Adenovirus Research Articles

Epidemiology of Respiratory Viruses in Korean Children Before and After the COVID-19 Pandemic: A Prospective Study From National Surveillance System.

The coronavirus disease 2019 (COVID-19) pandemic led to a decrease in the seasonal incidence of many respiratory viruses worldwide due to the impact of nonpharmaceutical interventions (NPIs). However, as NPI measures were relaxed, respiratory viral infections re-emerged. We aimed to characterize the epidemiology of respiratory viruses in Korean children during post-COVID-19 pandemic years compared to that before the pandemic. A nationwide prospective ongoing surveillance study has been conducted for detection of respiratory viruses between January 2017 and June 2023. We included data on adenovirus (AdV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus (HMPV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV), and respiratory syncytial virus (RSV), which were detected in children and adolescents younger than 20 years. We analyzed the weekly detection frequency of individual viruses and the age distribution of the affected children. The study period was divided into prepandemic (2017-2019) and postpandemic (2021-2023) periods. A total of 19,589 and 14,068 samples were collected in the pre- and postpandemic periods, respectively. The overall detection rate of any virus throughout the study period was 63.1%, with the lowest occurring in the 2nd half of 2020 (50.6%) and the highest occurring in the 2nd half of 2021 (72.3%). Enveloped viruses (HCoV, HMPV, IFV, PIV, and RSV) almost disappeared, but nonenveloped viruses (AdV, HBoV, and HRV) were detected even during the peak of the COVID-19 pandemic. The codetection rate increased from 15.0% prepandemic to 19.1% postpandemic (P < 0.001). During the postpandemic period, a large out-of-season PIV and HMPV epidemic occurred, but the usual seasonality began to be restored in 2023. The mean age of children with each virus detected in 2023 was significantly greater than that in prepandemic years (P = 0.003 and 0.007 for AdV and HCoV, respectively; P < 0.001 for others). The mean age of children with IFV increased in 2022 (11.1 ± 5.2 years) from prepandemic years (7.9 ± 4.6 years) but decreased to 8.7 ± 4.1 years in 2023. With the relaxation of NPI measures, several seasonal respiratory viruses cocirculated with unusual seasonal epidemic patterns and were associated with increasing age of infected children.

Effects of regulator of G protein signaling 2 (RGS2) overexpression in the paraventricular nucleus on blood pressure in rats with angiotensin II-induced hypertension.

The hypothalamic paraventricular nucleus (PVN) regulates sympathetic activity and blood pressure. The regulator of G protein signaling 2 (RGS2) is a negative G protein regulator, which selectively regulates G⍺q signaling, a potential cause of hypertension. This study aimed to examine angiotensin II (ANG II)-G protein-RGS2 signaling on the central mechanisms of blood pressure control, sympathetic activation, and kidney function. The Sprague Dawley rats were infused with ANG II (200ng/kg/min) via osmotic mini pump to induce hypertension. Adenovirus (AV) vectors encoding RGS2 was transfected into the PVN in vivo. By radio telemetry measurements, we found AV-RGS2 transfection to the PVN significantly attenuated the increase of mean arterial pressure in ANG II infusion rats from days 2-7 of the 2-week experiment (Day 7: ANG II + AV-RGS2 141.3 ± 10.0mmHg vs. ANG II 166.9 ± 9.3mmHg, p < 0.05). AV-RGS2 transfection significantly reduced the serum norepinephrine level and acute volume reflex and increased daily urine volume and sodium excretion in ANG II-infused hypertensive rats. AV-RGS2 transfection significantly reduced G⍺q and PKC protein expressions within the PVN in ANG II infusion rats. In cultured mouse hypothalamic cells, real-time PCR study showed ANG II treatment increased mRNA expression of G⍺q, G⍺s, and RGS2, and AV-RGS2 treatment decreased ANG II-induced mRNA expression of G⍺q and G⍺s. Using confocal imagery, we found that AV-RGS2 attenuated the increase of calcium influx in ANG II-treated cells. Our results suggest that central overexpression of RGS2 in the PVN attenuated the increase of blood pressure and sympathetic outflow, and improves kidney excretory function in hypertensive rats. This may be via the alteration of ANG II-G-protein-RGS2 signaling in the central nervous system.

Use of Capsid Integrity-qPCR for Detecting Viral Capsid Integrity in Wastewater.

Quantifying viruses in wastewater via RT-qPCR provides total genomic data but does not indicate the virus capsid integrity or the potential risk for human infection. Assessing virus capsid integrity in sewage is important for wastewater-based surveillance, since discharged effluent may pose a public health hazard. While integrity assays using cell cultures can provide this information, they require specialised laboratories and expertise. One solution to overcome this limitation is the use of photo-reactive monoazide dyes (e.g., propidium monoazide [PMAxx]) in a capsid integrity-RT-qPCR assay (ci-RT-qPCR). In this study, we tested the efficiency of PMAxx dye at 50 μM and 100 μM concentrations on live and heat-inactivated model viruses commonly detected in wastewater, including adenovirus (AdV), hepatitis A (HAV), influenza A virus (IAV), and norovirus GI (NoV GI). The 100 μM PMAxx dye concentration effectively differentiated live from heat-inactivated viruses for all targets in buffer solution. This method was then applied to wastewater samples (n = 19) for the detection of encapsulated AdV, enterovirus (EV), HAV, IAV, influenza B virus (IBV), NoV GI, NoV GII, and SARS-CoV-2. Samples were negative for AdV, HAV, IAV, and IBV but positive for EV, NoV GI, NoV GII, and SARS-CoV-2. In the PMAxx-treated samples, EV, NoV GI, and NoV GII showed -0.52-1.15, 0.9-1.51, and 0.31-1.69 log reductions in capsid integrity, indicating a high degree of potentially infectious virus in wastewater. In contrast, SARS-CoV-2 was only detected using RT-qPCR but not after PMAxx treatment, indicating the absence of encapsulated and potentially infectious virus. In conclusion, this study demonstrates the utility of PMAxx dyes to evaluate capsid integrity across a diverse range of viruses commonly monitored in wastewater.

