian HPV prevalence survey were tested with Linear Array HPV Genotyping Test. Prevalence of cervical infections with any of the 25 non-HR-HPV types was 10.0% (95% CI: 8.1-11.9%) and with exclusively non-HR-HPV types 4.5% (95% CI: 3.2-5.8%). Prevalence of infections with any non-HR-HPV types among women with normal cytology was 8.8%, with atypical squamous cells of undetermined significance 30.4%, with low-grade squamous intraepithelial lesions 60.0%, and with high-grade squamous intraepithelial lesions 7.7%. Non-HR-HPV types without coexisting HR-HPV types were found in 4.0% of women with normal cytology, 26.1% with atypical squamous cells of undetermined significance, 6.7% with low-grade squamous intraepithelial lesions, and none with high-grade squamous intraepithelial lesion. Non-HR-HPV type cervical infections without coexisting HR-HPV infections were common among Slovenian women in cervical cancer screening with atypical squamous cells of undetermined significance, while rare in those with low-grade squamous intraepithelial lesions or worse. J. Med. Virol. 86: 1772-1779, 2014. © 2014 Wiley Periodicals, Inc.

Comparison of clinical and analytical performance of the Abbott Realtime High Risk HPV test to the performance of hybrid capture 2 in population-based cervical cancer screening.

The clinical performance of the Abbott RealTime High Risk HPV (human papillomavirus) test (RealTime) and that of the Hybrid Capture 2 HPV DNA test (hc2) were prospectively compared in the population-based cervical cancer screening setting. In women >30 years old (n = 3,129), the clinical sensitivity of RealTime for detection of cervical intraepithelial neoplasia of grade 2 (CIN2) or worse (38 cases) and its clinical specificity for lesions of less than CIN2 (3,091 controls) were 100% and 93.3%, respectively, and those of hc2 were 97.4% and 91.8%, respectively. A noninferiority score test showed that the clinical specificity (P < 0.0001) and clinical sensitivity (P = 0.011) of RealTime were noninferior to those of hc2 at the recommended thresholds of 98% and 90%. In the total study population (women 20 to 64 years old; n = 4,432; 57 cases, 4,375 controls), the clinical sensitivity and specificity of RealTime were 98.2% and 89.5%, and those of hc2 were 94.7% and 87.7%, respectively. The analytical sensitivity and analytical specificity of RealTime in detecting targeted HPV types evaluated with the largest sample collection to date (4,479 samples) were 94.8% and 99.8%, and those of hc2 were 93.4% and 97.8%, respectively. Excellent analytical agreement between the two assays was obtained (kappa value, 0.84), while the analytical accuracy of RealTime was significantly higher than that of hc2. RealTime demonstrated high intralaboratory reproducibility and interlaboratory agreement with 500 samples retested 61 to 226 days after initial testing in two different laboratories. RealTime can be considered to be a reliable and robust HPV assay clinically comparable to hc2 for the detection of CIN2+ lesions in a population-based cervical cancer screening setting.

Acceptance of Seasonal Influenza Vaccination Among Slovenian Physicians, 2016.

INTRODUCTION: Vaccination against seasonal influenza is recommended for all healthcare workers including physicians in Slovenia to protect vulnerable individuals and reduce transmission of influenza viruses. The aim of our study is to determine the uptake of seasonal influenza vaccination among Slovenian physicians, to identify factors associated with that vaccination and assess their attitudes and beliefs regarding vaccination and vaccine-preventable diseases. METHODS: A cross-sectional survey was performed among physician members of the Slovenian Medical Chamber. The link to the anonymous web-based questionnaire was sent to 8,297 physicians. We estimated the overall proportion of physicians who vaccinate against influenza, while the possible associations with collected explanatory variables were explored in univariate analyses. RESULTS: The response rate to the survey was 10.8%. 75.9% (95% CI: 73.1-78.7%) physicians vaccinate themselves against influenza (regularly or occasionally) and 24.1% (95% CI: 21.2-26.8%) do not vaccinate (not any more or never). In univariate analysis only, the area of work was statistically significant when associated with vaccinating against influenza (p=0.002). Among physicians who expressed some misconceptions regarding vaccination and vaccine-preventable diseases (it is better to overcome disease naturally as vaccines pose a higher risk than disease) the proportion of vaccinated against influenza was low (43.2%; 95% CI: 27.9-58.4%, 27.3%; 95% CI: 7.1-47.5%). CONCLUSION: Not trusting in vaccination or professional recommendations regarding vaccination and some misconceptions regarding vaccination and vaccine-preventable diseases may influence the decision to be vaccinated against seasonal influenza among Slovenian physicians.

Vaccine confidence among mothers of young children, Slovenia, 2016.

