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Dengue virus (DENV) causes dengue fever (DF) and dengue hemorrhagic fever in humans. Some DF patients suddenly develop severe symptoms around the defervescent period. Although the pathogenic mechanism of the severe symptoms has not been fully elucidated, the viremia level in the early phase has been shown to correlate with the disease severity. One of the hypotheses is that a phenomenon called antibody-dependent enhancement (ADE) of infection leads to high level of viremia. To examine the plausibility of this hypothesis, we examined the relationship between in vitro ADE activity and in vivo viral load quantity in six patients with dengue diseases. Blood samples were collected at multiple time points between the acute and defervescent phases, and the balance between neutralizing and enhancing activities against the autologous and prototype viruses was examined. As the antibody levels against DENV were rapidly increased, ADE activity was decreased over time or partially maintained against some viruses at low serum dilution. In addition, positive correlations were observed between ADE activity representing in vitro progeny virus production and viremia levels in patient plasma samples. The measurement of ADE activity in dengue-seropositive samples may help to predict the level of viral load in the subsequent DENV infection.

Background: Brescia Province, northern Italy, was one of the worst epicenters of the COVID-19 pandemic. The division of infectious diseases of ASST (Azienda Socio Sanitaria Territoriale) Spedali Civili Hospital of Brescia had to face a great number of inpatients with severe COVID-19 infection and to ensure the continuum of care for almost 4000 outpatients with HIV infection actively followed by us. In a recent manuscript we described the impact of the pandemic on continuum of care in our HIV cohort expressed as number of missed visits, number of new HIV diagnosis, drop in ART (antiretroviral therapy) dispensation and number of hospitalized HIV patients due to SARS-CoV-2 infection. In this short communication, we completed the previous article with data of HIV plasmatic viremia of the same cohort before and during pandemic., Methods: We considered all HIV-patients in stable ART for at least 6 months and with at least 1 available HIV viremia in the time window March 01-November 30, 2019, and another group of HIV patients with the same two requisites but in different time windows of the COVID-19 period (March 01-May 31, 2020, and June 01-November 30, 2020). For patients with positive viremia (PV) during COVID-19 period, we reported also the values of viral load (VL) just before and after PV., Results: the percentage of patients with PV during COVID-19 period was lower than the previous year (2.8% vs 7%). Only 1% of our outpatients surely suffered from pandemic in term of loss of previous viral suppression., Conclusions: Our efforts to limit the impact of pandemic on our HIV outpatients were effective to ensure HIV continuum of care.

Avian leukosis virus subgroup J (ALV-J) causes oncogenic disease in chickens in China, resulting in great harm to poultry production, and remains widespread in China. Herein, we employed a cross-priming amplification (CPA) approach and a nucleic acid detection device to establish a visual rapid detection method for ALV-J. The sensitivity of CPA, polymerase chain reaction (PCR) and real-time PCR (RT-PCR) was compared, and the three methods were used to detect ALV-J in the cell cultures which inoculated with clinical plasma. The result showed when the amplification reaction was carried out at 60 °C for just 60 min, the sensitivity of CPA was 10 times higher than conventional PCR, with high specificity, which was comparable with RT-PCR, based on detection of 123 cell cultures which inoculated with clinical plasma, the coincidence rate with real-time PCR was 97.3% (71/73). CPA detection of ALV-J does not require an expensive PCR instrument; a simple water bath or incubator is sufficient for complete DNA amplification, and the closed nucleic acid detection device avoids aerosol pollution, making judgment of results more intuitive and objective. The CPA assay would be a promising simple, rapid and sensitive method for identification of ALV-J.

Circoviruses infect vertebrates where they can result in a wide range of disease signs or in asymptomatic infections. Using viral metagenomics we analyzed a pool of five sera from four healthy and one sick horse. Sequences from parvovirus-H, equus anellovirus, and distantly related to mammalian circoviruses were recognized. PCR identified the circovirus reads as originating from a pregnant mare with fever and hepatitis. That horse's serum was also positive by real time PCR for equine parvovirus H and negative for the flavivirus equine hepacivirus. The complete circular genome of equine circovirus 1 strain Charaf (EqCV1-Charaf) was completed using PCR and Sanger sequencing. EqCV1 replicase showed 73-74% identity to those of their closest relatives, pig circoviruses 1/2, and elk circovirus. The closest capsid proteins were from the same ungulate circoviruses with 62-63% identity. The overall nucleotide identity of 72% to its closest relative indicates that EqCV1 is a new species in the Circovirus genus, the first reported in genus Equus. Whether EqCV1 alone or in co-infections can result in disease and its prevalence in different equine populations will require further studies now facilitated using EqCV1's genome sequence.

During the acute febrile phase of dengue virus (DENV) infection, viremia can cause severe systemic immune responses accompanied by hematologic disorders. This study investigated the potential induction and mechanism of the cytopathic effects of DENV on peripheral blood cells ex vivo . At one day postinfection, there was viral nonstructural protein NS1 but no further virus replication measured in the whole blood culture. Notably, DENV exposure caused significant vacuolization in monocytic phagocytes. With a minor change in the complete blood cell count, except for a minor increase in neutrophils and a significant decrease in monocytes, the immune profiling assay identified several changes, particularly a significant reduction in CD14-positive monocytes as well as CD11c-positive dendritic cells. Abnormal production of TNF- α was highly associated with the induction of vacuolization. Manipulating TNF- α expression resulted in cytopathogenic effects. These results demonstrate the potential hematological damage caused by ex vivo DENV-induced TNF- α ., Competing Interests: The authors declare that there is no conflict of interest., (Copyright © 2021 Rahmat Dani Satria et al.)

Human pegivirus 1 (HPgV-1) belongs to the genus Pegivirus, family Flaviviridae, and until now has been considered a non-pathogenic agent, despite being considered a risk factor for non-Hodgkin lymphoma. However, a beneficial impact of HPgV-1 on HIV disease progression has been extensively reported. Given the high prevalence of HIV in sub-Saharan Africa and the scarcity of epidemiological data for many countries of West Africa, we conducted the first study of HPgV-1 in HIV-infected individuals from Cabo Verde. To obtain new data regarding prevalence and genetic diversity of HPgV-1 in Africa, serum samples from 102 HIV-infected Cabo Verdeans were tested for the presence of viral RNA, and the circulating genotypes were identified by sequencing of the 5' untranslated region. HPgV-1 RNA was detected in 19.6% (20/102) of the samples. In 72.2% (13/18) of the samples, the virus was identified as genotype 2 (11/13 subtype 2a and 2/13 subtype 2b), and in 27.8% (5/18), it was identified as genotype 1. The estimated substitution rate of HPgV-1 genotype 2 was 5.76 × 10 -4 , and Bayesian analysis indicated the existence of inner clusters within subtypes 2a and 2b. The prevalence of HPgV-1 viremia in Cabo Verde agrees with that reported previously in Africa. Genotypes 1 and 2 cocirculate, with genotype 2 being more common, and HIV/HPgV-1 coinfection was not associated with higher CD4 T cell counts in the studied population. This finding contributes for the expansion of the pegivirus research agenda in African countries.