Assessment of the cytolytic potential of a multivirus-targeted T cell therapy using a vital dye-based, flow cytometric assay.

Reliable and sensitive characterization assays are important determinants of the successful clinical translation of immunotherapies. For the assessment of cytolytic potential, the chromium 51 (51Cr) release assay has long been considered the gold standard for testing effector cells. However, attaining the approvals to access and use radioactive isotopes is becoming increasingly complex, while technical aspects [i.e. sensitivity, short (4-6 hours) assay duration] may lead to suboptimal performance. This has been the case with our ex vivo expanded, polyclonal (CD4+ and CD8+) multivirus-specific T cell (multiVST) lines, which recognize 5 difficult-to-treat viruses [Adenovirus (AdV), BK virus (BKV), cytomegalovirus (CMV), Epstein Barr virus (EBV), and human herpes virus 6 (HHV6)] and when administered to allogeneic hematopoietic stem cell (HCT) or solid organ transplant (SOT) recipients have been associated with clinical benefit. However, despite mediating potent antiviral effects in vivo, capturing in vitro cytotoxic potential has proven difficult in a traditional 51Cr release assay. Now, in addition to cytotoxicity surrogates, including CD107a and Granzyme B, we report on an alternative, vital dye -based, flow cytometric platform in which superior sensitivity and prolonged effector:target co-culture duration enabled the reliable detection of both CD4- and CD8-mediated in vitro cytolytic activity against viral targets without non-specific effects.

An Integrated ddPCR Lab-on-a-Disc Device for Rapid Screening of Infectious Diseases.

Digital droplet PCR (ddPCR) is a powerful amplification technique for absolute quantification of viral nucleic acids. Although commercial ddPCR devices are effective in the lab bench tests, they cannot meet current urgent requirements for on-site and rapid screening for patients. Here, we have developed a portable and fully integrated lab-on-a-disc (LOAD) device for quantitively screening infectious disease agents. Our designed LOAD device has integrated (i) microfluidics chips, (ii) a transparent circulating oil-based heat exchanger, and (iii) an on-disc transmitted-light fluorescent imaging system into one compact and portable box. Thus, droplet generation, PCR thermocycling, and analysis can be achieved in a single LOAD device. This feature is a significant attribute for the current clinical application of disease screening. For this custom-built ddPCR setup, we have first demonstrated the loading and ddPCR amplification ability by using influenza A virus-specific DNA fragments with different concentrations (diluted from the original concentration to 107 times), followed by analyzing the droplets with an external fluorescence microscope as a standard calibration test. The measured DNA concentration is linearly related to the gradient-dilution factor, which validated the precise quantification for the samples. In addition to the calibration tests using DNA fragments, we also employed this ddPCR-LOAD device for clinical samples with different viruses. Infectious samples containing five different viruses, including influenza A virus (IAV), respiratory syncytial virus (RSV), varicella zoster virus (VZV), Zika virus (ZIKV), and adenovirus (ADV), were injected into the device, followed by analyzing the droplets with an external fluorescence microscope with the lowest detected concentration of 20.24 copies/µL. Finally, we demonstrated the proof-of-concept detection of clinical samples of IAV using the on-disc fluorescence imaging system in our fully integrated device, which proves the capability of this device in clinical sample detection. We anticipate that this integrated ddPCR-LOAD device will become a flexible tool for on-site disease detection.

Preliminary Results of a Phase 2a Clinical Trial to Evaluate Safety, Tolerability and Antiviral Activity of Intravenous Brincidofovir (BCV IV) in Immunocompromised Patients with Adenovirus Infection

Background: Adenovirus (AdV) may cause life threatening or fatal infections in immunosuppressed patients including recipients of allogeneic hematopoietic cell transplant (allo-HCT). Brincidofovir (BCV) is a lipid conjugate of cidofovir, that crosses target cell membranes by means of facilitated and passive diffusion and has a long intracellular half-life. The safety, tolerability and antiviral activity of intravenous BCV (BCV IV) were evaluated in a dose ascending Phase 2a study (BCV-PA01: ATHENA study, NCT04706923) in sequential cohorts. Methods: Eligible patients aged 2 months or older who were immunocompromised due to allo-HCT, organ transplant, immunosuppressive medications, or congenital immunodeficiency, and had AdV viremia or disseminated AdV disease were included. AdV viremia was defined as 1) AdV viral load in the blood &amp;gt; 10,000 copies/mL OR 2) two samples greater than 48 hours apart with the second result higher than the first and both greater than 1000 copies/mL, within 7 days prior to initiation of BCV IV treatment. BCV IV was administered intravenously twice weekly for 4 weeks or until resolution of AdV viremia up to 14 weeks, whichever occurred later. The dose escalation was as follows: 0.2 mg/kg (Cohort 1), 0.3 mg/kg (Cohort 2), or 0.4 mg/kg (Cohort 3) for patients weighing &amp;lt; 50 kg and 10 mg/dose, 15 mg/dose, or 20 mg/dose, respectively for patients weighing ≥ 50 kg. The patients were subsequently followed up for 30 days after the last BCV IV dosing. AdV viral loads in blood were monitored weekly by quantitative real-time polymerase chain reaction tests (lower limit of detection (LOD) 25 copies/mL, lower limit of quantification 190 copies/mL, upper limit of quantification 1 x 10 9 copies/mL). Viral clearance was defined as two consecutive plasma viral load test results below the LOD. Results: Of 27 patients treated with BCV IV, 8 were in Cohort 1, 9 in Cohort 2 and 10 in Cohort 3. Baseline characteristics of patients are shown in Table 1. Treatment-related adverse events (TRAE) were observed in 7 patients, as shown in Table 2. No serious TRAEs including gastrointestinal and hepatic toxicities were observed. All TRAEs were reversible and resolved after the completion of the treatment. AE-related discontinuations of treatment were observed in 3 of 8 patients in Cohort 1; 2 of 9 patients in Cohort 2; and 1 of 10 patients in Cohort 3 (Table 2). The reason for discontinuation of treatment beyond 4 weeks of treatment in Cohort 3 was successful clearance of AdV viremia. Antiviral activity was dose-dependent, and viral clearance was achieved in 25% (2/8) in Cohort 1; 56 % (5/9) in Cohort 2; and 100% (10/10) in Cohort 3. The duration of treatment with BCV IV and viral responses are summarized in Table 2. In Cohort 3, it is notable that 90 % of patients achieved AdV viremia clearance in ≤ 4 weeks of treatment with BCV IV. In Cohorts 2 and 3, all patients who achieved AdV viremia clearance maintained undetectable AdV in the blood through the follow-up period. Conclusions: BCV IV was found to be safe and well tolerated in immunocompromised patients. Notably, the potentially serious gastrointestinal and hepatic toxicities described with the oral BCV formulation were not observed. BCV IV was highly effective in a dose-dependent manner, led to rapid clearance of AdV viremia within a short treatment period and provided sustained virologic response. In view of promising results and in the absence of any other approved treatments for AdV infection, our results support the need for further exploration and additional clinical trials of BCV IV as a treatment for AdV infection.

