Poor Prognosis for Puumala Virus Infections Predicted by Lymphopenia and Dyspnea

We investigated a prospective cohort of 23 patients who had Puumala virus infection in Austria to determine predictors of infection outcomes. We reviewed routinely available clinical and laboratory parameters collected when patients initially sought care. Low absolute lymphocyte count and dyspnea were parameters associated with a severe course of infection.

Rapid, early and accurate SARS-CoV-2 detection using RT-qPCR in primary care: a prospective cohort study (REAP-1)

OBJECTIVES

We explore the importance of SARS-CoV-2 sentinel surveillance testing in primary care during a regional COVID-19 outbreak in Austria.

DESIGN

Prospective cohort study.

SETTING

A single sentinel practice serving 22 829 people in the ski-resort of Schladming-Dachstein.

PARTICIPANTS

All 73 patients presenting with mild-to-moderate flu-like symptoms between 24 February and 03 April, 2020.

INTERVENTION

Nasopharyngeal sampling to detect SARS-CoV-2 using real-time reverse transcriptase-quantitative PCR (RT-qPCR).

OUTCOME MEASURES

We compared RT-qPCR at presentation with confirmed antibody status. We split the outbreak in two parts, by halving the period from the first to the last case, to characterise three cohorts of patients with confirmed infection: early acute (RT-qPCR reactive) in the first half; and late acute (reactive) and late convalescent (non-reactive) in the second half. For each cohort, we report the number of cases detected, the accuracy of RT-qPCR, the duration and variety of symptoms, and the number of viral clades present.

RESULTS

Twenty-two patients were diagnosed with COVID-19 (eight early acute, seven late acute and seven late convalescent), 44 patients tested SARS-CoV-2 negative and 7 were excluded. The sensitivity of RT-qPCR was 100% among all acute cases, dropping to 68.1% when including convalescent. Test specificity was 100%. Mean duration of symptoms for each group were 2 days (range 1-4) among early acute, 4.4 days (1-7) among late acute and 8 days (2-12) among late convalescent. Confirmed infection was associated with loss of taste. Acute infection was associated with loss of taste, nausea/vomiting, breathlessness, sore throat and myalgia; but not anosmia, fever or cough. Transmission clusters of three viral clades (G, GR and L) were identified.

CONCLUSIONS

RT-qPCR testing in primary care can rapidly and accurately detect SARS-CoV-2 among people with flu-like illness in a heterogeneous viral outbreak. Targeted testing in primary care can support national sentinel surveillance of COVID-19.

COVID-19 autopsies: Procedure, technical aspects and cause of fatal course. Experiences from a single-center

Autopsies on COVID-19 have provided deep insights into a novel disease with unpredictable and potentially fatal outcome. A standardized autopsy procedure preferably with an in-situ technique and systematic tissue processing is important. Strict safety measures include personal protective equipment with a standardized protocol for dressing and undressing, usage of FFP-3 masks and minimization of aerosol production. The use of an airborne infection isolation (AIIR) room is preferred. Viral RNA analysis using swabs from throat, both lungs and other organs provides information on cross-organ viral dynamics. To correctly determine the full extent of pathological organ changes an adequate processing procedure is of the utmost importance. Systematic dissection and processing of the lungs revealed pulmonary infarction caused by thrombosis and thromboembolism and bacterial bronchopneumonia as the most frequent cause of death. Fungal pneumonia (aspergillus) was found in one case. The quality of the tissue was sufficient for histopathological and immunohistochemistry analyses in all cases. Viral RNA from throat or lung swabs was detectable post mortem in 89 % of the cases and could also be detected from paraffin-embedded tissue by real-time PCR. Complete COVID-19 autopsies including extensive histopathological studies and viral RNA analysis require approximately three times more human and technical resources and time compared to standard non-COVID autopsies. Autopsies on COVID-19 are feasible, present a manageable risk, while following a strict protocol, and provide novel insights into disease pathogenesis and the clinician with important feedback.