OBJECTIVES: We conducted the first nationwide survey in Slovenia to measure and characterise vaccine confidence among mothers of young children. This survey measured confidence in routine vaccines for children <2 years of age and in the information sources about these vaccinations to provide baseline data for public health actions to maintain and improve vaccination coverage. METHODS: We randomly selected women giving birth in 2014-15 from the national perinatal information system (N = 39,497). Participants were asked to rate statements measuring vaccine confidence, including confidence in their child's paediatrician, the Slovenian healthcare system, and different paediatric vaccination information sources. We estimated vaccine confidence with 95% confidence intervals (CI), for seven socio-demographic characteristics for mothers with young children. Spearman's rank correlation coefficient was used to assess correlations between vaccine confidence and the confidence in the health system or child's paediatrician. RESULTS: We sent out 3854 questionnaires, the response rate was 44.4%. While 46.8% (95% CI: 44.4-49.2%) mothers were confident in vaccines, 34.2% (95% CI: 32.0-36.6%) were undecided. We found a correlation (Spearman's rho = 0.457) between vaccine confidence and confidence in the child's paediatrician. Mothers that were confident in paediatrician were more likely to be confident in vaccines (odds ratio: 7.7; 95% CI: 5.3-11.3). Overall, the most frequently trusted information source were physicians (84.6%). In contrast, among mothers not at all confident in vaccines, 51.9% reported friends as the trusted information source. CONCLUSION: More than half of mothers had low vaccine confidence or were undecided regarding their confidence. While vaccination coverage in Slovenia is high, these levels warrant public health intervention, particularly with the undecided mothers. Communication strategies should focus first on undecided parents and involve physicians, who for many are the most trusted vaccine information source. Different approaches will likely be required for those who are not at all confident in vaccines.

An outbreak of acute gastroenteritis associated with group A Rotavirus in long-term care facility in Slovenia.

BACKGROUND: In April 2013, an outbreak of acute gastroenteritis was reported in a residential long-term care facility (LTCF) in Ljubljana. We carried out an outbreak investigation to describe the outbreak, identify factors associated with contracting infection and to recommend control measures. METHODS: We conducted descriptive epidemiology of the outbreak and a case-control study among residents; a case was a resident or staff member of the LTCF with acute diarrhoea and at least one of the following symptoms: fever, vomiting, nausea, fatigue, headache and abdominal pain between 11 and 23 April 2013. Controls had no gastrointestinal symptoms during the outbreak period. Stool specimens were tested for enteric pathogens, including Rotavirus. RESULTS: Of 244, 33 (13.5 %) and 4 of 106 staff (3.8 %) were affected. Twenty-eight (84.8 %; median age 85 years; range 71-95 years) among affected residents and four (100 %; median age 35 years; range 30-45 years) among affected staff were women. The main symptoms besides acute diarrhoea were fatigue (54.1 %) and nausea (45.9 %). The average duration of gastroenteritis symptoms was 3.6 days in residents and 1.3 days in staff. None of the affected persons was hospitalized. Rotavirus group A was detected in a single stool specimen. In the multivariable analysis, being ambulant (aOR = 12.3; 95 % CI: 1.14-133.1), and having more than two comorbidities (aOR = 4.7; 95 % CI: 1.14-19.0) were significantly associated with acute gastroenterocolitis. CONCLUSIONS: Contact precautions of affected persons and controlled staff interactions between outbreak ward and unaffected ward are recommended in times of outbreak, with additional effort in targeting mobile residents and those with comorbidities.

A Five Site Clostridium Perfringens Food-Borne Outbreak: A Retrospective Cohort Study.

INTRODUCTION: In May of 2012, we investigated a food-borne Clostridium perfringens outbreak in Slovenia involving a single kitchen and five venues, with 477 exposed persons. METHODS: In order to identify the causative agent, vehicle of infection and source of contamination, we conducted microbiological and environmental investigations and an analytical cohort study (n = 138). RESULTS: The case definition in the outbreak was met by 104 persons. Predominant symptoms were diarrhoea, nausea and abdominal cramps. Median incubation time and duration of illness were 12 and 22.5 hours respectively. Stool samples were collected from 18 persons and in 13 C. perfringens spores were present; enterotoxin was detected in 9 persons. PCR and PFGE analysis of isolates from a cook with earlier onset time, who did not consume the implicated food, and cases from four venues showed the same strain of C. perfringens type A (with cpe-gene), indistinguishable by PFGE analysis. No food samples could be obtained. An analytical study showed that one food item (French salad) was the most likely vehicle of infection (RR: 6.35; 95% CI: 1.62-24.90). CONCLUSIONS: This was the largest C. perfringens outbreak in Slovenia to date. Proper analytical study in combination with detailed laboratory investigation with genotypisation enabled us to identify a causative agent, vehicle of infection and possible source of contamination. Fast response and interdisciplinary collaboration led to timely implementation of control measures. These have led to the kitchen acquiring new equipment and improving staff knowledge of risks and processes, thus reducing the likelihood of future reoccurrences.

