Collaborative national multicenter for the identification of conversion factors from copies/mL to international units/mL for the normalization of HCMV DNA load.

The present multicentric (n = 11 laboratories) study aimed to identify conversion factors from copies/mL to international units (IU)/mL for the normalization of HCMV DNA load using the first WHO International Standard for HCMV nucleic acid amplification techniques and to enhance interlaboratory agreement of HCMV DNA quantification methods. Study protocols for whole blood and plasma (extraction and amplification) were performed to calculate conversion factors from HCMV DNA copy number to IU. The greatest variability was observed in samples with lower HCMV concentrations (3.0 Log10) in both biological matrices. Overall, 73.1% (206/282) of whole blood and 82.2% (324/394) of plasma samples analyzed fell within an acceptable variation range (±0.5 Log10 difference). An average of 0.64 (range 0.21-1.17) was the conversion factor calculated for the HCMV whole blood panel and 0.82 (range 0.39-2.2) for the HCMV plasma panel.

Neonatal pertussis diagnosis: low procalcitonin level and high lymphocyte count are able to discriminate pertussis from bacterial and viral infections.

Pertussis is quite frequent and severe among infants; therefore, rapid diagnosis and timely targeted therapy are essential. Although a molecular test for etiological diagnosis is now available, it may not be available everywhere, and therefore adjunctive diagnostic tests are still useful for presumptive diagnosis. We describe the use of procalcitonin (PCT) and lymphocyte count to discriminate among pertussis, bacterial and viral infections. Fourteen infants per group were studied. The decision tree, built considering all available variables, showed a major role of PCT in predicting the different groups. A PCT value equal to or greater than 0.75 ng/ml selected for bacterial infections. A PCT value lower than 0.75 ng/ml and a lymphocyte count equal to or greater than 10,400/mm3 selected the subjects with pertussis, while a lymphocyte count lower than 10,400/mm3 selected for viral etiology. PCT should be used in the diagnosis of infants suspected of having pertussis.

KPC-producing Klebsiella pneumoniae gut decolonisation following ceftazidime/avibactam-based combination therapy: A retrospective observational study.

OBJECTIVES: KPC-producing Klebsiella pneumoniae (KPC-Kp) gut colonisation is a major risk factor for developing systemic infection. Ceftazidime/avibactam (CAZ/AVI) may have a role as decolonisation therapy in special situations. METHODS: This was a retrospective, observational, multicentre study. The KPC-Kp gut decolonisation rate of CAZ/AVI-based therapy (Group A) was compared with other antimicrobial regimens (Group B) in patients with KPC-Kp infection. RESULTS: Among 12 patients in Group A, 11 (91.7%) achieved gut decolonisation. None of the 24 patients of Group B were decolonised. CONCLUSION: CAZ/AVI-based therapy could be useful in KPC-Kp gut decolonisation in high-risk patients.

Imported arboviral infections in Italy, July 2014-October 2015: a National Reference Laboratory report.

BACKGROUND: Imported cases of infections due to Dengue (DENV) and Chikungunya (CHIKV) viruses and, more recently, Zika virus (ZIKV) are commonly reported among travelers returning from endemic regions. In areas where potentially competent vectors are present, the risk of autochthonous transmission of these vector-borne pathogens is relatively high. Laboratory surveillance is crucial to rapidly detect imported cases in order to reduce the risk of transmission. This study describes the laboratory activity performed by the National Reference Laboratory for Arboviruses (NRLA) at the Italian National Institute of Health in the period from July 2014 to October 2015. METHODS: Samples from 180 patients visited/hospitalized with a suspected DENV/CHIKV/ZIKV infection were sent to the NRLA from several Italian Hospitals and from Regional Reference Laboratories for Arboviruses, in agreement with the National Plan on human surveillance of vector-borne diseases. Both serological (ELISA IgM test and Plaque Reduction Neutralization Test-PRNT) and molecular assays (Real Time PCR tests, RT-PCR plus nested PCR and sequencing of positive samples) were performed. RESULTS: DENV infection was the most frequently diagnosed (80 confirmed/probable cases), and all four genotypes were detected. However, an increase in imported CHIKV cases (41 confirmed/probable cases) was observed, along with the detection of the first ZIKV cases (4 confirmed cases), as a consequence of the recent spread of both CHIKV and ZIKV in the Americas. CONCLUSIONS: Main diagnostic issues highlighted in our study are sensitivity limitations of molecular tests, and the importance of PRNT to confirm serological results for differential diagnosis of Arboviruses. The continuous evaluation of diagnostic strategy, and the implementation of laboratories networks involved in surveillance activities is essential to ensure correct diagnosis, and to improve the preparedness for a rapid and proper identification of viral threats.

Viability of pegIFNα-RBV for CHC in the direct acting antiviral era: a practical algorithm between efficacy and cost containment.

The classical pegylated interferon α (peg-IFNα) and ribavirin (RBV) treatment of chronic hepatitis C (CHC) is progressively being replaced by new direct acting antivirals, whose costs remain a major barrier to widespread use. Using baseline data and viral kinetics, we developed a predictive algorithm to allocate to DAA patients who are not going to respond to peg-IFNα/RBV. This prospective study evaluated 205 CHC patients treated with peg-IFNα/RBV. HCVRNA kinetics during the initial 3 days of therapy and baseline variables including age, genotype, fibrosis and ALTs were used to construct a prediction rule in terms of sustained virological response (SVR). One hundred and twenty-one patients achieved an SVR (59%). Variables independently associated with SVR were HCVRNA, ALT, glycaemia, viral genotype, and fibrosis. The decline of viremia from baseline to 48/72 h was significantly different in SVR compared to non-SVR patients (2.2 vs. 0.65 log10 IU/mL; p < 0.001), and was influenced by viral genotype, levels of ALT, stage of fibrosis and IL28B polymorphism. In genotype 1, HCVRNA decline <0.8 logs had a negative predictive value of 90%, and in genotype 2, HCVRNA decline >1.2 logs had a positive predictive value of 92%. A combination of HCVRNA kinetics and a score based on pre-treatment parameters was highly accurate in predicting SVR in most patients. Outcome of peg-IFNα/RBV treatment may be predicted combining evaluation of baseline variables and HCVRNA kinetics. This allows to individualize treatment, reserving newer and more expensive DAAs to CHC patients who are in most need of them.