Memory T Cell Donor Lymphocyte Infusion As a Treatment for Viral Reactivations after Pediatric Haploidentical Hematopoietic Stem Cell Transplant

Introduction Viral reactivations, including cytomegalovirus (CMV), Epstein-Barr virus (EBV), adenovirus (ADV), human herpesvirus 6 (HHV6), and BK virus (BKV), constitute significant infectious complications following pediatric hematopoietic stem cell transplant (HSCT). abT cell depletion of haploidentical graft prevents risk of graft-versus-host disease (GVHD) but leads to delayed immune recovery and increased risk of viral reactivations. Donor lymphocyte infusion (DLI) with CD45RA-depleted memory T cells has been reported as an effective method to rapidly recover T cell immunity post HSCT. We hereby report the experience of CD45RA-depleted memory T cell infusion to treat viral reactivation following pediatric abT cell depleted haploidentical HSCT in our center over the last three years. Methods We retrospectively reviewed pediatric patients with abT cell depleted haploidentical transplant from related donors in our center from 2021-2023, and those who received memory T cell DLI for one or more viral reactivations. We routinely infuse CD45RA depleted memory T cells (dose at 1x10 6 CD3 T cells/kg) on the day of stem cell infusion prophylactically. Surplus of memory T cells harvested was cryopreserved for future use. Viral reactivations were monitored regularly after transplant by blood PCR assays (twice weekly for CMV; once weekly for EBV, ADV, and HHV-6). BK virus of urine and blood were monitored if patients became symptomatic for hemorrhagic cystitis. Once virus reactivation is identified, we start antiviral medications and infuse cryopreserved donor memory T cells for treatment. If subsequent virus PCR tests remain positive, donor memory T cells are infused every 1-2 weeks until the test is negative. Results A total of 52 memory T cell infusions were administered to 22 patients for viral reactivation after HSCT. Half of the patients (n=11) required only one infusion for viral clearance, whereas the other half received memory T cell infusion for 2-9 times. 19 patients (86.4%) are alive at time of data collection and analysis (July 2023), and 18 patients (81.8%) are in complete remission. The characteristics of patients and transplants are summarized in Table 1. The viral reactivations, which are intended to treat, include CMV (57.7%), EBV (7.7%), ADV (23.1%), BKV (15.4%) and HHV6 (9.6%), and some patients suffered from multiple viral reactivations at the time of memory T cell infusion (so the total percentage is more than 100%). The median day of memory T cell infusion post-transplant was day 46 (range 4-183). The median and most commonly used cell dose was 2 (0.025 - 20.5) x 10 6/kg CD3+ memory T cells (CD45RA depleted). The median duration to achieve negative PCR test for each virus are 13 days (CMV), 24 days (EBV),72 days (ADV), 15 days (HHV-6) and 88 days (BKV) (Figure 1). Thus most of the patients were CMV PCR negative within 15 days after DLI. All DLI were well tolerated. One patient (4.5%) was reported to suffer from stage 2 skin GVHD post donor memory T cell infusion. Conclusions CD45RA-depleted donor memory T cell infusion is a safe, feasible and effective treatment for viral reactivation following pediatric haploidentical stem cell transplant.

2652. Detection of respiratory viruses by air sampling and student and staff surveillance testing in two elementary schools

