Prolonged Viremia Research Articles

Interleukin-18 and cytotoxic impairment are independent and synergistic causes of murine virus-induced hyperinflammation

AbstractHemophagocytic lymphohistiocytosis (HLH) and macrophage activation syndrome (MAS) are life-threatening hyperinflammatory syndromes typically associated with underlying hematologic and rheumatic diseases, respectively. Familial HLH is associated with genetic cytotoxic impairment and thereby to excessive antigen presentation. Extreme elevation of serum interleukin-18 (IL-18) has been observed specifically in patients with MAS, making it a promising therapeutic target, but how IL-18 promotes hyperinflammation remains unknown. In an adjuvant-induced MAS model, excess IL-18 promoted immunopathology, whereas perforin deficiency had no effect. To determine the effects of excess IL-18 on virus-induced immunopathology, we infected Il18-transgenic (Il18tg) mice with lymphocytic choriomeningitis virus (LCMV; strain Armstrong). LCMV infection is self-limited in wild-type mice, but Prf1−/− mice develop prolonged viremia and fatal HLH. LCMV-infected Il18-transgenic (Il18tg) mice developed cachexia and hyperinflammation comparable to Prf1−/− mice, albeit with minimal mortality. Like Prf1−/− mice, immunopathology was largely rescued by CD8 depletion or interferon-γ (IFNg) blockade. Unlike Prf1−/− mice, they showed normal target cell killing and normal clearance of viral RNA and antigens. Rather than impairing cytotoxicity, excess IL-18 acted on T lymphocytes to amplify their inflammatory responses. Surprisingly, combined perforin deficiency and transgenic IL-18 production caused spontaneous hyperinflammation specifically characterized by CD8 T-cell expansion and improved by IFNg blockade. Even Il18tg;Prf1-haplosufficient mice demonstrated hyperinflammatory features. Thus, excess IL-18 promotes hyperinflammation via an autoinflammatory mechanism distinct from, and synergistic with, cytotoxic impairment. These data establish IL-18 as a potent, independent, and modifiable driver of life-threatening innate and adaptive hyperinflammation and support the rationale for an IL-18–driven subclass of hyperinflammation.

VP23.06: Prolonged maternal Zika viremia associated with higher risks of congenital infection and adverse fetal outcomes

VP23.06: Prolonged maternal Zika viremia associated with higher risks of congenital infection and adverse fetal outcomes

The CD4+ T Cell Response to Human Cytomegalovirus in Healthy and Immunocompromised People.

While CD8+ T cells specific for human cytomegalovirus (HCMV) have been extensively studied in both healthy HCMV seropositive carriers and patients undergoing immunosuppression, studies on the CD4+ T cell response to HCMV had lagged behind. However, over the last few years there has been a significant advance in our understanding of the importance and contribution that CMV-specific CD4+ T cells make, not only to anti-viral immunity but also in the potential maintenance of latently infected cells. During primary infection with HCMV in adults, CD4+ T cells are important for the resolution of symptomatic disease, while persistent shedding of HCMV into urine and saliva is associated with a lack of HCMV specific CD4+ T cell response in young children. In immunosuppressed solid organ transplant recipients, a delayed appearance of HCMV-specific CD4+ T cells is associated with prolonged viremia and more severe clinical disease, while in haematopoietic stem cell transplant recipients, it has been suggested that HCMV-specific CD4+ T cells are required for HCMV-specific CD8+ T cells to exert their anti-viral effects. In addition, adoptive T-cell immunotherapy in transplant patients has shown that the presence of HCMV-specific CD4+ T cells is required for the maintenance of HCMV-specific CD8+ T cells. HCMV is a paradigm for immune evasion. The presence of viral genes that down-regulate MHC class II molecules and the expression of viral IL-10 both limit antigen presentation to CD4+ T cells, underlining the important role that this T cell subset has in antiviral immunity. This review will discuss the antigen specificity, effector function, phenotype and direct anti-viral properties of HCMV specific CD4+ T cells, as well as reviewing our understanding of the importance of this T cell subset in primary infection and long-term carriage in healthy individuals. In addition, their role and importance in congenital HCMV infection and during immunosuppression in both solid organ and haemopoietic stem cell transplantation is considered.