Nation-wide measure of variability in HCMV, EBV and BKV DNA quantification among centers involved in monitoring transplanted patients.

BACKGROUND: Inter-laboratory variability in quantifying pathogens involved in viral disease following transplantation may have a great impact on patient care, especially when pre-emptive strategies are used for prevention. OBJECTIVES: The aim of this study was to analyze the variability in quantifying CMV, EBV and BKV DNA from 15 virology laboratories of the Italian Infections in Transplant Working Group (GLaIT) involved in monitoring transplanted patients. STUDY DESIGN: Panels from international Quality Control programs for Molecular Diagnostics (QCMD, year 2012), specific for the detection of CMV in plasma, CMV in whole blood (WB), EBV and BKV were used. Intra- and inter-laboratory variability, as well as, deviations from QCMD consensus values were measured. RESULTS: 100% specificity was obtained with all panels. A sensitivity of 100% was achieved for EBV and BKV evaluations. Three CMV samples, with concentrations below 3 log10 copies/ml, were not detected by a few centers. Mean intra-laboratory variability (% CV) was 1.6 for CMV plasma and 3.0 for CMV WB. Mean inter-laboratory variability (% CV) was below 15% for all of the tested panels. Inter-laboratory variability was higher for CMV in WB with respect to the CMV plasma panel (3.0 vs 1.6% CV). The percentiles 87.7%, 58.6%, 89.6% and 74.7% fell within±0.5 log10 difference of the consensus values for CMV plasma, CMV WB, EBV and BKV panels, respectively. CONCLUSIONS: An acceptable intra- and inter-laboratory variability, in comparison with international standards was observed in this study. However, further harmonization in viral genome quantification is a reasonable goal for the future.

Differential antiviral effects of pegylated interferon-α2a and pegylated interferon-α2b in chronic hepatitis C.

BACKGROUND AND OBJECTIVES: Pegylated interferon (peg-IFN)-α2a and -α2b show different pharmacokinetic properties but are used interchangeably for hepatitis C treatment in traditional dual combinations and with newer agents. We assessed whether peg-IFN antiviral effects vary with peg-IFN subtype, affecting viral response in a differential manner. METHODS: Chronic hepatitis C patients treated with ribavirin combined with peg-IFN-α2a (N = 109) or -α2b (N = 114) were studied. Hepatitis C virus RNA quantitation was performed by Cobas TaqMan 5 min before treatment start and subsequently after 48/72 h and 7, 14, 28 and 90 days. Antiviral effect was assessed in terms of viraemia changes over treatment. Histology grading and staging, interleukin-28B (IL28B) status and baseline viral genotype, alanine aminotransferase, gamma glutamyltransferase and glucose were analysed. RESULTS: Viraemia decline after 48/72 h and 7 days was significantly greater with peg-IFN-α2b (1.96 and 2.12 vs 1.49 and 1.20 log10 IU/mL with peg-IFN-α2a; p < 0.001). Differences were of larger extent in patients with advanced fibrosis (p = 0.002), genotype 1 infection (p = 0.002) and CT/TT genotypes of IL28B (p = 0.001). A rebound in viral load was observed significantly more often after the first dose in patients treated with peg-IFN-α2b (78 vs 28 % in those with peg-IFN-α2a; p = 0.0001). Differences between peg-IFNs disappeared by day 28 of treatment. CONCLUSION: There are significant pharmacodynamic differences between peg-IFN-α2a and -α2b in the early phase of chronic hepatitis C treatment. The greater early viral decline observed with peg-IFN-α2b was essentially confined to 'difficult to treat' patients. Whether this could affect response-guided treatment decision making, as well as triple drug regimens, needs to be assessed.

Clinico-pathological significance of hepatitis C virus core antigen levels in chronic infection.

Hepatitis C virus core antigen (HCVcoreAg) may be measured in serum with a sensitive, recently validated assay. Beyond its value as a marker of viral infection, there are little data on its relation with clinical, histological, and virological parameters. In this study, the significance of HCVcoreAg levels was studied in a prospective cohort of 114 patients with chronic hepatitis C. HCVcoreAg was measured by a commercial chemiluminescent microparticle immunoassay. Clinical and virological data included quantitative HCV-RNA, HCV genotype, ALT, GGT, IL28B rs12979860 polymorphism as well as liver histology parameters. HCVcoreAg levels were correlated significantly with HCV-RNA (r=0.56; P<0.0001) but also with ALT levels (r=0.258; P<0.01) and liver necroinflammatory activity (r=0.205; P<0.04). Patients harbouring HCV genotype 3 showed lower levels of HCVcoreAg than both genotype 1 and two patients. In genotype 3, a direct correlation between steatosis and HCVcoreAg was found. Levels of HCVcoreAg also varied according to the IL28B genotype. These data suggest that the evaluation of HCVcoreAg serum levels may provide relevant data for the baseline clinical evaluation of chronic hepatitis C patients. HCVcoreAg serum levels may be a useful tool to further the understanding of chronic hepatitis C pathobiology.