Abstract Background The COVID-19 pandemic highlighted the need for better data to understand how ventilation may impact respiratory virus transmission. We evaluated if there was an association between respiratory viruses detected in school room air samples and nasal swabs from students/ staff in the same room. Methods We performed air and respiratory sampling to detect respiratory viruses at 3 time points between Feb 27 - Mar 28, 2023 in 2 elementary schools. Three classrooms, a multipurpose room, and school nurse’s office in each school had 1 air sample/ room collected using Thermo Scientific AerosolSense™ sampler during 8 school hours. Concomitant respiratory viral testing, using self-collected nasal swabs, was performed in students/ staff enrolled in a respiratory virus surveillance school testing program. Air and respiratory specimens were tested for adenovirus (AdV); coronaviruses (CoV) 229E, HKU1, NL63, OC43; human metapneumovirus (hMPV), influenza A and B (Flu), parainfluenza virus 1-4 (PIV), respiratory syncytial virus (RSV), rhinovirus/ enterovirus (RV/EV), and SARS-CoV-2 using the Hologic® Panther Fusion® Respiratory Assay. Detected respiratory viruses in room air and respiratory samples were compared to determine likelihood of capturing current human respiratory viral infections in room air and additional viruses circulating from unsampled students/ staff in the same room. RV and AdV in human respiratory samples were typed by partial genomic sequencing to understand if viruses were similar. Results Ten rooms, including 6 classrooms with ≈25 people/ room, were sampled at 3 occasions. At least 1 respiratory virus was detected in 27/ 30 (90%) air samples. 59 samples were obtained from 20 students and 5 staff in these rooms; 24 (41%) were positive for ≥1 virus and 11/24 (46%) rooms with concomitant air and respiratory samples had the same viruses detected (Table). RV typing demonstrates that both participants from Room E, Round 1 and 2 had RV-B27. Both participants from Room F, Round 2 with single AdV infections had AdV B3.Table.Concomitant respiratory virus detection from student and staff nasal swabs and air samplers (N=student/staff tested per room) Conclusion Concomitant respiratory virus surveillance in air samples and students/ staff can be performed to better understand the role of ventilation and respiratory virus transmission. Additional studies, including sequencing data and symptom assessment, are needed. Disclosures Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Honoraria|Altona Diagnostics: Grant/Research Support|Baebies Inc: Advisor/Consultant|BioMerieux: Advisor/Consultant|BioMerieux: Grant/Research Support|Bio-Rad: Grant/Research Support|Cepheid: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Lab Simply: Advisor/Consultant|Luminex: Grant/Research Support

Safety of Cidofovir Treatment for Suspected or Confirmed Adenovirus Infection in Immunocompetent Pediatric Population.

Cidofovir (CDV), a nucleoside phosphonate analogue, exhibits activity against severe cytomegalovirus and adenoviral (ADV) infection. Nevertheless, reports of elevated nephrotoxicity rates limited its use to highly vulnerable cases, mainly immunocompromised children with fulminant infection. Limited data exists regarding CDV safety in immunocompetent children. To evaluate CDV-related toxicity, mainly nephrotoxicity, in immunocompetent children with severe ADV/cytomegalovirus infection. We conducted a retrospective review of medical records for all immunocompetent children under 18 years of age treated with intravenous CDV from January 2005 to December 2019. Among the 23 patients identified, 21 were diagnosed with severe ADV infection. Median age was 15 months. Twenty-one (91%) children were admitted to the pediatric intensive care unit. Eighteen patients (78%) received standard CDV protocol (5 mg/kg CDV weekly for 2 weeks), 4 (17%) according to nephroprotective low-dose protocol and 1 patient transitioned. The median duration of CDV treatment was 14 days (range: 1-21 days). All patients received hyperhydration and probenecid with each infusion. Acute kidney injury was recorded in 1 patient (with concurrent septic shock) during CDV treatment. Two children exhibited acute kidney injury before CDV initiation, but renal function normalized during CDV treatment. One patient developed transient neutropenia (600 cells/L), apparently as a result of sepsis. No other major adverse effects were noted. Mortality rate was 3/23 (13%), unrelated to CDV toxicity. Our findings suggest that CDV-related nephrotoxicity rate in immunocompetent children may be lower than previously reported, perhaps lower than in the severely immunocompromised population.

2653. Duration of Respiratory Virus Detection by Multipathogen PCR Testing after Acute Respiratory Illness

Abstract Background Persons with respiratory viral infections (RVI) may shed detectable virus after symptom recovery. Duration of detection by molecular methods is not well described for non-SARS-CoV-2 respiratory viruses. Methods School KIDS is a prospective respiratory viral surveillance program in a Missouri school district. Participating students and staff with RVI symptoms can receive respiratory viral testing using self-collected nasal swabs. Symptomatic participants with detectable virus(es) on primary swabs were scheduled to receive 2 convalescent swabs weekly after initial test during weekly school surveillance testing. All convalescent tests performed within 21 days of the primary specimen were included. Only participants providing ≥ 1 convalescent swab were included. Specimens were tested using Hologic® Panther Fusion® or QIAstat-Dx PCR assays that included adenovirus (AdV); seasonal coronaviruses (sCoV) 229E, HKU1, NL63, OC43; human metapneumovirus, influenza A and B (Flu), parainfluenza viruses 1-4, respiratory syncytial virus, rhinovirus/ enterovirus (RV/EV), and SARS-CoV-2. We used survival analysis to quantify median number of days until individuals tested negative for each virus. Results From November 3, 2022 – April 14, 2023, 344 symptomatic participants (141 preK/elem, 49 middle, 22 high, 132 staff) submitted 586 primary specimens; 292 (50%) were positive for a virus. For positive primary specimens, median [IQR] time of symptom onset to specimen collection was 2 [1,3] days. A total of 320 viruses were detected; most common were RV/EV (37%) and sCoVs (25%) (Table). An additional 370 convalescent specimens were collected (87 specimens on days 1-7 following primary positive; 166 specimens on days 8-14; and 117 specimens on days 15-21). Median number of days [95% confidence interval] when repeat convalescent tests became negative varied by virus (AdV 15 [11,undefined] days, Flu A 14 [9,19] days, RV/EV 12 [11,14] days, SARS-CoV-2 14 [14,17] days, sCoV 10 [9,12] days) (Figure).Table.Characteristics of primary positive and convalescent testing (i.e. ongoing positivity) of nasal swabs from preK—12 grade students and staff with respiratory symptoms—Missouri, November 2022 -April 2023Figure.Cumulative probability of testing negative for a respiratory virus on subsequent respiratory viral testing Conclusion Students and staff continued to have detectable virus by nasal swabs 10-15 days after symptomatic positive specimen. Further data are needed to determine when participants are no longer infectious. Disclosures Rangaraj Selvarangan, BVSc, PhD, D(ABMM), FIDSA, FAAM, Abbott: Honoraria|Altona Diagnostics: Grant/Research Support|Baebies Inc: Advisor/Consultant|BioMerieux: Advisor/Consultant|BioMerieux: Grant/Research Support|Bio-Rad: Grant/Research Support|Cepheid: Grant/Research Support|GSK: Advisor/Consultant|Hologic: Grant/Research Support|Lab Simply: Advisor/Consultant|Luminex: Grant/Research Support