Cardiac Allograft Vasculopathy in Heart Transplant Recipients from Hepatitis C Viremic Donors

Heart transplantation from Hepatitis C (HCV) viremic donors is becoming increasingly used due to advent of direct acting antiviral drugs with almost 100% cure. There are limited data about its impact on cardiac allograft vasculopathy (CAV). We report the incidence of CAV in heart transplant recipients from HCV viremic donors (nucleic amplification test positive; NAT+) compared to non-HCV infected donors (NAT-). We retrospectively reviewed coronary angiograms with intravascular ultrasound (IVUS) of heart transplant recipients at our institution from January 5, 2018 to September 17, 2019. The presence of CAV was graded according to ISHLT guidelines. IVUS was performed as per our lab protocol on the left main and left anterior descending arteries. Maximal intimal thickness (MIT) was measured with advanced quantification software as per protocol. MIT ≥ 5mm was considered significant for future adverse outcomes. LHC and IVUS was performed on 24 heart transplant recipients (mean age 56; 70% male) at 1- year post transplant. Eleven of these patients were transplanted from NAT+ donors. Thirteen patients received a NAT- donor heart. Two recipients (18.7%) of NAT+ donors had CAV grade ≥ 1 compared to 2 (16.7%) from NAT- donors (p=1). MIT ≥ 5mm was seen in 88.9% of NAT+ vs 50% of NAT- recipients (p=0.14) (Figure). The mean MIT was 76mm and 65mm for NAT+ and NAT- group, respectively. Both NAT+ and NAT- donor recipients exhibit mostly eccentric (84.2%) and few (15.7%) demonstrated concentric plaques. There was no heterogeneity in the data after adjusting for risk factors for CAD and donor LHC. Our data show no difference in the presence of (CAV ≥ grade 1) or subclinical atherosclerosis at 1 year among NAT+ donor recipients. HCV viremia is a known risk factor for accelerated atherosclerosis and the consequence of prolonged donor viremia on the recipient is not known. A larger cohort and further longitudinal follow-up is needed to assess the validity of this trend and its prognostic implications.

Woolly Monkey-HBV Infection in Squirrel Monkeys as a Surrogate Nonhuman Primate Model of HBV Infection.

Development of curative therapies for chronic hepatitis B virus (HBV) infection will likely require new animal models. Here, we evaluate HBV infection in squirrel monkeys based on the high‐sequence homology of the HBV receptor, Na+/taurocholate co‐transporting peptide (NTCP), between humans and squirrel monkeys. HBV PreS1 peptide was examined for binding human and squirrel monkey NTCP. Immunodeficient Fah −/−, NOD, Rag1 −/−, Il2Rg null (FNRG) mice engrafted with human or squirrel monkey hepatocytes were challenged with HBV or Woolly Monkey HBV (WMHBV). In addition, adult squirrel monkeys were inoculated with HBV, WMHBV, adeno‐associated virus containing an infectious genome of HBV (AAV‐HBV), and AAV‐WMHBV. Finally, neonate squirrel monkeys were assessed for the potential of chronic infection with WMHBV. PreS1 peptide efficiently bound to human and squirrel monkey NTCP but not to mouse or capuchin NTCP. FNRG mice engrafted with squirrel monkey hepatocytes were susceptible to infection by WMHBV but not human HBV. Similarly, adult squirrel monkeys could be infected with WMHBV but not human HBV, whereas chimeric mice engrafted with human hepatocytes were susceptible to HBV but not WMHBV. Infection of squirrel monkeys with AAV‐WMHBV yielded maximum viremia of 108 genomes/mL with detectable virus for up to 8 months. Notably, covalently closed circular DNA was detected in the liver of these animals. Infection of neonates with WMHBV led to detectable viremia for up to 6 months. Conclusions: Adult and neonate squirrel monkeys exhibited prolonged WMHBV viremia lasting 6‐8 months. This is greater than twice the duration of viremia achieved in other nonhuman primates and suggests that squirrel monkeys may be a suitable model for testing HBV therapeutics.

DNA vaccination before conception protects Zika virus-exposed pregnant macaques against prolonged viremia and improves fetal outcomes.

