[SARS-CoV-2 Exposure and Seroprevalence of SARS-CoV-2 Antibodies among Medical Students in the First Phase of the Pandemic 2020-2021]. / SARS-CoV-2 Exposition und Seroprävalenz von SARS-CoV-2-Antikörpern bei Medizinstudierenden in der ersten Phase der Pandemie, 2020­2021.

BACKGROUND: Due to their clinical training and secondary activities in the hospital, medical students are exposed to contact with SARS-CoV-2 infected people more often than the general population. We determined the seroprevalence of SARS-CoV-2 antibodies in medical students in clinical training at different times during the pandemic and asked participants about possible SARS-CoV-2 exposures in both medical and private settings. METHODS: From May 2020 to June 2021, medical students each in their 3rd year of training at the University Hospital Würzburg participated in the cross-sectional survey. All SARS-CoV-2 unvaccinated students were offered a determination of their SARS-CoV-2 serostatus. The blood samples were tested by an immunoassay (Elecsys, Roche) for IgG/IgM/IgA antibodies against the SARS-CoV-2 N antigen. Demographic data, SARS-CoV-2 disease and vaccination status, as well as possible SARS-CoV-2 exposures were collected using a questionnaire. RESULTS: Overall, 383 (86.1%) of 445 students took part in the cross-sectional survey (65% female; median age 22 years; IQR 21-24). Serostatus was determined in 223 (58.2% of 383) SARS-CoV-2 unvaccinated participants. In the period between the beginning of the pandemic in Germany (February 2020) and the time of the survey, 332 (86.7% of 383) students stated that they worked in the medical field, mainly in the context of clinical traineeships (76.8%) or secondary activities with patient contact (48.8%); 129 (33.7%) reported previous contact with a COVID-19 patient, of which 78.3% of contacts took place at a medical facility. Antibodies against SARS-CoV-2 were detected in 8 (3.6%) of the 223 unvaccinated participants tested, and in 3 infected persons an association between infection and contact in the course of medical activity seemed likely. CONCLUSION: Despite frequent patient contact and the associated increased risk of infection, medical students in their 3rd year of training did not show an increased seroprevalence compared to the general population and showed a lower or similar seroprevalence rate than medical students in other European countries in the first 18 months of the pandemic. This indicates sufficient protection of medical students at the beginning of clinical training through the hygiene and infection protection measures implemented at that time during medical activities.

[Can SARS-CoV-2 Infection Status in Preschool Children be Predicted by Pandemic-related Attitudes and Concerns of their Parents? Data from the Würzburg Daycare Centre Studies (Wü-KiTa-CoV, 2020-2022)]. / Lässt sich der SARS-CoV-2-Infektionsstatus bei Kindern über pandemiebezogene Einstellungen und Sorgen ihrer Eltern vorhersagen? Daten der Würzburger Kindertagesstätten-Studien (Wü-KiTa-CoV, 2020­2022).

As part of the Würzburg KiTa-CoV study series, SARS-CoV-2 pandemic-related attitudes/concerns of parents of preschool children attending day care centres were surveyed over a 21-month period. We expected associations between these parental attitudes/concerns and their change over the course of the pandemic, on the one hand, and the SARS-CoV-2 infection status of the children, on the other. Parents of children from nine day-care centres who completed a survey on pandemic-related attitudes/concerns in October 2020, July 2021 and July 2022, were included in the analysis. In July 2022, the children's infection status was determined by measuring nucleocapsid protein antibodies (N-AK) and, in the case of N-AK negative, unvaccinated children, the measurement results of spike protein antibodies (S-AK) against SARS-CoV-2 as indicators of previous infection were also taken into account. Changes in parental attitudes/concerns were analysed using trend tests, and their significance in predicting the child's infection status was analysed using multiple binomial regression analyses. Data were available from parents of 159 children (mean age 3.2 years). The overall group of parents showed an increasingly relaxed attitude towards the pandemic over the study period, although the parents' concerns towards a possible infection of their own increased. The infection status of the children could not be predicted from the initial attitudes and concerns of the parents. However, the subgroup of parents with an uninfected child tended to have a higher level of concerns over the course of the pandemic than the parents with an infected child and did not show the same increasing composure towards the pandemic event. The parents' increasing composure is understandable in the context of the reduced virulence of the virus variants prevailing over time, the increasing availability of testing strategies and vaccinations, and the withdrawal of pandemic-related restrictions. In addition, the mildness of most children's infections may have contributed to their parents' sense of security. The seemingly contradictory increase in parental concerns about infection may be related to the strong increase in the incidence due to omicron variant infections in the population since January 2022. It is possible that the higher level of concerns among parents of uninfected children had a protective effect behaviourally.

Hospitalizations due to respiratory syncytial virus (RSV) infections in Germany: a nationwide clinical and direct cost data analysis (2010-2019).

