Epidemiological impact of human adenovirus as causative agent of respiratory infections: An Italian multicentre retrospective study, 2022-2023.

Human adenoviruses are the causative agents of 5-7% of viral respiratory infections, mainly caused by species B and C. They can infect all age groups, but children are usually at high risk of infections. Adenovirus epidemiology is well documented in East-Asian countries but little is known about adenovirus circulation in Europe in recent years. This multicentre retrospective study aimed to investigate the circulation and molecular epidemiology of hAdVs. This surveillance collected a total of 54463 respiratory specimens between January 1, 2022 and June 20, 2023 were tested for the presence of respiratory viruses. Our results showed that adenovirus was detected in 6.6 % of all cases of acute respiratory infection included in the study and the median age of positive patients was 3 years, with male children in 1-2 years age group being the most affected. 43.5 % of adenovirus cases were co-infected with at least one other respiratory virus, and rhinovirus was co-detected in 54 % of cases. Genotyping of adenovirus allowed the identification of 6 different genotypes circulating in Italy, among which type B3 was the most frequently detected.

The Auditory Pathway in Congenitally Cytomegalovirus-Infected Human Fetuses.

Congenital cytomegalovirus (CMV) infection is the main cause of non-hereditary sensorineural hearing loss (SNHL). In order to shed light on SNHL pathophysiology, we examined the auditory pathway in CMV-infected fetuses; the temporal lobe, in particular the auditory cortex, and the inner ear. We investigated both inner ears and temporal lobes of 20 human CMV-infected fetuses at 21 weeks of gestation. As a negative group, five fetuses from spontaneous miscarriages without CMV infection were studied. Inner ears and temporal lobes were histologically examined, immunohistochemistry for CMV and CMV-PCR were performed. On the auditory cortex, we evaluated the local microglial reaction to the infection. CMV-positive cells were found in 14/20 brains and the damage was classified as severe, moderate, or mild, according to histological features. Fetuses with severe brain damage had a statistically higher temporal lobe viral load and a higher number of activated microglial cells in the auditory cortex compared to fetuses with mild brain damage (p: 0.01; p: 0.01). In the inner ears, the marginal cells of the stria vascularis were the most CMV positive. In our study, CMV affected the auditory pathway, suggesting a tropism for this route. In addition, in the auditory cortex, microglial activation may favor further tissue damage contributing to hearing loss.

Fetal Brain Damage in Human Fetuses with Congenital Cytomegalovirus Infection: Histological Features and Viral Tropism.

Human cytomegalovirus (HCMV) causes congenital neurological lifelong disabilities. To date, the neuropathogenesis of brain injury related to congenital HCMV (cCMV) infection is poorly understood. This study evaluates the characteristics and pathogenetic mechanisms of encephalic damage in cCMV infection. Ten HCMV-infected human fetuses at 21 weeks of gestation were examined. Specifically, tissues from different brain areas were analyzed by: (i) immunohistochemistry (IHC) to detect HCMV-infected cell distribution, (ii) hematoxylin-eosin staining to evaluate histological damage and (iii) real-time PCR to quantify tissue viral load (HCMV-DNA). The differentiation stage of HCMV-infected neural/neuronal cells was assessed by double IHC to detect simultaneously HCMV-antigens and neural/neuronal markers: nestin (a marker of neural stem/progenitor cells), doublecortin (DCX, marker of cells committed to the neuronal lineage) and neuronal nuclei (NeuN, identifying mature neurons). HCMV-positive cells and viral DNA were found in the brain of 8/10 (80%) fetuses. For these cases, brain damage was classified as mild (n = 4, 50%), moderate (n = 3, 37.5%) and severe (n = 1, 12.5%) based on presence and frequency of pathological findings (necrosis, microglial nodules, microglial activation, astrocytosis, and vascular changes). The highest median HCMV-DNA level was found in the hippocampus (212 copies/5 ng of human DNA [hDNA], range: 10-7,505) as well as the highest mean HCMV-infected cell value (2.9 cells, range: 0-23), followed by that detected in subventricular zone (1.7 cells, range: 0-19). These findings suggested a preferential viral tropism for both neural stem/progenitor cells and neuronal committed cells, residing in these regions, confirmed by the expression of DCX and nestin in 94% and 63.3% of HCMV-positive cells, respectively. NeuN was not found among HCMV-positive cells and was nearly absent in the brain with severe damage, suggesting HCMV does not infect mature neurons and immature neural/neuronal cells do not differentiate into neurons. This could lead to known structural and functional brain defects from cCMV infection.

