HIV-Associated Microbial Translocation May Affect Cytokine Production of CD56bright NK Cells via Stimulation of Monocytes.

The mechanisms involved in HIV-associated natural killer (NK) cell impairment are still incompletely understood. We observed HIV infection to be associated with increased plasma levels of IFABP, a marker for gut epithelial barrier dysfunction, and LBP, a marker for microbial translocation. Both IFABP and LBP plasma concentrations were inversely correlated with NK cell interferon-γ production, suggesting microbial translocation to modulate NK cell functions. Accordingly, we found lipopolysaccharide to have an indirect inhibitory effect on NK cells via triggering monocytes' transforming growth factor-ß production. Taken together, our data suggest increased microbial translocation to be involved in HIV-associated NK cell dysfunction.

Infection fatality rate of SARS-CoV2 in a super-spreading event in Germany.

A SARS-CoV2 super-spreading event occurred during carnival in a small town in Germany. Due to the rapidly imposed lockdown and its relatively closed community, this town was seen as an ideal model to investigate the infection fatality rate (IFR). Here, a 7-day seroepidemiological observational study was performed to collect information and biomaterials from a random, household-based study population. The number of infections was determined by IgG analyses and PCR testing. We found that of the 919 individuals with evaluable infection status, 15.5% (95% CI:[12.3%; 19.0%]) were infected. This is a fivefold higher rate than the reported cases for this community (3.1%). 22.2% of all infected individuals were asymptomatic. The estimated IFR was 0.36% (95% CI:[0.29%; 0.45%]) for the community and 0.35% [0.28%; 0.45%] when age-standardized to the population of the community. Participation in carnival increased both infection rate (21.3% versus 9.5%, p < 0.001) and number of symptoms (estimated relative mean increase 1.6, p = 0.007). While the infection rate here is not representative for Germany, the IFR is useful to estimate the consequences of the pandemic in places with similar healthcare systems and population characteristics. Whether the super-spreading event not only increases the infection rate but also affects the IFR requires further investigation.

When polyuria does not stop: a case report on an unusual complication of hantavirus infection.

BACKGROUND: The clinical features, course and outcome of hantavirus infection is highly variable. Symptoms of the central nervous system may occur, but often present atypically and diagnostically challenging. Even though the incidence of hantavirus infection is increasing worldwide, this case is the first to describe diabetes insipidus centralis as a complication of hantavirus infection in the Western world. CASE PRESENTATION: A 49-year old male presenting with severe headache, nausea and photophobia to our neurology department was diagnosed with acute haemorrhage in the pituitary gland by magnetic resonance imaging. In the following days, the patient developed severe oliguric acute kidney failure. Diagnostic workup revealed a hantavirus infection, so that the pituitary haemorrhage resulting in hypopituitarism was seen as a consequence of hantavirus-induced hypophysitis. Under hormone replacement and symptomatic therapy, the patient's condition and kidney function improved considerably, but significant polyuria persisted, which was initially attributed to recovery from kidney injury. However, water deprivation test revealed central diabetes insipidus, indicating involvement of the posterior pituitary gland. The amount of urine production normalized with desmopressin substitution. CONCLUSION: Our case report highlights that neurological complications of hantavirus infection should be considered in patients with atypical clinical presentation.

Ad hoc laboratory-based surveillance of SARS-CoV-2 by real-time RT-PCR using minipools of RNA prepared from routine respiratory samples.

BACKGROUND: A novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in China in late 2019 and subsequently caused a pandemic. Surveillance is important to better appreciate this evolving pandemic and to longitudinally monitor the effectiveness of public health measures. OBJECTIVES: We aimed to provide a rapid, easy to establish and costeffective laboratory-based surveillance tool for SARS-CoV-2. STUDY DESIGN: We used minipools of RNA prepared from nucleic acid extractions of routine respiratory samples. We technically validated the assay and distributed the protocol within an informal network of five German university laboratories. RESULTS: We tested a total of 70 minipools resembling 700 samples shortly before the upsurge of cases in Germany from 17.02.2020 to 10.03.2020. One minipool reacted positive and after resolution one individual sample tested SARS-CoV-2 positive. This sample was from a hospitalized patient not suspected of having contracted SARS-CoV-2. CONCLUSIONS: Our approach of a laboratory-based surveillance for SARSCoV-2 using minipools proved its concept is easily adaptable and resource-saving. It might assist not only public health laboratories in SARS-CoV-2 surveillance.