Letermovir is an antiviral agent indicated for primary prophylaxis of cytomegalovirus (CMV) infection and disease in adult allogeneic hematopoietic stem cell transplant recipients. In this case, UL97 mutation that conferred resistance to ganciclovir was seen in a patient 8 months after renal transplant. We report the off-label use of letermovir with adjunct hyperimmune CMV immunoglobulin in the successful treatment of CMV disease. This report is the first to use this combination for treatment of CMV infection with a high viral load. It contributes to the limited available literature supporting the use of letermovir in the treatment of resistant CMV, where current therapeutic options can be suboptimal due to adverse effects and the risk of cross-resistance., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Option B+ marked a milestone in prevention of mother-to-child transmission (PMTCT) of HIV by recommending lifelong antiretroviral therapy (ART) for all pregnant women with HIV. Nevertheless, concerns remain regarding long-term outcomes in settings with a high HIV burden. We analysed long-term virological outcomes in women enrolled on option B+ in Tanzania., Methods: In this prospective cohort study, we extracted data for pregnant women with HIV starting PMTCT care between Oct 1, 2014, and Sept 30, 2016, in routine health-care settings in Dar es Salaam, Tanzania, from national HIV and district health information system databases. We then excluded women who exited study sites before 6 months of ART follow-up and women who did not have a viral load test. Women were followed up until March 8, 2019. We used Poisson generalised estimating equations to examine trends in HIV viral suppression (<400 copies per mL) and virological failure (≥400 copies per mL), reporting relative risks (RRs) and 95% CIs adjusted for maternal age, gestational age, and several clinical characteristics., Findings: We identified 15 586 pregnant women with HIV, of whom 10 161 were eligible for follow-up. Women were followed up for a median of 37 months (IQR 31-45) and a maximum of 53 months. The median age at PMTCT initiation was 31 years (IQR 27-35). At PMTCT enrolment, 1245 (17·0%) of 7318 women with available data were in their third trimester, 4901 (48·2%) of 10 161 women started ART at least 1 month before PMTCT enrolment, and 3380 (33·4%) of 10 131 women with available data had advanced HIV. Overall, a viral suppression rate of 88·2% (95% CI 87·8-88·7) was observed over the entire follow-up period, ranging from 85·1% (84·3-85·9) in viral load tests done at 0-11 months to 90·6% (89·7-91·4) at 36 months or longer since PMTCT enrolment. In a complete-case analysis (ie, including patients with <30% missing data; n=7306), the risk of virological failure among women who remained in HIV care decreased over time (adjusted RR 0·87 [95% CI 0·80-0·95] at 12-23 months since PMTCT enrolment; 0·65 [0·59-0·72] at 24-35 months; and 0·63 [0·55-0·71] at ≥36 months vs at 0-11 months). Younger women (aged <20 years: 1·76 [1·40-2·23] vs aged 30-39 years) and those starting PMTCT late in pregnancy (third trimester: 1·28 [1·10-1·50] vs first trimester) or with advanced HIV (1·33 [1·16-1·51] vs without advanced HIV) had increased risk of virological failure. Women who attended an antenatal care facility where more than 50% of attendees received couples HIV testing had a decreased risk of virological failure (adjusted RR 0·81 [0·65-0·99] vs <50% having couples testing)., Interpretation: High rates of viral suppression among women starting option B+ who remain in HIV care are sustainable, and might increase, at least up to 53 months. This rate might be further improved by addressing challenges of adolescent mothers, late presenters, and couples HIV testing at antenatal care., Funding: Swedish International Development Agency., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Introduction: Dengue and Malaria are the most important mosquito-borne viral diseases affecting humans. Fever is transmitted between human hosts by infected female aedes mosquitoes. The modeling study of viral infections is very useful to show how the virus replicates in an infected individual and how the human antibody response acts to control that replication, which antibody playing a key role in controlling infection., Objectives: Optimal control of a novel variable-order nonlinear model of dengue virus is studied in the present work. Bang-bang control is suggested to minimize the viral infection as well as quick clearance of the virus from the host. Necessary conditions for the control problem are given. The variable-order derivatives are given in the sense of Caputo. Moreover, the parameters of the proposed model are dependent on the same variable-order fractional power. Two numerical schemes are constructed for solving the optimality systems. Comparative studies and numerical simulations are implemented. The variable-order fractional derivative can be describe the effects of long variable memory of time dependent systems than the integer order and fractional order derivatives., Methods: Both the nonstandard generalized fourth order Runge-Kutta and the nonstandard generalized Euler methods are presented., Results: We have successfully applied a kind of Pontryagin's maximum principle with bang-bang control and were able to reduce the viraemia level by adding the dose of DI particles. The nonstandard generalized fourth order Runge-Kutta method has the best results than nonstandard generalized Euler method., Conclusion: The combination of the variable-order fractional derivative and bang-bang control in the Dengue mathematical model improves the dynamics of the model. The nonstandard generalized Euler method and the nonstandard generalized fourth order Runge-Kutta method can be used to study the variable order fractional optimal control problem simply., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2021 The Authors. Published by Elsevier B.V. on behalf of Cairo University.)

Importance: Current recommendations are to avoid tissue for corneal transplant from donors with coronavirus disease 2019 (COVID-19) or those who were recently exposed to COVID-19 owing to the lack of knowledge about the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in corneal tissues. Evidence of SARS-CoV-2 in corneal tissue would seem to have clinical relevance for corneal transplant., Objectives: To investigate the presence of viral SARS-CoV-2 RNA in corneal discs of deceased patients with confirmed COVID-19 and assess viral genomic and subgenomic RNA load, possible infectivity, and histologic abnormalities., Design, Setting, and Participants: A case series was conducted of 11 deceased patients with COVID-19 who underwent autopsy between March 20 and May 14, 2020. Eleven corneal discs (1 corneal disc per patient) were harvested for molecular detection of viral genomic and subgenomic RNA, virus isolation, and immunohistochemistry. The SARS-CoV-2 RNA loads were compared with RNA loads in the conjunctival and throat swab samples and aqueous humor, vitreous humor, and blood samples., Main Outcomes and Measures: Evidence of SARS-CoV-2 RNA in human corneas., Results: This study comprised 11 patients (6 women [55%]; mean [SD] age, 68.5 [18.8] years). In 6 of 11 eyes (55%), SARS-CoV-2 genomic RNA was detected in the cornea; subgenomic RNA was present in 4 of these 6 eyes (67%). Infectivity or the presence of viral structural proteins could not be confirmed in any eye. However, patients whose corneal disc was positive for SARS-CoV-2 RNA also had positive results for SARS-CoV-2 RNA in 4 of 6 conjunctival swab samples, 1 of 3 aqueous humor samples, 3 of 5 vitreous humor samples, and 4 of 5 blood samples. Overall, conjunctival swab samples had positive results for SARS-CoV-2 RNA in 5 of 11 cases. Postmortem SARS-CoV-2 viremia was detected in 5 of 9 patients., Conclusions and Relevance: Viral genomic and subgenomic RNA of SARS-CoV-2 was detected in the cornea of patients with COVID-19 viremia. The risk of COVID-19 infection via corneal transplant is low even in donors with SARS-CoV-2 viremia, but further research is necessary to assess the rate of SARS-CoV-2 transmission via corneal transplant.

Even in the era of PCR-based monitoring, prophylaxis, and preemptive therapy, Cytomegalovirus (CMV) viremia remains a relevant cause of non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (HCT). However, studies using binary analysis (presence/absence of CMV) reported contradicting data for NRM, overall survival and leukemia relapse. Here, we analyzed CMV replication kinetics in 11 508 whole blood PCR samples of 705 patients with HCT between 2012 and 2017. Using two independent models based on CMV peak titers and on the time point of first CMV reactivation, we stratified patients into risk cohorts. Each cohort had distinct cellular immune reconstitution profiles and differentiated for relevant clinical outcomes. Patients with high CMV peak titers had significantly reduced overall survival (HR 2.13, 95% CI 1.53-2.96; p < .0001), due to high NRM. Early impaired T cell reconstitution was a risk factor for high CMV peak titers, however relevant CMV viremia also related to boosted T cell reconstitution. Importantly, intermediate CMV peak titers associated with a significantly reduced relapse probability (HR 0.53, 95% CI 0.31-0.91; p = .022). In short, CMV kinetics models distinguished relevant clinical outcome cohorts beyond the R+ serostatus with distinct immune reconstitution patterns and resolve in part contradicting results of previous studies exclusively focused on the presence or absence of CMV., (© 2021 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Objectives: The impact of very low-level viremia (VLLV) and low-level viremia (LLV) are rarely investigated among people living with HIV (PLWH) receiving dolutegravir- vs protease inhibitor (PI)-based antiretroviral therapy (ART)., Methods: Virally suppressed PLWH receiving long-term PI-containing ART were included in this study. The incidences of developing VLLV (plasma HIV RNA load (PVL) 20-49 copies/ml), LLV (PVL 50-999 copies/ml), and virological failure (any PVL ≥ 1000 copies/ml) were compared between those switched to dolutegravir-based ART and those remaining on PI-containing ART., Results: A total of 183 PLWH were switched to dolutegravir-based regimens and 309 remained on PI-containing regimens. The incidences of VLLV and LLV were 26.5 and 13.2 per 100 person-years of follow-up in the dolutegravir group, respectively, and 17.1 and 7.0 per 100 person-years of follow-up in the PI group; there were no statistically significant differences after adjusting for confounders. The rate of virological failure was 1.3 per 100 person-years of follow-up in the dolutegravir group and 1.9 per 100 person-years of follow-up in the PI group (p = 0.32). Neither VLLV nor LLV was related to subsequent virological failure., Conclusions: Among virally suppressed PLWH, the risk of developing VLLV or LLV were similar between those switched to dolutegravir-based therapy and those who continued PI-based therapy. VLLV and LLV were not associated with subsequent virological failure., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The antiviral properties of broadly neutralizing antibodies against HIV are well-documented but no vaccine is currently able to elicit protective titers of these responses in primates. While current vaccine modalities can readily induce non-neutralizing antibodies against simian immunodeficiency virus (SIV) and HIV, the ability of these responses to restrict lentivirus transmission and replication remains controversial. Here, we investigated the antiviral properties of non-neutralizing antibodies in a group of Indian rhesus macaques (RMs) that were vaccinated with vif , rev, tat, nef , and env , as part of a previous study conducted by our group. These animals manifested rapid and durable control of viral replication to below detection limits shortly after SIVmac239 infection. Although these animals had no serological neutralizing activity against SIVmac239 prior to infection, their pre-challenge titers of Env-binding antibodies correlated with control of viral replication. To assess the contribution of anti-Env humoral immune responses to virologic control in two of these animals, we transiently depleted their circulating antibodies via extracorporeal plasma immunoadsorption and inhibition of IgG recycling through antibody-mediated blockade of the neonatal Fc receptor. These procedures reduced Ig serum concentrations by up to 80% and temporarily induced SIVmac239 replication in these animals. Next, we transferred purified total Ig from the rapid controllers into six vaccinated RMs one day before intrarectal challenge with SIVmac239. Although recipients of the hyperimmune anti-SIV Ig fraction were not protected from infection, their peak and chronic phase viral loads were significantly lower than those in concurrent unvaccinated control animals. Together, our results suggest that non-neutralizing Abs may play a role in the suppression of SIVmac239 viremia., Competing Interests: JL was employed by Leidos Biomedical Research Inc. MM has a consulting financial interest in Emmune, Inc., a company that is developing HIV immunotherapies based on the immunoadhesin eCD4-Ig. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Pedreño-Lopez, Rosen, Flores, Gorman, Voigt, Ricciardi, Crosno, Weisgrau, Parks, Lifson, Alter, Rakasz, Magnani, Martins and Watkins.)

