Risk Factors For Virus Infection Research Articles

Immune reconstitution in children after haploidentical haematopoietic stem cell transplantation.

Immune reconstitution (IR) kinetics of paediatric patients underwent haploidentical haematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PTCy) have not been extensively studied. We compared IR patterns of children receiving HSCT from haploidentical (n = 92) and HLA-matched donors (n = 36), and analysed risk factors for viral infection in these patients. We prospectively measured lymphocyte subset numbers before HSCT and at 1, 3, 6 and 12 months after HSCT. Blood cytomegalovirus (CMV), Epstein-Barr virus, adenovirus, BK virus (BKV) and urine adenovirus and BKV viral loads were measured at designated time points. The median numbers of total T and T helper cells at 1 month were significantly lower in the haploidentical group compared with the HLA-matched group. Haploidentical HSCT recipients had significantly lower median numbers of several T cell subsets and B cells for 1 year after HSCT. The median NK cell count of the haploidentical group was lower at 1 month. BKV haemorrhagic cystitis, blood CMV and urine adenovirus reactivation were more frequently found in the haploidentical group. Post-haploidentical HSCT patients receiving anti-T lymphocyte globulin (ATG) had significantly lower median numbers of total T cells (at 1 month) and T helper cells (at 6 and 12 months) and higher rate of blood BKV reactivation compared with those without ATG. Paediatric patients who undergo haploidentical HSCT with PTCy are likely to have delayed IR and an increased risk of viral reactivation/infection compared with HLA-matched HSCT. The addition of ATG to PTCy delayed T cell recovery and increased risk of BKV reactivation.

Binary Logistic Regression Analysis on Risk Factors Associated with Hepatitis B Disease in Gusau Local Government Zamfara State, Nigeria

This study focused on creating a binary logistic regression model to evaluate the risk factors for hepatitis B viral disease in the Gusau Local Government of Zamfara State, Nigeria. Secondary data was utilised, and the model identified independent predictors of hepatitis-b disease based on variables with a P-value < 0.05 and a 95% confidence interval for the odds ratio not less than 1. The results indicated that marital status, history of blood transfusion, multiple sex partners, and alcohol consumption were statistically associated with hepatitis-B virus infection, while gender and having an infected family member were not. Model selection criteria, including Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC), favoured a model with only significant predictors, revealing the existence of Hepatitis-B virus infection risk factors in patients from Gusau Local Government of Zamfara State.

Epidemiology and Risk Factors for Viral Infections in Pediatric Liver Transplant Recipients and Impact on Outcome.

Infections after liver transplantation (LT) are risk factors for morbidity and mortality. Infections, especially of viral etiologies, still have an impact on the graft function and overall outcome. The aim was to review the epidemiology and risk factors of EBV, CMV and non-EBV non-CMV viral infections and their impacts on outcomes after LT. Demographic, clinical, and laboratory data were retrieved from patients' electronic databases. Over 2 years, 96 patients were transplanted at the Pediatric Liver Centre at Kings College Hospital. The majority of the infections were of viral origin; 73 (76%) patients. The incidence of EBV viremia was 60.4%, CMV infection 35.4%, and other viruses 30%. Older donor age, auxiliary graft, and bacterial infections were risk factors for EBV infection. Younger recipient age, D+R- CMV IgG, and left lateral segment graft were risk factors for CMV infection. More than 70% of patients with non-EBV and CMV viral infections stayed positive post-LT but did not contribute to increased complications. Despite the high prevalence of viral infections, EBV, CMV, and non-EBV non-CMV viral infections were not associated with rejection, morbidity, or mortality. Although some of the risk factors for viral infections are unavoidable, identifying the characteristics and risk pattern will help improve the care for pediatric LT recipients.

Epidemiology, Risk Factors and Outcome of Bacterial, Fungal, and Viral Infections in Pediatric Allogeneic and Autologous Hematopoietic Stem Cell Transplantation Recipients