Hepatitis B virus subgenotype F3 reactivation with vaccine escape mutations: A case report and review of the literature.

Hepatitis B represents a global health threat because its chronic course and sequelae contribute to a high morbidity and mortality. Hepatitis B virus (HBV) infection can be controlled by vaccines, antiviral treatment, and by interrupting transmission. Rare vaccine escape mutants are serious because they eliminate vaccine protection. Here, we present a 74-year-old vaccinated patient with HBV reactivation 11 years after kidney transplantation. The patient was HBV-positive but HBsAg-negative prior to vaccination 6 years before transplantation. The reactivated virus was HBV genotype F3 with vaccine escape mutations G145R, P120Q, and Q129P. The patient was successfully treated with entecavir. The epidemiological reasons for this subgenotype, which is extremely rare in Western Europe, were unclear. This case illustrates that second-generation vaccines are not always effective in a specific group of patients.

Evaluation of cellulose pads as a method to detect cytomegalovirus DNA in neonatal urine.

Background Several approaches exist to screen neonates for congenital cytomegalovirus infection. We here describe a new method using cellulose pads for urine collection and its evaluation in an experimental and a clinical setting. Methods We systematically tested the effect of storage duration of the pads after exposure to cytomegalovirus-positive urine, meconium contamination and specimen handling on the cytomegalovirus load and the detection rate. Further, the method was tested in clinical practice in a cohort of 500 neonates. Results Following exposure of urine pads with cytomegalovirus-positive urine, the viral load decreased after 15 min, 12 h, 24 h, and 7 days to 63.2%, 42.1%, 31.6%, and 9.3% of the baseline value. Cytomegalovirus detection rate after seven days was 100%. Contamination with meconium resulted in a comparable reduction of the viral load. The detection rate for dried urine pads after seven days was 93.3%. In clinical practice, urine collection from pads was successful in 73.6% by the first attempt and in 26.4% by the second attempt. Conclusions Urine collection using cellulose pads seems feasible regardless of a reduction of the cytomegalovirus load due to exposure to the pad itself or to meconium. Drying of the exposed urine pad should be avoided.

A Therapeutic Antiviral Antibody Inhibits the Anterograde Directed Neuron-to-Cell Spread of Herpes Simplex Virus and Protects against Ocular Disease.

Herpes simplex virus (HSV) is a leading cause of blindness and viral encephalitis in the developed world. Upon reactivation from sensory neurons, HSV returns via axonal transport to peripheral tissues where it causes, e.g., severe, potentially blinding ocular diseases. In the present study we investigated whether the HSV-1/2 glycoprotein B-specific antibody mAb 2c or its humanized counterpart mAb hu2c can protect from ocular disease in a mouse model of HSV-1-induced acute retinal necrosis (ARN). In this model the viral spread from the initially infected to the contralateral eye resembles the routes taken in humans upon HSV reactivation. Systemic antibody treatment prior or early after infection effectively protected the mice from the development of ARN. These observations suggest that the antibody potently neutralized the infection and inhibited the viral transmission, since there was almost no virus detectable in the contralateral eyes and trigeminal ganglia of antibody treated mice. Besides of neutralizing free virus or limiting the infection via activating the complement or cellular effector functions, blocking of the anterograde directed neuron-to-cell spread of HSV represents a viable mode of action how mAb 2c protected the mice from ARN. We proved this hypothesis using a microfluidic chamber system. Neurons and epithelial cells were cultured in two separate compartments where the neurons sent axons via connecting microgrooves to the epithelial cells. Neurons were infected with a reporter HSV-1 strain expressing mCherry, and the co-culture was treated with neutralizing antibodies. In contrast to commercial polyclonal human HSV-neutralizing immunoglobulins, mAb 2c effectively blocked the anterograde directed neuron-to-cell transmission of the virus. Our data suggest that the humanized HSV-1/2-gB antibody protects mice from ocular disease by blocking the neuronal spread of HSV. Therefore, mAb hu2c may become a potent novel therapeutic option for severe ocular HSV infections.