Zika virus (ZIKV) infection of pregnant women is associated with congenital Zika syndrome (CZS) and no vaccine is available, although several are being tested in clinical trials. We tested the efficacy of ZIKV DNA vaccine VRC5283 in a rhesus macaque model of congenital ZIKV infection. Most animal vaccine experiments have a set pathogen exposure several weeks or months after vaccination. In the real world, people encounter pathogens years or decades after vaccination, or may be repeatedly exposed if the virus is endemic. To more accurately mimic how this vaccine would be used, we immunized macaques before conception and then exposed them repeatedly to ZIKV during early and mid-gestation. In comparison to unimmunized animals, vaccinated animals had a significant reduction in peak magnitude and duration of maternal viremia, early fetal loss, fetal infection, and placental and fetal brain pathology. Vaccine-induced neutralizing antibody titers on the day of first ZIKV exposure were negatively associated with the magnitude of maternal viremia, and the absence of prolonged viremia was associated with better fetal outcomes. These data support further clinical development of ZIKV vaccine strategies to protect against negative fetal outcomes.

Hepatitis E Virus Infections Among Human Immunodeficiency Virus-Positive Individuals During an Outbreak of Acute Hepatitis A in Taiwan.

Hepatitis A virus (HAV) and hepatitis E virus (HEV) share the similar fecal-oral transmission route. During an outbreak of sexually transmitted acute hepatitis A among men who have sex with men (MSM) worldwide between 2015 and 2017, we investigated the possibility of sexual transmission and related morbidity of HEV infection among human immunodeficiency virus (HIV)-positive patients. From March 1, 2015 to August 31, 2017, anti-HEV immunoglobulin G was retrospectively determined among 3,293 HIV-positive patients, who were mainly MSM (87.6%) with a median CD4 count of 575 cells/μL. Prevalence and incidence of HEV infection were 3.7% (123 of 3,293) and 4.35 per 1,000 person-years of follow-up (PYFU), respectively, which were significantly lower compared with those of HAV infection (31.1% [996 of 3,204] and 12.61 per 1,000 PYFU, respectively). The number of patients with HEV infection did not increase with the hepatitis A epidemic. The factor associated with prevalent HEV infection was older age (per 1-year increase, adjusted odds ratio, 1.07; 95% confidence interval, 1.05-1.09), but neither sexual orientation nor acquisition of sexually transmitted infections was related to prevalent or incident HEV infection. Among 23 patients with incident HEV infection, 22 patients had viremia caused by HEV genotype 4. No patients had prolonged HEV viremia or clinical symptoms, and only a mild elevation of serum aminotransferase, ranging from 34 to 77 IU/L, was noted. Although 4 patients had hepatitis for a prolonged duration of between 8 and 17 months, no abdominal imaging revealed liver fibrosis or cirrhosis. Conclusion: HEV endemicity remained low among HIV-positive patients in Taiwan during the outbreak of acute hepatitis A. Our data suggest that sexual transmission of HEV with significant morbidity of HEV infection, if any, is rare in this population.

HIV RNA, CD4+ Percentage, and Risk of Hepatocellular Carcinoma by Cirrhosis Status.

Despite increasing incidence of hepatocellular carcinoma (HCC) among HIV-infected patients, it remains unclear if HIV-related factors contribute to development of HCC. We examined if higher or prolonged HIV viremia and lower CD4+ cell percentage were associated with HCC. We conducted a cohort study of HIV-infected individuals who had HIV RNA, CD4+, and CD8+ cell counts and percentages assessed in the Veterans Aging Cohort Study (1999-2015). HCC was ascertained using Veterans Health Administration cancer registries and electronic records. Cox regression was used to determine hazard ratios (HR, 95% confidence interval [CI]) of HCC associated with higher current HIV RNA, longer duration of detectable HIV viremia (≥500 copies/mL), and current CD4+ cell percentage less than 14%, adjusting for traditional HCC risk factors. Analyses were stratified by previously validated diagnoses of cirrhosis prior to start of follow-up. Among 35659 HIV-infected patients, 302 (0.8%) developed HCC over 281441 person-years (incidence rate = 107.3 per 100000 person-years). Among patients without baseline cirrhosis, higher HIV RNA (HR = 1.25, 95% CI = 1.12 to 1.40, per 1.0 log10 copies/mL) and 12 or more months of detectable HIV (HR = 1.47, 95% CI = 1.02 to 2.11) were independently associated with higher risk of HCC. CD4+ percentage less than 14% was not associated with HCC in any model. Hepatitis C coinfection was a statistically significant predictor of HCC regardless of baseline cirrhosis status. Among HIV-infected patients without baseline cirrhosis, higher HIV RNA and longer duration of HIV viremia increased risk of HCC, independent of traditional HCC risk factors. This is the strongest evidence to date that HIV viremia contributes to risk of HCC in this group.