Objectives Infection remains a major cause of morbidity and mortality after hematopoietic stem cell transplant (HSCT). With recent changes in transplant practices, such as the increasing use of alternative donors and T-cell depletion, how various risk factors interplay and affect the timeline of infections have not been well elucidated in children. While the epidemiology and risk factors for viral infections post-HSCT were well described for cytomegalovirus (CMV) and Epstein-Barr virus (EBV), the corresponding information on human herpes virus 6 (HHV-6), adenovirus (ADV) and BK virus (BKV) infection in children is limited. This study aims to review comprehensively the epidemiology, risk factors and outcome of bacterial, viral and fungal infections after contemporary HSCT to inform future infection prophylaxis strategies. Method We retrospectively reviewed the first 100 consecutive HSCT for malignant and non-malignant diseases from April 2019 to October 2021 in the only pediatric HSCT center in Hong Kong. The incidences were recorded and risk factors were analyzed for bacterial, viral and fungal infections and infection-related mortality. Results The vast majority of the allogeneic transplant recipients (69/74, 93.2%) had infections after HSCT, amongst which bacterial, viral and fungal infection rate was 35.1%, 90.5% and 9.5% respectively. In contrast, only 30.8% (8/26) of autologous transplant recipients had infections, and their respective rate of bacterial, viral and fungal infection was 19.2%, 15.4% and 3.8%. HHV-6 and BKV typically occurred early after HSCT, ADV and varicella zoster virus (VZV) thereafter, and CMV and EBV throughout the entire 2.5-year observation period. The cumulative incidences of HHV-6 and BKV were significantly higher in patients receiving umbilical cord blood (UCB) or haploidentical stem cell transplant (p = 0.0001; p <0.0001, respectively) when compared with matched sibling (MSD) or matched unrelated donor (MUD) transplant (Figure 1 and 2). Ex vivo T-cell depletion was a general risk factor for viral infection with HHV-6 (HR = 3.03), BKV (HR = 3.36), CMV (HR = 4.45) and EBV (HR = 7.15); all p < 0.02. Cancer in second- compared with first-complete remission was a risk factor for bacterial infection in multivariate analyses (OR = 6.0, 95% CI = 1.12-32.2, p = 0.037). Patients with gut graft-versus-host disease were at risk for fungal infections (OR = 12.3, 95% CI = 1.33-114.4, p = 0.027). The infection-related mortality (IRM) rate was 10%, which occurred only in allogeneic HSCT patients with hematological malignancies receiving cord blood (n = 4) or haploidentical HSCT (n = 6). History of bacterial infection after HSCT was associated with an increased risk of IRM (HR = 4.13, 95% CI = 1.05-16.3, p = 0.042). Conclusion Not all HSCT recipients are of equal risk to infections and IRM. Our findings in pediatric patients after contemporary HSCT support both time-dependent and risk-adapted measures against infective complications to improve transplant outcome. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

The detection of urinary viruses is associated with aggravated symptoms and altered bacteriome in female with overactive bladder.

Although it is known that changes in bacterial components of the urinary microbiome are associated with overactive bladder (OAB), the specific role of viruses is still insufficiently investigated. The aim of the present study is to evaluate the role of urinary viruses in woman with OAB, and analyze the potential relationship between viruses, bacteria and disease. Catheterized urine samples were collected from 55 women with OAB and 18 control individuals. OAB patients fulfilling the following criteria were considered eligible for this study: female, 18 years of age or older; presented with classic OAB symptoms defined by the International Continence Society; and OAB Symptom Score (OABSS) total score ≥ 3 points and question 3 (urgency) score ≥ 2 points. Based on results of metagenomic next-generation sequencing (mNGS), all participants were divided into virus-infected and virus-uninfected groups for analysis. The results of mNGS showed that the diversity of the OAB group was lower than that of the control group when focused on bacterial sequences, which was consistent with our previous study. According to the questionnaire filled out by the patients, OABSS and 8-item OAB questionnaire, female OAB patients who had viruses detected in their urine had more severe symptoms. In parallel, John Cunningham virus (mainly subtype 7 and subtype 2) was the most frequently detected virus in urine. Correlation analysis indicated that risk factors for virus infection in OAB patients include age, habit of holding urine and pelvic surgery history. Given our preliminary data, viral infection can aggravate OAB severity and affect the composition of bacterial. Further research is required to explain how viral infections can aggravate OAB patient symptoms and cause bacterial changes.

Coexistence of HLA and KIR ligand mismatches as a risk factor for viral infection early after cord blood transplantation.

Viral infection is one of the lethal adverse events after cord blood transplantation (CBT). Human leukocyte antigen (HLA) and killer immunoglobulin-like receptor (KIR) ligand divergences can increase the risk of viral infection due to conflicting interactions between virus-infected cells and immune cells. However, the relationship between these disparities and the frequency of viral infection after CBT remains to be evaluated. Herein, we have conducted a retrospective multicenter study to assess the effect of HLA and KIR ligand mismatches on viral infections after CBT. The study included 429 patients, among which 126 viral infections occurred before day 100. Viral infection was significantly associated with poorer overall survival (OS; hazard ratio [HR] 1.74, p < 0.01). Patients harboring ≥3 mismatches in the HLA allele and inhibitory KIR ligand mismatches (HLA & KIR mismatches) had a significantly greater prevalence of viral infection (HR 1.66, p = 0.04). Thus, patients with HLA & KIR mismatches had poorer outcomes in terms of non-relapse mortality (HR 1.61, p = 0.05). Our study demonstrates the unfavorable impacts of HLA & KIR mismatches on viral infections and non-relapse mortality after CBT. Evaluating the viral infection risk and performance of an appropriate and early intervention in high-risk patients and optimizing the graft selection algorithm could improve the outcome of CBTs.