Positive and negative viral associations in patients with acute respiratory tract infections in primary care: the ECOVIR study.

Acute respiratory infections (ARIs) are the most common viral infections encountered in primary care settings. The identification of causal viruses is still not available in routine practice. Although new strategies of prevention are being identified, knowledge of the relationships between respiratory viruses remains limited. ECOVIR was a multicentric prospective study in primary care, which took place during two pre-pandemic seasons (2018-2019 and 2019-2020). Patients presenting to their General practitioner (GP) with ARIs were included, without selecting for age or clinical conditions. Viruses were detected on nasal swab samples using a multiplex Polymerase Chain Reaction test focused on 17 viruses [Respiratory Syncytial Virus-A (RSV-A), RSV-B, Rhinovirus/Enterovirus (HRV), human Metapneumovirus (hMPV), Adenovirus (ADV), Coronaviruses (CoV) HKU1, NL63, 229E, OC43, Influenza virus (H1 and H3 subtypes), Influenza virus B, Para-Influenza viruses (PIVs) 1-4, and Bocavirus (BoV)]. Among the 668 analyzed samples, 66% were positive for at least one virus, of which 7.9% were viral codetections. The viral detection was negatively associated with the age of patients. BoV, ADV, and HRV occurred more significantly in younger patients than the other viruses (p < 0.05). Codetections were significantly associated with RSV, HRV, BoV, hMPV, and ADV and not associated with influenza viruses, CoV, and PIVs. HRV and influenza viruses were negatively associated with all the viruses. Conversely, a positive association was found between ADV and BoV and between PIVs and BoV. Our study provides additional information on the relationships between respiratory viruses, which remains limited in primary care.

Infection Burden and Timing in the First Year After Pediatric Allogeneic Hematopoietic Cell Transplantation: A Single-Center Experience

Abstract Background Infection is a leading cause of morbidity and non-relapsed mortality (NRM) after allogeneic hematopoietic cell transplant (allo-HCT). This study aimed to describe the contemporary epidemiology of infections, overall survival (OS) as well as NRM at 1 year post pediatric allo-HCT. Methods Retrospective review of laboratory-confirmed infections among patients who underwent first allo-HCT from January 2014 to December 2020 at a single, quaternary pediatric hospital. Cytomegalovirus (CMV), Adenovirus (AdV), Epstein-Barr virus (EBV) and Human Herpes Virus-6 (HHV-6) weekly viral surveillance was performed on blood using polymerase chain reaction until day +100. We reviewed Clostridioides difficile, bacterial blood stream infections (BSIs), and fungemia until 1 year post allo-HCT or death. Results During the six-year study period, 146 subjects underwent allo-HCT at a median age of 8.75 years (IQR 2.6-14.28), predominantly males (58%) with hematologic malignancies (60%), and bone marrow as stem cell source (71%). Matched unrelated donors were used in 53% after myeloablative conditioning in 62%. A total of 126 patients (86%) experienced at least one infection, primarily with DNA viral infections (n=113, 77%). EBV DNAemia occurred in 50%, CMV in 30%, HHV-6 in 23%, and AdV in 17%. The time to first DNAemia detection post HCT was 15 days for CMV (IQR 6-28.5), 20 days for AdV (IQR 6-89), 22 days for HHV-6 (IQR 17-31), and 55 days for EBV (IQR 41-92.5). Bacterial BSIs were identified in 37% (54/146) of patients at a median of 12.5 days post-HCT (IQR 5-146.3), 80% (43/54) experienced a single episode, while 20% (11/54) had multiple episodes, resulting in 68 BSIs total. Among all BSIs, 38% (26/68) were classified as mucosal barrier injury laboratory confirmed bloodstream infections, while 59% (40/68) as central line associated BSIs. In total, 89 pathogens were identified. Gram-negative pathogens (GN) were predominant in 56% (50/89) of the isolates, with lactose fermenters representing 72% (36/50). Gram-positive pathogens (GP) accounted for 44% (39/89), primarily Staphylococcus species (36%, 14/39, predominantly Staphylococcus aureus in 10 cases) and Viridans Group Streptococcus (31%, 12/39). Clostridioides difficile was detected by PCR in 19% (27/146), with a median onset of 54 days post-HCT (IQR 19-125). Fungemia occurred on 3% (4/146) at a median of 150 days post-HCT (IQR 40.23 - 226.8), 3 had candidemia and 1 had fusariosis. The overall mortality rate at 1 year was 15% (22/146), with a median time from transplant to death of 188 days (IQR 44-233.5) and documented active infection at the time of death in 41% (9/22). Only the presence of fungemia showed a significantly difference in OS (25% vs 87%, p &amp;lt; 0.0001) and NRM (50% vs 5.6%, p &amp;lt; 0.001) Conclusions Infections occurred frequently in our cohort affecting 86% (126/146), most commonly as viral DNAemia [77% (113/146)] with EBV &amp;gt; CMV &amp;gt; HHV-6 &amp;gt; AdV, followed by bacterial BSI [37% (54/146)] with GN (56%) vs GP (44%). Despite CLABSI prevention efforts, CLABSI occurred 40 (59%) of total bacterial BSI episodes. Despite the higher frequency of bacterial and viral infections, only fungemia was significantly associated with decreased OS and higher NRM.

