Analysis of norovirus outbreaks reveals the need for timely and extended microbiological testing.

BACKGROUND: Norovirus outbreaks in hospitals remain a substantial threat despite many recommendations for prevention published recently. AIM: To analyse the factors contributing to onset of a norovirus outbreak in hospitals in order to identify new prevention options. METHODS: Data from 71 norovirus outbreaks occurring in five German hospitals between 2002 and 2012 were analysed focusing on the start conditions: the weekday of outbreak, the time span between the first symptomatic cases and the outbreak onset date, the timing of a positive norovirus test result in an outbreak, and presence of concomitant Clostridium difficile infections. FINDINGS: In 68 (96%) outbreaks index cases were identifiable. In 30 of 44 (68%) outbreaks the index case patient acquired norovirus infection in hospital. In 20% of all outbreaks, the index case was a staff member. Nine outbreaks were caused by not isolating contact patients during the incubation time after their exposure to a symptomatic case. Case numbers in norovirus outbreaks were lower when the norovirus test results were available before the outbreak onset (P = 0.028). In 30 of 46 (64%) norovirus outbreaks, C. difficile toxin tests were positive in up to ten patients. Co-infection or subsequent infection with norovirus and C. difficile in single patients occurred in nine (20%) outbreaks. CONCLUSION: Future prevention strategies should focus not only on patients but also on staff. Constant surveillance for new cases of diarrhoea and vomiting and timely adherence to contact precautions for all exposed persons is crucial in outbreak control, as is the need for extended microbiological testing.

Improved quantitative PCR protocols for adenovirus and CMV with an internal inhibition control system and automated nucleic acid isolation.

With the establishment of routine virus load (DNAemia) screening for Human adenovirus (HAdV) and Cytomegalovirus (CMV) in post-transplant care quality standards for quantitative PCR-assays are increasing. Established real-time PCR assays were improved with a fully automated DNA-extraction and with a competitive internal control DNA packaged into a lambda phage which serves as an extraction and amplification control in each sample. HAdV and CMV DNA were detected and quantified simultaneously in various types of diagnostic samples like blood, feces or respiratory tract materials. Inhibition was observed in 0.33-0.66% of over 14,000 diagnostic samples, an infrequent but nevertheless not negligible event, which is observed mainly in stool samples. CMV viral load in broncho-alveolar lavage fluid (BALF) ranged between positive but below the quantitation limit of 1,000 copies/ml up to 1.8 × 10(7) copies/ml with a median of 6.0 × 10(3) copies/ml. Forty-one (4.7%) BALF samples had a viral load above 5.0 × 10(5) copies/ml, which was proposed as a threshold for the diagnosis of pneumonia. HAdV viral loads ranged between positive but below the quantitation limit of 1,000 copies/ml to a very high concentration of 1.3 × 10(11) copies/ml in stool and BALF samples. A HAdV-DNAemia of >10(4) copies/ml was found only in patients with stool viral load of above 10(5) copies/ml. These data support the hypothesis that quantitation in diagnostic materials other than blood may give valuable diagnostic information and that further evaluation of this approach is reasonable.

CXCL13 as a novel marker for diagnosis and disease monitoring in pediatric PTLD.

Posttransplant lymphoproliferative disease (PTLD) is a severe complication of immunosuppressive treatment in organ-grafted children. Early diagnosis of PTLD is hampered by both unspecific clinical symptoms and lack of easy accessible markers. The homeostatic chemokine CXCL13, which plays a crucial role in B-cell homing and lymphoid organ development, is expressed in some lymphomatous diseases. This study aims to investigate whether serum CXCL13 (sCXCL13) levels correlate with occurrence and regression of PTLD in pediatric solid-organ graft recipients. Serum samples from PTLD patients (n = 21), patients with Epstein-Barr virus (EBV) reactivation (n = 18), and healthy age-matched controls (n = 19) were tested for CXCL13 using a commercially available ELISA kit. sCXCL13 levels were significantly higher in PTLD patients than in healthy children. PTLD patients had also higher sCXCL13 values than pediatric solid-organ recipients with EBV reactivation. An increase in sCXCL13 levels was observed from EBV reactivation to PTLD diagnosis in most cases. Elevated sCXCL13 levels were detected up to 2 years prior to PTLD diagnosis and correlated well with response to cytoreductive treatment in individual patients. sCXCL13, thus, may be a readily available surrogate marker for the diagnosis of PTLD and for monitoring of response to treatment in patients with initially elevated sCXCL13 levels.