PURPOSE: Clinical and direct medical cost data on RSV-related hospitalizations are relevant for public health decision-making. We analyzed nationwide data on RSV-coded hospitalizations from Germany in different age and risk groups. METHODS: Assessment of RSV-coded hospitalizations (ICD-10-GM RSV-code J12.1/J20.5/J21.0 as primary discharge diagnosis) from 01/2010 to 12/2019, using remote data retrieval from the Hospital Statistics Database of the German Federal Statistical Office. RESULTS: Overall, 205,352 RSV-coded hospitalizations (198,139 children < 18 years, 1,313 adults, 5,900 seniors > 59 years) were reported (median age < 1 year, IQR 0; 1; 56% males, 32% with RSV pneumonia). Annual median RSV-coded hospitalization incidence was 24.8/100,000 persons (IQR 21.3; 27.5); children reported a median incidence of 145.8 (IQR 130.9; 168.3). Between 2010 and 2019, hospitalization incidence increased 1.7-fold/15.1-fold/103-fold in children/adults/seniors. Adults and seniors reported higher rates of underlying chronic conditions, complications, and intensive care treatment than children; of 612 in-hospital fatalities, 103/51/458 occurred in children/adults/seniors. Per-patient mean costs varied between 3286€ ± 4594 in 1-4-year-olds and 7215€ ± 13,564 among adults. Increased costs were associated with immune disorders (2.55-fold increase compared to those without), nervous system disorders (2.66-fold), sepsis (7.27-fold), ARDS (12.85-fold), intensive care (4.60-fold) and ECMO treatment (16.88-fold). CONCLUSION: The economic burden of RSV-related hospitalizations in Germany is substantial, even when only considering cases with RSV-coded as the primary discharge diagnosis. Children represented the vast majority of RSV-coded hospitalizations. However, adults and seniors hospitalized for RSV were at a higher risk of severe complications, required more costly treatments, and had higher fatality rates; although their RSV-coded hospitalization incidence showed a clear upward trend since 2017, their true hospitalization incidence is still likely to be underestimated due to lack of routine RSV testing in these age groups. Hence, new treatments and vaccines for RSV ideally should also target adults and seniors in addition to children.

SARS-CoV-2 sero-immunity and quality of life in children and adolescents in relation to infections and vaccinations: the IMMUNEBRIDGE KIDS cross-sectional study, 2022.

PURPOSE: The study evaluates the effects on sero-immunity, health status and quality of life of children and adolescents after the upsurge of the Omicron variant in Germany. METHODS: This multicenter cross-sectional study (IMMUNEBRIDGE Kids) was conducted within the German Network University Medicine (NUM) from July to October 2022. SARS-CoV-2- antibodies were measured and data on SARS-CoV-2 infections, vaccinations, health and socioeconomic factors as well as caregiver-reported evaluation on their children's health and psychological status were assessed. RESULTS: 497 children aged 2-17 years were included. Three groups were analyzed: 183 pre-schoolchildren aged 2-4 years, 176 schoolchildren aged 5-11 years and 138 adolescents aged 12-18 years. Positive antibodies against the S- or N-antigen of SARS-CoV-2 were detected in 86.5% of all participants (70.0% [128/183] of pre-schoolchildren, 94.3% of schoolchildren [166/176] and 98.6% of adolescents [136/138]). Among all children, 40.4% (201/497) were vaccinated against COVID-19 (pre-schoolchildren 4.4% [8/183], schoolchildren 44.3% [78/176] and adolescents 83.3% [115/138]). SARS-CoV-2 seroprevalence was lowest in pre-school. Health status and quality of life reported by the parents were very positive at the time of the survey (Summer 2022). CONCLUSION: Age-related differences on SARS-CoV-2 sero-immunity could mainly be explained by differences in vaccination rates based on the official German vaccination recommendations as well as differences in SARS-CoV-2 infection rates in the different age groups. Health status and quality of life of almost all children were very good independent of SARS-CoV-2 infection and/or vaccination. TRIAL REGISTRATION: German Registry for Clinical Trials Identifier Würzburg: DRKS00025546 (registration: 11.09.2021), Bochum: DRKS00022434 (registration:07.08.2020), Dresden: DRKS 00022455 (registration: 23.07.2020).

Clinical Burden of Respiratory Syncytial Virus in Hospitalized Children Aged ≤5 Years (INSPIRE Study).

