Diagnosis of neuroinvasive astrovirus infection in an immunocompromised adult with encephalitis by unbiased next-generation sequencing.

Metagenomic next-generation sequencing (NGS) was used to diagnose an unusual and fatal case of progressive encephalitis in an immunocompromised adult presenting at disease onset as bilateral hearing loss. The sequencing and confirmatory studies revealed neuroinvasive infection of the brain by an astrovirus belonging to a recently discovered VA/HMO clade.

Investigation of anti-middle East respiratory syndrome antibodies in blood donors and slaughterhouse workers in Jeddah and Makkah, Saudi Arabia, fall 2012.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel, potentially zoonotic human coronavirus (HCoV). We investigated MERS-CoV antibodies using a staged approach involving an immunofluorescence assay (IFA), a differential recombinant IFA, and a plaque-reduction serum neutralization assay. In 130 blood donors sampled during 2012 in Jeddah and 226 slaughterhouse workers sampled in October 2012 in Jeddah and Makkah, Saudi Arabia, 8 reactive sera were seen in IFA but were resolved to be specific for established HCoVs by discriminative testing. There is no evidence that MERS-CoV circulated widely in the study region in fall 2012, matching an apparent absence of exported disease during the 2012 Hajj.

Absence of xenotropic murine leukaemia virus-related virus in UK patients with chronic fatigue syndrome.

BACKGROUND: Detection of a retrovirus, xenotropic murine leukaemia virus-related virus (XMRV), has recently been reported in 67% of patients with chronic fatigue syndrome. We have studied a total of 170 samples from chronic fatigue syndrome patients from two UK cohorts and 395 controls for evidence of XMRV infection by looking either for the presence of viral nucleic acids using quantitative PCR (limit of detection <16 viral copies) or for the presence of serological responses using a virus neutralisation assay. RESULTS: We have not identified XMRV DNA in any samples by PCR (0/299). Some serum samples showed XMRV neutralising activity (26/565) but only one of these positive sera came from a CFS patient. Most of the positive sera were also able to neutralise MLV particles pseudotyped with envelope proteins from other viruses, including vesicular stomatitis virus, indicating significant cross-reactivity in serological responses. Four positive samples were specific for XMRV. CONCLUSIONS: No association between XMRV infection and CFS was observed in the samples tested, either by PCR or serological methodologies. The non-specific neutralisation observed in multiple serum samples suggests that it is unlikely that these responses were elicited by XMRV and highlights the danger of over-estimating XMRV frequency based on serological assays. In spite of this, we believe that the detection of neutralising activity that did not inhibit VSV-G pseudotyped MLV in at least four human serum samples indicates that XMRV infection may occur in the general population, although with currently uncertain outcomes.

Differential effects of prednisolone and azathioprine on the development of human cytomegalovirus replication post liver transplantation.

BACKGROUND: We sought to investigate the impact of different immunosuppressive regimens on human cytomegalovirus (HCMV) incidence and replication dynamics in a cohort of 256 patients after liver transplantation. METHODS: A time-updated approach was used to determine the risk of developing HCMV replication (>200 genomes/mL blood) within the first 100 days after liver transplantation according to the immunosuppressive regimen being received at specific time points. RESULTS: In patients receiving tacrolimus, the addition of prednisolone was associated with a significant increased risk of HCMV replication both at baseline (relative rate of infection [RRI]=4.34; P=0.0001) and in a time-updated analysis (RRI=4.68; P=0.0001). However, the addition of azathioprine substantially reduced the risk of HCMV replication to that observed with tacrolimus alone. As expected donor/recipient HCMV serostatus was also a risk factor for viraemia. Multivariable models showed that the tacrolimus plus prednisolone regimen and donor/recipient serostatus were independent risk factors for HCMV replication. Viral replication dynamics showed that the duration of HCMV viraemia, the peak viral load, and the growth rate of HCMV were greatest in patients receiving tacrolimus plus prednisolone although these differences did not reach statistical significance. CONCLUSIONS: The combination of prednisolone plus tacrolimus as baseline immunosuppression after liver transplantation is associated with a high risk of HCMV replication. This effect can be negated by the addition of azathioprine.

Exploring the bidirectional interactions between human cytomegalovirus and hepatitis C virus replication after liver transplantation.

Recurrence of Hepatitis C (HCV) post-liver transplantation (LT) is universal and its course is more aggressive than in immunocompetent individuals. Human cytomegalovirus (CMV) infection is a common post-LT infection and has immunomodulatory effects that could adversely affect the outcome of HCV. To date, the effect of HCV replication on the dynamics of CMV have not been investigated. From 2000 to 2004, a cohort of 69 HCV-infected liver transplant recipients and 188 HCV-negative liver transplant recipients (NON-HCV cohort) were monitored for CMV infection twice weekly by CMV polymerase chain reaction (PCR) with preemptive therapy initiated after 2 consecutive positive results. None of the patients received CMV prophylaxis. A subset of 18 HCV-infected patients had their HCV viral load monitored regularly post-LT by quantitative PCR. CMV DNAemia (>200 genomes/mL blood) did not influence the level of HCV replication within 150 days posttransplantation or the stage of liver fibrosis in liver biopsies at 1 yr post-LT. There were no differences in the incidence of CMV DNAemia or replication dynamics in the HCV cohort compared to the NON-HCV cohort. In conclusion, short term CMV viremia does not enhance the replication of HCV after LT, while HCV replication does not alter the replication dynamics of CMV.

A randomized, controlled trial comparing ganciclovir to ganciclovir plus foscarnet (each at half dose) for preemptive therapy of cytomegalovirus infection in transplant recipients.

Forty-eight patients who provided 2 consecutive blood samples that tested positive for cytomegalovirus DNA by polymerase chain reaction (PCR) were randomized to receive either full-dose ganciclovir (5 mg/kg intravenously [iv] twice daily) or half-dose ganciclovir (5 mg/kg iv once daily) plus half-dose foscarnet (90 mg/kg iv once daily) for 14 days. In the ganciclovir arm, 17 (71%) of 24 patients reached the primary end point of being CMV negative by PCR within 14 days of initiation of therapy, compared with 12 (50%) of 24 patients in the ganciclovir-plus-foscarnet arm (P = .12). Toxicity was greater in the combination-therapy arm. In patients who failed to reach the primary end point, baseline virus load was 0.77 log10 higher, the replication rate before therapy was faster (1.5 vs. 2.7 days), and the viral decay rate was slower (2.9 vs. 1.1 days) after therapy. Bivariable logistic regression models identified baseline virus load, bone-marrow transplantation, and doubling time and half-life of decay as the major factors affecting response to therapy within 14 days. This study did not support a synergistic effect of ganciclovir plus foscarnet in vivo.