Opportunistic Infections in Patients Receiving Post-Transplantation Cyclophosphamide: Impact of Haploidentical versus Unrelated Donor Allograft

Post-transplant cyclophosphamide (PTCy) is an effective strategy for graft-versus-host disease (GVHD) prophylaxis and is the standard of care for haploidentical hematopoietic cell transplantation (HCT). It is increasingly used for matched and mismatched unrelated donor (MUD/MMUD) HCT, but infections remain a concern. The objective of this study was to evaluate the characteristics and risk factors for infections in haploidentical and unrelated donor HCT recipients treated with PTCy-based GVHD prophylaxis. This single-center retrospective study examined 354 consecutive adults undergoing HCT with PTCy-based GVHD prophylaxis (161 MUD/MMUD; 193 haploidentical) between 2015 and 2022. Opportunistic infections (OIs) including cytomegalovirus (CMV), adenovirus (AdV), Epstein-Barr virus (EBV), and invasive fungal disease (IFD) were assessed from day 0 through day +365. The one-year cumulative incidence function of OIs and non-relapse mortality were calculated using dates of relapse and repeat HCT as competing risks. Secondary analysis evaluated risk factors for OIs and NRM using univariate and multivariable Cox regression models. Haploidentical HCT recipients had an increased risk of OIs compared to unrelated donor allograft recipients (39% haploidentical vs. 25% MUD/MMUD; HR 1.70; 95% CI 1.16 - 2.49; p=0.006). On multivariable analysis, haploidentical donor (HR 1.50; 95% CI 1.01 - 2.23; p=0.046), prior HCT (HR 1.99; 95% CI 1.29 - 3.09; p=0.002), and diagnosis of acute GVHD (HR 1.47; 95% CI 1.02 - 2.14; p=0.041) were associated with an increased risk of OIs. Non-relapse mortality within the first year was not significantly different between the two groups (HR 1.11; 95% CI 0.64 - 1.93; p=0.70). Overall, haploidentical donor was a significant risk factor for OIs in patients receiving PTCy, although one-year NRM was not different between haploidentical and MUD/MMUD HCT recipients. CMV and adenovirus infections were significantly increased amongst haploidentical HCT recipients, while the incidence of EBV infection and IFD was similar between the groups. Our findings may have implications for infection monitoring and prophylaxis in the setting of PTCy, particularly in haploidentical HCT recipients.

The risk factors involved in airway mucus plug in children with ADV Pneumonia

BackgroundThe risk factors for mucus plug in children with adenovirus (ADV) pneumonia.Methods and materialsA retrospective analysis was conducted of children diagnosed ADV pneumonia and underwent fiberoptic bronchoscopy admitted to the Xiamen Children's Hospital from September 2018 to September 2021.The patients were divided into a mucus plug group (39 cases) and a non-mucus plug group (53 cases). The children's data including sex, age, clinical presentation, laboratory test parameters, imaging and bronchoscopic data were collected. The risk factors for the development of airway mucus plug were analysed by multifactorial logistic regression.ResultsThere were no statistically significant differences in sex, age, fever, hospitalization days, mixed infection, white blood cells (WBC) count, percentage of neutrophils (NE%), C-reactive protein(CRP), and D-dimer (all P > 0.05); Thermal range, procalcitonin (PCT), lactate dehydrogenase (LDH), Pleural effusion and associated decreased breath sounds was significantly higher in mucus plug group than in non-mucus plug group, and the differences were statistically significant (all P < 0.05); multifactorial logistic regression analysis showed that the duration of fever, PCT, and LDH were independent risk factors for the formation of mucus plugs. The critical values of ROC curves were pyroprocedure ≥ 6.5 d, PCT ≥ 0.705 ng/ml and LDH ≥ 478.5 U/L.ConclusionDuration of fever, PCT and LDH levels were the independent risk factors for the formation of an airway mucus plug in children with ADV pneumonia.

Treatment of Refractory Adenovirus (ADV) Infections Using Adv-Specific Cytotoxic T-Lymphocytes (CTLs) in Children, Adolescents and Young Adults (CAYA) Post Allogeneic Hematopoietic Stem Cell Transplantation (AlloHSCT), Solid Organ Transplantation (SOT), or with Primary Immunodeficiency (PID)