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of hospitalizations in children (≤5 years of age); limited data compare burden by age. METHODS: This single-center retrospective study included children (≤5 years of age) hospitalized for >24 hours with reverse-transcription polymerase chain reaction (RT-PCR)-confirmed RSV infection (2015-2018). Hospital length of stay (LOS), intensive care unit (ICU) admissions, ICU LOS, supplemental oxygen, and medication use were assessed. Multivariate logistic regression analyses identified predictors of hospital LOS >5 days. RESULTS: Three hundred twelve patients had RSV infection (ages 0 to <6 months [35%], 6 to <12 months [15%], 1 to <2 years [25%], and 2-5 years [25%]); 16.3% had predefined comorbidities (excludes preterm infants). Median hospital LOS was 5.0 days and similar across age; 5.1% (16/312) were admitted to ICU (ICU LOS, 5.0 days), with those aged 0 to <6 months admitted most frequently (10/108 [9.3%]). Supplemental oxygen was administered in 57.7% of patients, with similar need across ages. Antibiotics were administered frequently during hospitalization (43.6%). Predictors of prolonged LOS included pneumonia (odds ratio [OR], 2.33), supplemental oxygen need (OR, 5.09), and preterm births (OR, 3.37). High viral load (RT-PCR RSV cycle threshold value <25) was associated with greater need for supplemental oxygen. CONCLUSIONS: RSV causes substantial burden in hospitalized children (≤5 years), particularly preterm infants and those aged <6 months.

Similar severity of influenza primary and re-infections in pre-school children requiring outpatient treatment due to febrile acute respiratory illness: prospective, multicentre surveillance study (2013-2015).

BACKGROUND: Influenza virus infections in immunologically naïve children (primary infection) may be more severe than in children with re-infections who are already immunologically primed. We compared frequency and severity of influenza virus primary and re-infections in pre-school children requiring outpatient treatment. METHODS: Influenza-unvaccinated children 1-5 years of age presenting at pediatric practices with febrile acute respiratory infection < 48 h after symptom onset were enrolled in a prospective, cross-sectional, multicenter surveillance study (2013-2015). Influenza types/subtypes were PCR-confirmed from oropharyngeal swabs. Influenza type/subtype-specific IgG antibodies serving as surrogate markers for immunological priming were determined using ELISA/hemagglutination inhibition assays. The acute influenza disease was defined as primary infection/re-infection by the absence/presence of influenza type-specific immunoglobulin G (IgG) and, in a second approach, by the absence/presence of subtype-specific IgG. Socio-demographic and clinical data were also recorded. RESULTS: Of 217 influenza infections, 178 were due to influenza A (87 [49%] primary infections, 91 [51%] re-infections) and 39 were due to influenza B (38 [97%] primary infections, one [3%] re-infection). Children with "influenza A primary infections" showed fever with respiratory symptoms for a shorter period than children with "influenza A re-infections" (median 3 vs. 4 days; age-adjusted p = 0.03); other disease characteristics were similar. If primary infections and re-infections were defined based on influenza A subtypes, 122 (87%) primary infections (78 "A(H3N2) primary infections", 44 "A(H1N1)pdm09 primary infections") and 18 (13%) re-infections could be classified (14 "A(H3N2) re-infections" and 4 "A(H1N1)pdm09 re-infections"). Per subtype, primary infections and re-infections were of similar disease severity. Children with re-infections defined on the subtype level usually had non-protective IgG titers against the subtype of their acute infection (16 of 18; 89%). Some patients infected by one of the influenza A subtypes showed protective IgG titers (≥ 1:40) against the other influenza A subtype (32/140; 23%). CONCLUSIONS: Pre-school children with acute influenza A primary infections and re-infections presented with similar frequency in pediatric practices. Contrary to expectation, severity of acute "influenza A primary infections" and "influenza A re-infections" were similar. Most "influenza A re-infections" defined on the type level turned out to be primary infections when defined based on the subtype. On the subtype level, re-infections were rare and of similar disease severity as primary infections of the same subtype. Subtype level re-infections were usually associated with low IgG levels for the specific subtype of the acute infection, suggesting only short-time humoral immunity induced by previous infection by this subtype. Overall, the results indicated recurring influenza virus infections in this age group and no or only limited heterosubtypic antibody-mediated cross-protection.

Epidemiology and direct healthcare costs of Influenza-associated hospitalizations - nationwide inpatient data (Germany 2010-2019).