Occupational swine exposure and Hepatitis E virus, Leptospira, Ascaris suum seropositivity and MRSA colonization in Austrian veterinarians, 2017-2018-A cross-sectional study

We investigated the prevalence of Hepatitis E Virus (HEV), Leptospira and Ascaris suum (A. suum) seropositivity, and of nasal methicillin-resistant Staphylococcus aureus (MRSA) colonization among Austrian practising veterinarians, and assessed the association with occupational swine livestock exposure. The 261 participants completed a questionnaire on demographics, intensity of occupational swine livestock contact and glove use during handling animals and their secretions. Participants' blood samples were tested for HEV, Leptospira and A. suum seropositivity and nasal swabs cultured for MRSA. We compared swine veterinarians (defined as >3 swine livestock visits/week) to non-swine veterinarians (≤3 swine livestock visits/week) with regard to the outcomes through calculating prevalence ratio (PR) and 95% confidence interval (CI). Furthermore, the relationship between occupational swine livestock contact and the study outcomes was examined by age (</≥55 years) and glove usage. The prevalence of nasal MRSA colonization was 13.4% (95% CI: 9.3-17.6), of HEV seropositivity 20.8% (95% CI: 15.8-25.7) and A. suum seropositivity 44% (95% CI: 37.7-50.2). The highest anti-leptospiral antibodies titres were 1:200 (L. hebdomadis) and 1:100 (L. autumnalis, L. caicola) found in three non-swine veterinarians. Compared to non-swine veterinarians, swine veterinarians were 1.9 (95% CI: 1.0-3.4) and 1.5 (95%CI: 1.0-2.3) times more likely HEV seropositive and A. suum seropositive, respectively, and 4.8 (95%CI: 2.5; 9.3) times more likely nasally colonized with MRSA. Among glove-using veterinarians, occupational swine contact was no longer a determinant for HEV seropositivity (PR 1.6; 95% CI: 0.8-2.9). Similar was found for A. suum seropositivity, which was no longer associated with occupational swine livestock contact in the subgroup of glove using, ≥55-year-old veterinarians (PR: 1.07; 95% CI: 0.4-3.3). Our findings indicate that >3 occupational swine livestock visits per week is associated with HEV and A. suum seropositivity and nasal MRSA colonization and that glove use may play a putative preventive role in acquiring HEV and A. suum. Further analytical epidemiological studies have to prove the causality of these associations.

Ongoing rubella outbreak in Austria, 2008-2009

Since October 2008, a total of 143 cases of rubella have affected the two Austrian provinces Styria and Burgenland. The index case occurred in mid-October 2008, but was not notified to the public health authorities until February 2009, when the Austrian Agency for Health and Food Safety was asked to investigate a cluster of 32 rubella cases (24 laboratory-confirmed and eight clinically suspected cases). No case of rubella had been reported in the two affected provinces between February 2007 - when statutory notification for rubella was implemented - and mid-October 2008. 113 of the 143 cases (79%) were confirmed: 101 (89.3% of the 113 cases) clinical-laboratory confirmed and 12 clinical-epidemiological confirmed. Thirty cases fulfilled the criteria of a probable outbreak case only (laboratory results or data on epidemiological link are pending). For 140 outbreak cases data on age was known; the median age was 19 years (range: 2-60 years). 20 cases occurred in soldiers in seven military camps in the area. 55 cases (38.5 %) were female. One case of a laboratory-confirmed rubella infection, affecting an unvaccinated pregnant 18-years old native Austrian in the early first trimenon of pregnancy, led to voluntary abortion

Ongoing rubella outbreak in Austria, 2008-2009

Since October 2008, a total of 143 cases of rubella have affected the two Austrian provinces Styria and Burgenland. The index case occurred in mid-October 2008, but was not notified to the public health authorities until February 2009, when the Austrian Agency for Health and Food Safety was asked to investigate a cluster of 32 rubella cases (24 laboratory-confirmed and eight clinically suspected cases). No case of rubella had been reported in the two affected provinces between February 2007 - when statutory notification for rubella was implemented - and mid-October 2008. 113 of the 143 cases (79%) were confirmed: 101 (89.3% of the 113 cases) clinical-laboratory confirmed and 12 clinical-epidemiological confirmed. Thirty cases fulfilled the criteria of a probable outbreak case only (laboratory results or data on epidemiological link are pending). For 140 outbreak cases data on age was known; the median age was 19 years (range: 2-60 years). 20 cases occurred in soldiers in seven military camps in the area. 55 cases (38.5 %) were female. One case of a laboratory-confirmed rubella infection, affecting an unvaccinated pregnant 18-years old native Austrian in the early first trimenon of pregnancy, led to voluntary abortion.

