Licia Bordi

Cross-subtype Immunity against Avian Influenza in Persons Recently Vaccinated for Influenza

Seasonal influenza vaccination may induce heterosubtypic immunity against avian influenza virus (H5N1).

Phylogenetic analysis of West Nile virus isolates, Italy, 2008-2009.

To determine the lineage of West Nile virus that caused outbreaks in Italy in 2008 and 2009, several West Nile virus strains were isolated from human specimens and sequenced. On the basis of phylogenetic analyses, the strains isolated constitute a distinct group within the western Mediterranean cluster.

underevaluation of Hiv-1 Plasma Viral Load by a Commercially Available Assay in a Cluster of Patients Infected With Hiv-1 A/g Circulating Recombinant Form (crf02)

The authors studied the correlation and agreement of commercially available assays in detection and quantification of the HIV-1 intersubtype A/G circulating recombinant form CRF02. The assays under comparison were Bayer Versant HIV-1 RNA, version 3.0; Roche Amplicor HIV-1 Monitor, version 1.5 (standard procedure); and Organon Teknika NucliSens HIV-1 RNA QT. Plasma samples from 114 patients infected with CRF02 were tested by the three assays under standard conditions. Although correlation among the assays was high and statistically significant for subtype B and CRF02, in the latter instance, NucliSens measured average viral load values (3.29 +/- 0.71 log(10) copies/mL) about 4 and >8 times lower than those obtained by Versant (3.90 +/- 0.90 log(10) copies/mL) and Amplicor (4.22 +/- 1.05 log(10) copies/mL), respectively. Furthermore, in a statistically significant percentage of CRF02-harboring samples, NucliSens produced viral load values undetectable or 1 log(10) lower than those obtained in Versant and Amplicor assays. Altogether, these data underline a low performance of NucliSens in detecting and quantifying viremia in plasma samples harboring the CRF02. These results are potentially important as global distribution of new HIV-1 subtypes is expanding, and recombinant strains, particularly CRF02, are emerging and becoming highly prevalent.

Anti–Severe Acute Respiratory Syndrome Coronavirus Immune Responses: The Role Played by Vγ9Vδ2 T Cells

Abstract Severe acute respiratory syndrome (SARS) is caused by a novel coronavirus (SARS-CoV) strain. Analyses of T cell repertoires in health care workers who survived SARS-CoV infection during the 2003 outbreak revealed that their effector memory Vγ9Vδ2 T cell populations were selectively expanded ∼3 months after the onset of disease. No such expansion of their αβ T cell pools was detected. The expansion of the Vγ9Vδ2 T cell population was associated with higher anti–SARS-CoV immunoglobulin G titers. In addition, in vitro experiments demonstrated that stimulated Vγ9Vδ2 T cells display an interferon-γ–dependent anti–SARS-CoV activity and are able to directly kill SARS-CoV–infected target cells. These findings are compatible with the possibility that Vγ9Vδ2 T cells play a protective role during SARS

Cytomegalovirus pneumonia in immunocompetent host: Case report and literature review

CMV infection is highly prevalent in general population and its clinical picture generally ranges from asymptomatic disease to mononucleosis-like syndrome. While severe life-threatening CMV disease is well documented in certain immunocompromised risk groups, severe infection with symptomatic pneumonia in immunocompetent hosts has been rarely documented. In this paper we describe a case of primary CMV infection, complicated by severe CMV pneumonia in an immunocompetent host, successfully treated with oral valganciclovir. Moreover, we reviewed CMV pneumonia cases in immunocompetent adults reported in the literature.

Frequency of Detection of Upper Respiratory Tract Viruses in Patients Tested for Pandemic H1N1/09 Viral Infection

ABSTRACT Molecular testing of 270 consecutive nasopharyngeal swab samples taken in May and June 2009 and 274 samples from patients hospitalized between July and December 2009 showed similar findings of respiratory viruses, with influenza A pandemic virus H1N1/09 being the most represented, followed by human parainfluenza virus type 3 and rhinoviruses. Statistical analyses suggested virus cocirculation in the absence of viral interference.