Background: AlloHSCT induces long-term, cure in CAYA with malignant and non-malignant disorders, including those with primary immunodeficiencies (PID). However, post-transplant complications secondary to immunosuppression and slow or delayed immune reconstitution remains a cause of morbidity and mortality amongst AlloHSCT recipients (Satwani/Cairo, BBMT, 2009). Major complications include refractory viral infections, most importantly adenovirus (ADV), which is secondary to absent or decreased adenovirus specific T-cell immunity which occurs due to delayed immune reconstitution and/or continued immunosuppression (George/Cairo, BJH, 2012). The use of virus-specific (vs) CTLs in immunocompromised patients offer an opportunity to restore temporary virus specific immunity. From the Viral Cytotoxic T-Lymphocyte Consortium (VIRCTLC), we present safety and efficacy results on immune compromised, AlloHSCT, or SOT patients treated with familial ADV specific CTLs. Objective: Determine the safety and efficacy of familial ADV specific CTLs for the treatment of refractory systemic ADV infections. Design/Methods: Patient were deemed eligible if they had a history of AlloHSCT, SOT, or PID and had evidence of ADV infections refractory to anti-viral agents. Refractory ADV infection was defined by increasing serum RT-PCR DNA (by 1 log) after 7 days or persistent quantitative RT-PCR DNA copies after 14 days of appropriate anti-viral therapy, and/or known resistance/intolerance to anti-viral agents. Related donors were required to be matched ≥3 HLA (A, B, or DRB1) loci and have an adequate T-cell response to viral specific MACS ADV PepTivators®. We chose a direct selection method to facilitate more rapid generation of cellular products in a point of care setting (and with 14 hrs eligibility determination). Peripheral blood mononuclear cells were collected from eligible family donors using non-mobilized apheresis. vsCTLs were isolated using the CliniMACS ® Prodigy following stimulation with viral specific MACS® GMP PepTivator® AdV5 Hexon, generously provided by Miltenyi Biotec®. ADV specific CTLs were enriched using a Cytokine Capture System (CCS). CD4+ and CD8+ vsCTLs were quantified by flow cytometry (Feuchtinger et al, Blood, 2010). The target cell dose was 0.5x10 4 CD3+ cells/kg (recipient weight) for haploidentical related donors and 2.5x10 4 CD3+ cells/kg for matched related donors. Repeated doses were permitted every 2 weeks to a maximum of doses in the absence of a complete response (CR) and adverse events. The following were used to define response: CR - undetected ADV PCR, partial response (PR) - at least one log decrease from baseline, progressive disease (PD) - at least one log increase from baseline, and patients with stable disease. Results: Fifteen patients were enrolled: 10 females and 5 males; aged 1-19 years. All patients were post-AlloHSCT. All vsCTL donors were haploidentical: 8 were the original HSCT donors and 7 were third party donors (5 maternal, 2 paternal). The mean number of ADV CTL infusions was 3.7 (range: 1-16). One patient with underlying aplastic anemia had progressive disease complicated by increased adenoviral load despite 5 infusions of vsCTLs. Patient received FDA approval for additional CTLs, totaling 16 doses. Thirteen patients achieved CR as defined and 2 achieved PR. The overall response (OR) was 100% and the CR was 88%. The average time to OR was 33 days (range 6-112 days) and time to CR was 34 days (range 6-112 days). Day 100 and 365 overall survival (OS) post-HSCT was 86.1% (CI95: 49.4-95.7) and 70.5% (CI95: 38.9-87.8), respectively (Figure 1). For patients who achieved CR, the Day 100 OS post AlloHSCT was 83.9% (CI95: 55.0-94.3) and Day 365 post AlloHSCT was 74.6% (CI95: 39.8-91.1). Day 100 and 365 probability of ADV related mortality was 0% (Figure 2). One patient developed acute grade 2 skin GVHD possibly related to infusion, which resolved. Conclusion: Our preliminary data demonstrate that haploidentical ADV specific CTLs manufactured by direct selections using the CCS with the CliniMACS® Prodigy and ADV specific peptivators are safe, well-tolerated, and efficacious in patients with refractory/persistent ADV infections after AlloHSCT. Manufacturing is rapid, reproducible, and effective. Accrual is ongoing. This research is supported by FDA RO1006301A1.

Role of Polyomavirus BK and Adenovirus in the Development of Urinary Tract Complications in Pediatric Hematopoietic Stem Cell Transplantation

One of the major challenges in pediatric hematopoietic stem cell transplantation (HSCT) is the susceptibility to viral infections and reactivations that can lead to potentially life-threatening complications and increase the transplant-related mortality (TRM). Polyomavirus BK (BKPyV) and Adenovirus (AdV) represent the predominant causes of urinary tract complications, in particular hemorrhagic cystitis (HC), in HSCT recipients. Treatment options for BKPyV and AdV infections are limited and there is no accepted standard of care for the prevention and treatment of these HSCT complications. The aim of our retrospective study was to analyze the incidence of BKPyV and AdV infection in urinary and plasma samples of pediatric patients undergoing HSCT for both malignant and non-malignant disease at a single pediatric Hematology-Oncology unit. Endpoints were the cumulative incidence of infection, measured on blood and urine samples, in the first 100 days after HSCT, prevalence of asymptomatic and symptomatic infection, and correlation between BKPyV and AdV DNAemia and DNAuria and the development of HC. A total of 79 patients were analyzed. Thirty-seven (47%) patients were positive for BKPyV on urine samples and 20 (30%) on blood samples within the first 30 days after transplantation. As for AdV, 11 (9%) patients were positive on urine samples and 18 (15%) on blood samples. In our pediatric cohort, BKPyV DNAuria was a frequent event after HSCT, while BKPyV DNAemia was observed less frequently, and was accompanied by higher viruria values (p-value &amp;lt;0,001, with a median viral load in the urine of 3.8 x 10 9 copies/mL). Conversely, AdV positivity in urine is rare, while AdV DNAemia was more frequent, due to the modality of BKPyV and AdV distribution (urothelium is the main reservoir for BKPyV, while intestinal lymphocytes represents the main reservoir for AdV). Of the 37 patients with BKPyV DNA on urine samples, 11 (30%) developed a symptomatic infection with grade II (5 patients, 40%) and grade III (6 patients, 60%) HC. We did not observe any correlation between BKPyV DNA urinary levels and the development of HC, as higher viral loads have not been shown to be good predictors of occurrence or severity of HC. Cumulative incidence (CI) of BKPyV infection was higher in haploidentical HSCT (51%) and matched unrelated donors (MUD) (48%) than in HSCT from matched familiar donors (31%). Similarly, CI of AdV reactivation was higher in haploidentical HSCT (16%) than MUD (6%) and matched familiar donors (9%). Choice of donor, the type of immunosuppression used and the intensity of conditioning regimen represented predictors of both blood and urine DNA positivity for both viruses. In our cohort, positivity for BKPyV on blood and/or urine did not increase the risk of transplant-related mortality and did not affect the overall survival after HSCT. On the basis of our data, we now perform screening of BKPyV viruria only in symptomatic patients or in transplant recipients with specific risk factors (type of donor, severity of immunosuppression). Similarly, search for BKPyV DNAemia is reserved to subjects with a high viral load on urine. Likewise, search for AdV on urine samples is performed on symptomatic patients with high-load AdV DNAemia.