Risk factors for SARS-CoV-2 infection and epidemiological profile of Brazilian anesthesiologists during the COVID-19 pandemic: cross-sectional study

IntroductionThe devasting effects of COVID-19 have caused economic and health impacts worldwide. Anesthesiologists were one of the key professionals fighting the pandemic and have been highly exposed at their multiple sites of clinical practice. Thus, the importance of determining the nature of the infection in this population that provides care to SARS-CoV-2 patients. MethodWe conducted a cross-sectional study administering an online questionnaire to examine the demographic and epidemiological profile of these professionals in Brazil, and to describe the risk factors for viral infection during the pandemic. ResultsA total of 1,127 anesthesiologists answered the questionnaire, 55.2% were men, more than 90% with age below 60 years, with infection and reinfection rates of 14.7% and 0.5%, respectively, and 47.2% reported a significant income reduction. The predictors of COVID-19 contamination were practicing in operating rooms (OR = 0.42; 95% CI 0.23–0.78), direct contact with infected patients (OR = 5.74; 95% CI 3.05–11.57), indirect contact with infected patients (OR = 2.43; 95% CI 1.13–5.33), working in a pre-hospital setting (OR = 2.36; 95% CI 1.04–5.03), and presence of immunosuppression, except for cancer (OR = 4.89; 95% CI 1.16–19.01). ConclusionCOVID-19 had enormous consequences on Brazilian anesthesiologists regarding sociodemographic aspects and contamination rates (5.57 times higher than in the general population). These are alarming and unprecedented findings for this professional group, as they reveal the considerable risk of infection and its independent predictor variables.

Predictors of incident viral symptoms ascertained in the era of COVID-19.

BackgroundIn the absence of universal testing, effective therapies, or vaccines, identifying risk factors for viral infection, particularly readily modifiable exposures and behaviors, is required to identify effective strategies against viral infection and transmission.MethodsWe conducted a world-wide mobile application-based prospective cohort study available to English speaking adults with a smartphone. We collected self-reported characteristics, exposures, and behaviors, as well as smartphone-based geolocation data. Our main outcome was incident symptoms of viral infection, defined as fevers and chills plus one other symptom previously shown to occur with SARS-CoV-2 infection, determined by daily surveys.FindingsAmong 14, 335 participants residing in all 50 US states and 93 different countries followed for a median 21 days (IQR 10–26 days), 424 (3%) developed incident viral symptoms. In pooled multivariable logistic regression models, female biological sex (odds ratio [OR] 1.75, 95% CI 1.39–2.20, p<0.001), anemia (OR 1.45, 95% CI 1.16–1.81, p = 0.001), hypertension (OR 1.35, 95% CI 1.08–1.68, p = 0.007), cigarette smoking in the last 30 days (OR 1.86, 95% CI 1.35–2.55, p<0.001), any viral symptoms among household members 6–12 days prior (OR 2.06, 95% CI 1.67–2.55, p<0.001), and the maximum number of individuals the participant interacted with within 6 feet in the past 6–12 days (OR 1.15, 95% CI 1.06–1.25, p<0.001) were each associated with a higher risk of developing viral symptoms. Conversely, a higher subjective social status (OR 0.87, 95% CI 0.83–0.93, p<0.001), at least weekly exercise (OR 0.57, 95% CI 0.47–0.70, p<0.001), and sanitizing one’s phone (OR 0.79, 95% CI 0.63–0.99, p = 0.037) were each associated with a lower risk of developing viral symptoms.InterpretationWhile several immutable characteristics were associated with the risk of developing viral symptoms, multiple immediately modifiable exposures and habits that influence risk were also observed, potentially identifying readily accessible strategies to mitigate risk in the COVID-19 era.

