A number of biomarkers have been studied for the diagnosis of sepsis in paediatrics, but no gold standard has been identified. Procalcitonin (PCT) was demonstrated to be an accurate biomarker for the diagnosis of sepsis in adults and showed to be promising in paediatrics. Our study reviewed the diagnostic accuracy of PCT as an early biomarker of sepsis in neonates and children with suspected sepsis. A comprehensive literature search was carried out in Medline/Pubmed, Embase, ISI Web of Science, CINAHL and Cochrane Library, for studies assessing PCT accuracy in the diagnosis of sepsis in children and neonates with suspected sepsis. Studies in which the presence of infection had been confirmed microbiologically or classified as “probable” by chart review were included. Studies comparing patients to healthy subjects were excluded. We analysed data on neonates and children separately. Our primary outcome was the diagnostic accuracy of PCT at the cut-off of 2-2.5 ng/ml, while as secondary outcomes we analysed PCT cut-offs 2.5 ng/ml. Pooled sensitivities and specificities were calculated by a bivariate meta-analysis and heterogeneity was graphically evaluated. We included 17 studies, with a total of 1408 patients (1086 neonates and 322 children). Studies on neonates with early onset sepsis (EOS) and late onset sepsis (LOS) were grouped together. In the neonatal group, we calculated a sensitivity of 0.85, confidence interval (CI) (0.76; 0.90) and specificity of 0.54, CI (0.38; 0.70) at the PCT cut-off of 2.0-2.5 ng/ml. In the paediatric group it was not possible to undertake a pooled analysis at the PCT cut-off of 2.0-2.5 ng/ml, due to the paucity of the studies. PCT shows a moderate accuracy for the diagnosis of sepsis in neonates with suspected sepsis at the cut-off of 2.0-2.5 ng/ml. More studies with high methodological quality are warranted, particularly in neonates, studies considering EOS and LOS separately are needed to improve specificity. PROSPERO Identifier: CRD42016033809 . Registered 30 Jan 2016.

Bloodstream infections caused by multidrug-resistant, Gram-negative (MDRGN) bacteria represent a significant cause of morbidity and mortality. Prompt diagnosis and appropriate empiric treatment are the most important determinants of patient outcome. The objective of our study was to assess the epidemiology and clinical outcome of MDRGN sepsis in a tertiary-care pediatric hospital during a 12-month period. It was a retrospective, observational study of MDRGN bacteremia including all patients <18 years of age, hospitalized during 2011, with documented bacteremia caused by Enterobacteriaceae or non-fermentative bacteria. Overall, 136 blood cultures in 119 patients were included. The median age of patients was 1.1 years; 86.3% of patients had an underlying disease. The cumulative incidence of Gram-negative bloodstream infections was 5.4/1000 hospital admissions and the infection rate was 0.65/1000 hospital days. Most frequently isolated strains were Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa; 67.6% of infections were hospital acquired. The percentage of multidrug-resistant (MDR) organisms among isolated species was 39%. The crude rate of mortality was 16% and sepsis-related mortality was 9.2%. The mortality rate among patients with an antibiotic-resistant isolate was 22.6%. Factors significantly associated with sepsis-related mortality were antibiotic resistance (odds ratio: 4.26, 95% confidence interval: 1.07-16.9) and hospital acquisition of infection (odds ratio: 1.13, 95% confidence interval: 1.05-1.22). This study demonstrates the high mortality of hospital-acquired MDRGN bacteremia in children. International networks focusing on clinical management and outcomes of MDRGN in children are required. Study of novel antibiotics active against Gram-negative bacteria should include children early in the clinical trial development programs.

In humans, the interaction of the natural killer group 2 member D (NKG2D)‐activating receptor on natural killer (NK) and CD8 ⁺ T cells with its major histocompatibility complex class I‐related chain (MIC) and UL16 binding protein (ULBP) ligands (NKG2DLs) promotes recognition and elimination of stressed cells, such as tumor or infected cells. Here, we investigated the capacity of HIV‐1 to modulate NKG2DL expression and escape NGK2D‐mediated immunosurveillance. In CD4 ⁺ T lymphocytes, both cell surface expression and release of MICA, MICB, and ULBP2 were up‐regulated > 2‐fold by HIV‐1 infection. In HIV‐infected CD4 ⁺ T lymphocytes or Jurkat T‐cell lines, increased shedding of soluble NKG2DLs (sNKG2DLs) was impaired by a matrix metalloproteinase inhibitor (MMPI). Moreover, naive HIV ⁺ patients displayed increased plasma sMICA and sULBP2 levels and reduced NKG2D expression on NK and CD8 ⁺ T cells compared to patients receiving highly active antiretroviral therapy (HAART) or healthy donors. In individual patients, HAART uptake resulted in the drop of sNKG2DL and recovery of NKG2D expression. Finally, sNKG2DLs in patients' plasma down‐regulated NKG2D on NK and CD8 ⁺ T cells and impaired NKG2D‐mediated cytotoxicity of NK cells. Thus, NKG2D detuning by sNKG2DLs may promote HIV‐1 immune evasion and compromise host resistance to opportunistic infections, but HAART and MMPI have the potential to avoid such immune dysfunction.—Matusali, G., Tchidjou, H. K., Pontrelli, G., Bernardi, S., D'Ettorre, G., Vullo, V., Buonomini, A. R., Andreoni, M., Santoni, A., Cerboni, C., Doria, M. Soluble ligands for the NKG2D receptor are released during HIV‐1 infection and impair NKG2D expression and cytotoxicity of NK cells. FASEB J. 27, 2440–2450 (2013). www.fasebj.org

SUMMARY: A large outbreak of hepatitis A virus (HAV) infection occurred in 2004 in Campania, a region of southern Italy, with 882 cases reported between 1 January and 1 August. The local public health authorities and the Italian National Institute of Health carried out investigations in order to characterize the agent, identify the source of infection and the route of transmission, and implement appropriate control measures. A web-based reporting system enhanced the flow of information between public health authorities, providing real-time epidemic curves and frequency distributions. The same 1B HAV genotype was found in 90% of sera from a subset of patients with acute disease, suggesting a local common source. A case-control study in the municipality with the highest attack rate showed that raw seafood consumption, in particular if illegally sold in water, was strongly associated with HAV illness. Samples of seafood systematically collected from retailers were found contaminated by HAV.