INTRODUCTION: Detailed and up-to-date data on the epidemiology and healthcare costs of Influenza are fundamental for public health decision-making. We analyzed inpatient data on Influenza-associated hospitalizations (IAH), selected complications and risk factors, and their related direct costs for Germany during ten consecutive years. METHODS: We conducted a retrospective cost-of-illness study on patients with laboratory-confirmed IAH (ICD-10-GM code J09/J10 as primary diagnosis) by ICD-10-GM-based remote data query using the Hospital Statistics database of the German Federal Statistical Office. Clinical data and associated direct costs of hospital treatment are presented stratified by demographic and clinical variables. RESULTS: Between January 2010 to December 2019, 156,097 persons were hospitalized due to laboratory-confirmed Influenza (J09/J10 primary diagnosis). The annual cumulative incidence was low in 2010, 2012 and 2014 (1.3 to 3.1 hospitalizations per 100,000 persons) and high in 2013 and 2015-2019 (12.6 to 60.3). Overall direct per patient hospitalization costs were mean (SD) 3521 EUR (± 8896) and median (IQR) 1805 EUR (1502; 2694), with the highest mean costs in 2010 (mean 8965 EUR ± 26,538) and the lowest costs in 2012 (mean 2588 EUR ± 6153). Mean costs were highest in 60-69 year olds, and in 50-59, 70-79 and 40-49 year olds; they were lowest in 10-19 year olds. Increased costs were associated with conditions such as diabetes (frequency 15.0%; 3.45-fold increase compared to those without diabetes), adiposity (3.3%; 2.09-fold increase) or immune disorders (5.6%; 1.88-fold increase) and with Influenza-associated complications such as Influenza pneumonia (24.3%; 1.95-fold), bacterial pneumonia (6.3%; 3.86-fold), ARDS (1.2%; 10.90-fold increase) or sepsis (2.3%; 8.30-fold). Estimated overall costs reported for the 10-year period were 549.6 Million euros (95% CI 542.7-556.4 million euros). CONCLUSION: We found that the economic burden of IAH in Germany is substantial, even when considering solely laboratory-confirmed IAH reported as primary diagnosis. The highest costs were found in the elderly, patients with certain underlying risk factors and patients who required advanced life support treatment, and median and mean costs showed considerable variations between single years. Furthermore, there was a relevant burden of disease in middle-aged adults, who are not covered by the current vaccination recommendations in Germany.

Spread and clinical severity of respiratory syncytial virus A genotype ON1 in Germany, 2011-2017.

BACKGROUND: The Respiratory Syncytial Virus (RSV) A genotype ON1, which was first detected in Ontario (Canada) in 2010/11, appeared in Germany in 2011/12. Preliminary observations suggested a higher clinical severity in children infected with this new genotype. We investigated spread and disease severity of RSV-A ON1 in pediatric in- and outpatient settings. METHODS: During 2010/11 to 2016/17, clinical characteristics and respiratory samples from children with acute respiratory tract infections (RTI) were obtained from ongoing surveillance studies in 33 pediatric practices (PP), one pediatric hospital ward (PW) and 23 pediatric intensive care units (PICU) in Germany. RSV was detected in the respiratory samples by PCR; genotypes were identified by sequencing. Within each setting, clinical severity markers were compared between RSV-A ON1 and RSV-A non-ON1 genotypes. RESULTS: A total of 603 children with RSV-RTI were included (132 children in PP, 288 in PW, and 183 in PICU). Of these children, 341 (56.6%) were infected with RSV-A, 235 (39.0%) with RSV-B, and one child (0.2%) with both RSV-A and RSV-B; in 26 (4.3%) children, the subtype could not be identified. In the 341 RSV-A positive samples, genotype ON1 was detected in 247 (72.4%), NA1 in 92 (26.9%), and GA5 in 2 children (0.6%). RSV-A ON1, rarely observed in 2011/12, was the predominant RSV-A genotype in all settings by 2012/13 and remained predominant until 2016/17. Children in PP or PW infected with RSV-A ON1 did not show a more severe clinical course of disease compared with RSV-A non-ON1 infections. In the PICU group, hospital stay was one day longer (median 8 days, inter-quartile range (IQR) 7-12 vs. 7 days, IQR 5-9; p = 0.02) and duration of oxygen treatment two days longer (median 6 days, IQR 4-9 vs. 4 days, IQR 2-6; p = 0.03) for children infected with RSV-A ON1. CONCLUSIONS: In children, RSV-A ON1 largely replaced RSV-A non-ON1 genotypes within two seasons and remained the predominant RSV-A genotype in Germany during subsequent seasons. A higher clinical severity of RSV-A ON1 was observed within the group of children receiving PICU treatment, whereas in other settings clinical severity of RSV-A ON1 and non-ON1 genotypes was largely similar.

Heterogeneity in coverage for measles and varicella vaccination in toddlers - analysis of factors influencing parental acceptance.

BACKGROUND: In 2004, routine varicella vaccination was introduced in Germany for children aged 11-14 months. Routine measles vaccination had already been introduced in 1973 for the same age group, but coverage is still too low (<95%) in some areas to eliminate measles. The present study assessed varicella and measles vaccination coverage and determinants of parental acceptance in two study regions, situated in Northern and Southern Bavaria (Germany). METHODS: From 2009 to 2011, annual cross-sectional parent surveys were performed on random samples of 600 children aged 18-36 months in the Bavarian regions of both Munich and Würzburg. Logistic regression models were used to identify factors associated with varicella and measles vaccination. RESULTS: In 2009, 2010 and 2011, vaccination coverage was lower in Munich than in Würzburg, for both varicella (Munich 53%, 67%, 69% vs. Würzburg 72%, 81%, 83%) and for measles (Munich 88%, 89%, 91% vs. Würzburg 92%, 93%, 95%). Recommendation by the physician was the main independent factor associated with varicella vaccination in both regions (adjusted odd ratios (OR) with 95% confidence interval (CI): Munich OR 19.7, CI 13.6-28.6; Würzburg OR 34.7, CI 22.6-53.2). Attendance at a childcare unit was positively associated with a higher acceptance of varicella vaccination in Munich (OR 1.5, CI 1.1-2.2). Regarding measles vaccination, attendance at a childcare unit was positively associated in both regions (Munich OR 2.0; CI 1.3-3.0; Würzburg OR 1.8; CI 1.1-3.1), and a higher level of parental school education was negatively associated in Würzburg (OR 0.5, CI 0.3-0.9). CONCLUSIONS: Vaccination rates differed between regions, with rates constantly higher in Würzburg. Within each region, vaccination rates were lower for varicella than for measles. Measles vaccination status was mainly dependent upon socio-demographic factors (attendance at a childcare unit, parental school education), whereas for the more recently introduced varicella vaccination recommendation by the physician had the strongest impact. Hence, different strategies are needed to further improve vaccination rates for both diseases.