Seroprevalence of the viral pig diseases among backyard pigs in Chiang Mai, Thailand

The Participatory One-Health Disease Detection project (PODD) (www.cmonehealth.org) developed a health-based surveillance system with the local government of Chiang Mai community ownership that has been created a mobile application on smartphone for reporting an abnormal event, especially animal health. Previously, the PODD project has obtained a significant number of pig abnormal events. Therefore, there are likely to be some diseases that are currently circulating among backyard pigs. A cross-sectional serological study was undertaken to determine the risk factors for virus infection and prevalence of antibodies against the classical swine fever virus (CSFV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2) and influenza A virus (IAV) among backyard pigs in Chiang Mai, Thailand. Antibodies against the CSFV, PRRSV and PCV2 in backyard pigs were shown in swine level to be 14 % (95 % CI: 9–20), 14 % (95 % CI: 10–19), and 15 % (95 % CI: 8–23), respectively. For the household level, antibodies against the CSFV, PRRSV and PCV2 were found to be 23 % (95 % CI: 13–37), 22 % (95 % CI: 14–23), and 48 % (95 % CI: 32–63), respectively, while antibodies against IAV were shown to be absent. The use of artificial insemination for breeding purposes has been considered to be a significant risk factor associated with PRRSV (OR = 21.08, 95 % CI: 1.92–232.02) and CSFV (OR = 7.7, 95 % CI: 1.49–39.90) infections. Meanwhile, a risk factor for PCV2 infection was found to significantly involve the feeding of pigs with commercial feed (OR = 9.64, 95 % CI: 1.85–50.26). The findings of this study indicate that infections with CSFV, PRRSV, and PCV2 remain a significant concern and may have an impact on the growth performance of the backyard pigs. The lack of antibodies against the influenza A virus has indicated a low degree of interspecies transmission of influenza A among backyard pigs in Chiang Mai, Thailand. Effective control measures need to be prepared and implemented, and these should include the strict regulation of pig imports as a free source of the viruses along with effective animal quarantine, policies, and appropriate vaccination programs.

Night shift schedule alters endogenous regulation of circulating cytokines

Night shift work is a risk factor for viral infection, suggesting that night shift schedules compromise host defense mechanisms. Prior studies have investigated changes in the temporal profiles of circulating cytokines important for priming and restraining the immune response to infectious challenges from night shift work, but not by way of a 24-h constant routine of continuous wakefulness devoid of behavioral or environmental influences. Hence the true endogenous pattern of cytokines, and the combined effect of sleep loss and circadian misalignment on these cytokines remains unknown. Here, 14 healthy young men and women underwent three days of either a simulated night shift or a simulated day shift schedule under dim light in a controlled in-laboratory environment. This was followed by a 24-h constant routine protocol during which venous blood was collected at 3-h intervals. Those who had been in the night shift schedule showed lower mean circulating TNF-α (t13 = -6.03, p < 0.001), without any significant differences in IL-1β, IL-8 and IL-10, compared with those who had been in the day shift (i.e., control) schedule. Furthermore, circulating IL-6 increased with time awake in both shift work conditions (t13 = 6.03, p < 0.001), such that temporal changes in IL-6 were markedly shifted relative to circadian clock time in the night shift condition. These results indicate that night shift work compromises host defense by creating cytokine conditions that initially impede anti-viral immunity (lower TNF-α) and may eventually promote autoimmunity (mistimed rise in IL-6).

Hepatitis C virus infection risk factors and test uptake in an English prison

Background: People in prison are a key demographic in the drive to eliminate hepatitis C virus (HCV). There is insufficient knowledge about risk factors for HCV among the prison population, which may partially explain low test uptake. Aims: This study aimed to understand the HCV risk factors present and HCV test uptake in an English prison. Methods: Men in prison were surveyed. The questions included whether they had been tested in current sentence, reasons for not being tested and risk factors for HCV. Findings: Of 109 respondents, 71% had not been tested in their current prison, 45% had not tested in their current sentence and 35% reported ever injecting drugs. Additional risk factors for hepatitis C included: sharing prison hair clippers (76%) and fighting in prison (44%). Conclusions: Not all people in prison with risk factors for HCV were tested. The role of intra-prison risks, such as fighting and sharing hair clippers, requires furtherexploration.

Comparative Review of SARS-CoV-2, SARS-CoV, MERS-CoV, and Influenza A Respiratory Viruses

The 2019 novel coronavirus (SARS-CoV-2) pandemic has caused a global health emergency. The outbreak of this virus has raised a number of questions: What is SARS-CoV-2? How transmissible is SARS-CoV-2? How severely affected are patients infected with SARS-CoV-2? What are the risk factors for viral infection? What are the differences between this novel coronavirus and other coronaviruses? To answer these questions, we performed a comparative study of four pathogenic viruses that primarily attack the respiratory system and may cause death, namely, SARS-CoV-2, severe acute respiratory syndrome (SARS-CoV), Middle East respiratory syndrome (MERS-CoV), and influenza A viruses (H1N1 and H3N2 strains). This comparative study provides a critical evaluation of the origin, genomic features, transmission, and pathogenicity of these viruses. Because the coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 is ongoing, this evaluation may inform public health administrators and medical experts to aid in curbing the pandemic's progression.