Large-scale analysis of herpesviridae in epilepsy-patients with signs of autoimmune encephalitis.

PURPOSE: Epilepsy is one of the most common primary brain disorders. Nonparaneoplastic autoimmune encephalitis is increasingly recognized as an important cause of adult onset epilepsy. However, only in rare cases an initiating factor of the syndrome can be identified. Autoantibody detection after central nervous herpesvirus infection indicates a postviral etiology in a subgroup of patients. In order to analyze a possible underrecognition of postinfectious autoimmunity we performed a large-scale analysis of herpesvirus DNA in cerebrospinal fluid samples from patients with clinical signs of autoimmune encephalitis. METHODS: Real time PCR for HSV 1/2, CMV, EBV, VZV, HHV-6A, HHV-6B, HHV-7 and HHV-8 was performed in cerebrospinal fluid samples from 113 patients with epilepsy and suspected autoimmune encephalitis. Indirect immunofluorescence analysis was used for autoantibody analysis. RESULTS: Antineuronal autoantibodies could be identified in 48 patients with definite autoimmune encephalitis. No autoantibodies were detected in 65 additional patients with probable or possible autoimmune encephalitis. Real-time PCR analysis revealed in three autoantibody-negative patients positive results for HSV, but no evidence for further virus DNA. CONCLUSION: The findings argue against longstanding herpesvirus infection of the CNS as frequent trigger for autoimmunity. However, appearance of autoantibodies after a short period of active virus infection cannot be excluded.

Misdirection of endosomal trafficking mediated by herpes simplex virus-encoded glycoprotein B.

Herpes simplex virus (HSV)-encoded glycoprotein B (gB) is the most abundant protein in the viral envelope and promotes fusion of the virus with the cellular membrane. In the present study, we found that gB impacts on the major histocompatibility complex (MHC)-II pathway of antigen presentation by fostering homotypic fusion of early endosomes and trapping MHC-II molecules in these altered endosomes. By using an overexpression approach, we demonstrated that transient expression of gB induces giant vesicles of early endosomal origin, which contained Rab5, early endosomal antigen 1 (EEA1), and large amounts of MHC-II molecules [human leukocyte antigen (HLA)-DR, and HLA-DM], but no CD63. In HSV-1-infected and stably transfected cell lines that expressed lower amounts of gB, giant endosomes were not observed, but strongly increased amounts of HLA-DR and HLA-DM were found in EEA1+ early endosomes. We used these giant vesicles as a model system and revealed that gB interacts with Rab5 and EEA1, and that gB-induced homotypic fusion of early endosomes to giant endosomes requires phosphatidylinositol 3-phosphate, the activity of soluble N-ethylmaleimide-sensitive factor attachment protein receptors, and the cytosolic gB sequence 889YTQVPN894 We conclude that gB expression alters trafficking of molecules of the HLA-II processing pathway, which leads to increased retention of MHC-II molecules in early endosomal compartments, thereby intercepting antigen presentation.-Niazy, N., Temme, S., Bocuk, D., Giesen, C., König, A., Temme, N., Ziegfeld, A., Gregers, T. F., Bakke, O., Lang, T., Eis-Hübinger, A. M., Koch, N. Misdirection of endosomal trafficking mediated by herpes simplex virus-encoded glycoprotein B.

Assay optimization for molecular detection of Zika virus.