Universal Mass Vaccination Against Rotavirus: Indirect Effects on Rotavirus Infections in Neonates and Unvaccinated Young Infants Not Eligible for Vaccination.

BACKGROUND: Rotavirus (RV)-associated infections account for high numbers of hospitalizations in neonates and young infants. Universal mass vaccination (UMV) has been shown to prevent the burden of disease in vaccinated children. METHODS: The present study investigated the long-term effects of UMV on RV-associated hospitalizations in children with particular focus on neonates and young infants (≤42 days old) not eligible for vaccination. Ten years of Austrian surveillance data were compared, including 10 960 laboratory-confirmed RV cases before (prevaccination period [PreVP]) and after (postvaccination period [PostVP]) introduction of UMV. RESULTS: A postvaccination decrease in hospitalized community-acquired RV infections by 89.3% was seen in all age groups, including unvaccinated neonates and young infants. Of the latter, 27.6% had a nosocomial RV infection in PreVP, and 19.3% in PostVP. Overall, the proportion of nosocomial RV infections increased from 5.5% in PreVP to 13.0% in PostVP. Breakthrough infections, usually after incomplete RV vaccination, could be identified in 6.2% of patients. CONCLUSIONS: Unvaccinated neonates and infants ≤42 days old may indirectly benefit from UMV by reduction of RV infections. Breakthrough infections underline the importance of early and complete protection by the vaccine. In older patients, heightened awareness of nosocomial RV infections is warranted. Identification of RV reservoirs is also needed.

Varicella in pediatric oncology patients in the post-vaccine era-Analysis of routine hospital data from Bavaria (Germany), 2005-2011.

Varicella in oncology patients can result in serious complications. We analyzed trends in hospitalization rates and characteristics of pediatric oncology and non-oncology patients hospitalized with varicella during the first 7 years after introduction of routine varicella vaccination. Our data included children <17 years of age with an International Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) main or secondary discharge diagnosis of varicella identified by annual database queries in 22-29 pediatric hospitals in Bavaria (Germany) in 2005-2011. Of a total of 1,245 varicella-associated hospitalizations, 42 children (median age 4 years, interquartile range 3-5) had an underlying malignancy (67% with acute lymphoblastic leukemia). Overall, additional diagnoses potentially associated with varicella were reported less often in oncology than in non-oncology varicella patients (62% vs. 77%, p = 0.041), suggesting earlier hospitalization of high-risk patients. Acute hematological diagnoses (29% vs. 3%, p < 0.001) and coinfections (invasive 12% vs. 2%, p = 0.001; noninvasive 19% vs. 8%, p = 0.019) were more frequent, whereas neurological (5% vs. 19%, p = 0.023) and upper respiratory tract diagnoses (2% vs. 16%, p = 0.014) were less frequent in oncology compared to non-oncology varicella patients. Oncology varicella patients showed a longer hospital stay (median 5 vs. 3 days, p < 0.001). Hospitalization rates in non-oncology varicella patients declined constantly since 2006, from 114.8 (2006) to 30.5 (2011) per 1,000 pediatric beds. The rates of varicella-associated hospitalizations in oncology patients indicated an overall decreasing trend (3.8, 1.9, 4.6, 3.5, 0.4, 2.1 and 0.6 cases per 1,000 pediatric beds in 2005-2011). Thus, pediatric oncology patients potentially profit from herd protection effects, resulting from increasing vaccine coverage in the general population.

Continued high incidence of children with severe influenza A(H1N1)pdm09 admitted to paediatric intensive care units in Germany during the first three post-pandemic influenza seasons, 2010/11-2012/13.