Measles virus and cytomegalovirus co-infection, in a child with recent SARS-CoV-2 infection, during COVID-19 pandemic: a case report.

Measles virus (MV) and cytomegalovirus (CMV) may cause pediatric infection. We report the first described case of MV and CMV co-infection in an unvaccinated 13-mo-old girl, with a recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, occurred during coronavirus disease 2019 (COVID-19) pandemic. The COVID-19 pandemic context, combined with patient's complex clinical scenario, presenting symptoms as persistent fever, diarrhea, vomiting, maculopapular rash and edema, in addition to high level of inflammatory markers, led to a suspicion of multisystemic inflammatory syndrome in children (MIS-C). The final diagnosis and the successfully management of the case, discharged after resolution of symptoms, was achieved by a proper virological diagnosis and a close two-way cooperation between pediatricians and clinical microbiologists. The report mainly highlights that awareness about measles should be raised in unvaccinated patients with consistent symptoms, even in the COVID-19 era.

Positive HCMV DNAemia in stem cell recipients undergoing letermovir prophylaxis is expression of abortive infection.

Letermovir (LMV) inhibits HCMV replication by binding to components of the HCMV-terminase complex showing a potential role in prevention of HCMV-related complications in allogenic hematopoietic stem cell transplant recipients (allo-HSCTRs). However, little is known about breakthrough HCMV infection and the relevance of HCMV DNAemia during prophylaxis. We reported the results of a multicenter prospective study involving five Italian centers in the management of HCMV DNAemia in 75 adult HCMV-seropositive allo-HSCTRs undergoing LMV prophylaxis. The aim of the present study was to characterize the presence of real HCMV reactivation during LMV prophylaxis. Then, the presence of circulating infectious HCMV particles was determined by virus isolation and degradation of free-floating viral DNA. This report provides the first evidence that during LMV prophylaxis the clinical relevance of HCMV DNAemia should be critically considered.

Microbial Contamination of Medical Staff Clothing During Patient Care Activities: Performance of Decontamination of Domestic Versus Industrial Laundering Procedures.

The efficacy of domestic laundering of healthcare staff clothing is still debated. This study aimed to compare the performance of decontamination of different domestic laundering with that of industrial laundering. Fourteen naturally contaminated white coats of healthcare workers (5 fabric squares from each coat) and fabric squares of artificially contaminated cotton cloth (30 fabric squares per each bacterial strain used) were included. Four domestic laundering procedures were performed; two different washing temperatures (40 °C and 90 °C) and drying (tumble dry and air dry) were used. All fabric squares were ironed. Presence of bacterial bioburden on the fabric squares after domestic and industrial laundering was investigated. None of the naturally contaminated fabric squares resulted completely decontaminated after any of the domestic washes. At 24, 48, and 72 h of incubation, bacterial growth was observed in all the laundered fabric squares. Besides environmental microorganisms, potentially pathogenic bacteria (i.e., Acinetobacter lwoffii, Micrococcus luteus, coagulase-negative staphylococci) were isolated. On the artificially contaminated fabric squares, the bioburden was reduced after the domestic laundries; nevertheless, both Gram-negative and -positive pathogenic bacteria were not completely removed. In addition, a contamination of the fabric squares by environmental Gram-negative bacteria was observed. In both the naturally and artificially contaminated fabric squares, no bacterial growth at all the time-points analyzed was observed after industrial laundering, which provided to be more effective in bacterial decontamination than domestic washes. For those areas requiring the highest level of decontamination, the use of specialized industrial laundry services should be preferred.

Clinical utility of measuring Epstein-Barr virus-specific cell-mediated immunity after HSCT in addition to virological monitoring: results from a prospective study.

