Human Adenovirus Disease Research Articles

Approach for defining human adenovirus infection and disease for central review adjudication in clinical studies.

Pediatric allogeneic hematopoietic cell transplant (allo-HCT) recipients are at risk for morbidity and mortality from human adenovirus (HAdV). HAdV can be detected in an asymptomatic state, referred to as infection or with signs or symptoms of illness, referred to as disease. Standardized case definitions are needed to distinguish infection from disease and allow for consistent reporting in both observational cohort studies and therapeutic clinical trials. A working group of experts in virology, transplant infectious disease, and HCT was assembled to develop HAdV infection and disease definitions with the degree of certainty (i.e., possible, probable, and proven). Definitions were further refined through an iterative process and independently applied by two central review committees (CRCs) to 20 pediatric allo-HCT recipients with at least one HAdV-positive PCR. Initial HAdV infection and disease definitions were developed and updated through an iterative process after reviewing clinical and virological details for 81 subjects with at least one positive HAdV PCR detected in a clinical specimen. Independent application of final definitions to 20 HAdV positive allo-HCT recipients by two CRCs yielded similar number of HAdV infection or disease events but with variation of degree of certainty for some events. Application of definitions by a CRC for a study of HAdV infection and disease is feasible and can provide consistency in the assignment of outcomes. Definitions need further refinement to improve reproducibility and to provide guidance on determining clinical improvement or worsening after initial diagnosis of HAdV infection or disease.

Clinical Characteristics and Genotyping of Pediatric Adenovirus Pneumonia Disease and Coinfection in Southeast China.

Introduction: Human adenovirus (HAdV) is a common pathogen that can cause acute respiratory infections (ARIs) in children. Adenovirus pneumonia is the most severe respiratory disease associated with HAdV. Objective: We aimed to investigate the clinical characteristics of children hospitalized with adenovirus pneumonia in Quanzhou, China, in 2019. We also sought to determine the viral genotype in these cases and explore cases associated with severe adenovirus pneumonia. Methods: We collected oropharyngeal swabs from 99 children who were hospitalized with pneumonia in Quanzhou Women and Children's Hospital, these samples were tested for the presence of HAdV. Genotyping of the viruses was performed by real-time polymerase chain reaction. Logistic regression analysis was employed to analyze risk factors related to severe adenovirus pneumonia. The epidemiological data were examined using the Statistical Package for Social Sciences software (SPSS). Results: Among the 99 patients in our study, the median age was 21 months. We observed a 4% mortality rate among those diagnosed with adenovirus pneumonia. Adenovirus pneumonia often presents as a coinfection. Lactate dehydrogenase and neutrophil percentages of WBC's were significantly increased in patients with severe adenovirus pneumonia compared with mild HAdV disease. The predominant viral genotypes identified were type 3 and type 7. Conclusions: In the Quanzhou area of southeast China, the incidence of adenovirus pneumonia was found to be high among children younger than two years old. Type 7 HAdV was identified as the primary pathogen. A long duration of fever, dyspnea and digestive system complications were risk factors for severe adenovirus pneumonia after HAdV infection. Clinical Trial Registration number: ChiCTR2200062358.

Adenovirus Infection in Pediatric Hematopoietic Cell Transplantation: A Challenge Still Open for Survival.

Human Adenovirus (HAdV) infection occurs in 14–16% of patients in the early months after pediatric hematopoietic cell transplantation (HCT) and this correlates with a higher risk of developing HAdV disease and overall 6-month mortality. The main risk factors for HAdV infection are T-cell depletion of the graft by ex vivo CD34+ selection or in vivo use of alemtuzumab or anti-thymocyte serum, the development of grade III-IV graft versus host disease (GVHD), the type of donor (unrelated donor, cord blood, haploidentical, or HLA mismatched parent), and severe lymphopenia (<0.2 × 109/L). The prevention of HAdV disease is based on early intervention with antivirals in the asymptomatic patient when the permitted viral load threshold in the blood (≥102–3 copies/mL) and/or in the stool (109 copies/g stool) is exceeded. Cidofovir, a monophosphate nucleotide analog of cytosine, is the primary drug for preemptive therapy, used at 5 mg/kg/week for 2 weeks followed by 3–5 mg/kg every 2 weeks. The alternative schedule is 1 mg/kg every other day (three times/week). Enhancing virus-specific T-cell immunity in the first months post-HCT by donor-derived or third-party-derived virus-specific T cells represents an innovative and promising way of intervention, applicable both in prevention and therapeutic settings.