Plasma viremia reoccurs in most HIV-infected individuals once antiretroviral therapy (ART) is interrupted. The kinetics of viral rebound, specifically the time until plasma virus becomes detectable, differ quite substantially between individuals, and associations with virological and immunological factors have been suggested. Standard clinical measures, like CD4 T-cell counts and plasma HIV RNA levels, however, are poor predictive markers. Antibody features, including Fc functionality and Fc glycosylation have been identified as sensitive surrogates for disease activity in multiple diseases. Here, we analyzed HIV-specific antibody quantities and qualitative differences like antibody-mediated functions, Fc gamma receptor (FcγR) binding, and IgG Fc glycosylation as well as cytokine profiles and cellular HIV DNA and RNA levels in 23 ART-suppressed individuals prior to undergoing an analytical ART interruption (ATI). We found that antibodies with distinct functional properties and Fc glycan signatures separated individuals into early and delayed viral rebounders (≤4 weeks versus >4 weeks) and tracked with levels of inflammatory cytokines and transcriptional activity of the viral reservoir. Specifically, individuals with early viral rebound exhibited higher levels of total HIV-specific IgGs carrying inflammatory Fc glycans, while delayed rebounders showed an enrichment of highly functional antibodies. Overall, only four features, including enhanced antibody-mediated NK cell activation in delayed rebounders, were necessary to discriminate the groups. These data suggest that antibody features can be used as sensitive indicators of HIV disease activity and could be included in future ATI studies. IMPORTANCE Plasma viremia reoccurs in most HIV-infected individuals once antiretroviral therapy is interrupted, and interindividual differences in the kinetics of viral rebound have been associated with virological and immunological factors. Antibody features, including Fc functionality and Fc glycosylation, have been identified as sensitive surrogates for disease activity in multiple diseases. Here, we systematically analyzed HIV-specific antibody quantities and qualitative differences in 23 ART-suppressed individuals prior to undergoing an analytical ART interruption (ATI). We found that antibodies with distinct functional properties and Fc glycan signatures separated individuals into early and delayed viral rebounders and tracked with levels of inflammatory cytokines and transcriptional activity of the viral reservoir. These data suggest that antibody features can be used as sensitive indicators of HIV disease activity and could be included in future HIV eradication studies., (Copyright © 2021 Bartsch et al.)

The humoral immune response plays a crucial role in the combat and protection against many pathogens including the economically most important, highly prevalent, and diverse pig pathogen PRRSV - the Porcine Reproductive and Respiratory Syndrome Virus. In addition to viremia and viral shedding analyses, this study followed the local and systemic humoral immune response of pigs for 63 days upon inoculation with one of three types of Type-2 PRRSV (PRRSV-2) strains - one modified live virus (MLV) vaccine strain, and two lineage 1 PRRSV-2 strains, NC134 and NC174. The local response was analyzed by quantifying immunoglobulin (Ig)A in nasal swabs. The systemic response was studied by the quantification of IgG with ELISA and homo- and heterologous neutralizing antibodies (NAs) utilizing a novel method of flow cytometry. In all PRRSV-2 inoculated groups, viral nasal shedding started at 3 dpi, peaked between 3 and 7 days post inoculation, and was cleared at 28-35 dpi with sporadic rebounds thereafter. The local IgA response started 4-7 days after viral shedding occurred and showed a bi-phasic course with peaks at 14 dpi and at 28-35 dpi. Of note, the NC134 and NC174 strains induced a much stronger local IgA response. As reported earlier, main viremia lasted from 7 dpi to 28 dpi (NC174), 42 dpi (NC134) or until the end of the study (MLV). Similar to the local IgA response, the systemic IgG response started 4-7 days after viremia; but in contrast to viremia, serum IgG levels stayed high for all PRRSV-2 inoculated groups until the end of the study. A significant finding was that while the serum NA response in the MLV group was delayed by 28 days, serum NAs in pigs infected with our two NC134 and NC174 strains could be detected as early as 7 dpi (NC134) and 14 dpi (NC174). Compared to homologous NA responses, the NA responses against heterologous strains was strong but slightly delayed between our lineage 1 one strains or non-existent between the MLV and lineage 1 strains. This study improves our understanding of the relationship between local and systemic infections and the humoral immune response induced by PRRSV-2 infection or MLV vaccination. Our data also provide novel insights into the timeline of the development of homologous and heterologous NA levels - by both MLV vaccination or infection with two strains from the currently prevalent PRRSV-2 lineage 1., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kick, Amaral, Frias-De-Diego, Cortes, Fogle, Crisci, Almond and Käser.)

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne viral hemorrhagic disease with a high fatality rate. It is caused by the SFTS virus and is endemic in East Asian countries such as China, South Korea, and Japan. Previous studies have shown that plasmablasts appear transiently in peripheral blood during the acute phase of SFTS, but do not specify the characteristics of these plasmablasts. In this report, we describe the features of peripheral blood plasmablasts in a patient with SFTS. Immunohistochemical and immunofluorescence staining detected a small number of atypical lymphocytes expressing the SFTS virus antigen among peripheral leukocytes in a blood sample. The phenotype of the virus-infected cells was CD27+, CD38+, MUM1+, and CD138+, which is consistent with that of plasmablasts. This novel study demonstrates that plasmablasts in the peripheral blood of patients with SFTS are targets of the SFTS virus.

We document two cases of viremic and prolonged active infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) where the viral genome was conserved for two months, but infection was with little or no symptoms. The first infection persisted for 80 days and the second for 62 days. Clearance of infection occurred 40 and 41 days, respectively, after development of detectable antibodies. Both cases were identified incidentally in an investigation of reinfection in a cohort of 133,266 laboratory-confirmed infected persons., (Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Despite a dramatic reduction in HCV drug costs and simplified models of care, many countries lack important information on prevalence and risk factors to structure effective HCV services., Methods: A cross-sectional, multi-stage cluster survey of HCV seroprevalence in adults 18 years and above was conducted, with an oversampling of those 45 years and above. One hundred forty-seven clusters of 25 households were randomly selected in two sets (set 1=24 clusters ≥18; set 2=123 clusters, ≥45). A multi-variable analysis assessed risk factors for sero-positivity among participants ≥45. The study occurred in rural Moung Ruessei Health Operational District, Battambang Province, Western Cambodia., Results: A total of 5098 individuals and 3616 households participated in the survey. The overall seroprevalence was 2.6% (CI95% 2.3-3.0) for those ≥18 years, 5.1% (CI95% 4.6-5.7) for adults ≥ 45 years, and 0.6% (CI95% 0.3-0.9) for adults 18-44. Viraemic prevalence was 1.9% (CI95% 1.6-2.1), 3.6% (CI95% 3.2-4.0), and 0.5% (CI95% 0.2-0.8), respectively. Men had higher prevalence than women: ≥18 years male seroprevalence was 3.0 (CI95% 2.5-3.5) versus 2.3 (CI95% 1.9-2.7) for women. Knowledge of HCV was poor: 64.7% of all respondents and 57.0% of seropositive participants reported never having heard of HCV. Risk factor characteristics for the population ≥45 years included: advancing age (p< 0.001), low education (higher than secondary school OR 0.7 [95% CI 0.6-0.8]), any dental or gum treatment (OR 1.6 [95% CI 1.3-1.8]), historical routine medical care (medical injection after 1990 OR 0.7 [95% CI 0.6-0.9]; surgery after 1990 OR 0.7 [95% CI0.5-0.9]), and historical blood donation or transfusion (blood donation after 1980 OR 0.4 [95% CI 0.2-0.8]); blood transfusion after 1990 OR 0.7 [95% CI 0.4-1.1])., Conclusions: This study provides the first large-scale general adult population prevalence data on HCV infection in Cambodia. The results confirm the link between high prevalence and age ≥45 years, lower socio-economic status and past routine medical interventions (particularly those received before 1990 and 1980). This survey suggests high HCV prevalence in certain populations in Cambodia and can be used to guide national and local HCV policy discussion.