Lack of virus-specific cell-mediated immunity (CMI) is associated with worse viral infection outcome in hematopoietic stem cell transplantation (HSCT). We aimed to evaluate the role of immunological monitoring of Epstein-Barr virus (EBV) infection in addition to virological one in 33 adult and 18 pediatric allogeneic HSCT recipients. Virological monitoring of infection was performed on whole blood samples by a quantitative real-time PCR assay. Immunological monitoring was performed by Enzyme-linked ImmunoSPOT assay, evaluating EBV-specific CMI, at fixed time-points and when EBV DNAemia was ≥ 10,000 copies/mL. Fifty-one percent of patients developed a post-transplant EBV infection and reduced-intensity conditioning regimen was the only factor associated to infection (P = 0.023). Lack of EBV-specific CMI during active EBV infection was associated with a greater severity of infection. Patients without EBV-specific CMI showed higher median peak level of EBV DNAemia than patients with EBV-specific CMI (P = 0.014), and consequently received more frequently, at EBV DNAemia peak, anti-CD20 therapy (0 versus 54.5%, P = 0.002). No patients with EBV-specific CMI versus 27.2% without EBV-specific CMI developed EBV-related complications (P = 0.063), including two lethal EBV-related post-transplant lymphoproliferative disorders. Combined immunological and virological measurements could improve EBV infection management in HSCT, anticipating the beginning of preemptive treatment from the EBV DNAemia peak to the finding of the lack of EBV-specific CMI.

Histological Analysis of Term Placentas from Hyperimmune Globulin-Treated and Untreated Mothers with Primary Cytomegalovirus Infection.

BACKGROUND: The Congenital Human Cytomegalovirus Infection Prevention (CHIP) study, a randomized, blinded, placebo-controlled trial, demonstrated that the efficacy of hyperimmune globulin (HIG) was not different from that of placebo regarding transmission of cytomegalovirus (CMV) from mothers to newborns. Our aim was to analyze histologically HIG effects on placentas collected for the CHIP study. MATERIALS AND METHODS: Virological and histological analyses were performed on 40 placentas from transmitter and nontransmitter HIG-treated and untreated mothers by assessing the number of CMV-positive cells, tissue viral load, tissue damage, and compensatory mechanisms. RESULTS: The HIG and placebo groups showed no significant differences in the number of CMV-positive cells (median number in 10 fields at 10 high-power fields: 2.5 vs. 2, p = 0.969) and viral load (median load: 5 copies/5 ng vs. 10.5 copies/5 ng, p = 0.874). Regarding histological examination, the scores of parameters related to tissue damage and hypoxic parenchymal compensation were higher in transmitters except for chorangiosis, with statistically significant differences observed for chronic villitis (p = 0.007), calcification (p = 0.011), and the total score of tissue damage (p < 0.001). The HIG and placebo groups showed no significant differences for all tissue damage and compensation parameters and overall scores. DISCUSSION: HIGs are not able to reduce placental viral load and histological damage, which was significantly associated only with infection.

Cytomegalovirus and Epstein-Barr Virus DNA Kinetics in Whole Blood and Plasma of Allogeneic Hematopoietic Stem Cell Transplantation Recipients.

Currently, no consensus has been reached on the optimal blood compartment to be used for surveillance of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) DNAemia. Although several comparative studies have been performed correlating CMV and EBV DNA loads in whole blood (WB) versus plasma, to our knowledge, no studies to date have analyzed the kinetics of both viruses in the 2 blood compartments. In this retrospective noninterventional multicenter cohort study, the kinetics of CMV and EBV DNA in 121 hematopoietic stem cell transplantation (HSCT) recipients were investigated by analyzing in parallel 569 and 351 paired samples from 80 and 58 sequential episodes of CMV and EBV DNAemia, respectively. Unlike previous studies, this study used a single automated molecular method that was CE-marked and Food and Drug Administration-approved for use in quantifying CMV and EBV DNA in both plasma and WB. Furthermore, the complete viral replication kinetics of all episodes (including both the ascending and the descending phases of the active infection) was examined in each patient. The previously observed overall correlation between CMV DNA levels in WB and plasma was confirmed (Spearman's ρ = .85; P < .001). However, although WB and plasma CMV DNAemia reached peak levels simultaneously, in the ascending phase, the median CMV DNA levels in plasma were approximately 1 log10 lower than WB. Furthermore, in patients who received preemptive therapy, CMV DNA showed a delayed decrease in plasma compared with WB. A lower correlation between EBV DNA levels in plasma versus WB was found (Spearman's ρ = .61; P < .001). EBV DNA kinetics was not consistent in the 2 blood compartments, mostly due to the lower positivity in plasma. Indeed, in 19% of episodes, EBV DNA was negative at the time of the EBV DNA peak in WB. Our results suggest a preferential use of WB for surveillance of CMV and EBV infection in HSCT recipients.

Monitoring of Cytomegalovirus (CMV)-Specific Cell-Mediated Immunity in Heart Transplant Recipients: Clinical Utility of the QuantiFERON-CMV Assay for Management of Posttransplant CMV Infection.