Recent Advances in Novel Antiviral Therapies against Human Adenovirus.

Human adenovirus (HAdV) is a very common pathogen that typically causes minor disease in most patients. However, the virus can cause significant morbidity and mortality in certain populations, including young children, the elderly, and those with compromised immune systems. Currently, there are no approved therapeutics to treat HAdV infections, and the standard treatment relies on drugs approved to combat other viral infections. Such treatments often show inconsistent efficacy, and therefore, more effective antiviral therapies are necessary. In this review, we discuss recent developments in the search for new chemical and biological anti-HAdV therapeutics, including drugs that are currently undergoing preclinical/clinical testing, and small molecule screens for the identification of novel compounds that abrogate HAdV replication and disease.

Identification of human adenovirus replication inhibitors from a library of small molecules targeting cellular epigenetic regulators

Human adenovirus (HAdV) can cause severe disease in certain at-risk populations such as newborns, young children, the elderly and individuals with a compromised immune system. Unfortunately, no FDA-approved antiviraldrug is currently available for the treatment of HAdV infections. Within the nucleus of infected cells, the HAdV genome associates with histones and forms a chromatin-like structure during early infection, and viral gene expression appears to be regulated by cellular epigenetic processes. Thus, one potential therapeutic strategy to combat HAdV disease may be to target the cellular proteins involved in modifying the viral nucleoprotein structure and facilitating HAdV gene expression and replication. We have screened a panel of small molecules that modulate the activity of epigenetic regulatory proteins for compounds affecting HAdV gene expression. Several of the compounds, specifically chaetocin, gemcitabine and lestaurtinib, reduced HAdV recovery by 100- to 1000-fold, while showing limited effects on cell health, suggesting that these compounds may indeed be promising as anti-HAdV therapeutics.

2341. Trends in Adenovirus Infections in Singapore Children and Outcomes of Cidofovir Treatment in the Severely Ill

BackgroundAn increase in human adenovirus (HAdV) infections among hospitalized children in Singapore was observed since 2013. Cidofovir is often used to treat severe HAdV infections despite limited data. This study describes the epidemiology and outcomes of children with severe HAdV disease requiring high dependency (HD) or intensive care unit (ICU) admission in our hospital (KKH).MethodsThis is a retrospective cohort study of HAdV-infected children admitted to HD and ICU in KKH from January 2013 to September 2017. Characteristics and outcomes of those who received IV cidofovir was also reviewed.ResultsHAdV admissions and genotype profiles in KKH are described in Figures 1 and 2, respectively. There were 85 children with severe HAdV infection, of which 17 (20%) received cidofovir for mainly viremia (8, 47.1%) and pneumonia (7, 41.2%). Of these 17 patients, 7 (41.2%) died. More children treated with cidofovir had genotype 7 infection (8 of 17, 47.1%) vs. 13 of 68 (19.1%) who did not (P = 0.027). Characteristics of patients who received cidofovir are described in Table 1. None experienced adverse reactions from cidofovir. Table 1:Comparison of Characteristics of 17 Children Who Received IV CidofovirDischarged (N = 10)Death (N = 7) P ValueAge in years (median, IQR)2.6 (1.7–3.7)2.2 (1.2–5.9)0.922Male5 (50.0)6 (85.7)0.304Significant co-morbidities5 (50.0)6 (85.7)0.304Prematurity0 (0.0)1 (14.3)0.412Neurological1 (10.0)3 (42.9)0.250Cardiopulmonary0 (0.0)1 (14.3)0.412Immunodeficiency3 (30.0)1 (14.3)0.603Others1 (10.0)0 (0.0)1.000Disease presentationPneumonia1 (10.0)6 (85.7)0.004Gastroenteritis1 (10.0)0 (0.0)1.000Neutropenic sepsis0 (0.0)1 (14.3)0.412Viremia8 (80.0)0 (0.0)0.002Days of symptoms prior admission (median, IQR)6.5 (2.3–10.8)4.0 (0.0–5.0)0.350Adenovirus genotype 74 (40.0)4 (57.1)0.637Required ICU stay5 (50.0)7 (100.0)0.044Days to cidofovir (median, IQR)7.0 (1.5–25.8)12.0 (4.0–40.0)0.434Length of stay in days (median, IQR)21.5 (15.0–63.5)34.0 (16.0–43.0)0.696All are n (%) unless stated otherwise.ConclusionMore children with HAdV genotype 7 infection required cidofovir treatment. HAdV pneumonia and ICU admission are potential risk factors for mortality despite cidofovir treatment.Disclosures All authors: No reported disclosures.