Background: Previous studies have demonstrated an association between adenovirus viremia and disease severity in immunocompromised children. However, few studies have focused on this association in immunocompetent children. This study explored the association between adenovirus viremia and adenovirus pneumonia severity in immunocompetent children., Methods: We performed a retrospective, observational study of immunocompetent children with adenovirus pneumonia admitted to Shenzhen Children's Hospital in Shenzhen, China. Pneumonia was classified as severe or mild based on the Chinese guideline for the classification of pneumonia severity. Serum samples from all the children included in the study were tested for adenovirus DNA with a quantitative polymerase chain reaction. Clinical manifestations, laboratory examinations, and disease severity were compared between children with severe and mild pneumonia., Results: A total of 111 immunocompetent children with adenovirus pneumonia (60 severe, 51 mild) were included. The median age was 40 months, and 64 patients were male. Five patients were admitted to the intensive care unit, and two underwent endotracheal intubation. All patients were discharged after recovery or improvement. Univariate analysis and binary logistic regression analysis showed that leukocytosis (OR = 1.1; 95% CI: 1.0 to 1.2; P = 0.033), co-infection with Mycoplasma pneumoniae (OR = 5.0; 95% CI: 2.1 to 12.3; P <  0.001), and high blood viral load (OR = 1.5; 95% CI: 1.2 to 2.0; P = 0.001) may be risk factors for severe adenovirus pneumonia., Conclusions: Leukocytosis, co-infection with Mycoplasma pneumoniae, and high blood viral load may be risk factors for severe adenovirus pneumonia in immunocompetent children. Blood viral load may predict pneumonia severity.

The Tembusu virus (TMUV) PS strain, derived by several passages and plaque purifications in BHK-21 cells, displays markedly lower virulence in Pekin ducklings relative to a natural isolate of TMUV, but the potential virulence determinants and the in vivo mechanisms for substantial virulence attenuation of the passage variant remain unknown. Here, we constructed a series of chimeric and mutant viruses and assessed their virulence using a 2-day-old Pekin duckling model. We showed that residue 304 in the envelope (E) protein is the molecular determinant of TMUV virulence. Further investigations with mutant and parental viruses demonstrated that acquisition of positive charges at E protein residue 304 plays a critical role in substantial attenuation of neurovirulence and neuroinvasiveness, which is linked to enhanced binding affinity for glycosaminoglycans (GAGs). In Pekin ducklings infected by subcutaneous inoculation, an Arg at residue 304 in the E protein was shown to contribute to more rapid virus clearance from the circulation, markedly reduced viremia, and significantly decreased viral growth in the extraneural tissues and the central nervous system, relative to a Met at the corresponding residue. These findings suggest that the in vivo mechanism of virulence attenuation of the TMUV passage variant closely resembles that proposed previously for GAG-binding variants of other flaviviruses. Overall, our study provides insight into the molecular basis of TMUV virulence and the in vivo consequences of acquisition of a GAG-binding determinant at residue 304 in the E protein of TMUV. IMPORTANCE TMUV-related disease emerged in 2010 and has a significant economic impact on the duck industry. Although the disease was originally recognized to affect adult ducks, increasing evidence has shown that TMUV also causes severe disease of young ducklings. It is, therefore, essential to investigate the pathogenesis of TMUV infection in a young duckling model. The significance of our studies is in identifying E protein residue Arg304 as the molecular determinant for TMUV virulence and in clarifying the crucial role of positive charges at E protein residue 304 in virulence attenuation of a TMUV passage variant. These data will greatly enhance our understanding of the pathogenesis of TMUV infection in ducklings and have implications for development of a safe and efficient vaccine., (Copyright © 2021 American Society for Microbiology.)

The human immunodeficiency virus (HIV) reservoir is responsible for persistent viral infection, and a small number of mosaic latent cellular reservoirs promote viral rebound upon antiretroviral therapy interruption, which is the major obstacle to a cure. However, markers that determine effective therapy and viral rebound posttreatment interruption remain unclear. In this study, we comprehensively and longitudinally tracked dynamic decay of cell-associated viral RNA/DNA in systemic and lymphoid tissues in simian immunodeficiency virus (SIV)-infected rhesus macaques on prolonged combined antiretroviral therapy (cART) and evaluated predictors of viral rebound after treatment cessation. The results showed that suppressive ART substantially reduced plasma SIV RNA, cell-associated unspliced, and multiply spliced SIV RNA to undetectable levels, yet viral DNA remained detectable in systemic tissues and lymphoid compartments throughout cART. Intriguingly, a rapid increase of integrated proviral DNA in peripheral mononuclear cells was detected once treatment was withdrawn, accompanied by the emergence of detectable plasma viral load. Notably, the increase of peripheral proviral DNA after treatment interruption correlated with the emergence and degree of viral rebound. These findings suggest that measuring total viral DNA in SIV infection may be a relatively simple surrogate marker of reservoir size and may predict viral rebound after treatment interruption and inform treatment strategies. IMPORTANCE Viral reservoirs are involved in persistent HIV infection, and a small number of mosaic latent cellular reservoirs promote viral rebound upon analytical treatment interruption, which is the major obstacle to a cure. However, early indicators that can predict resurgence of viremia after treatment interruption may aid treatment decisions in people living with HIV. Utilizing the rhesus macaque model, we demonstrated that increased proviral DNA in peripheral cells after treatment interruption, rather than levels of proviral DNA, was a useful marker to predict the emergence and degree of viral rebound after treatment interruption, providing a rapid approach for monitoring HIV rebound and informing decisions., (Copyright © 2021 Ziani et al.)

Background: Porcine reproductive and respiratory syndrome (PRRS) is a threat to pig production worldwide. Our objective was to understand mechanisms of persistence of PRRS virus (PRRSV) in tonsil. Transcriptome data from tonsil samples collected at 42 days post infection (dpi) were generated by RNA-seq and NanoString on 51 pigs that were selected to contrast the two PRRSV isolates used, NVSL and KS06, high and low tonsil viral level at 42 dpi, and the favorable and unfavorable genotypes at a genetic marker (WUR) for the putative PRRSV resistance gene GBP5., Results: The number of differentially expressed genes (DEGs) differed markedly between models with and without accounting for cell-type enrichments (CE) in the samples that were predicted from the RNA-seq data. This indicates that differences in cell composition in tissues that consist of multiple cell types, such as tonsil, can have a large impact on observed differences in gene expression. Based on both the NanoString and the RNA-seq data, KS06-infected pigs showed greater activation, or less inhibition, of immune response in tonsils at 42 dpi than NVSL-infected pigs, with and without accounting for CE. This suggests that the NVSL virus may be better than the KS06 virus at evading host immune response and persists in tonsils by weakening, or preventing, host immune responses. Pigs with high viral levels showed larger CE of immune cells than low viral level pigs, potentially to trigger stronger immune responses. Presence of high tonsil virus was associated with a stronger immune response, especially innate immune response through interferon signaling, but these differences were not significant when accounting for CE. Genotype at WUR was associated with different effects on immune response in tonsils of pigs during the persistence stage, depending on viral isolate and tonsil viral level., Conclusions: Results of this study provide insights into the effects of PRRSV isolate, tonsil viral level, and WUR genotype on host immune response and into potential mechanisms of PRRSV persistence in tonsils that could be targeted to improve strategies to reduce viral rebreaks. Finally, to understand transcriptome responses in tissues that consist of multiple cell types, it is important to consider differences in cell composition.

Toll-like receptor 7 (TLR7) agonist and PGT121 (broadly neutralizing antibody, bnAb) administration previously delayed viral rebound and induced SHIV remission. We evaluated the impact of GS-986 (TLR7 agonist) and dual bnAbs on viral rebound after antiretroviral therapy (ART) interruption. Rhesus macaques inoculated with SHIV-1157ipd3N4 were initiated on daily suppressive ART from Day 14 post SHIV inoculation. Active arm animals (n = 8) received GS-986, N6-LS and PGT121 after plasma viral suppression, starting from week 14. GS-986 induced immune activation and SHIV-specific T cell responses but not viral expression in all the active arm animals. After ART interruption, median time to viral rebound was 6 weeks in the active and 3 weeks in the control arm (p = 0.024). In this animal model, the administration of the combination of GS-986 and dual bnAbs was associated with a modest delay in viral rebound. This strategy should be further evaluated to better understand the underlying mechanisms for the induction of virus-specific immune responses and delay in viral rebound., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests:RG is an employee of Gilead Sciences. JRM is an inventor on an NIH patent for N6.