The clinical utility of the QuantiFERON-CMV (QFN-CMV) assay in heart transplant recipients was assessed. Forty-four cytomegalovirus (CMV)-seropositive patients were enrolled: 17 received antiviral prophylaxis, and 27 were managed preemptively. CMV-DNAemia monitoring was performed by the use of a quantitative real-time PCR assay. The QFN-CMV assay was retrospectively performed on blood samples collected at five posttransplant time points. A higher proportion of patients with an indeterminate QFN-CMV result after the suspension of prophylaxis than of patients who showed a global T-cell responsiveness developed CMV infection (P = 0.036). Patients who reconstituted a CMV-specific response following the first CMV-DNAemia-positive result (42.9%) showed a median CMV-DNAemia peak 1 log of magnitude lower than that seen with patients with indeterminate results, and all controlled viral replication spontaneously. The 25% of patients with an indeterminate result developed CMV disease. In the preemptive strategy group, no differences in the development of subsequent infection, magnitude of viral load, and viral control were observed on the basis of QFN-CMV measurements performed before and after the first CMV-DNAemia-positive result. Considering both CMV prevention strategies, viral relapse was associated with the failure to reconstitute CMV-specific cell-mediated immunity (CMI) after the resolution of the first episode of CMV infection (P = 0.032). QFN-CMV measurements can be a useful tool for identifying patients (i) at higher risk of developing infection after discontinuing antiviral prophylaxis, (ii) with late CMV infection who would benefit from appropriate antiviral interventions, and (iii) at higher risk of viral relapses. QFN-CMV measurements taken within 1 month posttransplantation (early period) are not revealing.

Infectious meningitis/encephalitis: evaluation of a rapid and fully automated multiplex PCR in the microbiological diagnostic workup.

Infectious diseases of the central nervous system (CNS) such as meningitis/encephalitis (ME) require rapid identification of causative pathogens for effective treatment. This study evaluated the analytical performance and clinical utility of a fully automated multiplex PCR test to improve the microbiological diagnostic workup of ME. Seventy-seven cerebrospinal fluid (CSF) samples from 77 patients with suspected ME were studied. The samples were tested by FilmArray™ (FA) ME Panel test and the results were compared with those obtained using conventional microbiological procedures (CMP). Furthermore, the assay's validity was evaluated testing 5 pooled CSF samples positive for different pathogens. The data showed a good concordance (90.9%) between the FA ME panel test and CMP results. Discrepant results were observed in CSF samples with low viral load (5/77) and in samples of patients (2/77) undergoing antimicrobial therapy for fungal infection. The ability of the FA ME panel test to correctly detect the target pathogens was confirmed. Faster microbiological diagnosis was obtained by the FA ME test in comparison to CMP for both bacterial and viral analytes (P<0.001). Implementation of microbiological diagnostic workup with FA ME panel test may improve the management of patients with suspected CNS infection.

Salivary glands and human congenital cytomegalovirus infection: What happens in early fetal life?

Salivary glands are a site of human cytomegalovirus (CMV) replication, latency, and persistence. Prolonged secretion of virus in saliva for months following a primary infection contribute to horizontal transmission. In order to better understand the early effects of CMV on salivary glands and the mechanisms of viral persistent replication, submandibular glands of six CMV congenitally infected fetuses at 21 weeks gestation were studied. Three fetuses at the same gestational age from CMV-seronegative women were compared as negative controls. Tissue viral load and the type of inflammatory infiltrate were evaluated. Moreover, development and branching of salivary glands, the number of myoepithelial cells, cellular proliferation, and expression of secretory proteins of the saliva (Gross Cystic Disease Fluid Protein-15 and lysozyme) were studied. A low viral load and rare CMV-positive cells associated with T CD8 cytotoxic lymphocytes were observed. Branching was impaired with a decrease in terminal acinar structures, the number of myoepithelial cells, and cellular proliferation were reduced. In addition, a compromised secretion of defense proteins involved in the oral humoral immunity was observed. These findings suggest that CMV may affect salivary glands, impairing structure development and secretion of defense proteins, probably responsible for the prolonged viral shedding in saliva. J. Med. Virol. 89:318-323, 2017. © 2016 Wiley Periodicals, Inc.

Infectious agents after liver transplant: etiology, timeline and patients' cell-mediated immunity responses.