BACKGROUND: Previous influenza surveillance at paediatric intensive care units (PICUs) in Germany indicated increased incidence of PICU admissions for the pandemic influenza subtype A(H1N1)pdm09. We investigated incidence and clinical characteristics of influenza in children admitted to PICUs during the first three post-pandemic influenza seasons, using active screening. METHODS: We conducted a prospective surveillance study in 24 PICUs in Bavaria (Germany) from October 2010 to September 2013. Influenza cases among children between 1 month and 16 years of age admitted to these PICUs with acute respiratory infection were confirmed by PCR analysis of respiratory secretions. RESULTS: A total of 24/7/20 influenza-associated PICU admissions were recorded in the post-pandemic seasons 1/2/3; incidence estimates per 100,000 children were 1.72/0.76/1.80, respectively. Of all 51 patients, 80% had influenza A, including 65% with A(H1N1)pdm09. Influenza A(H1N1)pdm09 was almost absent in season 2 (incidence 0.11), but dominated PICU admissions in seasons 1 (incidence 1.35) and 3 (incidence 1.17). Clinical data was available for 47 influenza patients; median age was 4.8 years (IQR 1.6-11.0). The most frequent diagnoses were influenza-associated pneumonia (62%), bronchitis/bronchiolitis (32%), secondary bacterial pneumonia (26 %), and ARDS (21%). Thirty-six patients (77 %) had underlying medical conditions. Median duration of PICU stay was 3 days (IQR 1-11). Forty-seven per cent of patients received mechanical ventilation, and one patient (2%) extracorporeal membrane oxygenation; 19% were treated with oseltamivir. Five children (11%) had pulmonary sequelae. Five children (11%) died; all had underlying chronic conditions and were infected with A(H1N1)pdm09. In season 3, patients with A(H1N1)pdm09 were younger than in season 1 (p = 0.020), were diagnosed more often with bronchitis/bronchiolitis (p = 0.004), and were admitted to a PICU later after the onset of influenza symptoms (p = 0.041). CONCLUSIONS: Active screening showed a continued high incidence of A(H1N1)pdm09-associated PICU admissions in the post-pandemic seasons 1 and 3, and indicated possible underestimation of incidence in previous German studies. The age shift of severe A(H1N1)pdm09 towards younger children may be explained by increasing immunity in the older paediatric population. The high proportion of patients with underlying chronic conditions indicates the importance of consistent implementation of the current influenza vaccination recommendations for risk groups in Germany.

Empiric Antibiotic Therapy in 1402 Children With Parapneumonic Effusion/Pleural Empyema in Germany: A Long-term Surveillance Study.

OBJECTIVE: This study investigated empiric antibiotic treatment (EAT), guideline adherence, antibiotic streamlining and clinical outcomes in 1402 hospitalized children with pediatric parapneumonic effusion/pleural empyema (PPE/PE). METHODS: A nationwide surveillance study collected data on EAT, clinical course/outcome, pathogens, susceptibility testing and antibiotic streamlining of children with PPE/PE in Germany between 2010 and 2018. Subgroups were compared using χ2 test/Fisher exact test, Mann-Whitney U test and linear regression analysis adjusting for patient age where appropriate. RESULTS: Complete data on EAT were available for 1402 children. In children with monotherapy (n = 567) and in children with combination therapy of 2 antibiotics (n = 589), the most commonly used antibiotics were aminopenicillin/beta-lactamase inhibitor [138/567 (24.3%) and 102/589 (17.3%)] and cefuroxime [291/567 (51.3%) and 294/589 (49.9%)]. The most common combinations with these beta-lactams were macrolides, aminoglycosides and clindamycin. We observed no difference in clinical severity/outcome between EAT with aminopenicillin/beta-lactamase inhibitor and cefuroxime, neither when used in monotherapy nor when used in combination therapy of 2 antibiotics. Species diagnosis of Streptococcus pneumoniae (n = 192), Streptococcus pyogenes (n = 111) or Staphylococcus aureus (n = 38) in polymerase chain reaction or culture from pleural fluid or blood resulted in a switch to an appropriate narrow-spectrum beta-lactam therapy in 9.4%, 18.9 % and 5.2% of children. In a subset of children with reported bacterial susceptibility testing, penicillin resistance was reported in 3/63 (4.8%) of S. pneumoniae and methicillin resistance in S. aureus was reported in 10/32 (31.3%) of children. CONCLUSION: This study points to antibiotic overtreatment in children with PPE/PE, particularly the frequent use of combinations of antibiotics. Children receiving combinations of antibiotics did not show differences in clinical outcomes. The low rate of children with streamlined antibiotic therapy even upon pathogen detection indicates a necessity for antibiotic stewardship measures in PPE/PE and the need of investigating other potential therapeutic strategies as anti-inflammatory therapy.

[Continuous SARS-CoV-2 monitoring in day care centres: A qualitative interview study on the experiences of childcare workers and parents with different self-sampling methods in the home environment]. / Kontinuierliche Überwachung von SARS-CoV-2 Infektionen in Kindertagesstätten: eine qualitative Interviewstudie über die Erfahrungen von Betreuer*innen und Eltern mit verschiedenen Testverfahren im häuslichen Umfeld.

