@article{GoettlerNieklerLieseetal.2022,
  author    = {Goettler, David and Niekler, Patricia and Liese, Johannes G. and Streng, Andrea},
  title     = {Epidemiology and direct healthcare costs of Influenza-associated hospitalizations - nationwide inpatient data (Germany 2010-2019)},
  series = {BMC Public Health},
  volume    = {22},
  journal   = {BMC Public Health},
  doi       = {10.1186/s12889-022-12505-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265888},
  year      = {2022},
  abstract  = {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.},
  language  = {en}
}
@article{Prelog2012,
  author    = {Prelog, Martina},
  title     = {Differential Approaches for Vaccination from Childhood to Old Age},
  series = {Gerontology},
  volume    = {59},
  journal   = {Gerontology},
  number    = {3},
  issn      = {0304-324X},
  doi       = {10.1159/000343475},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196602},
  pages     = {230-239},
  year      = {2012},
  abstract  = {Primary prevention strategies, such as vaccinations at the age extremes, in neonates and elderly individuals, demonstrate a challenge to health professionals and public health specialists. The aspects of the differentiation and maturation of the adaptive immune system, the functional implications of immunological immaturity or immunosenescence and its impact on vaccine immunogenicity and efficacy will be highlighted in this review. Several approaches have been undertaken to promote Th1 responses in neonates and to enhance immune functions in elderly, such as conjugation to carrier proteins, addition of adjuvants, concomitant vaccination with other vaccines, change in antigen concentrations or dose intervals or use of different administration routes. Also, early protection by maternal vaccination seems to be beneficial in neonates. However, it also appears necessary to think of other end points than antibody concentrations to assess vaccine efficacy in neonates or elderly, as also the cellular immune response may be impaired by the mechanisms of immaturity, underlying health conditions, immunosuppressive treatments or immunosenescence. Thus, lifespan vaccine programs should be implemented to all individuals on a population level not only to improve herd protection and to maintain protective antibody levels and immune memory, but also to cover all age groups, to protect unvaccinated elderly persons and to provide indirect protection for neonates and small infants.},
  language  = {en}
}
@article{RommelMildeEberleetal.2020,
  author    = {Rommel, Marcel G. E. and Milde, Christian and Eberle, Regina and Schulze, Harald and Modlich, Ute},
  title     = {Endothelial-platelet interactions in influenza-induced pneumonia: A potential therapeutic target},
  series = {Anatomia, Histologia, Embryologia},
  volume    = {49},
  journal   = {Anatomia, Histologia, Embryologia},
  number    = {5},
  doi       = {10.1111/ahe.12521},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213610},
  pages     = {606 -- 619},
  year      = {2020},
  abstract  = {Every year, influenza viruses spread around the world, infecting the respiratory systems of countless humans and animals, causing illness and even death. Severe influenza infection is associated with pulmonary epithelial damage and endothelial dysfunction leading to acute lung injury (ALI). There is evidence that an aggressive cytokine storm and cell damage in lung capillaries as well as endothelial/platelet interactions contribute to vascular leakage, pro-thrombotic milieu and infiltration of immune effector cells. To date, treatments for ALI caused by influenza are limited to antiviral drugs, active ventilation or further symptomatic treatments. In this review, we summarize the mechanisms of influenza-mediated pathogenesis, permissive animal models and histopathological changes of lung tissue in both mice and men and compare it with histological and electron microscopic data from our own group. We highlight the molecular and cellular interactions between pulmonary endothelium and platelets in homeostasis and influenza-induced pathogenesis. Finally, we discuss novel therapeutic targets on platelets/endothelial interaction to reduce or resolve ALI.},
  language  = {en}
}
@article{RoseDammGreineretal.2014,
  author    = {Rose, Markus A. and Damm, Oliver and Greiner, Wolfgang and Knuf, Markus and Wutzler, Peter and Liese, Johannes G. and Kr{\"u}ger, Hagen and Wahn, Ulrich and Schaberg, Tom and Schwehm, Markus and Kochmann, Thomas F. and Eichner, Martin},
  title     = {The epidemiological impact of childhood influenza vaccination using live-attenuated influenza vaccine (LAIV) in Germany: predictions of a simulation study},
  series = {BMC Infectious Diseases},
  volume    = {14},
  journal   = {BMC Infectious Diseases},
  number    = {40},
  issn      = {1471-2334},
  doi       = {10.1186/1471-2334-14-40},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117563},
  year      = {2014},
  abstract  = {Background: Routine annual influenza vaccination is primarily recommended for all persons aged 60 and above and for people with underlying chronic conditions in Germany. Other countries have already adopted additional childhood influenza immunisation programmes. The objective of this study is to determine the potential epidemiological impact of implementing paediatric influenza vaccination using intranasally administered live-attenuated influenza vaccine (LAIV) in Germany. Methods: A deterministic age-structured model is used to simulate the population-level impact of different vaccination strategies on the transmission dynamics of seasonal influenza in Germany. In our base-case analysis, we estimate the effects of adding a LAIV-based immunisation programme targeting children 2 to 17 years of age to the existing influenza vaccination policy. The data used in the model is based on published evidence complemented by expert opinion. Results: In our model, additional vaccination of children 2 to 17 years of age with LAIV leads to the prevention of 23.9 million influenza infections and nearly 16 million symptomatic influenza cases within 10 years. This reduction in burden of disease is not restricted to children. About one third of all adult cases can indirectly be prevented by LAIV immunisation of children. Conclusions: Our results demonstrate that vaccinating children 2-17 years of age is likely associated with a significant reduction in the burden of paediatric influenza. Furthermore, annual routine childhood vaccination against seasonal influenza is expected to decrease the incidence of influenza among adults and older people due to indirect effects of herd protection. In summary, our model provides data supporting the introduction of a paediatric influenza immunisation programme in Germany.},
  language  = {en}
}
@article{StrengPrifertWeissbrichetal.2015,
  author    = {Streng, Andrea and Prifert, Christiane and Weissbrich, Benedikt and Liese, Johannes G.},
  title     = {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},
  series = {BMC Infectious Diseases},
  volume    = {15},
  journal   = {BMC Infectious Diseases},
  number    = {573},
  organization    = {Bavarian PICU Study Group on Influenza and Other Viral ARI},
  doi       = {10.1186/s12879-015-1293-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125280},
  year      = {2015},
  abstract  = {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.},
  language  = {en}
}
@article{StrengPrifertWeissbrichetal.2022,
  author    = {Streng, Andrea and Prifert, Christiane and Weissbrich, Benedikt and Sauerbrei, Andreas and Krumbholz, Andi and Schmid-Ott, Ruprecht and Liese, Johannes G.},
  title     = {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)},
  series = {BMC Infectious Diseases},
  volume    = {22},
  journal   = {BMC Infectious Diseases},
  doi       = {10.1186/s12879-021-06988-7},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-265841},
  year      = {2022},
  abstract  = {Background Influenza virus infections in immunologically na{\"i}ve 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.},
  language  = {en}
}