Infections continue to be one of the leading causes of morbidity and mortality in liver transplant recipients. We retrospectively reviewed the symptomatic infectious episodes that occurred during the first year post-transplant to determine time of onset, causative pathogens and cell-mediated immunity response patterns. Ninety-eight of the 202 (48.5%) recipients enrolled developed at least one infectious episode. The total number of infectious episodes was 135: 77 (57.1%) bacterial, 45 (33.3%) viral and 13 (9.6%) fungal. The most frequently isolated bacteria were Escherichia coli (21 isolates) and Klebsiella pneumoniae (19 isolates). Overall, extended-spectrum beta lactamase-producing and methicillin-resistant organisms were responsible for 29 (29/77; 37.7%) infectious episodes. Members of the herpes virus group, in particular cytomegalovirus (34/45 viral infections, 75.5%), were detected. Candida species (9 isolates) followed by Aspergillus species (4 isolates) were isolated. The majority of infections (63%) occurred during the early post-transplant phase (<1 month), whereas only 8/135 episodes (5.9%) were detected after the sixth month (late phase). Significantly lower median ImmuKnow® intracellular ATP values in patients who developed bacterial and fungal infections compared to infection-free patients were observed (P < 0.0001 and P = 0.0016, respectively), whereas patients who developed a viral infection had a median intracellular ATP level not statistically different compared to uninfected patients (P = 0.4). Our findings confirm that bacteria are responsible for the majority of symptomatic infections and occur more frequently during the first month post-transplant. The ImmuKnow® measurements can be a useful tool for identifying patients at high risk of developing infection, particularly of fungal and bacterial etiology.

Atypical Forms of Hand, Foot, and Mouth Disease: A Prospective Study of 47 Italian Children.

BACKGROUND: Atypical forms of hand, foot, and mouth disease (HFMD) caused by coxsackievirus A6 have been reported in recent years. High fever and severe cutaneous lesions are common, whereas neurologic complications are rare. Eczematous areas of patients with atopic dermatitis show more lesions. The goal of the current study was to describe the clinical characteristics of children with atypical HFMD and to investigate the involvement of the different enterovirus serotypes associated. METHODS: All patients referred to our service for atypical HFMD from January 2012 to February 2014 were enrolled and classified as having the diffuse form (lesions extended to the trunk), the acral form (lesions with a mainly acral distribution), or eczema coxsackium (lesions on preexisting eczematous areas). RESULTS: Data from 47 patients were analyzed (median age 22 months [range 4-84 mos]); viral genotyping was performed in 11 cases. Sixty-two percent of the subjects developed the acral form, 23% eczema coxsackium, and 15% the diffuse form. Most patients had a nonclassical vesicular eruption and moderate to severe extent of cutaneous involvement. Approximately 80% of patients had palmoplantar purpuric macules. Most children younger than 2 years old had the acral form, most patients with eczema coxsackium were age 2 years and older, and the diffuse form was similarly distributed between the two age groups. Coxsackievirus A6 was detected in 9 of 11 genotyped cases. CONCLUSION: Our prospective study allowed the identification of three HFMD phenotypes differing from the classical form. Clinical care of these patients should include symptomatic treatment of extracutaneous features and, if necessary, hospitalization for complications.

Outbreak of a new measles B3 variant in the Roma/Sinti population with transmission in the nosocomial setting, Italy, November 2015 to April 2016.

A measles outbreak occurred from November 2015 to April 2016 in two northern Italian regions, affecting the Roma/Sinti ethnic population and nosocomial setting. Overall, 67 cases were reported. Median age of 43 cases in three Roma/Sinti camps was four years, nosocomial cases were mainly adults. The outbreak was caused by a new measles virus B3.1 variant. Immunisation resources and strategies should be directed at groups with gaps in vaccine coverage, e.g. Roma/Sinti and healthcare workers.

From the Colon to the Liver: How Gut Microbiota May Influence Colorectal Cancer Metastatic Potential.

The gut microbiota's influence on human tumorigenesis is a burning topic in medical research. With the new ontological perspective, which considers the human body and its pathophysiological processes as the result of the interaction between its own eukaryotic cells and prokaryotic microorganisms living in different body niches, great interest has arisen in the role of the gut microbiota on carcinogenesis. Indeed, dysbiosis is currently recognized as a cancer-promoting condition, and multiple molecular mechanisms have been described by which the gut microbiota may drive tumor development, especially colorectal cancer (CRC). Metastatic power is undoubtedly one of the most fearsome features of neoplastic tissues. Therefore, understanding the underlying mechanisms is of utmost importance to improve patients' prognosis. The liver is the most frequent target of CRC metastasis, and new evidence reveals that the gut microbiota may yield an effect on CRC diffusion to the liver, thus defining an intriguing new facet of the so-called "gut-liver axis". In this review, we aim to summarize the most recent data about the microbiota's role in promoting or preventing hepatic metastasis from CRC, highlighting some potential future therapeutic targets.