Monophyletic outbreak of Hepatitis A involving HIV-infected men who have sex with men, Rome, Italy 2008-2009

BACKGROUND Outbreaks of Acute Hepatitis A Virus (HAV) among men who have sex with men (MSM) have been reported in Europe and, recently, in Italy. From July 2008 through January 2010, 162 HAV infections were diagnosed at National Institute for Infectious Diseases, Rome, Italy, with high male-to-female ratio (M:F=7.5). OBJECTIVES The aim of this study was to characterize viral strains involved in this outbreak. STUDY DESIGN The sequences of VP1-2A junction of HAV genome, obtained from 67/97 HAV-RNA-positive samples, were used for phylogenetic analysis. RESULTS All but 1 of the HAV sequences were genotype 1A, 1 was genotype 1B. A monophyletic cluster, including 59/66 genotype IA sequences, was identified by phylogenetic analysis. This cluster included also 2 HAV strains isolated in Germany (2007) and France (2008) from MSM, that, in turn, were reported to be genetically correlated to HAV strains circulating in Tuscany in 2008. Among the males harboring an HAV strain belonging to the cluster, 62% reported to be MSM, and 25% were HIV-positive, 2 with acute HIV infection. CONCLUSION The outbreak occurred in Rome in 2008-2010, involving high proportion of HIV-infected MSM, is sustained by a monophyletic HAV strain, circulating around the same period also in other European countries. Possible factors favouring HAV spread among HIV-infected persons, such as high risk behavior and prolonged fecal excretion, need to be further elucidated. Timely identification of outbreaks with one or the same source of infection may be helpful to implement preventive measures addressing at risk populations.

Bcl-2 inhibits the caspase-dependent apoptosis induced by SARS-CoV without affecting virus replication kinetics

Summary.Vero cells transfected with either neo- or bcl-2-plasmid were infected with SARS-CoV at a high multiplicity of infection. Apoptosis appeared after the onset of CPE and completion of virus replication, and could be prevented by Bcl-2 expression. Apoptosis is likely mediated by the mitochondrial pathway, as demonstrated by its inhibition using Bcl-2, and by the activation of the caspase cascade, resulting in PARP cleavage. Prevention of apoptosis did not affect susceptibility to infection, kinetics and extent of viral replication and release, thus implying that apoptosis is not involved in facilitating release and/or dissemination of SARS-CoV in Vero cells.

Coordinate induction of IFN-α and -γ by SARS-CoV also in the absence of virus replication

Abstract Background: Severe acute respiratory syndrome (SARS) is an emerging infection caused by a novel coronavirus known as SARS-CoV, characterized by an over-exuberant immune response with lung lymphomononuclear cells infiltration and proliferation that may account for tissue damage more than the direct effect of viral replication. This study is aimed at investigating the capability of SARS-CoV to activate IFN-α and -γ expression in lymphomonocytes (PBMC) from healthy donors, evaluating whether viral replication is necessary for this activation. Results: SARS-CoV virus is able to induce both IFN-α and -γ mRNA accumulation and protein release in a dose-dependent manner, MOI 10 being the most effective. The time course curve indicated that IFN-α mRNA induction peaked at 24 h.p.i,. whereas IFN-γ mRNA was still increasing at 48 h.p.i. Released IFN (both types) reached a plateau after 24–48 h.p.i. and remained rather stable over a 5-day period. A transient peak of negative strand viral RNA was detected after 1–2 days of infection, but neither infectious virus progeny yield nor newly produced viral genomic RNA could be evidenced in infected cultures, even after prolonged observation time (up to 13 days). Cocultivation of PBMC with fixed SARS-CoV-infected Vero cells was even more efficient than exposure to live virus in eliciting IFN-α and -γ induction. A combination of IFN-α and -γ strongly inhibited SARS-CoV replication in Vero cells, while the single cytokines were much less effective. Conclusions: This study provides evidence that SARS-CoV is able to induce in normal PBMC a coordinate induction of IFN-α and -γ gene expression. Virus replication is not necessary for IFN induction since efficient IFN expression could be obtained also by the cocultivation of normal PBMC with fixed SARS-CoV-infected cells. Concomitant activation of IFN-α and -γ gene expression by SARS-CoV in vivo may be relevant for the pathogenesis of the disease, both for the possible involvement in immunomediated damage of the tissues and for the strong inhibition of SARS-CoV replication as a result of combined cytokine action.

Comparison of LCx with Other Current Viral Load Assays for Detecting and Quantifying Human Immunodeficiency Virus Type 1 RNA in Patients Infected with the Circulating Recombinant Form A/G (CRF02)

ABSTRACT LCx was compared to other assays in measuring human immunodeficiency virus type 1 (HIV-1) CRF02 viremia. LCx showed significant but low correlation with the other methods. Values of <2.60 log10 cp/ml were observed in 29.6% of specimens with LCx and in only 14.8% with bDNA and PCR, suggesting suboptimal performance of LCx with CRF02.