Human parvovirus B19: a new emerging pathogen of inflammatory cardiomyopathy

The human parvovirus B19 (PVB19), an erythrovirus causing diverse clinical manifestations ranging from asymptomatic or mild to more severe outcomes such as hydrops fetalis, is the only known human pathogenic parvovirus so far. Although enteroviruses have long been considered the most common cause of inflammatory cardiomyopathy, PVB19 is emerging as a important candidate. Recent studies have indicated an association of PVB19 with paediatric and adult inflammatory cardiac disease. However, whether or not PVB19 has an impact on inflammatory cardiomyopathy in adult patients is still unclear. The first hints for a possible aetiopathogenetic role of the PVB19-infection and the development of cardiac dysfunction were demonstrated by molecular biology utilizing in situ hybridization (ISH) and polymerase chain reaction (PCR). According to available evidence, PVB19-associated inflammatory cardiomyopathy is characterized by infection of endothelial cells of small intracardiac arterioles and venules, which may be associated with endothelial dysfunction, impairment of myocardial microcirculation, and penetration of inflammatory cells into the myocardium.

Screening for possible failure of herpes simplex virus PCR in cerebrospinal fluid for the diagnosis of herpes simplex encephalitis

The objectives of this study were to evaluate the reliability of herpes simplex virus (HSV) PCR testing in cerebrospinal fluid (CSF) for the detection of herpes simplex encephalitis. This was done by examining retrospectively the clinical follow-up of a large group of patients tested routinely by HSV-PCR. In addition, an attempt was made to assess the incidence of herpes simplex encephalitis in a central European population. CSF samples from 1,427 patients from all Vienna hospitals were submitted for HSV-PCR testing during a period of 4 years and 8 months. Herpes simplex encephalitis was detected by PCR in 12 cases and by serological methods in one additional patient. Retrospective analysis of the course of disease, which was possible in 799 PCR-negative patients, led to the identification of three additional cases in which herpes simplex encephalitis appears to have occurred despite negative PCR results. Failure of the PCR in these patients is most likely due to the time of obtaining CSF during the course of disease. A high specificity of the assay was demonstrated by the lack of false positive results in any of the 708 cases in which other causes for the neurological symptoms had been identified in the follow-up. The incidence of herpes simplex encephalitis in the population of Vienna was between 1 case/469,000-577,000 individuals/year. The highest annual incidence was detected in the age group between 3 months and 3 years, which, however, could not be confirmed statistically.

Changes of endothelial nitric oxide synthase level and activity during endothelial cell proliferation

The goal of this study was to investigate the effect of endothelial cell proliferation on the expression and activity of endothelial nitric oxide synthase (eNOS). Bovine atrial endothelial cells (BAtEC) were studied between day 1 and 6 after seeding. During this period the number of cells in S-phase decreased progressively, while cell number and protein content increased, reaching a maximum at confluence (day 4). Expression of eNOS (determined by ELISA) and eNOS activity (determined by L-arginine to L-citrulline conversion) increased with culture duration with a maximum at confluence. Nitric oxide (*NO) release from BAtEC was determined after stimulation with Ca2+ ionophore A23187 (10 microM, 30 min) by .NO chemiluminescence in the absence of a chemical reduction system. Total *NO release (measured in the presence of 100 U/ml superoxide dismutase) did not change with state of cell proliferation/growth, whereas "bioavailable" *NO (measured in the absence of superoxide dismutase) was low in highly proliferating BAtEC. Relative eNOS activity (.NO and L-citrulline production per eNOS protein) was highest in proliferating BAtEC. The novel finding of this study is that the specific eNOS activity is upregulated in proliferating BAtEC and downregulated in quiescent BAtEC. The amount of "bioavailable" *NO is determined by eNOS activity and *NO inactivation (probably by superoxide), both high in proliferating BAtEC.

Identification of selective estrogen receptor modulators by their gene expression fingerprints

Clinical studies have shown that estrogen replacement therapy (ERT) reduces the incidence and severity of osteoporosis and cardiovascular disease in postmenopausal women. However, long term estrogen treatment also increases the risk of endometrial and breast cancer. The selective estrogen receptor (ER) modulators (SERMs) tamoxifen and raloxifene, cause antagonistic and agonistic responses when bound to the ER. Their predominantly antagonistic actions in the mammary gland form the rationale for their therapeutic utility in estrogen-responsive breast cancer, while their agonistic estrogen-like effects in bone and the cardiovascular system make them candidates for ERT regimens. Of these two SERMs, raloxifene is preferred because it has markedly less uterine-stimulatory activity than either estrogen or tamoxifen. To identify additional SERMs, a method to classify compounds based on differential gene expression modulation was developed. By analysis of 24 different combinations of genes and cells, a selected set of assays that permitted discrimination between estrogen, tamoxifen, raloxifene, and the pure ER antagonist ICI164384 was generated. This assay panel was employed to measure the activity of 38 compounds, and the gene expression fingerprints (GEFs) obtained for each compound were used to classify all compounds into eight groups. The compound's GEF predicted its uterine-stimulatory activity. One group of compounds was evaluated for activity in attenuating bone loss in ovariectomized rats. Most compounds with similar GEFs had similar in vivo activities, thereby suggesting that GEF-based screens could be useful in predicting a compound's in vivo pharmacological profile.

