Terminal Ileitis as the Exclusive Manifestation of COVID-19 in Children.

The clinical presentation, organ involvement, and severity of disease caused by SARS-CoV-2 are highly variable, ranging from asymptomatic or mild infection to respiratory or multi-organ failure and, in children and young adults, the life-threatening multisystemic inflammatory disease (MIS-C). SARS-CoV-2 enters cells via the angiotensin-converting enzyme-2 receptor (ACE-2), which is expressed on the cell surfaces of all organ systems, including the gastrointestinal tract. GI manifestations have a high prevalence in children with COVID-19.

Immune response after two doses of the BNT162b2 COVID-19 vaccine and risk of SARS-CoV-2 breakthrough infection in Tyrol, Austria: an open-label, observational phase 4 trial.

Background: Correlates of protection could help to assess the extent to which a person is protected from SARS-CoV-2 infection after vaccination (so-called breakthrough infection). We aimed to clarify associations of antibody and T-cell responses after vaccination against COVID-19 with risk of a SARS-CoV-2 breakthrough infection and whether measurement of these responses enhances risk prediction.

Methods: We did an open-label, phase 4 trial in two community centres in the Schwaz district of the Federal State of Tyrol, Austria, before the emergence of the omicron (B.

BA.2 and BA.5 omicron differ immunologically from both BA.1 omicron and pre-omicron variants.

Several studies have shown that SARS-CoV-2 BA.1 omicron is an immune escape variant. Meanwhile, however, omicron BA.

Seroprevalence of SARS-CoV-2 infection in the Tyrolean district of Schwaz at the time of the rapid mass vaccination in March 2021 following B.1.351-variant outbreak.

In order to curb the rapid dissemination of the B.1.351 variant of SARS-CoV-2 in the district of Schwaz and beyond, the EU allocated additional vaccine doses at the beginning of March 2021 to implement a rapid mass vaccination of the population (16+).

Persistence of immunity to SARS-CoV-2 over time in the ski resort Ischgl.

Background In early March 2020, a SARS-CoV-2 outbreak in the ski resort Ischgl in Austria triggered the spread of SARS-CoV-2 throughout Austria and Northern Europe. In a previous study, we found that the seroprevalence in the adult population of Ischgl had reached 45% by the end of April, representing an exceptionally high level of local seropositivity in Europe. We performed a follow-up study in Ischgl, which is the first to show persistence of immunity and protection against SARS-CoV-2 and some of its variants at a community level.

Estimating seroprevalence of SARS-CoV-2 antibodies using three self-reported symptoms: development of a prediction model based on data from Ischgl, Austria.

We report the development of a regression model to predict the prevalence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) antibodies on a population level based on self-reported symptoms. We assessed participant-reported symptoms in the past 12 weeks, as well as the presence of SARS-CoV-2 antibodies during a study conducted in April 2020 in Ischgl, Austria. We conducted multivariate binary logistic regression to predict seroprevalence in the sample.

Analysis of humoral immune responses in rhesus macaques vaccinated with attenuated SIVmac239Deltanef and challenged with pathogenic SIVmac251.

Background: To determine the correlation between protection and humoral immune response against simian immunodeficiency virus (SIVmac251), 11 macaques were immunized with live-attenuated SIVmac239Deltanef either intravenously or via the tonsils and exposed to SIVmac251 after either 6 or 15 months along with unvaccinated controls.

Results: Independent of the route of vaccine application, viremia was significantly reduced in vaccinees compared with controls 2 weeks post-challenge. Concomitantly, viremia correlated inversely with SIV-specific IgG, complement-mediated lysis and neutralizing antibodies and these parameters seemed to contribute to reduced viremia.

Role of complement and antibodies in controlling infection with pathogenic simian immunodeficiency virus (SIV) in macaques vaccinated with replication-deficient viral vectors.

Background: We investigated the interplay between complement and antibodies upon priming with single-cycle replicating viral vectors (SCIV) encoding SIV antigens combined with Adeno5-SIV or SCIV pseudotyped with murine leukemia virus envelope boosting strategies. The vaccine was applied via spray-immunization to the tonsils of rhesus macaques and compared with systemic regimens.

Results: Independent of the application regimen or route, viral loads were significantly reduced after challenge with SIVmac239 (p < 0.

Basidiomycete metabolites attenuate virulence properties of Candida albicans in vitro.

Secreted aspartic proteases (Saps) represent an important virulence factor facilitating fungal adherence. Several protease inhibitors (PIs), including HIV PIs, have been shown to reduce Candida adhesion. The aim of this study was to ascertain whether or not the recently discovered PIs Aureoquinone and Laccaridiones A and B, isolated from Basidiomycete cultures, or Bestatin, act as Sap-inhibitors and/or inhibitors of fungal adhesion.

HIV-1 induced generation of C5a attracts immature dendriticcells and promotes infection of autologous T cells.

For the recruitment of dendritic cells (DC) to the site of infection, DC express several sensors for danger signals, such as receptors for C5a. This anaphylatoxin is generated upon complement activation. As HIV-1 triggers the complement cascade, we determined whether C5a is generated by the virus and tested the functional activity of C5a in migration and infection assays.