Risk factors for ribavirin treatment failure in Asian organ transplant recipients with chronic hepatitis E infection.

BACKGROUNDHepatitis E virus (HEV) infection is a cause of chronic hepatitis in immunosuppressed patients. Sustained virologic response rates to a 12-wk course of ribavirin therapy were reported to be > 70% in the West. This study describes the outcome of HEV treatment in a transplant center in Singapore.AIMTo study the outcome of ribavirin treatment in a series of chronic HEV patients, and the cause of treatment failure.METHODSWe studied all of the transplant recipients who were diagnosed with HEV infection between 2012 to 2015. The outcome of therapy and virologic relapse are monitored for three years after the end of therapy.RESULTSTen transplant recipients (4 liver, 5 kidney, and 1 bone marrow transplantation) with positive HEV RNA were studied. Nine patients received at least 12 wk of ribavirin therapy, and the remaining patient resolved after reducing immunosuppression therapy. Two subjects had prolonged viremia that lasted more than one year, despite continuous ribavirin therapy. Four ribavirin-treated patients (44.4%) had HEV RNA relapse after achieving a virologic response by the end of treatment. The overall failure rate is 66.7%. Being a kidney transplant recipient is the strongest risk factor for not achieving an initial sustained virologic response (0/5 treated, Chi-Square test, P < 0.05). The most common side effect of ribavirin is anemia (100%) (haemoglobin reduction of 3-6.2 g/dL). Seven patients required either a blood transfusion or erythropoietin therapy.CONCLUSIONThe sustained virologic response rate of 12-wk ribavirin therapy for HEV infection in this Asian series was lower than expected. Kidney transplant recipients had a higher rate of treatment failure due to higher immunosuppression requirements and adverse effects.

Association of immunosuppression and HIV viraemia with non-Hodgkin lymphoma risk overall and by subtype in people living with HIV in Canada and the USA: a multicentre cohort study

Research is needed to better understand relations between immunosuppression and HIV viraemia and risk for non-Hodgkin lymphoma, a common cancer in people living with HIV. We aimed to identify key CD4 count and HIV RNA (viral load) predictors of risk for non-Hodgkin lymphoma, overall and by subtype. We studied people living with HIV during 1996-2014 from 21 Canadian and US cohorts participating in the North American AIDS Cohort Collaboration on Research and Design. To determine key independent predictors of risk for non-Hodgkin lymphoma, we assessed associations with time-updated recent, past, cumulative, and nadir or peak measures of CD4 count and viral load, using demographics-adjusted, cohort-stratified Cox models, and we compared models using Akaike's information criterion. Of 102 131 people living with HIV during the study period, 712 people developed non-Hodgkin lymphoma. The key independent predictors of risk for overall non-Hodgkin lymphoma were recent CD4 count (ie, lagged by 6 months; <50 cells per μL vs ≥500 cells per μL, hazard ratio [HR] 3·2, 95% CI 2·2-4·7) and average viral load during a 3-year window lagged by 6 months (a cumulative measure; ≥100 000 copies per mL vs ≤500 copies per mL, HR 9·6, 95% CI 6·5-14·0). These measures were also the key predictors of risk for diffuse large B-cell lymphoma (recent CD4 count <50 cells per μL vs ≥500 cells per μL, HR 2·4, 95% CI 1·4-4·2; average viral load ≥100 000 copies per mL vs ≤500 copies per mL, HR 7·5, 95% CI 4·5-12·7). However, recent CD4 count was the sole key predictor of risk for CNS non-Hodgkin lymphoma (<50 cells per μL vs ≥500 cells per μL, HR 426·3, 95% CI 58·1-3126·4), and proportion of time viral load was greater than 500 copies per mL during the 3-year window (a cumulative measure) was the sole key predictor for Burkitt lymphoma (100% vs 0%, HR 41·1, 95% CI 9·1-186·6). Both recent immunosuppression and prolonged HIV viraemia have important independent roles in the development of non-Hodgkin lymphoma, with likely subtype heterogeneity. Early and sustained antiretroviral therapy to decrease HIV replication, dampen B-cell activation, and restore overall immune function is crucial for preventing non-Hodgkin lymphoma. National Institutes of Health, Centers for Disease Control and Prevention, US Agency for Healthcare Research and Quality, US Health Resources and Services Administration, Canadian Institutes of Health Research, Ontario Ministry of Health and Long Term Care, and the Government of Alberta.