OBJECTIVE: To examine the diagnostic performance of real-time reverse transcription (RT)-polymerase chain reaction (PCR) assays for Zika virus detection. METHODS: We compared seven published real-time RT-PCR assays and two new assays that we have developed. To determine the analytical sensitivity of each assay, we constructed a synthetic universal control ribonucleic acid (uncRNA) containing all of the assays' target regions on one RNA strand and spiked human blood or urine with known quantities of African or Asian Zika virus strains. Viral loads in 33 samples from Zika virus-infected patients were determined by using one of the new assays. FINDINGS: Oligonucleotides of the published real-time RT-PCR assays, showed up to 10 potential mismatches with the Asian lineage causing the current outbreak, compared with 0 to 4 mismatches for the new assays. The 95% lower detection limit of the seven most sensitive assays ranged from 2.1 to 12.1 uncRNA copies/reaction. Two assays had lower sensitivities of 17.0 and 1373.3 uncRNA copies/reaction and showed a similar sensitivity when using spiked samples. The mean viral loads in samples from Zika virus-infected patients were 5 × 104 RNA copies/mL of blood and 2 × 104 RNA copies/mL of urine. CONCLUSION: We provide reagents and updated protocols for Zika virus detection suitable for the current outbreak strains. Some published assays might be unsuitable for Zika virus detection, due to the limited sensitivity and potential incompatibility with some strains. Viral concentrations in the clinical samples were close to the technical detection limit, suggesting that the use of insensitive assays will cause false-negative results.

Molecular epidemiology and the evolution of human coxsackievirus A6.

Coxsackievirus A6 (CV-A6) is a major aetiologic agent for hand, foot and mouth disease (HFMD) in recent years. HFMD outbreaks associated with CV-A6 resulted from the evolutionary dynamics of CV-A6 and the appearance of novel recombinant forms (RFs). To examine this, 151 variants collected in 2013 and 2014 from Germany, Spain, Sweden, Denmark and Thailand were genotyped for the VP1 capsid and 3Dpol genes. Analysis of the VP1 gene showed an increasing correspondence between CV-A6 genome recombination and sequence divergence (estimated substitution rate of 8.1×10-3 substitutions site-1 year-1 and RF half-life of 3.1 years). Bayesian phylogenetic analysis showed that recent recombination groups (RF-E, -F, -H, -J and -K) shared a common ancestor (RF-A). Thirty-nine full-length genomes of different RFs revealed recombination breakpoints between the 2A-2C and the 5' UTRs. The emergence of new CV-A6 recombination groups has become widespread in Europe and Asia within the last 8 years.

Non-paraneoplastic limbic encephalitis and central nervous HHV-6B reactivation: Causality or coincidence?

Autoantibody-related encephalopathies represent an important differential diagnosis in adult onset epilepsy. Here, we report the case of a 25-year-old patient with new-onset epilepsy and psychotic syndrome, who underwent biopsy resection for etiological classification. MRI analysis and neuropathological examination showed a T-lymphocytic dominated encephalitis with involvement of the limbic system. An indirect immunohistochemistry approach identified autoantibodies against glutamic acid decarboxylase (GAD) in cerebral spinal fluid and serum, which were confirmed by affinity purification / mass spectrometry analysis. Further examinations revealed evidence of chromosomally integrated human herpes virus type 6B (HHV-6B). However, astrocytic expression of HHV-6 lytic protein was detected by double immunofluorescence analysis. The cerebral expression of HHV-6 antigen, a clinical improvement under antiviral therapy as well as an initial finding of HHV-6 IgM antibodies strongly argue for an additional active HHV-6B infection. Review of the literature reveals singular reports of patients with GAD antibody-positive limbic encephalitis and central nervous system infections with HHV-6B. Since herpes simplex virus encephalitis has been recently reported as a trigger of N-methyl-D-aspartate receptor antibody encephalitis, it is tempting to speculate that HHV-6B infections may trigger a non-paraneoplastic form of limbic encephalitis in a parallel cascade.

Fatal outcome of human coronavirus NL63 infection despite successful viral elimination by IFN-alpha in a patient with newly diagnosed ALL.