BACKGROUND: Since the beginning of the corona pandemic in Germany in January 2020, day care centres (DCC) have faced the challenge of reliably detecting cases of SARS-CoV-2 infection as early and reliably as possible in order to avoid major outbreaks and closures. Conducting regular virological screening tests for asymptomatic DCC children and childcare workers requires a high level of acceptance among participants and should be as easy as possible to implement. The present study aimed to evaluate childcare workers' and parents' attitudes and experiences regarding the acceptance and feasibility of various screening methods. This assessment was conducted using additional qualitative interviews designed for home-based screening in the context of a screening study in DCCs. METHOD: From May to July 2021, childcare workers and parents of children in nine DCCs in Wuerzburg independently carried out screening tests for SARS-CoV-2 at home twice a week as part of the "Würzburg Child Care Study in the COVID-19 Pandemic 2.0". The participants were offered two self-sampling methods (mouth-rinsing fluid for pooled PCR tests and/or nasal rapid antigen self-tests). Before and after the 12-week test phase, telephone interviews were conducted with a selected sample of childcare workers and parents in order to ascertain initial attitudes and further experiences with the two self-sampling methods and their implementation. The interviews were fully transcribed for analysis and subjected to a qualitative content analysis according to Kuckartz. RESULTS: Of the 1,026 eligible participants, 591 individuals, including 139 childcare workers and the parents of 452 children, agreed to take part in the screening tests. A total of 49 interviews were conducted with a specifically selected sample (20 before the start of the test, 29 after the end of the test). In the qualitative content analysis, three overarching topics emerged: 'aspects of the test performance', 'aspects of the perception of safety' and 'aspects of the testing in children'. Regardless of the fact that the various test methods and test features were perceived very differently, conducting the tests at home was found to be feasible. DISCUSSION: The differentiated insights into the participants' perspectives provide valuable information about factors that influence the acceptance of self-testing. These should be taken into account before such a measure is introduced in DCCs if necessary. CONCLUSION: The assessment of test procedures is strongly influenced by individual preferences. Test concepts should be implemented with as little time and organisational effort as possible in order to promote willingness to participate. Clear study information and quick feedback on test results can enhance the sense of security among parents and childcare workers.

Varicella routine vaccination and the effects on varicella epidemiology - results from the Bavarian Varicella Surveillance Project (BaVariPro), 2006-2011.

BACKGROUND: In 2004, routine varicella vaccination was recommended in Germany for children 11-14 months of age with one dose, and since 2009, with a second dose at 15-23 months of age. The effects on varicella epidemiology were investigated. METHODS: Data on varicella vaccinations, cases and complications were collected from annual parent surveys (2006-2011), monthly paediatric practice surveillance (Oct 2006 - Sep 2011; five varicella seasons) and paediatric hospital databases (2005-2009) in the area of Munich (about 238,000 paediatric inhabitants); annual incidences of cases and hospitalisations were estimated. RESULTS: Varicella vaccination coverage (1st dose) in children 18-36 months of age increased in two steps (38%, 51%, 53%, 53%, 66% and 68%); second-dose coverage reached 59% in the 2011 survey. A monthly mean of 82 (62%) practices participated; they applied a total of 50,059 first-dose and 40,541 second-dose varicella vaccinations, with preferential use of combined MMR-varicella vaccine after recommendation of two doses, and reported a total of 16,054 varicella cases <17 years of age. The mean number of cases decreased by 67% in two steps, from 6.6 (95%CI 6.1-7.0) per 1,000 patient contacts in season 2006/07 to 4.2 (95%CI 3.9-4.6) in 2007/08 and 4.0 (95%CI 3.6-4.3) in 2008/09, and further to 2.3 (95%CI 2.0-2.6) in 2009/10 and 2.2 (95%CI 1.9-2.5) in 2010/11. The decrease occurred in all paediatric age groups, indicating herd protection effects. Incidence of varicella was estimated as 78/1,000 children <17 years of age in 2006/07, and 19/1,000 in 2010/11. Vaccinated cases increased from 0.3 (95%0.2-0.3) per 1,000 patient contacts in 2006/07 to 0.4 (95%CI 0.3-0.5) until 2008/09 and decreased to 0.2 (95%CI 0.2-0.3) until 2010/11. The practices treated a total of 134 complicated cases, mainly with skin complications. The paediatric hospitals recorded a total of 178 varicella patients, including 40 (22.5%) with neurological complications and one (0.6%) fatality due to varicella pneumonia. Incidence of hospitalisations decreased from 7.6 per 100,000 children <17 years of age in 2005 to 4.3 in 2009, and from 21.0 to 4.7 in children <5 years of age. CONCLUSIONS: Overall, the results show increasing acceptance and a strong impact of the varicella vaccination program, even with still suboptimal vaccination coverage.

The impact of Rotavirus mass vaccination on hospitalization rates, nosocomial Rotavirus gastroenteritis and secondary blood stream infections.