Co-circulation of dengue virus serotypes in Central India: Evidence of prolonged viremia in DENV-2

In view of paucity of information on serotype distribution of Dengue virus (DENV) in Central India, we undertook a cross-sectional study to identify clinical and virological characteristics of DENV serotypes that circulated in this region during the 2016 outbreak. Suspected cases were screened by ELISA for NS1 antigen and anti-DENV IgM antibodies. Serologically confirmed cases were subjected to RT-PCR based detection and serotyping. The RT-PCR results were confirmed by nucleotide sequencing. Genome-wide association was undertaken with DENV sequences from ViPR database and the immune evasion potential of infecting serotypes was ascertained by computing antigenic variability in B cell and Cytotoxic T cell (CTL) epitopes of all DENV proteins. The immunological basis of more prolonged viremia in DENV2-infected patients was also addressed through sequencing of NS2a gene and comparing the CTL activity in NS2a sequences identified among patients with ≤5 days and >5 days of illness. Among 166 serologically confirmed Dengue patients, 75 were positive for DENV RNA. Serotyping revealed predominance of DENV-1 and DENV-2, followed by DENV-3. Co-infection with multiple serotypes was observed in 15.5% of cases. In ~40% cases, DENV RNA was detectable beyond 5 days, among whom majority were DENV-2 infected (p = .044). Highest prevalence of antigenic variability was observed in B cell and CTL epitopes of DENV-2. The potential association between prolonged viremia and higher ability for immune evasion in DENV-2 patients was further corroborated with the observation of poorer HLA-I binding affinity in CTL epitopes observed in NS2a sequences retrieved from patients with >5 days of illness, compared to those with ≤5 days. This is the first report from central India revealing circulation of all DENV serotypes and high prevalence of co-infection with multiple serotypes. We also observed prolonged viremia upon DENV-2 infection, which could be potentially associated with its superior immune evasion potential.

Healthcare Utilization and Cost Associated with Cytomegalovirus Infection Among Pediatric Allogeneic Hematopoietic Cell Transplant Recipients.

Understanding the cost and healthcare utilization associated with cytomegalovirus (CMV) treatment is particularly important as new alternative agents for CMV prevention and treatment such as letermovir and anti-CMV cytotoxic T lymphocytes become available. Literature on the impact of CMV-related hospitalization in allogeneic hematopoietic cell transplant (alloHCT) pediatric patients is limited. We hypothesized that CMV infections post-alloHCT will result in increased length of stay (LOS) in hospital and higher healthcare costs. The aim of this study was to determine healthcare utilization and outcomes of CMV-related hospitalization in alloHCT patients using a single-center clinical database. This was a retrospective study of 240 children ages 3 months to 21 years old who were transplanted between 2005 and 2016. Impact of CMV-related length of stay and total healthcare costs were quantified. Factors associated with prolonged CMV viremia (>25 days) were also examined. The median age of patients was 9.5 years old. In at risk CMV patients, the incidence of CMV viremia was 38%, the median time to onset was 33 days (range 0-292 days), and the median time to resolution was 25 days (range 3-148 days). The median LOS in the first year post-alloHCT for patients with viremia was higher compared to those without viremia (101 days [range 25-319 days] vs 72 days [range 26-354 days], p In the regression analyses, the unadjusted association between CMV infection and LOS was 27.4 days (p=0.003). In multivariable analysis, patients with CMV infection had an average of 23.3 days (p=0.004) longer LOS compared to patients without infection [Table] and added hospital costs of US$45,443 (p=0.162) compared to patients without CMV infection. In multivariable analysis, alemtuzumab was associated with CMV viremia >25 days (p=0.027). In conclusion, CMV viremia is associated with prolonged LOS and higher healthcare costs and indicates a need for improved and cost-effective CMV prevention strategies. Further study into patient outcomes and costs in alloHCT pediatric populations is needed.