INTRODUCTION: Human coronavirus NL63 (HCoV-NL63) is one of four common human respiratory coronaviruses. Despite high incidence, HCoV infections are grossly understudied. We here report a case of HCoV infection in a leukemia patient with fatal ARDS despite successful virus elimination by pegylated interferon-alpha (PEG-IFN-α). CASE: The 27-year-old female pre-T-ALL patient was treated according to the German-Multicenter Trial for Adult ALL protocol. No relevant infectious complications were seen until day 35 when the neutropenic patient developed fever without any clinical focus. Antibiotic prophylaxis was switched to meropenem. The patient deteriorated rapidly with respiratory failure due to ARDS. Anti-infectious therapy was escalated to additional linezolid and liposomal amphotericine-B. BAL revealed a significant viral load of HCoV-NL63. Based on successful application of PEG-IFN against the related SARS coronavirus in animal experiments, a single injection of 180 µg PEG-IFN-α2b was applied. Despite immediate initiation of treatment and elimination of virus in subsequent tests, the progressive lung failure led to death 7 d after onset of fever with massive lung bleeding as a consequence of diffuse alveolar hemorrhage. CONCLUSION: This report emphasizes the fatal consequences of common respiratory virus infections in immunocompromised patients. HCoV-NL63 replication can be reduced by treatment with peg-IFN if diagnosed early.

Salivirus type 1 and type 2 in patients with acute gastroenteritis, Germany.

BACKGROUND: Salivirus (SaV-A) is a novel member of the family Picornaviridae and has been associated with acute gastroenteritis. Recently, a second type of SaV-A, SaV-A2, was identified in a sewage sample from Bangkok, Thailand. No information is available on the prevalence of SaV-A in Western Europe. OBJECTIVES: Stool samples from patients with symptoms of acute viral gastroenteritis were analyzed for SaV-A and the clinical course of SaV-A-positive individuals was evaluated. STUDY DESIGN: A total of 3019 fecal samples collected during 2012-2013 from 1941 hospitalized patients with acute gastroenteritis were screened for SaV-A by a newly designed real-time reverse transcription polymerase chain reaction targeting a conserved sequence in the 5'-untranslated region. Positive results were verified by sequencing the viral capsid protein 1 gene also allowing typing of the virus. Medical records of SaV-A-infected patients were reviewed for clinical features and laboratory data. RESULTS: SaV-A was detected in five patients. Viral RNA concentrations ranged from 7.1×10(6) to 7.2×10(8)copies/g feces. The viruses from four patients were classified as SaV-A1 while SaV-A2 was present in one patient. After reviewing the medical records, SaV-A could not be considered as the sole possible cause of gastroenteritis symptoms given the presence of other plausible causes in all five patients. CONCLUSION: SaV-A infection can be detected in Germany, Western Europe, albeit at low levels. The detection of SaV-A2 in Europe suggests wider spread of SaV-A2. Presence of SaV-A, even at high concentrations, in a stool sample provides no conclusive evidence that SaV is the major cause of the patient's gastroenteritis symptoms.

Prevention of herpes simplex virus induced stromal keratitis by a glycoprotein B-specific monoclonal antibody.

The increasing incidence of acyclovir (ACV) and multidrug-resistant strains in patients with corneal HSV-1 infections leading to Herpetic Stromal Keratitis (HSK) is a major health problem in industrialized countries and often results in blindness. To overcome this obstacle, we have previously developed an HSV-gB-specific monoclonal antibody (mAb 2c) that proved to be highly protective in immunodeficient NOD/SCID-mice towards genital infections. In the present study, we examined the effectivity of mAb 2c in preventing the immunopathological disease HSK in the HSK BALB/c mouse model. Therefore, mice were inoculated with HSV-1 strain KOS on the scarified cornea to induce HSK and subsequently either systemically or topically treated with mAb 2c. Systemic treatment was performed by intravenous administration of mAb 2c 24 h prior to infection (pre-exposure prophylaxis) or 24, 40, and 56 hours after infection (post-exposure immunotherapy). Topical treatment was performed by periodical inoculations (5 times per day) of antibody-containing eye drops as control, starting at 24 h post infection. Systemic antibody treatment markedly reduced viral loads at the site of infection and completely protected mice from developing HSK. The administration of the antiviral antibody prior or post infection was equally effective. Topical treatment had no improving effect on the severity of HSK. In conclusion, our data demonstrate that mAb 2c proved to be an excellent drug for the treatment of corneal HSV-infections and for prevention of HSK and blindness. Moreover, the humanized counterpart (mAb hu2c) was equally effective in protecting mice from HSV-induced HSK when compared to the parental mouse antibody. These results warrant the future development of this antibody as a novel approach for the treatment of corneal HSV-infections in humans.