BACKGROUND: The aim of the study was to evaluate the effects of universal mass vaccination (UMV) against rotavirus (RV) on the hospitalization rates, nosocomial RV infections and RV-gastroenteritis (GE)-associated secondary blood stream infections (BSI). METHODS: The retrospective evaluation (2002-2009) by chart analysis included all clinically diagnosed and microbiologically confirmed RV-GE cases in a large tertiary care hospital in Austria. The pre-vaccination period (2002-2005) was compared with the recommended and early funded (2006-2007) and the funded (2008-2009) vaccination periods. Primary outcomes were RV-GE-associated hospitalizations, secondary outcomes nosocomial RV disease, secondary BSI and direct hospitalization costs for children and their accompanying persons. RESULTS: In 1,532 children with RV-GE, a significant reduction by 73.9% of hospitalized RV-GE cases per year could be observed between the pre-vaccination and the funded vaccination period, which was most pronounced in the age groups 0-11 months (by 87.8%), 6-10 years (by 84.2%) and 11-18 years (88.9%). In the funded vaccination period, a reduction by 71.9% of nosocomial RV-GE cases per year was found compared to the pre-vaccination period. Fatalities due to nosocomial RV-GE were only observed in the pre-vaccination period (3 cases). Direct costs of hospitalized, community-acquired RV-GE cases per year were reduced by 72.7% in the funded vaccination period. The reduction of direct costs for patients (by 86.9%) and accompanying persons (86.2%) was most pronounced in the age group 0-11 months. CONCLUSIONS: UMV may have contributed to the significant decrease of RV-GE-associated hospitalizations, to a reduction in nosocomial RV infections and RV-associated morbidity due to secondary BSI and reduced direct hospitalization costs. The reduction in nosocomial cases is an important aspect considering severe disease courses in hospitalized patients with co-morbidities and death due to nosocomial RV-GE.

Very Low Incidence of SARS-CoV-2, Influenza and RSV but High Incidence of Rhino-, Adeno- and Endemic Coronaviruses in Children With Acute Respiratory Infection in Primary Care Pediatric Practices During the Second and Third Wave of the SARS-CoV-2 Pandemic.

Respiratory viruses were detected by multiplex-polymerase chain reaction from oropharyngeal swabs in 114/168 (67.9%) children with acute respiratory infection presenting to 5 pediatric practices in Germany between November 2020 and April 2021. In contrast to rhino- (48.8%), adeno- (14.3%) and endemic coronaviruses (14.9%), SARS-CoV-2 and influenza virus were detected only once; respiratory syncytial virus was not detected. This demonstrates differing impacts of pandemic infection control measures on the spread of respiratory viruses.

Parents' and Childcare Workers' Perspectives Toward SARS-CoV-2 Test and Surveillance Protocols in Pre-school Children Day Care Centers: A Qualitative Study Within the German Wü-KiTa-CoV Project.

Background: Feasibility of surveillance through continuous SARS-CoV-2 testing in pre-school children and childcare workers (CCWs) to prevent closure of day care centers (DCCs) was proven in the Wü-KiTa-CoV study. The purpose of this study was to describe the factors that facilitate or hinder the implementation of continuous SARS-CoV-2 testing from the perspective of parents and CCWs involved in the study. Methods: A total of 148 semi-structured telephone interviews, repeated before and after the implementation of the surveillance protocols, were conducted with parents and CCWs belonging to the DCCs involved in Wü-KiTa-CoV and analyzed using qualitative content analysis. Results: Five main topical categories that influences implementation of surveillance protocols for SARS-CoV-2 in DCCs emerged: Generating valuable knowledge, Impact on daily life, Communication and information, Children's wellbeing and the Sense of security. Smooth integration in daily routines, quickly delivered test results, and efficient communication and information between the study team and the participants were identified as factors that had a positive impact on implementation. To ensure children's wellbeing, the introduction of non-invasive testing procedures such as saliva testing, parental involvement to motivate, and prepare children for the procedure, the creation of a child-friendly environment for testing, and use of child-friendly explanations were considered critical. The surveillance was found to increase the sense of security during the pandemic. Conversely, reliability of tests in the surveillance protocols, low participation rates, non-transparent communication, the need to travel to testing sites, fear of quarantine in case of positive test results, concerns about higher workloads, the fear of unpleasant feelings for children, their young age, and changing test teams were considered as hindering factors. Conclusion: This qualitative study of parents of children in day care and DCC staff under surveillance through continuous testing for SARS-CoV-2 in nine German DCCs identified several factors that facilitate or hinder its implementation. These should be considered when planning screening interventions to prevent the spread of SARS-CoV-2 or other infectious diseases in pre-school children DCCs.

Corrigendum: Parents' and childcare workers' perspectives toward SARS-CoV-2 test and surveillance protocols in pre-school children day care centers: A qualitative study within the german Wü-KiTa-CoV project.

[This corrects the article DOI: 10.3389/fmed.2022.897726.].