New real-time PCR detects prolonged norovirus excretion in highly immunosuppressed patients and children.

Noroviruses (NoV) are a major cause of epidemic nonbacterial gastroenteritis and affect all age groups worldwide. Three of five NoV genogroups, namely, genogroup I (GI), GII, and GIV, are associated with human disease. Unfortunately, these genogroups demonstrate a high degree of sequence diversity, complicating the design of pan-NoV diagnostic PCR tests. To decrease the risk of false-negative test results, we have developed a new one-step real-time TaqMan reverse transcription-PCR protocol. This protocol detects all human NoV genogroups in one reaction with a sensitivity of 400 virus genome equivalents/reaction for both GI and GII. The use of in vitro-transcribed NoV RNA as an external standard allows (semi)quantification of viral loads in samples. In a retrospective analysis of 206 stool samples from 77 patient episodes, the duration of NoV excretion and the amount of virus excreted were determined. Twenty (26.0%) of these episodes lasted longer than 10 days. Univariate risk factor analysis revealed the patient status after organ transplantation (odds ratio [OR], 7.49 [95% confidence interval, 2.06 to 28.32]; P < 0.001), immunosuppression (OR, 9.19 [95% confidence interval, 2.50 to 35.39]; P < 0.001), and age of less than 10 years (OR, 4.58 [95% confidence interval, 1.36 to 15.77]; P = 0.004) as risk factors for a NoV excretion period of more than 10 days. These findings were confirmed by time-dependent Kaplan-Meier analyses, whereas multivariate Cox regression analyses identified immunosuppression as the sole risk factor. Surprisingly, in contrast to the excretion periods, the viral loads in stools did not increase in connection with age or immunosuppressive status. This fact may be one important piece in the pattern of high-level NoV transmissibility and may have an impact on the development of transmission prevention strategies.

[Hospital emergency department preparedness for NBC mass casualties]. / Der Notfallplan des Krankenhauses bei ABC-Gefahrenlagen.

Hospital emergency department preparedness for mass-casualty incidents involving nuclear, biological or chemical (NBC) threats relies on close cooperation between hospital and pre-hospital emergency staff. It is essential that the hospital is immediately secured from unauthorized intrusion in order to avoid contamination of the hospital area and staff. The strategy of the pre-hospital emergency staff to avoid the unnecessary spread of contaminated material involves thorough decontamination of exposed persons near the site of the incident and coordinated transport to the primary care hospitals after decontamination. However, uncoordinated access of contaminated victims requires emergency decontamination by hospital staff. Thus, hospital staff must be prepared to provide in-hospital decontamination. Coordinated admission of contaminated patients into the NBC primary care hospital relies on a thorough decontamination by pre-hospital emergency staff at a decontamination site installed outside the hospital. Screening of patients is performed by hospital staff with special expertise in emergency medicine. Following admission, each patient is assigned to a team of specialists. Pre-hospital patient documentation is switched to inhospital documentation after admission using machine-readable electronic admission numbers.

Adverse effects of rabies pre- and postexposure prophylaxis in 290 health-care-workers exposed to a rabies infected organ donor or transplant recipients.

The recent unfortunate rabies transmissions through solid organ transplants of an infected donor in Germany required the initiation of a vaccination program to protect health care workers (HCWs) with close contact to rabies-infected patients. A systematic follow-up of adverse effects was initiated. Rabies postexposure prophylaxis (PEP) was started in 269 HCWs at four German hospitals. Pre-exposure prophylaxis (PreEP) was administered to 74 HCWs caring for an already diagnosed rabies patient. At each vaccination date, HCWs were interviewed for symptoms possibly representing adverse effects. Adverse effects of PEP and PrePEP were compared. Out of 269 HCWs, 216 were included for the investigation of adverse effects. Of these 216 HCWs, 114 (53%) individuals developed at least one systemic adverse effect. Incidences of tiredness (30.6%), malaise (26.4%), headache (26.9%), dizziness (14.8%), and chills (13.0%) declined in the course of PEP (p < 0.05), whereas incidences of fever (7.4%), paraesthesias (7.9%), arthralgias (1.9%), myalgias (4.2%), nausea (9.3%), diarrheas (2.8%) and vomiting (1.4%) did not. In 11 (5.1%) HCWs PEP was discontinued mostly due to adverse reactions (four suffered strong headaches, two HCWs meningeal irritations, two chills, one paraesthesia, one malaise, and one a rush). Systemic effects of PEP or PreEP did not differ significantly. Despite relatively high incidences of moderate severe adverse reactions rabies PEP is safe. Strong headache, tiredness, dizziness, and paraesthesias are the most important postvaccinal symptoms. Vaccinees suffering from adverse effects of PEP must be strongly encouraged to complete PEP, as it is to date the only protection against fatal rabies.