Background: Recent studies showed that plasma SARS-CoV-2 RNA seems to be associated with worse COVID-19 outcome. However, whether specific population can be at higher risk of viremia are to date unexplored., Methods: This cross-sectional proof-of-concept study included 41 SARS-CoV-2-positive adult individuals (six affected by haematological malignancies) hospitalized at two major hospital in Milan, for those demographic, clinical and laboratory data were available. SARS-CoV-2 load was quantified by ddPCR in paired plasma and respiratory samples. To assess significant differences between patients with and patients without viremia, Fisher exact test and Wilcoxon test were used for categorical and continuous variables, respectively., Results: Plasma SARS-CoV-2 RNA was found in 8 patients (19.5%), with a median (IQR) value of 694 (209-1023) copies/mL. Viremic patients were characterized by an higher mortality rate (50.0% vs 9.1%; p = 0.018) respect to patients without viremia. Viremic patients were more frequently affected by haematological malignancies (62.5% vs. 3.0%; p < 0.001), and had higher viral load in respiratory samples (9,404,000 [586,060-10,000,000] vs 1560 [312-25,160] copies/mL; p = 0.002)., Conclusions: Even if based on a small sample population, this proof-of-concept study poses the basis for an early identification of patients at higher risk of SARS-CoV-2 viremia, and therefore likely to develop severe COVID-19, and supports the need of a quantitative viral load determination in blood and respiratory samples of haematologic patients with COVID-19 in order to predict prognosis and consequently to help their further management.

Background: Although adipose tissue has been proposed to harbor part of the human immunodeficiency virus 1 (HIV-1) reservoir, the influence of host characteristics, including sex and body mass index (BMI), on measures of HIV-1 persistence during antiretroviral therapy (ART) are incompletely understood., Methods: We evaluated age, sex, BMI, waist circumference, years on ART, pre-ART HIV-1 RNA, pre-ART CD4+ T-cell count, and initial ART regimen with measures of HIV-1 persistence in blood (residual viremia, cellular HIV-1 DNA and RNA) in a cohort of 295 individuals with well-documented long-term virologic suppression (HIV-1 RNA <50 copies/mL) on ART (AIDS Clinical Trials Group study A5321)., Results: Men were more likely than women to have detectable plasma HIV-1 RNA by single-copy assay (52% vs 29%; P = .003), and the proportion of participants with detectable residual viremia increased in a stepwise fashion by BMI category (normal weight or underweight, 38%; overweight, 50%; and obese, 55%). ART regimen type was not associated with measures of HIV-1 persistence after controlling for ART duration., Conclusions: Sex and obesity are independently associated with residual viremia in people on long-term ART. Additional studies to confirm these relationships and to define the mechanisms by which sex and obesity affect HIV-1 persistence are needed to inform HIV-1 cure strategies., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background and Objectives: Kidneys from hepatitis C virus (HCV) viremic donors have become more commonly accepted for transplant, especially after effective direct-acting antiviral therapy became available in 2014. We examined the contemporary trend of kidney discard from donors with HCV seropositivity and viremia., Design, Setting, Participants, & Measurements: Data from the Organ Procurement and Transplantation Network were used to identify deceased donor kidneys recovered for transplant. The exposure was donor HCV antibody status in the first analyses, and donor HCV antibody and viremia status in the second analyses. Multilevel, multivariable logistic regression was used to assess the association of these HCV exposure measures with kidney discard, adjusted for donor characteristics. Multilevel analyses were conducted to account for similar kidney discard pattern within clusters of organ procurement organizations and regions., Results: Among 225,479 kidneys recovered from 2005 to 2019, 5% were from HCV seropositive donors. Compared with HCV seronegative kidneys, the odds of HCV seropositive kidney discard gradually declined, from a multivariable-adjusted odds ratio (aOR) of 7.06 (95% confidence interval [95% CI], 5.65 to 8.81) in 2014, to 1.20 (95% CI, 1.02 to 1.42) in 2019. Among 82,090 kidneys with nucleic acid amplification test results in 2015-2019, 4% were from HCV viremic donors and 2% were from aviremic seropositive donors. Compared with HCV aviremic seronegative kidneys, the odds of HCV viremic kidney discard decreased from an aOR of 4.89 (95% CI, 4.03 to 5.92) in 2018, to 1.48 (95% CI, 1.22 to 1.81) in 2019. By 2018 and 2019, aviremic seropositive status was not associated with higher odds of discard (2018: aOR, 1.13; 95% CI, 0.88 to 1.45; and 2019: aOR, 0.97; 95% CI, 0.76 to 1.23)., Conclusions: Despite the decrease in kidney discard in recent years, kidneys from viremic (compared with aviremic seronegative) donors still had 48% higher odds of discard in 2019. The potential of these discarded organs to provide successful transplantation should be explored., (Copyright © 2021 by the American Society of Nephrology.)

Background: Dengue human infection models (DHIM) have been used as a safe means to test the viability of prophylaxis and therapeutics., Methods: A phase 1 study of 12 healthy adult volunteers using a challenge virus, DENV-1-LVHC strain 45AZ5, was performed. A dose escalating design was used to determine the safety and performance profile of the challenge virus. Subjects were evaluated extensively until 28 days and then out to 6 months., Results: Twelve subjects received the challenge virus: 6 with 0.5 mL of 6.5 × 103 plaque-forming units (PFU)/mL (low-dose group) and 6 with 0.5 mL of 6.5 × 104 PFU/mL (mid-dose group). All except 1 in the low-dose group developed detectable viremia. For all subjects the mean incubation period was 5.9 days (range 5-9 days) and mean time of viremia was 6.8 days (range 3-9 days). Mean peak for all subjects was 1.6 × 107 genome equivalents (GE)/mL (range 4.6 × 103 to 5 × 107 GE/mL). There were no serious adverse events or long-term safety signals noted., Conclusions: We conclude that DENV-1-LVHC was well-tolerated, resulted in an uncomplicated dengue illness, and may be a suitable DHIM for therapeutic and prophylactic product testing., Clinical Trials Registration: NCT02372175., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Recently, a novel PCV species (PCV3) has been detected in cases associated with sow mortality, lesions consistent with porcine dermatitis and nephropathy syndrome, reproductive failure and multisystemic inflammation. The pathogenesis and clinical significance of PCV3 is still unclear. In this study, we investigated the immunopathogenesis of PCV3 in CD/CD pigs. Four treatment groups, PCV3 ( n =6), PCV3-KLH ( n =6), control ( n =3) and control-KLH ( n =3), were included with PCV3-positive tissue homogenate (gc=3.38×10 12 ml -1 and gc=1.04×10 11 ml -1 ), confirmed by quantitative PCR (qPCR) and next-generation sequencing. Clinical signs, viremia, viral shedding, systemic cytokines, humoral (IgG) and T-cellular response were evaluated for 42 days. At necropsy, tissues were collected for histological evaluation and PCV3 detection by qPCR and in situ hybridization. No significant clinical signs were observed through the study. Viremia was detected in both PCV3-inoculated groups from 3 days post-inoculation (p.i.) until the end of the study. Nasal shedding was detected from 3 to 28 days p.i. and faecal shedding was transient. PCV3 induced an early (7 days p.i.) and sustained (42 days p.i.) IgG response. No significant T-cell response was observed. Histological evaluation demonstrated lesions consistent with multisystemic inflammation and perivasculitis. All tissues evaluated were positive by qPCR and virus replication was confirmed by positive in situ hybridization. This study demonstrated the potential role of PCV3 in subclinical infection, producing a mild, multisystemic inflammatory response, prolonged viremia detectable for 42 days p.i., presence of IgG humoral response and viral shedding in nasal secretions. More research is required to understand and elucidate potential co-factors necessary in the manifestation and severity of clinical disease.

The appearance of human immunodeficiency virus type 1 (HIV-1) plasma viremia is associated with progression to symptomatic disease and CD4 + T cell depletion. To locate the source of systemic viremia, this study employed a novel method to trace HIV-1 infection in vivo. We created JRCSFξnef, a pool of infectious HIV-1 (strain JR-CSF) with highly mutated nef gene regions by random mutagenesis PCR and infected this mutated virus pool into both Jurkat-CCR5 cells and hematopoietic stem cell-transplanted humanized mice. Infection resulted in systemic plasma viremia in humanized mice and viral RNA sequencing helped us to identify multiple lymphoid organs such as spleen, lymph nodes, and bone marrow but not peripheral blood cells as the source of systemic viremia. Our data suggest that this method could be useful for the tracing of viral trafficking in vivo., (© 2020 The Societies and John Wiley & Sons Australia, Ltd.)