Quantitative measurement for endothelial constitutive nitric oxide synthase in cultured human endothelial cells

Constitutively expressed endothelial nitric oxide synthase (ecNOS) produces nitric oxide (NO) from L-arginine and is important for the maintenance of cardiovascular homeostasis. We report the development of a capture ELISA which is specific for ecNOS. The assay detection limit is 0.5 ng/ml ecNOS protein, allowing the measurement of ecNOS from as few as 6000 human endothelial cells cultured in 96-well microtiter plates. This ELISA has been used to measure a downregulation of ecNOS with 24-h TNFalpha treatment, consistent with results obtained by Western blot analysis. Quantitation of ecNOS in human endothelial cells showed a higher expression of ecNOS in human aortic endothelial cells (18.3+/-1.35 ng ecNOS per 10(6) cells, n = 3 donors) than in human umbilical vein endothelial cells (10.4+/-0.48 ng ecNOS per 10(6) cells, n = 3 donors). These studies demonstrate that this convenient, quantitative assay is currently the most sensitive method for investigating ecNOS protein regulation.

Immunoreactivity and bioactivity of lipopolysaccharide-binding protein in normal and heat-inactivated sera

The lipopolysaccharide (LPS)-potentiating effect of serum is due to LPS-binding protein (LBP), which facilitates the binding of LPS to CD14 receptors. We observed a remarkable heat sensitivity of recombinant LBP and various sera with respect to both immunoreactivity (measured by enzyme-linked immunosorbent assay) and bioactivity (potentiation of LPS induction of tumor necrosis factor in monocytes). Human sera were more active and more heat sensitive than fetal bovine sera. The commonly practiced heat inactivation of human serum (56 degrees C, 30 min) resulted in a 70% loss of bioactivity, which caused an apparent decrease in the potency of LPS.

Monocyte tissue factor induction by lipopolysaccharide (LPS): dependence on LPS-binding protein and CD14, and inhibition by a recombinant fragment of bactericidal/permeability-increasing protein

Mononuclear phagocytes, stimulated by bacterial lipopolysaccharide (LPS), have been implicated in the activation of coagulation in sepsis and endotoxemia. In monocytes LPS induces the synthesis of tissue factor (TF) which, assembled with factor VII, initiates the blood coagulation cascades. In this study we investigated the mechanism of LPS recognition by monocytes, and the consequent expression of TF mRNA and TF activity. We also studied the inhibition of these effects of LPS by rBPI23, a 23-kD recombinant fragment of bactericidal/permeability increasing protein, which has been shown to antagonize LPS in vitro and in vivo. Human peripheral blood mononuclear cells, or monocytes isolated by adherence, were stimulated with Escherichia coli O113 LPS at physiologically relevant concentrations (> or = 10 pg/mL). The effect of LPS was dependent on the presence of the serum protein LBP (lipopolysaccharide-binding protein), as shown by the potentiating effect of human recombinant LBP or serum. Furthermore, recognition of low amounts of LPS by monocytes was also dependent on CD14 receptors, because monoclonal antibodies against CD14 greatly reduced the LPS sensitivity of monocytes in the presence of serum or rLBP. Induction of TF activity and mRNA expression by LPS were inhibited by rBPI23. The expression of tumor necrosis factor showed qualitatively similar changes. Considering the involvement of LPS-induced TF in the potentially lethal intravascular coagulation in sepsis, inhibition of TF induction by rBPI23 may be of therapeutic benefit.