Absent reduction by HIV protease inhibitors of Candida albicans adhesion to endothelial cells.

Highly active antiretroviral therapy including HIV protease inhibitors has led to a marked reduction of clinically relevant mucosal candidiasis. We have previously shown that HIV protease inhibitors directly inhibit adhesion of Candida albicans to epithelial cells at concentrations that are reached in vivo during antiretroviral therapy. The aim of this study was to establish whether HIV protease inhibitors also inhibit adhesion of Candida to endothelial cells, which play a major role in systemic fungal disease.

Subtype and genotypic resistance analysis of HIV-1 infected patients in Austria.

Background: Analysis of HIV-1 subtypes and genotypic resistance have been shown to be relevant for epidemiologic and therapeutic studies or for vaccine development. In Europe, the majority of HIV-1 isolates belong to subtype B. Due to migration an increasing incidence for additional subtypes and complex recombinant forms are expected.

Lack of microbial DNA in tissue specimens of patients with abdominal aortic aneurysms and positive Chlamydiales serology.

In a case-control study that included a total of 98 patients and 83 controls, the possible link between various pathogens and abdominal aortic aneurysms was investigated. For 68 patients with abdominal aortic aneurysm and age-matched controls, no differences were detected in the levels of immunoglobulin (Ig)A and IgG Chlamydiaceae and Chlamydophila pneumoniae antibodies. Patients with IgA titers positive for Chlamydophila pneumoniae showed progressive disease (defined as an annual increase of the aneurysm diameter of > or = 0.

Targeting human immunodeficiency virus type 1 with antibodies derived from patients with connective tissue disease.

During the budding process, human immunodeficiency virus (HIV) acquires several cellular proteins from the host. Thus, antibodies against self antigens found in sera patients with autoimmune disorders may cross react with host-derived or the HIV-specific proteins gp120 and gp41 on the viral envelope and probably neutralize HIV infection. To verify this hypothesis, 88 sera from HIV negative patients suffering from systemic lupus erythematosus (SLE) and other autoimmune disorders were analysed for cross reacting antibodies against HIV-1 by Western blot and FACS analysis indicating that antibodies cross-react with epitopes expressed on HIV infected or non-infected cells.

Changes in HIV-specific antibody responses and neutralization titers in patients under ART.

In this study, we tested for antibody reactivities against gp120 and gp41-derived peptides, recombinant gp160, gp41 and tat in HIV-positive sera under antiretroviral therapy (ART) and determined their neutralization capacity. As a baseline, sera from patients in stage A, B and C of the disease, long term non-progressors (LNPs) and HIV-negative individuals were included. Compared to LNPs or sera from patients in group A, the reactivity of sera in stage B or C against gp120-derived peptides was reduced parallel to disease progression.

A single vaccination with attenuated SIVmac 239 via the tonsillar route confers partial protection against challenge with SIVmac 251 at a distant mucosal site, the rectum.

Elucidating the mechanisms that protect monkeys previously immunized with attenuated SIV (SIVDeltanef) against challenge infection with pathogenic virus may reveal new strategies for the development of an effective HIV vaccine. Here we show that a single atraumatic application of SIVDeltanef to the tonsils of four rhesus macaques conferred protection against SIVmac251 applied intrarectally 26 weeks later. While this protection was not complete, i.

Human granulocytic anaplasmosis in Austria: epidemiological, clinical, and laboratory findings in five consecutive patients from Tyrol, Austria.

We report five consecutive cases of Anaplasma (A.) phagocytophilum infection (the causative agent of human granulocytic anaplasmosis (HGA)) from western Austria. All infections were acquired between June and August in 2003 and 2004 in the Inn valley (Tyrol, Austria).

Complement dependent trapping of infectious HIV in human lymphoid tissues.

Objectives: HIV-1 bound extracellularly to follicular dendritic cells (FDC) in germinal centers (GC) of lymphoid tissues (LT) represents the largest viral reservoir in HIV-infected individuals; however there is no direct evidence as to whether HIV trapped in human GC remains infectious. In the GC, complement receptors and Fc gamma receptors have been suggested to participate in trapping of HIV; therefore, the relative contribution of complement- and Fc gamma receptors in binding HIV on LT was investigated and the infectivity of this virus was tested.

Design: As it is difficult to isolate FDC without contaminations of productively infected cells, HIV was detached from LT of HIV positive individuals using antibodies blocking complement- and Fc gamma receptors.

Drug monitoring and viral response to lopinavir/ritonavir or saquinavir/ritonavir containing regimens in individuals infected with the human immunodeficiency virus type 1.

The aim of this study was to correlate results of therapeutic drug monitoring, genotypic resistance and viral response to lopinavir/ritonavir (LPV/r) or saquinavir/ritonavir (SQV/r) containing antiretroviral regimens. The retrospective short-term study included 20 patients with LPV/r and 20 patients with SQV/r containing highly active antiretroviral therapy (HAART). At baseline 7 LPV/r patients and 10 SQV/r patients had CD4+T cell counts above 410 cells/microl.