One-shot immunization using a Measles/Lassa vaccine fully protects cynomolgus monkeys against Lassa fever

Purpose: Lassa fever is a major public health issue in Western Africa and there is still no licensed vaccine. Here we have used the Measles virus (MeV) vaccine platform to generate Lassa fever vaccine candidates expressing the Lassa virus (LASV) glycoprotein GPC alone or in combination with the nucleoprotein NP or the matrix protein Z. We have demonstrated that NP should be mutated to preserve a strong induction of the type I IFN response and activation of human antigen presenting cells in response to the vector. We selected two vaccines, MeV-NPmut/GPC and MeV-Z/GPC, for further testing in non-human primates. Methods & Materials: Cynomolgus monkeys were immunized with a single dose of MeV-NPmut/GPC, MeV-Z/GPC, or empty MeV vector as a control, one month before being challenged with a lethal dose of LASV. Animals were monitored for biological, clinical, virological, and immunological paramaters after immunization and challenge. Results: The two vectors were safe, did neither replicate in nor shed from vaccinees, and protected all cynomolgus monkeys while controls all died from Lassa fever. Interestingly, MeV-NPmut/GPC conferred almost a sterilizing immunity and animals only experienced a transient elevation in the body temperature but no biological alterations or clinical signs. On the contrary, MeV-Z/GPC –immunized monkeys developed more severe symptoms and a prolonged LASV viremia. Analysis of the immune responses showed that early and robust T cell responses against GPC are critical for enhanced protection after challenge and suggests that T cell immunity against NP may greatly enhance protection. Early transcriptomic and proteomic studies have also been performed after immunization to identify early biological markers correlated with vaccine efficiency. MeV-based vaccines induce a strong humoral response against MeV and could thus be used as bivalent vaccines to prevent Lassa fever and Measles in endemic areas where both MeV and LASV are circulating. Conclusion: The MeV-NPmut/GPC vaccine is safe, fully protects after a single shot cynomolgus monkeys against a lethal LASV challenge and could be used as a bivalent Measles-Lassa vaccine. Importantly, Themis Biosciences has been selected by the Coalition for Epidemic Preparedness Innovations (CEPI) to further develop the MeV-NPmut/GPC vaccine and test it in phase I and II clinical trials.

Persistent viremia and presence of hepatitis E virus RNA in pig muscle meat after experimental co-infection with porcine reproductive and respiratory syndrome virus

Although hepatitis E virus (HEV) transmission has been demonstrated after consumption of products containing infected pig liver, human cases can be also associated with other pig meat products, such as sausages. Data on HEV viremia and dissemination in muscle meat of infected animals are still sparse, especially during long-term infection. Previously, we have shown that experimental co-infection of pigs with HEV and porcine reproductive and respiratory syndrome virus (PRRSV) lengthens HEV infection up to 49 days and increases the likelihood of the presence of HEV RNA in the liver of the pig at a later stage of infection. In the present study, we show that during experimental HEV-PRRSV co-infection, prolonged HEV viremia, up to 49 days post-inoculation (dpi), is detected. The long-term viremia observed was statistically associated with the absence of HEV seroconversion. HEV RNA was also frequently detected, at a late stage of infection (49 dpi), in the three different types of muscle tested: femoral biceps, psoas major or diaphragm pillar. The HEV RNA load could reach up to 1 · 106 genome copies per gram of muscle. Detection of HEV in muscle meat was statistically associated with high HEV loads in corresponding liver and fecal samples. The presence of HEV in pig blood, femoral biceps and major psoas, corresponding to ham and tenderloin muscles respectively, is of concern for the food industry. Hence, these results indicate new potential risks for consumers and public health regarding pork products.

Clinical and Economic Impact of Cytomegalovirus Infection among Children Undergoing Allogeneic Hematopoietic Cell Transplantation.