A comparison of the demographic and clinical characteristics of laboratory-confirmed influenza B Yamagata and Victoria lineage infection.

BACKGROUND: The evolution of influenza viruses is characterized by the co-circulation of two antigenically and genetically distinct lineages B/Victoria/2/87-like viruses (Victoria) and B/Yamagata/16/88-like viruses (Yamagata). To date, there is not much data associating lineages variation with demographic and clinical data. OBJECTIVES: We compared the demographic and clinical characteristics of patients with laboratory-confirmed influenza B Victoria or Yamagata lineage infection. STUDY DESIGN: We retrospectively analyzed data from 6811 patients aged from <1 through 99 years with influenza like-illness who consulted the sentinel site or sentinel hospital in the seasons 2010/2011, 2011/2012 and 2012/2013. There were 662 patients positive for influenza B virus by multiplex real-time RT-PCR. Six hundred thirty-seven (96.8%) were successfully subtyped for Victoria or Yamagata lineage infection. The available demographic and clinical data was compared. RESULTS: Patients with the Victoria lineage were significantly younger compared to patients infected with the Yamagata lineage. The Victoria lineage was the predominant strain in the 15-34 age groups in patients consulting at primary care level and in hospitalized patients. In the youngest age group (0-4 years) approximately half of the confirmed influenza B cases belonged to the Victoria (55%) and the rest to the Yamagata lineage (45%). Aside from age, there was no statistically significant difference found in gender distribution, vaccination history, clinical presentation or risk factors for severe influenza infection in hospitalized patients after adjustment for the age. CONCLUSIONS: The frequency of influenza B Victoria and Yamagata infection is age dependent with no significant differences detected in clinical presentation comparing both lineages.

The impact of influenza and respiratory syncytial virus on hospitalizations for lower respiratory tract infections in young children: Slovenia, 2006-2011.

BACKGROUND: Influenza and respiratory syncytial viruses (RSV) are important viral pathogens in childhood. OBJECTIVES: Our aim was to estimate the effect of influenza and RSV on excess hospitalizations for acute lower respiratory tract infections (ALRTI) in children aged≤5. METHODS: Retrospective, population-based study was performed for five seasons (2006-2011). Slovenian national hospital discharge data and surveillance data were used to estimate the effect of influenza and/or RSV on ALRTI hospitalizations (acute bronchiolitis, pneumonia, and acute bronchitis) using rate difference method. RESULTS: An excess was observed in average weekly ALRTI hospitalizations per 100,000 among children aged≤5 in all five seasons during influenza and/or RSV active period. During three seasons, there was higher excess in ALRTI hospitalizations in the period when influenza/RSV cocirculated compared with the RSV period. In pandemic season (2009/2010), the only one without influenza/RSV overlap, excess hospitalization was higher in RSV period. The highest excess of hospitalizations was found among the youngest children (0-5 months old). In all five seasons, acute bronchiolitis was the most common ALRTI recorded in hospitalized young children. CONCLUSIONS: Respiratory syncytial viruses was leading viral pathogen associated with ALRTI hospitalizations in children aged≤5. The cocirculation of influenza virus increased the burden of ALRTI hospitalizations especially in seasons with A(H3) predominance.

Serum antibodies to human papillomavirus (HPV) pseudovirions correlate with natural infection for 13 genital HPV types.

BACKGROUND: Serology for human papillomaviruses (HPV) types -16 and -18 is established as an important tool for studies of HPV vaccinology and epidemiology. However, as there are a large number of oncogenic genital types of HPV there is a need for development of high-throughput, validated HPV serological assays that can be used for more comprehensive seroepidemiological studies and for research on multivalent HPV vaccines. OBJECTIVES: To develop a multiplexed pseudovirion-based serological assay (PsV-Luminex) encompassing 21 HPV types and validate the method by correlating the serology with the presence of type specific HPV DNA in cervical samples. STUDY DESIGN: Cervical swabs from 3,291 unvaccinated women attending organized cervical screening in Slovenia were tested with 3 different HPV DNA detection methods and presence of HPV DNA compared to presence of serum antibodies to pseudovirions from 15 genital HPV types (HPV-6,-11,-16,-18,-31,-33,-35,-39,-45,-52,-56,-58,-59,-68,-73). RESULTS: On average 51% of the HPV DNA positive women were seropositive for the same HPV type that was detected in the cervical specimen. We found a strong correlation with presence of HPV DNA and antibodies to the same HPV type for 13/15 genital HPV types (median OR = 5.7, CI 95% = 2.4-12.9). HPV-52 serology failed the validation and HPV-11 serology could not be validated because only a single woman was positive for HPV-11 DNA. The correlation between serology and HPV DNA status tended to be stronger among women infected with single HPV type (median OR=10.5, CI 95% = 2.4-48.4) than among women with multiple HPV infections (median OR = 4.6, CI 95% = 1.8-11.7). CONCLUSIONS: A multiplexed HPV PsV-Luminex assay has been developed and validated to correlate with natural HPV infection for 13 HPV types, thus enabling more comprehensive studies in HPV epidemiology and vaccine research.