Human immunodeficiency virus (HIV) remains incurable due to latent viral reservoirs established in non-activated CD4 T cells that cannot be eliminated via antiretroviral therapy. Current efforts to cure HIV are focused on identifying drugs that will induce viral gene expression in latently infected cells, commonly known as latency reversing agents (LRAs). Some drugs have been shown to reactivate latent HIV but do not cause a reduction in reservoir size. Therefore, finding new LRAs or new combinations or increasing the round of stimulations is needed to cure HIV. However, the effects of these drugs on viral rebound after prolonged treatment have not been evaluated. In a previous clinical trial, antiretroviral therapy intensification with maraviroc for 48 weeks caused an increase in residual viremia and episomal two LTR-DNA circles suggesting that maraviroc could reactivate latent HIV. We amended the initial clinical trial to explore additional virologic parameters in stored samples and to evaluate the time to viral rebound during analytical treatment interruption in three patients. Maraviroc induced an increase in cell-associated HIV RNA during the administration of the drug. However, there was a rapid rebound of viremia after antiretroviral therapy discontinuation. HIV-specific T cell response was slightly enhanced. These results show that maraviroc can reactivate latent HIV in vivo but further studies are required to efficiently reduce the reservoir size.

Background: Several species of soft ticks in genus Ornithodoros are known vectors and reservoirs of African swine fever virus (ASFV). However, the underlying mechanisms of vector competence for ASFV across Ornithodoros species remain to be fully understood. To that end, this study compared ASFV replication and dissemination as well as virus vertical transmission to descendants between Ornithodoros moubata, O. erraticus, and O. verrucosus in relation to what is known about the ability of these soft tick species to transmit ASFV to pigs. To mimic the natural situation, a more realistic model was used where soft ticks were exposed to ASFV by allowing them to engorge on viremic pigs., Methods: Ornithodoros moubata ticks were infected with the ASFV strains Liv13/33 (genotype I) or Georgia2007/1 (genotype II), O. erraticus with OurT88/1 (genotype I) or Georgia2007/1 (genotype II), and O. verrucosus with Ukr12/Zapo (genotype II), resulting in five different tick-virus pairs. Quantitative PCR (qPCR) assays targeting the VP72 ASFV gene was carried out over several months on crushed ticks to study viral replication kinetics. Viral titration assays were also carried out on crushed ticks 2 months post infection to confirm virus survival in soft ticks. Ticks were dissected. and DNA was individually extracted from the following organs to study ASFV dissemination: intestine, salivary glands, and reproductive organs. DNA extracts from each organ were tested by qPCR. Lastly, larval or first nymph-stage progeny emerging from hatching eggs were tested by qPCR to assess ASFV vertical transmission., Results: Comparative analyses revealed higher rates of ASFV replication and dissemination in O. moubata infected with Liv13/33, while the opposite was observed for O. erraticus infected with Georgia2007/1 and for O. verrucosus with Ukr12/Zapo. Intermediate profiles were found for O. moubata infected with Georgia2007/1 and for O. erraticus with OurT88/1. Vertical transmission occurred efficiently in O. moubata infected with Liv13/33, and at very low rates in O. erraticus infected with OurT88/1., Conclusions: This study provides molecular data indicating that viral replication and dissemination in Ornithodoros ticks are major mechanisms underlying ASFV horizontal and vertical transmission. However, our results indicate that other determinants beyond viral replication also influence ASFV vector competence. Further research is required to fully understand this process in soft ticks.

Background: Dengue infection is a global health threat. While symptomatic cases contribute to morbidity and mortality, the majority of infected people are asymptomatic but serve as an important reservoir. However, the kinetics of viremia in asymptomatic infections remains unknown., Methods: We enrolled 279 hospital-based symptomatic index cases and quantified dengue virus (DENV) RNA at enrollment and at the day of defervescence. To identify asymptomatic cases, 175 household members of index cases were monitored for clinical symptoms during follow-up, and blood was taken twice weekly to test for and quantify DENV RNA until cleared., Results: We detected DENV in thirteen asymptomatic household members (7.43%). Their DENV serotypes were primarily the same as those of their family index cases. The median peak DENV viremia in asymptomatic subjects was lower than that of symptomatic individuals during the febrile phase, and the viral decay rate was slower in asymptomatic infections., Conclusions: DENV level and kinetics in asymptomatic individuals differed significantly from those of symptomatic cases. Despite the lower viremia, the slower decay rate in asymptomatic infections could lead to their prolonging the infectious reservoir. The improvement of transmission control to prevent such long-lived asymptomatic infections from transmitting the DENV is needed., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Patients with human immunodeficiency virus (HIV) infection have a decreased risk of developing multiple sclerosis (MS) and MS patients very rarely contract HIV infection. We report on a 35-year-old woman with relapsing-remitting MS, who acquired HIV infection 8 years after MS onset. During 7 years of follow-up without combined antiretroviral therapy (cART), CD4+ counts decreased and HIV viremia increased progressively, but slightly. These trends reverted after starting cART, with optimal viro-immunological control. While the patient had many MS relapses before acquiring HIV infection, she had then only one relapse, shortly after HIV infection, despite irregular or no MS therapy. This case contributes to the discussion about MS and HIV potential interactions and describes for the first time the effects of the MS-targeting drug natalizumab in an HIV-positive patient.

Despite worldwide efforts to understand the transmission dynamics of Zika virus (ZIKV), scanty evaluation has been made on the vector competence of Aedes aegypti fed directly on viremic human and non-human primates (NHPs). We blood-fed Ae. aegypti from two districts in Rio de Janeiro on six ZIKV infected pregnant rhesus macaques at several time points, half of which were treated with Sofosbuvir (SOF). Mosquitoes were analyzed for vector competence after 3, 7 and 14 days of incubation. Although viremia extended up to eight days post monkey inoculation, only mosquitoes fed on the day of the peak of viremia, recorded on day two, became infected. The influence of SOF treatment could not be assessed because the drug was administered just after mosquito feeding on day two. The global infection, dissemination and transmission rates were quite low (4.09%, 1.91% and 0.54%, respectively); no mosquito was infected when viremia was below 1.26 × 10 5 RNA copies/mL. In conclusion, Ae. aegypti vector competence for ZIKV from macaques is low, likely to be due to low viral load and the short duration of ZIKV viremia in primates suitable for infecting susceptible mosquitoes. If ZIKV infection in human and macaques behaves similarly, transmission of the Zika virus in nature is most strongly affected by vector density.

HIV-1 persists indefinitely in multiple cellular reservoirs despite antiretroviral therapy. We previously demonstrated HIV-1 compartmentalization in kidney and urine. Here, we further characterized viruses in urine and when available, compared them to those present in semen from HIV-1 positive participants with detectable plasma viremia to further understand the viral dynamics in the upper and lower genitourinary tract.Blood and urine samples were obtained from 19 HIV-1 positive participants. Simultaneous semen samples were obtained from 16 of the 19 participants. HIV-1 envelope (env) gene sequences were obtained by single-genome amplification (SGA) and neighbor-joining trees were constructed using the Kimura 2-parameter model.HIV-1 env gene sequences were amplified from blood in 19/19 (100%) participants, urine in 18/19 (95%) participants, and semen in 12/16 (75%). In individuals from which both urine and semen samples were obtained, differences in viral shedding between the 2 sources were observed, where HIV-1 env sequences could only be amplified from either urine or semen. Longitudinal phylogenetic analysis of urine-derived env sequences from 1 participant demonstrated that urine clusters distinct from blood are maintained over time (20 weeks), consistent with viral compartmentalization and local replication. Comparison of urine and semen derived sequences demonstrated either virus compartmentalization or equilibration.Our results demonstrate that when present, viral compartmentalization in urine persists over time. Comparison of timing of viral shedding in urine and semen samples from our cohort suggest different viral kinetics between the upper and lower genitourinary tract and sequence analysis suggests that HIV-1 populations in urine and semen can either be imported from blood or produced locally.