The literature on the impact of cytomegalovirus (CMV)-related hospitalization in pediatric allogeneic hematopoietic cell transplantation (alloHCT) recipients is limited. The aim of this study was to determine utilization and outcomes of CMV-related hospitalization in alloHCT recipients using a single-center clinical database. This was a retrospective study of 240 children aged 3 months to 21 years (median age, 9.5 years) who underwent alloHCT between 2005 and 2016. The impacts of CMV-related length of stay (LOS) and total healthcare costs were quantified. Factors associated with prolonged CMV viremia (>25 days' duration) were also examined. In at-risk patients with CMV infection, the incidence of CMV viremia was 38% (59 of 155), the median time to onset was 33 days (range, 0 to 292 days), and the median time to resolution was 25 days (range, 3 to 48 days; n = 53). CMV infection was associated with a 23.3-day increase in LOS (P = .004) and added hospital costs of $45,443 (P = .162) compared with patients without CMV infection. In multivariable analysis, receipt of alemtuzumab (P = .027) was associated with CMV viremia of >25 days' duration. Our data show that CMV viremia is associated with prolonged LOS and higher hospital costs and indicate the need for improved and cost-effective CMV prevention strategies. Further studies of patient outcomes and costs in pediatric alloHCT recipients is needed.

HIV-1 capsids from B27/B57+ elite controllers escape Mx2 but are targeted by TRIM5α, leading to the induction of an antiviral state.

Elite controllers (ECs) are a rare subset of HIV-1 slow progressors characterized by prolonged viremia suppression. HLA alleles B27 and B57 promote the cytotoxic T lymphocyte (CTL)-mediated depletion of infected cells in ECs, leading to the emergence of escape mutations in the viral capsid (CA). Whether those mutations modulate CA detection by innate sensors and effectors is poorly known. Here, we investigated the targeting of CA from B27/B57+ individuals by cytosolic antiviral factors Mx2 and TRIM5α. Toward that aim, we constructed chimeric HIV-1 vectors using CA isolated from B27/B57+ or control subjects. HIV-1 vectors containing B27/B57+-specific CA had increased sensitivity to TRIM5α but not to Mx2. Following exposure to those vectors, cells showed increased resistance against both TRIM5α-sensitive and -insensitive HIV-1 strains. Induction of the antiviral state did not require productive infection by the TRIM5α-sensitive virus, as shown using chemically inactivated virions. Depletion experiments revealed that TAK1 and Ubc13 were essential to the TRIM5α-dependent antiviral state. Accordingly, induction of the antiviral state was accompanied by the activation of NF-κB and AP-1 in THP-1 cells. Secretion of IFN-I was involved in the antiviral state in THP-1 cells, as shown using a receptor blocking antibody. This work identifies innate activation pathways that are likely to play a role in the natural resistance to HIV-1 progression in ECs.

Course of HEV viremia and anti-HEV IgM/IgG response in asymptomatic blood donors

BackgroundGlobally, an estimated 20 million Hepatitis E infections occur every year. The course of viremia and antibody response has been investigated in patients with symptomatic hepatitis E. However, the majority of HEV infections in industrialized countries take a subclinical course. ObjectivesTo investigate the course of HEV viremia and epitope specific anti-HEV IgM/IgG response in asymptomatic blood donors in order to understand the immune response and viral clearance in asymptomatic blood donors with HEV infections. MethodsIn this study 27 HEV viremic donors were identified by HEV-PCR during routine screening of blood donors and the course of anti-HEV IgM/IgG and HEV-RNA was retrospectively studied using RT-PCR and a commercial immunoblot (Mikrogen®) allowing classification of the antibody response according to HEV epitopes. ResultsAt time of donation, serological testing failed to identify viremic donors as 70.4% had no detectable antibody response. Anti-HEV IgM could be detected in 22.2% of viremic donors while anti-HEV IgG could be found in 7.4%. At least three donors experienced prolonged viremia beyond 100 days. Spontaneous HEV-RNA clearance within a median time span of 57 days was observed in all 27 donors. In all donors anti-HEV IgG specific for the immunogenic viral epitope O2C could be detected in close temporal association with viral clearance. ConclusionSerological testing is inappropriate for identifying HEV-viremic blood donors. Acute HEV infection in asymptomatic blood donors can persist for more than 100 days. HEV-RNA clearance coincided with the appearance of anti-HEV IgM/IgG confirming the importance of a B-cell mediated response in clearing acute infections. Anti-HEV IgM and IgG specific for the epitope O2C are associated with the clearance of HEV-viremia.