Viral specific T cell therapy in kidney transplant recipients - A single-center experience.

Viral infections such as adenovirus (ADV), BK virus (BKV), and cytomegalovirus (CMV) after kidney transplantation negatively impact outcomes in transplant recipients despite advancements in screening and antiviral therapy. We describe our experience of using the virus-specific T cell therapy (VSTs) in kidney transplant recipients (KTR) at our transplant center. This is a retrospective, single center review of KTR with ADV, BKV and CMV infections between June 2021 and December 2022. These patients received third party VSTs as part of the management of infections. The immunosuppression, details of infection and outcome data were obtained from electronic medical records. Two cases of ADV infection resolved after one infusion of VSTs. The response rate of BKV and CMV infection was not as robust with close to 50% reduction in median viral load after VSTs. Out of 23 patients, two patients developed chronic allograft nephropathy from membranoproliferative glomerulonephritis and acute rejection. Patients that are resistant to antivirals or who have worsening viremia despite conventional management may benefit from VSTs therapy to treat underlying viral infection. Additional studies are needed to ascertain efficacy and short- and long-term risks secondary to VSTs.

Lack of detection of HPyV12 DNA using real-time PCR in Italian infants with diarrhea.

HPyV12 was found in organs of the digestive tract, in particular the liver but also in colon, rectum and feces. Until now, the prevalence of HPyV12 is not well characterized. In this study, we investigate the presence of this novel polyomavirus DNA in stool specimens collected from under-five-year-old children with gastroenteritis compared to healthy infants. A total of 190 fecal specimens previously screened for rotavirus (RV) and adenovirus (ADV) and 80 fecal samples from healthy infants, were tested for HPyV12 DNA using a home-made real time PCR. All fecal specimens were tested for the presence of HPyV12 with specific primers and probes. None of 190 (0%) episodes of acute gastroenteritis was associated with HPyV12. We did not detect HPyV12 DNA in any of 80 control subjects, as well. Our study represents a pilot study aiming to clarify the current epidemiological pattern in pediatric Italian patients regarding the novel and rare HPyV12. Based on our negative data and the recent observations reported in literature, doubts remain on human tropism of the HPyV12 and epidemiology: these issues need further investigations.

Ukrainian War Refugee Children With Particularly Severe Viral Infections: A Case Series Report.

The humanitarian crisis in Ukraine in 2022 led to a massive migration of refugees to Poland. Immigrant children, living in overcrowded humanitarian hubs, were exposed to multiple stressful factors likely affecting their immune systems. This case series study aimed to describe a particularly severe course of common viral infections, in Ukrainian refugee children. We present 2 case series of Ukrainian refugee children: 5 hospitalized due to either adenovirus (AdV) and 8 with rotavirus (RV) infection, admitted within 3 months in each case series, recruited retrospectively. Most patients lived in humanitarian hubs and were neglected on admission (dehydrated, with poor hygiene and anxious). All RV infection cases had symptoms of severe gastroenteritis requiring intravenous rehydration. Metabolic acidosis was present in 6 children, and hypoglycemia in 4 participants. None of them were vaccinated against RV. All children with AdV infection had prolonged fever, dyspnea requiring oxygen therapy and hyperinflammation. In 2 AdV infection cases with no clinical improvement and increasing inflammatory markers, intravenous immunoglobulins and glucocorticosteroids were used. The combination of stressful factors and living in overcrowded hubs during the high prevalence of viral infections led to a particularly severe course of viral infections in Ukrainian refugee children.

Superior anti-pulmonary viral potential of Natrialba sp. M6-producing surfactin and C50 carotenoid pigment with unveiling its action modes

BackgroundRespiratory viruses, particularly adenoviruses (ADV), influenza A virus (e.g., H1N1), and coronaviruses (e.g., HCoV-229E and SARS-CoV-2) pose a global public health problem. Therefore, developing natural wide-spectrum antiviral compounds for disrupting the viral life cycle with antioxidant activity provides an efficient treatment approach. Herein, biosurfactant (Sur) and C50 carotenoid pigment (Pig) of haloalkaliphilic archaeon Natrialba sp. M6 which exhibited potent efficacy against hepatitis and anti-herpes simplex viruses, were investigated against pulmonary viruses.MethodsThe cytotoxicity of the extracted Sur and Pig was examined on susceptible cell lines for ADV, HIN1, HCoV-229E, and SARS-CoV-2. Their potential against the cytopathic activity of these viruses was detected with investigating the action modes (including, virucidal, anti-adsorption, and anti-replication), unveiling the main mechanisms, and using molecular docking analysis. Radical scavenging activity was determined and HPLC analysis for potent extract (Sur) was performed.ResultsAll current investigations stated higher anti-pulmonary viruses of Sur than Pig via mainly virucidal and/or anti-replicative modes. Moreover, Sur had stronger ADV’s capsid protein binding, ADV’s DNA polymerase inhibition, suppressing hemagglutinin and neuraminidase of H1N1, and inhibiting chymotrypsin-like (3CL) protease of SARS-CoV-2, supporting with in-silico analysis, as well as radical scavenging activity than Pig. HPLC analysis of Sur confirmed the predominate presence of surfactin in it.ConclusionThis study declared the promising efficacy of Sur as an efficient pharmacological treatment option for these pulmonary viruses and considered as guide for further in vivo research.