Mollaret's Meningitis due to Herpes Simplex Virus 2: A Case Report and Review of the Literature.

Mollaret's meningitis is a rare neurological disorder characterized by recurrent episodes of aseptic lymphocytic meningitis, often associated with herpes simplex virus 2 (HSV-2) infection. We report the case of a 39 y.o. Italian woman who experienced four episodes of aseptic lymphocytic meningitis between 2004 and 2023, diagnosed as Mollaret's meningitis. In each episode, the patient presented with fever, severe headache and photophobia. In two episodes cutaneous vesicles in the left gluteal area preceding meningitis symptoms were also reported. A diagnostic evaluation included a physical-chemical analysis and a real-time PCR of the cerebrospinal fluid (CSF). The CSF presented pleocytosis with lymphocytic predominance and a positive HSV-2 load, with a peak of 1234 copies/mL. The patient was treated successfully with acyclovir, and the symptoms resolved without neurological sequelae. This case highlights the importance of comprehensive diagnostic testing and vigilant monitoring to manage Mollaret's syndrome effectively.

Navigating the Intersection: Sarcopenia and Sarcopenic Obesity in Inflammatory Bowel Disease.

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, sarcopenia exhibits a high prevalence in Crohn's disease (52%) and ulcerative colitis (37%). While computed tomography and magnetic resonance imaging remain gold-standard methods for assessing muscle mass, ultrasound is gaining traction as a reliable, cost-effective, and widely available diagnostic method. Muscle strength serves as a key indicator of muscle function, with grip strength test emerging nowadays as the most reliable assessment method. In IBDs, sarcopenia may arise from factors such as inflammation, malnutrition, and gut dysbiosis, leading to the formulation of the 'gut-muscle axis' hypothesis. This condition determines an increased need for surgery with poorer post-surgical outcomes and a reduced response to biological treatments. Sarcopenia and its consequences lead to reduced quality of life (QoL), in addition to the already impaired QoL. Of emerging concern is sarcopenic obesity in IBDs, a challenging condition whose pathogenesis and management are still poorly understood. Resistance exercise and nutritional interventions, particularly those aimed at augmenting protein intake, have demonstrated efficacy in addressing sarcopenia in IBDs. Furthermore, anti-TNF biological therapies showed interesting outcomes in managing this condition. This review seeks to furnish a comprehensive overview of sarcopenia in IBDs, elucidating diagnostic methodologies, pathophysiological mechanisms, and clinical implications and management. Attention will also be paid to sarcopenic obesity, exploring the pathophysiology and possible treatment modalities of this condition.

Inherited Chromosomally Integrated Human Herpesvirus 6: Laboratory and Clinical Features.

Inherited chromosomally integrated human herpesvirus 6 (iciHHV-6) is a condition in which the complete HHV-6 genome is integrated into the chromosomes of the host germ cell and is vertically transmitted. The aims of this study were to identify iciHHV-6 prevalence in hospitalized patients and clinical features in individuals carrying this integration. HHV-6 PCR on hair follicles was used to confirm iciHHV-6 status when the blood viral load was more than 5 Log10 copies/mL. From January 2012 to June 2022, HHV-6 DNAemia was investigated in 2019 patients. In particular, 49 had a viral load higher than 6 Log10 copies/mL and HHV-6 DNA in hair follicles was positive. A viral load between 5.0 and 5.9 Log10 copies/mL was observed in 10 patients: 6 infants with acute HHV-6 infection and 4 patients with leukopenia and HHV-6 integration. Therefore, the iciHHV-6 prevalence in our population was 2.6% (53/2019). Adult patients with integration presented hematological (24%), autoimmune (11%), autoimmune neurological (19%), not-autoimmune neurological (22%), and other diseases (19%), whereas 5% had no clinically relevant disease. Although in our study population a high percentage of iciHHV-6 adult hospitalized patients presented a specific pathology, it is still unknown whether the integration is responsible for, or contributes to, the disease development.