Competition between rBPI23, a recombinant fragment of bactericidal/permeability-increasing protein, and lipopolysaccharide (LPS)-binding protein for binding to LPS and gram-negative bacteria

Lipopolysaccharide (LPS)-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI) are two structurally related lipid A-binding proteins with divergent functional activities. LBP mediates activation of macrophage and other proinflammatory cells. In contrast, BPI has potent bactericidal and LPS-neutralizing activities. A recombinant fragment of BPI (rBPI23) retains the potent biological activities of the holo protein and may represent a novel therapeutic agent for the treatment of gram-negative infections, sepsis, and endotoxemia. For therapeutic effectiveness in many clinical situations, rBPI23 will have to successfully compete with high serum levels of LBP for binding to endotoxin and gram-negative bacteria. The relative binding affinities of rBPI23 and human recombinant LBP (rLBP) for lipid A and gram-negative bacteria were evaluated. The binding of both proteins to lipid A was specific and saturable with apparent Kds of 2.6 nM for rBPI23 and 58 nM for rLBP. rBPI23 was approximately 75-fold more potent than rLBP in inhibiting the binding of 125I-rLBP to lipid A. The binding affinity of rBPI23 (Kd = 70 nM) for Escherichia coli J5 bacteria was also significantly higher than that of rLBP (Kd = 1,050 nM). In addition, rBPI23 at 0.2 micrograms/ml was able to inhibit LPS-induced tumor necrosis factor release from monocytes in the presence of 20 micrograms of rLBP per ml. These results demonstrate that rBPI23 binds more avidly to endotoxin than does rLBP and that, even in the presence of a 100-fold weight excess of rLBP, rBPI23 effectively blocks the proinflammatory response of peripheral blood mononuclear cells to endotoxin.

TNF alpha induces expression of the chemoattractant cytokine RANTES in cultured mouse mesangial cells

We investigated the effect of several immune-relevant cytokines on expression of the chemoattractant intercrine/chemokine RANTES in a mouse mesangial cell line (MMC). Fifty ng/ml recombinant tumor necrosis factor alpha (TNF alpha) induced a marked increase in RANTES transcripts after two hours. RANTES mRNA remained elevated for 24 to 48 hours after stimulation, and could be abolished by co-incubation with 30 micrograms/ml of a neutralizing rabbit anti-TNF alpha antibody. Protein expression of RANTES, as assessed by indirect immunofluorescence and Western blotting, increased in MMCs 24 hours after TNF alpha stimulation. Interleukin-1 beta, tumor necrosis factor beta (TNF beta), and lipopolysaccharide (LPS) also increased expression of RANTES mRNA. In addition, RANTES mRNA expression was stimulated in glomeruli harvested from rats following renal in vivo perfusion with TNF alpha. Our results indicate that mesangial cells produce the small cytokine RANTES. This factor, in concert with other chemoattractants, may play a role in the glomerular recruitment of inflammatory cells like macrophages/monocytes.

Efficacy of an anti-CD7-ricin A chain immunoconjugate in a novel murine model of human T-cell leukemia

In vivo efficacy testing of monoclonal antibody-based drugs specific for human leukemias is hampered by the paucity of suitable animal models, due in part to the inability of many anti-human monoclonal antibodies to cross-react with antigens expressed in animal tissues or cells. Moreover, human leukemic cells have proven difficult to establish in immunosuppressed mice except as solid tumors. We report here the establishment of a murine model for human leukemia displaying features of human disease, such as growth of malignant cells and localization of such cells to lymphoid compartments, and the effective depletion of leukemic cells from these mice by an immunoconjugate. Human T-leukemia cells (CEM) injected into cyclophosphamide-pretreated NIH-III mice engrafted in all mice (n = 41), with CEM cells detected in the bone marrow, spleen, and blood 4 weeks after injection. There was no evidence of solid tumors. Treatment of CEM-engrafted mice with 4A2-RTA30, an immunoconjugate of an anti-CD7 monoclonal antibody and ricin A chain (RTA30), resulted in a 100- to 200-fold overall depletion of CEM cells from the spleen and the bone marrow (P less than 0.02). This depletion was specific and toxin-dependent, as a control immunoconjugate had no demonstrable effect (P greater than 0.5). Depletion of CEM cells was also observed after treatment with unconjugated anti-CD7 mAb, but this effect was not significantly different from controls (P greater than 0.1). Therefore, significant depletion of CEM cells required the presence of the ricin A chain moiety. Further investigations revealed that CEM cells recovered from NIH-III mice expressed less CD7 antigen, but remained sensitive to subsequent in vitro exposure to 4A2-RTA30. In conclusion, we have established a model for studying the efficacy of immunoconjugates and have successfully depleted human T-leukemic cells from lymphoid tissues in immunodeficient mice by treatment with an anti-CD7-RTA30 immunoconjugate.