Pre-vaccination seroprevalence of 15 human papillomavirus (HPV) types among women in the population-based Slovenian cervical screening program.

OBJECTIVES: To estimate seroprevalence of 11 high-risk (hr) HPV types and four low-risk (lr) HPV types among 20-64 years old Slovenian women participating in the population-based cervical cancer screening program. METHODS: Serum samples from 3259 women were tested for HPV type-specific antibodies with a multiplexed pseudovirion-based serological assay (PsV-Luminex). RESULTS: Seropositivity for any of the 15 HPV types was 65.7%, any of the 11 hr-HPV types 59.2%, and any of the four lr-HPV types 33.1%. Antibodies against at least one of the four vaccine HPV types (HPV 6, 11, 16, 18) were detected in 40.8% women. Among hr-HPV types, seropositivity was highest for HPV 16 (25.2%) and among lr-HPV types for HPV 6 (19.1%). Age-specific HPV16 seropositivity was highest among 30-39 years old (29.6%) and decreased with increasing age to 14.0% among 60-64 years old. CONCLUSION: The lifetime sexual exposure to genital HPV types is substantial, emphasising the need for HPV vaccination.

Current status of human papillomavirus vaccination implementation in central and eastern Europe.

We present a review of the current implementation status of vaccination against human papillomaviruses (HPV) and available data concerning the burden of HPV infection and HPV type-specific distribution in 16 central and eastern European countries: Albania, Bosnia and Herzegovina, Bulgaria, Croatia, the Czech Republic, Estonia, Montenegro, Poland, Romania, Serbia, Slovakia, Slovenia, and The Former Yugoslav Republic of Macedonia. At least one current HPV prophylactic vaccine is registered in all central and eastern European countries except Montenegro. Six counties-Bulgaria, the Czech Republic, Latvia, Romania, Slovenia, and Former Yugoslav Republic of Macedonia-have integrated the HPV vaccination into their national immunization program and currently provide routine vaccination free of charge to the primary target population. Ten countries have not integrated HPV vaccination into the national immunization program. The key reasons for lack of implementation of HPV vaccination into the national immunization program are the high vaccine cost and negative public perception. Vaccination of males is not recommended in any country in the region.

Pre-vaccination prevalence and distribution of high-risk human papillomavirus (HPV) types in Slovenian women: a cervical cancer screening based study.

To estimate the pre-vaccination prevalence of cervical infections with 14 high-risk human papillomavirus (hr-HPV) types among 20-64 years old Slovenian women screened for cervical cancer in 2010, we consecutively enrolled 4431 women in 16 outpatient gynaecology services. All were screened with Digene Hybrid Capture 2 HPV DNA Test and Abbott Real Time High Risk HPV Test and all positive specimens genotyped. Prevalence of cervical infection with any hr-HPV type examined was 12.9% with HPV16 3.5% and with HPV18 1.0%. Age specific prevalence estimates were the highest among 20-24 years old women and decreased with age. HPV16 prevalence was lowest among women without evidence of cervical disease and increased with the severity to 41.9% in women with high grade squamous intraepithelial lesion. Our results provide baseline data for monitoring the impact of Slovenian HPV vaccination program and development of future cervical cancer screening strategies in cohorts eligible for free HPV vaccination.

Surveillance of adverse events following immunization against pandemic influenza in Slovenia in season 2009/10.

The results of Slovenian surveillance system of AEFI which was in place for the early detection and investigation of rare adverse events were analysed. The reports about AEFI obtained from physicians, and self-assessment questionnaires from vaccinated persons showed predominantly non-serious and expected side effects. Nine reports (3%) included serious AEFI. No deaths consequent to vaccination were reported. A total of 1170 AEFI were reported by physicians and 1030 by self-assessment. Overall, the most commonly reported AEFI either by physicians or persons were local site reactions (37.3% and 50.5%), tiredness (11.9% and 6.8%) and fever or malaise (10.8% and 6.3%). More than 100,000 people were vaccinated with pandemic vaccines in Slovenia. The type and the frequency of AEFI detected through Slovenian AEFI surveillance system are comparable to the results from other surveillance systems. The benefit-risk balance for the pandemic vaccines used in Slovenia remains positive.