Patient, Virus, and Treatment-Related Risk Factors in Pediatric Adenovirus Infection after Stem Cell Transplantation: Results of a Routine Monitoring Program

Human adenovirus (HAdV) infection after hematopoietic stem cell transplantation (HSCT) is associated with significant morbidity and mortality in children. The optimal surveillance and treatment strategies are under discussion. Here, we present data from 238 consecutive pediatric allogeneic HSCT recipients who underwent transplantation in a single center who were included in a prospective, weekly HAdV DNAemia monitoring program by quantitative PCR. HAdV loads >1000 copies/mL were detected in 15.5% of all patients. Despite a low mortality directly attributed to HAdV infection (2 patients, 0.84%), blood HAdV loads >10,000 copies/mL (6.7% of all patients) were significant and independent risk factors for poor survival. We searched for patient, virus, and treatment-related risk factors of HAdV DNAemia and disease. Detection of HAdV in blood before day 50 post transplantation was a major independent risk factor for the development of blood HAdV loads >10,000 copies/mL. HAdV typing revealed A31, C1, and C2 as the predominant pathogens among several other HAdV strains with type C species detected in most patients with severe HAdV disease. Stool HAdV loads were prospectively monitored in 111 patients and correlated with but did not significantly precede detection in blood. Treatment with cidofovir led to stable or reduced viral load in 70% of patients with blood HAdV loads >1000 copies/mL. Thus, early occurrence of HAdV-DNA in blood of pediatric HSCT recipients predisposes for development of high viral loads. Control of HAdV infections was attempted by preemptive cidofovir treatment of patients with high blood HAdV loads or with symptomatic organ infections and correlated with low HAdV-attributed mortality.

European guidelines for diagnosis and treatment of adenovirus infection in leukemia and stem cell transplantation: summary of ECIL‐4 (2011)

Human adenovirus (HAdV) infections are increasingly recognized as important pathogens in immunocompromised hosts, especially in patients with severely suppressed T-cell function. The 4th European Conference of Infections in Leukemia (ECIL-4) has developed evidence-based guidelines for diagnosis and management of HAdV infections. The risk for HAdV-associated disease is increased in children, and risk factors for HAdV disease are T-cell depletion, unrelated and cord blood hematopoietic stem cell transplantation, graft-versus-host disease grades III-IV, and lymphopenia. The recommended technique for monitoring of high-risk patients is quantitative polymerase chain reaction. Cidofovir is the most used antiviral therapy, although no controlled study has been performed. HAdV-specific T-cell therapy is in development.

Human Adenovirus Infection in Kawasaki Disease: A Confounding Bystander?