The cytoplasmic tyrosine motifs in full-length glycoprotein 130 have different roles in IL-6 signal transduction.

The function of the signal-transducing receptor subunit glycoprotein 130 (gp130) in the IL-6-receptor complex has previously been studied using carboxyl-terminal deletion mutants or a truncated molecule of approximately 60 membrane-proximal amino acids (containing box 1 and box 2) linked to the individual gp130 tyrosine motifs. However, the redundancy of the tyrosine motifs within the cytoplasmic part of gp130 has been neglected. Here we describe the analysis of the function of the individual cytoplasmic tyrosine residues of gp130 in the context of the full-length receptor protein in IL-6 signaling as measured by STAT activation, acute phase protein induction, and stimulation of proliferation. Add-back receptor mutants containing only one cytoplasmic tyrosine have been generated and tested for their efficiency in IL-6 signal transduction. Our studies revealed that tyrosine motifs which have been described to recruit STAT proteins are not equivalent with respect to their potential to activate STAT factors and acute phase protein gene promoters: the two distal tyrosines, Tyr905 and Tyr915, of gp130 were more potent than Tyr767 and Tyr814. Surprisingly, Tyr905 and Tyr915 mediate acute phase protein gene promoter activation stronger than the wild-type receptor containing all six cytoplasmic tyrosine residues. In contrast, Ba/F3 cells stably transfected with add-back receptors containing Tyr767 or Tyr905 were more sensitive to IL-6-induced proliferation than cells expressing the other add-back receptor mutants. Thus, the tyrosine residues in the cytoplasmic part of gp130 were found to contribute differentially to IL-6 signal transduction in the full- length gp130 protein.

Activation of the protein tyrosine phosphatase SHP2 via the interleukin-6 signal transducing receptor protein gp130 requires tyrosine kinase Jak1 and limits acute-phase protein expression.

Stimulation of the interleukin-6 (IL-6) signalling pathway occurs via the IL-6 receptor-glycoprotein 130 (IL-6R-gp130) receptor complex and results in the regulation of acute-phase protein genes in liver cells. Ligand binding to the receptor complex leads to tyrosine phosphorylation and activation of Janus kinases (Jak), phosphorylation of the signal transducing subunit gp130, followed by recruitment and phosphorylation of the signal transducer and activator of transcription factors STAT3 and STAT1 and the src homology domain (SH2)-containing protein tyrosine phosphatase (SHP2). The tyrosine phosphorylated STAT factors dissociate from the receptor, dimerize and translocate to the nucleus where they bind to enhancer sequences of IL-6 target genes. Phosphorylated SHP2 is able to bind growth factor receptor bound protein (grb2) and thus might link the Jak/STAT pathway to the ras/raf/mitogen-activated protein kinase pathway. Here we present data on the dose-dependence, kinetics and kinase requirements for SHP2 phosphorylation after the activation of the signal transducer, gp130, of the IL-6-type family receptor complex. When human fibrosarcoma cell lines deficient in Jak1, Jak2 or tyrosine kinase 2 (Tyk2) were stimulated with IL-6-soluble IL-6R complexes it was found that only in Jak1-, but not in Jak 2- or Tyk2-deficient cells, SHP2 activation was greatly impaired. It is concluded that Jak1 is required for the tyrosine phosphorylation of SHP2. This phosphorylation depends on Tyr-759 in the cytoplasmatic domain of gp130, since a Tyr-759-->Phe exchange abrogates SHP2 activation and in turn leads to elevated and prolonged STAT3 and STAT1 activation as well as enhanced acute-phase protein gene induction. Therefore, SHP2 plays an important role in acute-phase gene regulation.