Torque teno virus (TTV) has been proposed as a surrogate biomarker of T-cell function in allogeneic-haematopoietic-stem-cell transplantation (allo-HSCT). Conflicting data exists regarding the value of TTV to assess the degree of immunosuppression. The aim of the present study was to investigate the correlation between TTV viral load and immune function. Using samples from a prospective cohort composed of healthy-volunteers (HV) and allo-HSCT recipients at 6 months post-transplantation, we assessed the correlation between TTV viraemia and immune cell counts or T-cell proliferation capacity post-phytohaemagglutinin stimulation. TTV viraemia was detected in 68% of HV ( n = 80) and 100% of allo-HSCT recipients ( n = 41; p < 0.001); it was significantly higher in allo-HSCT recipients (3.9 vs. 2.1 Log copies/mL, p < 0.001). There was no correlation between T-cell function and CD3 + T-cell count (rho: 0.002) suggesting that T-cell count can normalise without full functional recovery. Furthermore, no significant correlation was observed between TTV viraemia and absolute total/subset lymphocyte counts (rho: <0.13). The highest correlation was observed between TTV viral load and T-cell proliferation capacity (rho: -0.39). We therefore report an inverse correlation between T-cell function and TTV viraemia that is independent of T-cell count. Monitoring of TTV viraemia could be a fast suitable option to objectively assess the competence of immune function in at-risk populations.

HIV-1 Nef plays an essential role in enhancing virion infectivity by antagonizing the host restriction molecule SERINC5. Because Nef is highly polymorphic due to the selective forces of host cellular immunity, we hypothesized that certain immune-escape polymorphisms may impair Nef's ability to antagonize SERINC5 and thereby influence viral fitness in vivo. To test this hypothesis, we identified 58 Nef polymorphisms that were overrepresented in HIV-infected patients in Japan sharing the same HLA genotypes. The number of immune-associated Nef polymorphisms was inversely correlated with the plasma viral load. By breaking down the specific HLA allele-associated mutations, we found that a number of the HLA-B*51:01-associated Y120F and Q125H mutations were most significantly associated with a reduced plasma viral load. A series of biochemical experiments showed that the double mutations Y120F/Q125H, but not either single mutation, impaired Nef's ability to antagonize SERINC5 and was associated with decreasing virion infectivity and viral replication in primary lymphocytes. In contrast, other Nef functions such as CD4, CCR5, CXCR4 and HLA class I downregulation and CD74 upregulation remained unchanged. Taken together, our results suggest that the differential ability of Nef to counteract SERINC5 by naturally occurring immune-associated mutations was associated with the plasma viral load in vivo.

In this study, we aim to assess the association of dengue viremia with dengue severity. The study protocol was developed and registered in PROSPERO (CRD42016039864). We searched nine databases to find potential papers. Studies meeting the inclusion criteria were included. We, based our analysis on three outcomes which are disease severity, dengue serotype and disease infection type. Thirty studies with 3316 patients were included. Our analysis revealed that viremia is significantly higher in dengue hemorrhagic fever patients than dengue fever in days 5 to 6. Regarding the serotype of dengue, the maximum viremia titre of serotype 1 was significantly higher than serotype 3 and the viremia in dengue serotype 2 was significantly higher than serotype 4 in days 2 to 4. However, comparison of the daily viremia level between the primary and secondary dengue infection revealed that secondary infection was significantly higher than the primary infection on seventh day and on the eighth day. Viremia is strongly associated with disease severity and type of infection which gave viremia a high indicative power to be used as a clinical predictor. Dengue serotype is also associated with viral load with higher viremia in DENV-2/1., (© 2020 John Wiley & Sons, Ltd.)

Here we report a single-center cohort of 6 patients (4 kidney only, and 2 simultaneous liver/kidney transplants) diagnosed with COVID-19 at a median of 1.9 years (range = 0.2-9.3 years) post transplant. Five (of 6) patients required inpatient admission, 2 patients (mortality = 33%) died. Among those with mortality, an increased concentration of inflammatory biomarkers (interleukin-6 and C-reactive protein) was noted with a lack of response to interleukin-6 blockade, remdesivir, and/or convalescent plasma. None of the kidney-only transplants (4/6; 67%) had elevation in plasma donor-derived cell-free DNA above the previously published cut-off of 1%, suggesting absence of significant allo-immune injury. Four (of 5) admitted patients had detectable SARS-CoV-2 (severe acute respiratory syndrome-coronavirus 2) in blood on samples obtained at/during hospitalization. Of the 4 discharged patients, 2 patients with undetectable virus on repeat nasopharyngeal swabs had seroconversion with positive SARS-CoV-2 IgG formation at 30 to 48 days post infection. One patient had prolonged shedding of virus on nasopharyngeal swab at 28 days post discharge despite lack of symptoms. In this preliminary report, we find that immunocompromised transplant patients had higher rates of RNAemia (67%) than reported in the general population (15%), seeming absence of allo-immune injury despite systemic inflammation, and formation of IgG overtime after recovery from infection., (Copyright © 2020. Published by Elsevier Inc.)

Background: We aimed to assess the probability and factors associated with the presence of hepatitis C virus (HCV) antibody among HCV seronegative kidney transplant recipients receiving HCV-infected (nucleic acid testing positive) donor kidneys., Methods: This is a retrospective review examining HCV antibody seroconversion of all kidney transplant recipients receiving an organ from an HCV-infected donor between 1 March 2018 and 2 December 2019 at a high-volume kidney transplant center in the southeast United States., Results: Of 97 patients receiving HCV-infected kidneys, the final cohort consisted of 85 recipients with 5 (5.9%) recipients noted to have HCV antibody seroconversion in the setting of HCV viremia. The HCV RNA level at closest time of antibody measurement was higher in the seroconverted patients versus the ones who never converted [median and (interquartile range): 1,091,500 (345,000-8,360,000) vs 71,500 (73-313,000), p  = 0.02]. No other significant differences including type of immunosuppression were noted between the HCV antibody positive group and HCV antibody negative group. Donor donation after cardiac death status [Odds Ratio (OR) and 95% Confidence Interval (CI) was: 8.22 (1.14-59.14)], donor age [OR (95% CI) (+5 years) was: 3.19 (1.39-7.29)] and Kidney Donor Profile Index [OR (95% CI) (+1) was:1.07 (1.01-1.15)] showed a statistically significant association with HCV seroconversion., Conclusions: HCV antibody should not be considered routine screening for presence of infection in previously HCV naïve kidney transplant recipients receiving kidneys from HCV-infected donors, as only a modest percentage have antibody despite active viremia. The assessment of HCV viral load should be routine in all transplant recipients receiving organs from public health service increased risk donors.

The relationship between SARS-CoV-2 viral load and risk of disease progression remains largely undefined in coronavirus disease 2019 (COVID-19). Here, we quantify SARS-CoV-2 viral load from participants with a diverse range of COVID-19 disease severity, including those requiring hospitalization, outpatients with mild disease, and individuals with resolved infection. We detected SARS-CoV-2 plasma RNA in 27% of hospitalized participants, and 13% of outpatients diagnosed with COVID-19. Amongst the participants hospitalized with COVID-19, we report that a higher prevalence of detectable SARS-CoV-2 plasma viral load is associated with worse respiratory disease severity, lower absolute lymphocyte counts, and increased markers of inflammation, including C-reactive protein and IL-6. SARS-CoV-2 viral loads, especially plasma viremia, are associated with increased risk of mortality. Our data show that SARS-CoV-2 viral loads may aid in the risk stratification of patients with COVID-19, and therefore its role in disease pathogenesis should be further explored.

Globally, 1.8 million children are living with HIV-1. While antiretroviral therapy (ART) has improved disease outcomes, it does not eliminate the latent HIV-1 reservoir. Interventions to delay or prevent viral rebound in the absence of ART would be highly beneficial for HIV-1-infected children who now must remain on daily ART throughout their lifespan. Here, we evaluated therapeutic Ad48-SIV prime, MVA-SIV boost immunization in combination with the TLR-7 agonist GS-986 in rhesus macaque (RM) infants orally infected with SIVmac251 at 4 weeks of age and treated with a triple ART regimen beginning 4 weeks after infection. We hypothesized immunization would enhance SIV-specific T cell responses during ART-mediated suppression of viremia. Compared to controls, vaccinated infants had greater magnitude SIV-specific T cell responses (mean of 3475 vs 69 IFN-γ spot forming cells (SFC) per 106 PBMCs, respectively, P = 0.01) with enhanced breadth of epitope recognition and increased CD8+ and CD4+ T cell polyfunctionality (P = 0.004 and P = 0.005, respectively). Additionally, SIV-specific gp120 antibodies against challenge and vaccine virus strains were significantly elevated following MVA boost (P = 0.02 and P < 0.001, respectively). GS-986 led to expected immune stimulation demonstrated by activation of monocytes and T cells 24 hours post-dose. Despite the vaccine-induced immune responses, levels of SIV DNA in peripheral and lymph node CD4+ T cells were not significantly different from controls and a similar time to viral rebound and viral load set point were observed following ART interruption in both groups. We demonstrate infant RMs mount a robust immunological response to this immunization, but vaccination alone was not sufficient to impact viral reservoir size or modulate rebound dynamics following ART release. Our findings hold promise for therapeutic vaccination as a part of a combination cure approach in children and highlight the importance of a pediatric model to evaluate HIV-1 cure interventions in this unique setting of immune development., Competing Interests: RG declares ownership of stocks or shares and paid employement by Gilead Sciences. AC is a spouse of a member of the editorial board of a PLoS journal (Guido Silvestri, Associate Editor PLoS Pathogens).