Human adenovirus (HAdV) infection mimics Kawasaki disease (KD) but can also be detected in KD patients. Evidence suggests that HAdV-C species can persist in pediatric adenoids and/or tonsils. We sought to determine (1) the frequency of HAdV detection by real-time polymerase chain reaction in KD patients, (2) the differences in HAdV semiquantitative nasopharyngeal viral loads between KD patients with detectable HAdV vs those with HAdV disease, and (3) whether nasopharyngeal HAdV-C shedding is occurring in KD. From August 2009 through April 2011, HAdV-positive patients were identified in 1 of the following groups: group I, complete or incomplete KD as defined by the American Heart Association (AHA); group II, treated for incomplete KD but not fulfilling AHA criteria; and group III, otherwise healthy children with some KD-like features ultimately diagnosed with HAdV disease. Among 77 KD patients diagnosed, 8.8% (5/57) of group I and 25% (5/20) of group II KD patients had HAdV detected. Viral loads were significantly lower in group I (n = 5) vs group III (n = 26; P = .034). Of the 13 specimens available for HAdV typing, 7 of 7 group III and 1 of 3 group II specimens were determined to be HAdV-B using viral culture. The remaining 5 KD samples were unable to be cultured and molecular typing showed either HAdV-C (n = 3) or were nontypeable (n = 2). In KD, molecular-based HAdV detection is not uncommon, may represent persistence of HAdV-C, and should be interpreted with caution. Together, quantitative polymerase chain reaction and HAdV typing may aid in distinguishing HAdV disease mimicking KD from KD with concomitant HAdV detection.

Adenovirus DNA Positivity in Nasopharyngeal Aspirate Preceding Hematopoietic Stem Cell Transplantation: A Very Strong Risk Factor for Adenovirus DNAemia in Pediatric Patients

Human adenovirus (HAdV)-positive nasopharyngeal aspirate preceding hematopoietic stem cell transplantation was prospectively analyzed in 62 patients. By multivariate Cox proportional hazard models, HAdV-positive nasopharyngeal aspirate was the only predictor for HAdV DNAemia after hematopoietic stem cell transplantation (P < .001). HAdV DNAemia was a predictor for alloreactive disease. Early detection and intervention might help to prevent HAdV disease after hematopoietic stem cell transplantation.

Molecular typing of clinical adenovirus specimens by an algorithm which permits detection of adenovirus coinfections and intermediate adenovirus strains

Background Epidemiological data suggest that clinical outcomes of human adenovirus (HAdV) infection may be influenced by virus serotype, coinfection with multiple strains, or infection with novel intermediate strains. In this report, we propose a clinical algorithm for detecting HAdV coinfection and intermediate strains. Study design We PCR amplified and sequenced subregions of the hexon and fiber genes of 342 HAdV-positive clinical specimens obtained from 14 surveillance laboratories. Sequences were then compared with those from 52 HAdV prototypic strains. HAdV-positive specimens that showed nucleotide sequence identity with a corresponding prototype strain were designated as being of that strain. When hexon and fiber gene sequences disagreed, or sequence identity was low, the specimens were further characterized by viral culture, plaque purification, repeat PCR with sequencing, and genome restriction enzyme digest analysis. Results Of the 342 HAdV-positive clinical specimens, 328 (95.9%) were single HAdV strain infections, 12 (3.5%) were coinfections, and 2 (0.6%) had intermediate strains. Coinfected specimens and intermediate HAdV strains considered together were more likely to be associated with severe illness compared to other HAdV-positive specimens (OR = 3.8; 95% CI = 1.2–11.9). Conclusions The majority of severe cases of HAdV illness cases occurred among immunocompromised patients. The analytic algorithm we describe here can be used to screen clinical specimens for evidence of HAdV coinfection and novel intermediate HAdV strains. This algorithm may be especially useful in investigating HAdV outbreaks and clusters of unusually severe HAdV disease.