Zika virus infection in a pregnant Canadian traveler with congenital fetal malformations noted by ultrasonography at 14-weeks gestation

BackgroundFollowing emergence of Zika virus in the Americas, a devastating new congenital syndrome has been documented, leading to significant morbidity among Zika-infected fetuses and neonates.Case presentationA 29-year-old pregnant woman infected with Zika virus at 9-weeks gestation in Trinidad presented with one-month of fever, headache, and myalgia with persistent viremia. Significant fetal abnormalities were identified at 14-week ultrasound, which is the earliest ultrasound to describe a severely affected fetus following Zika virus infection to our knowledge.ConclusionsWe discuss the implications of prolonged maternal viremia and the spectrum of congenital Zika syndrome detectable by fetal ultrasound.

Fetal Neuropathology in Zika Virus-Infected Pregnant Female Rhesus Monkeys

The development of interventions to prevent congenital Zika syndrome (CZS) has been limited by the lack of an established nonhuman primate model. Here we show that infection of female rhesus monkeys early in pregnancy with Zika virus (ZIKV) recapitulates many features of CZS in humans. We infected 9 pregnant monkeys with ZIKV, 6 early in pregnancy (weeks 6-7 of gestation) and 3 later in pregnancy (weeks 12-14 of gestation), and compared findings withuninfected controls. 100% (6 of 6) of monkeys infected early in pregnancy exhibited prolonged maternal viremia and fetal neuropathology, including fetal loss, smaller brain size, and histopathologic brain lesions, including microcalcifications, hemorrhage, necrosis, vasculitis, gliosis, and apoptosis ofneuroprogenitor cells. High-resolution MRI demonstrated concordant lesions indicative of deep gray matter injury. We also observed spinal, ocular, andneuromuscular pathology. Our data show thatvascular compromise and neuroprogenitor cell dysfunction are hallmarks of CZS pathogenesis, suggesting novel strategies to prevent and to treat this disease.

HEV-positive blood donations represent a relevant infection risk for immunosuppressed recipients

Routine HEV testing of blood products has recently been implemented in Great Britain and the Netherlands. The relevance of transfusion-transmitted HEV infections is still controversially discussed in Europe. All blood donations at the University Medical Center Hamburg-Eppendorf were prospectively tested for HEV RNA by pooled PCR from October 2016 to May 2017. Reactive samples were individually retested. Additionally, stored samples from previous donations of positive donors were tested to determine the duration of HEV viraemia. HEV RNA-positive donors and a control cohort were asked to answer a questionnaire. Twenty-three out of 18,737 HEV RNA-positive donors were identified (0.12%). Only two of the positive donors (8.7%) presented with elevated aminotransferases at time of donation (alanine aminotransferase: 192 and 101 U/L). The retrospective analysis of all positive donors revealed that four asymptomatic donors had been HEV viraemic for up to three months with the longest duration of HEV viraemia exceeding four months. Despite the HEV-testing efforts, 14 HEV RNA-positive blood products were transfused into 12 immunocompromised and two immunocompetent patients. One recipient of these products developed fatal acute-on-chronic liver failure complicated by Pseudomonas septicemia. The questionnaire revealed that HEV RNA-positive donors significantly more often consumed raw pork meat (12 out of 18; 67%) than controls (89 out of 256; 35%; p = 0.01). In two donors, undercooked pork liver dishes were identified as the source of infection. HEV genotyping was possible in 7 out of 23 of HEV viraemic donors and six out of seven isolates belonged to HEV Genotype 3, Group 2. Prolonged HEV viraemia can be detected at a relatively high rate in Northern German blood donors, leading to transfusion-transmitted HEV infections in several patients with the risk of severe and fatal complications. Eating raw pork tartare represented a relevant risk for the acquisition of HEV infection. The relevance of transfusion-transmitted hepatitis E virus infections has been discussed controversially. Herein, we present the first report on routine hepatitis E virus screening of blood donations at a tertiary care centre in Germany. Hepatitis E viraemia was found at a relatively high rate of 0.12% among blood donors, which represents a relevant transfusion-related risk for vulnerable patient populations.