Background: Globally, the majority of people living with HIV have no or only limited access to HIV drug resistance testing to guide the selection of antiretroviral drugs. This is of particular concern for children and adolescents, who experience high rates of treatment failure. The GIVE MOVE trial assesses the clinical impact and cost-effectiveness of routinely providing genotypic resistance testing (GRT) to children and adolescents living with HIV who have an unsuppressed viral load (VL) while taking antiretroviral therapy (ART)., Methods: GIVE MOVE is an open-label randomised clinical trial enrolling children and adolescents (≥6 months to <19 years) living with HIV with a VL ≥400 copies/mL (c/mL) while taking first-line ART. Recruitment takes place at sites in Lesotho and Tanzania. Participants are randomised in a 1:1 allocation to a control arm receiving the standard of care (3 sessions of enhanced adherence counselling, a follow-up VL test, continuation of the same regimen upon viral resuppression or empiric selection of a new regimen upon sustained elevated viremia) and an intervention arm (GRT to inform onward treatment). The composite primary endpoint is the occurrence of any one or more of the following events during the 36 weeks of follow-up period: i) death due to any cause; ii) HIV- or ART-related hospital admission of ≥24 h duration; iii) new clinical World Health Organisation stage 4 event (excluding lymph node tuberculosis, stunting, oral or genital herpes simplex infection and oesophageal candidiasis); and iv) no documented VL <50 c/mL at 36 weeks follow-up. Secondary and exploratory endpoints assess additional health-related outcomes, and a nested study will assess the cost-effectiveness of the intervention. Enrolment of a total of 276 participants is planned, with an interim analysis scheduled after the first 138 participants have completed follow-up., Discussion: This randomised clinical trial will assess if the availability of resistance testing improves clinical outcomes in children and adolescents with elevated viremia while taking ART., Trial Registration: This trial is registered with ClinicalTrials.gov ( NCT04233242 ; registered 18.01.2020). More information: www.givemove.org .

Among people with perinatal HIV infection (PHIV), non-communicable diseases, such as chronic kidney disease, are increasing. Both HIV replication and antiretroviral therapy are recognised causes of renal impairment. Objective of the study is to describe the impact of viremia copy-years (VCY) and antiretroviral therapy on trend of estimated glomerular filtration rate (eGFR) in a cohort of adults with perinatal HIV infection. We conducted a multicentre observational study in sixty adults living with PHIV across a 9-year period, from January 2010 to December 2018. The mean values of eGFR were analysed at the first (T0) and last year of observation (T1). VCY was defined as the area under HIV-RNA curve during the study period. We analysed data according to antiretroviral therapy: tenofovir disoproxil (TDF), non-nucleoside reverse transcriptase inhibitors (NNRTI), boosted protease inhibitors (PI/b), integrase inhibitors (INI). We observed a mean overall eGFR reduction from 126.6 mL/min (95%CI: 119.6-133.5) to 105.0 mL/min (95%CI: 99.55-110.6) (p<0.001). Older age, higher baseline eGFR, higher VCY and longer exposure to INI treatment were associated with eGFR reduction at univariate analysis. In the multivariate model, older age (p = 0.039), baseline eGFR (p<0.001) and VCY (p = 0.069), were retained. We also observed a longer exposure to PI/b and INI in patients with lower control on HIV-RNA, expressed as VCY>2 log10. Our study outlines a progressive eGFR reduction in young adults with PHIV, related to the lower control on HIV-RNA VCY and related to aging., Competing Interests: NO authors have competing interests.

Zika virus (ZIKV) can establish infection in immune privileged sites such as the testes, eye, and placenta. Whether ZIKV infection of white blood cells is required for dissemination of the virus to immune privileged sites has not been definitively shown. To assess whether initial ZIKV replication in myeloid cell populations is critical for dissemination during acute infection, recombinant ZIKVs were generated that could not replicate in these specific cells. ZIKV was cell restricted by insertion of a complementary sequence to a myeloid-specific microRNA in the 3' untranslated region. Following inoculation of a highly sensitive immunodeficient mouse model, crucial immune parameters, such as quantification of leukocyte cell subsets, cytokine and chemokine secretion, and viremia, were assessed. Decreased neutrophil numbers in the spleen were observed during acute infection with myeloid-restricted ZIKV that precluded the generation of viremia and viral dissemination to peripheral organs. Mice inoculated with a nontarget microRNA control ZIKV demonstrated increased expression of key cytokines and chemokines critical for neutrophil and monocyte recruitment and increased neutrophil influx in the spleen. In addition, ZIKV-infected Ly6C hi monocytes were identified in vivo in the spleen. Mice inoculated with myeloid-restricted ZIKV had a decrease in Ly6C hi ZIKV RNA-positive monocytes and a lack of inflammatory cytokine production compared to mice inoculated with control ZIKV. IMPORTANCE Myeloid cells, including monocytes, play a crucial role in immune responses to pathogens. Monocytes have also been implicated as "Trojan horses" during viral infections, carrying infectious virus particles to immune privileged sites and/or to sites protected by physical blood-tissue barriers, such as the blood-testis barrier and the blood-brain barrier. In this study, we found that myeloid cells are crucial to Zika virus (ZIKV) pathogenesis. By engineering ZIKV clones to encode myeloid-specific microRNA target sequences, viral replication was inhibited in myeloid cells by harnessing the RNA interference pathway. Severely immunodeficient mice inoculated with myeloid-restricted ZIKV did not demonstrate clinical signs of disease and survived infection. Furthermore, viral dissemination to peripheral organs was not observed in these mice. Lastly, we identified Ly6C mid/hi murine monocytes as the major myeloid cell population that disseminates ZIKV.

The "shock-and-kill" human immunodeficiency virus type 1 (HIV-1) cure strategy involves latency reversal followed by immune-mediated clearance of infected cells. We have previously shown that activation of the noncanonical NF-κB pathway using an inhibitor of apoptosis (IAP), AZD5582, reverses HIV/simian immunodeficiency virus (SIV) latency. Here, we combined AZD5582 with bispecific HIVxCD3 DART molecules to determine the impact of this approach on persistence. Rhesus macaques (RMs) ( n  = 13) were infected with simian/human immunodeficiency virus SHIV.C.CH505.375H.dCT, and triple antiretroviral therapy (ART) was initiated after 16 weeks. After 42 weeks of ART, 8 RMs received a cocktail of 3 HIVxCD3 DART molecules having human A32, 7B2, or PGT145 anti-HIV-1 envelope (Env) specificities paired with a human anti-CD3 specificity that is rhesus cross-reactive. The remaining 5 ART-suppressed RMs served as controls. For 10 weeks, a DART molecule cocktail was administered weekly (each molecule at 1 mg/kg of body weight), followed 2 days later by AZD5582 (0.1 mg/kg). DART molecule serum concentrations were well above those considered adequate for redirected killing activity against Env-expressing target cells but began to decline after 3 to 6 weekly doses, coincident with the development of antidrug antibodies (ADAs) against each of the DART molecules. The combination of AZD5582 and the DART molecule cocktail did not increase on-ART viremia or cell-associated SHIV RNA in CD4 + T cells and did not reduce the viral reservoir size in animals on ART. The lack of latency reversal in the model used in this study may be related to low pre-ART viral loads (median, <10 5 copies/ml) and low preintervention reservoir sizes (median, <10 2 SHIV DNA copies/million blood CD4 + T cells). Future studies to assess the efficacy of Env-targeting DART molecules or other clearance agents to reduce viral reservoirs after latency reversal may be more suited to models that better minimize immunogenicity and have a greater viral burden. IMPORTANCE The most significant barrier to an HIV-1 cure is the existence of the latently infected viral reservoir that gives rise to rebound viremia upon cessation of ART. Here, we tested a novel combination approach of latency reversal with AZD5582 and clearance with bispecific HIVxCD3 DART molecules in SHIV.C.CH505-infected, ART-suppressed rhesus macaques. We demonstrate that the DART molecules were not capable of clearing infected cells in vivo , attributed to the lack of quantifiable latency reversal in this model with low levels of persistent SHIV DNA prior to intervention as well as DART molecule immunogenicity., (Copyright © 2020 American Society for Microbiology.)