Viral respiratory infections in very low birthweight infants at neonatal intensive care unit: prospective observational study

Background and objectiveVery low birthweight (VLBW) infants are highly susceptible to respiratory infections. Information about prevalence of viral respiratory infections (VRIs) in neonatal intensive care unit (NICU) is scarce. Recent...

Proton Pump Inhibitors are Risk Factors for Viral Infections: Even for COVID-19?

During the ongoing pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more attention should be paid to the balance of risks and benefits associated with proton pump inhibitors for the following reasons. One of the main functions of gastric juice is to inactivate swallowed microorganisms, thereby inhibiting infectious agents from reaching the intestine. Studies have documented that proton pump inhibitors are a risk factor for rotavirus, influenza virus, norovirus, and Middle East respiratory syndrome coronavirus infections, and are associated with an increased risk of acute gastroenteritis during periods of highest circulation of enteric viruses. In light of the evidence for gastrointestinal infection implying a fecal–oral transmission of SARS-CoV-2 and given the magnitude of the SARS-CoV-2/coronavirus disease 2019 pandemic, associated with the widespread misuse of proton pump inhibitors, this suggests that we should not rule out the hypothesis that patients treated with proton pump inhibitors may be more at risk of being infected by SARS-CoV-2.

Viral reactivations following hematopoietic stem cell transplantation in pediatric patients – A single center 11-year analysis

Viral reactivation occurs frequently in the context of immunodeficiency and immunosuppression after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and can cause severe complications. The aim of this single-center retrospective analysis was to characterize viral infections in the first year after HSCT, to investigate risk factors and to study the impact of viral infections on transplantation outcome. This will facilitate the identification of at-risk patients and the development of new preventive strategies. 107 pediatric allo-HSCT from January 2005 through December 2015 were analyzed for infections with Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), adenovirus (ADV), herpes simplex virus (HSV) and varicella zoster virus (VZV). Viral infections were detected after 68.2% of transplantations. The viruses most commonly encountered were HHV-6 (36/107) and EBV (30/107). Severe viral disease was rare (7/107) and none of the patients died as result of viral reactivation. Important risk factors for viral infections were higher age at HSCT, donor type and occurrence of acute graft-versus-host disease (aGvHD). Especially for EBV, transplant from an unrelated donor and in-vivo T-cell depletion (TCD) had a significant effect on infection rates, whereas for CMV the strongest effect was seen by donor and recipient serostatus with recipient seropositivity most predictive for reactivation. The occurrence of severe aGvHD was associated with EBV and ADV infections. For HSV, the recipient serostatus was identified as prognostic factor for HSV infections, while we found higher age at time of HSCT as risk factor for VZV infections. The overall survival of patients with or without viral infections did not differ significantly. Interestingly, when looking at the 85 patients in our cohort who had received an HSCT for a malignant disease, a tendency towards lower relapse rates was seen in patients affected by viral infections (HR 0.51, 95% CI 0.25 – 1.06, p = 0.072). Viral reactivations are common after pediatric allo-HSCT, though severe complications were rare in our collective. Determining risk factors for viral reactivations may help to identify patients in need of intensified monitoring and to individualize preventive strategies.

Epidemiology, Outcome and Risk Factors Analysis of Viral Infections in Children and Adolescents Undergoing Hematopoietic Cell Transplantation: Antiviral Drugs Do Not Prevent Epstein-Barr Virus Reactivation.

ObjectiveThe analysis of epidemiology, risk factors and outcome of viral infections in children and adolescents after hematopoietic cell transplantation (HCT).MethodsIn this multicenter nationwide study a total of 971 HCT procedures (741 allo-HCT; 230 auto-HCT) over a period of 6 years were analyzed.ResultsDuring this period 801 episodes of viral infections were diagnosed in 442 patients. The incidence of viral infections was 57.9% in allo-HCT and 4.8% in auto-HCT patients. The most frequent infections after allo-HCT were caused by cytomegalovirus (CMV), polyoma BK virus (BKV) and Epstein–Barr virus (EBV). The majority of infections occurred within the first 4 months after allo-HCT and over 80% required pharmacotherapy or symptomatic therapy. The median time of treatment of specific viral infection ranged from 7 (for EBV) to 24 (for CMV) days. The highest mortality was observed in case of CMV infection. The risk factors for viral infections were allo-HCT, acute leukemia, acute and chronic graft versus host disease (a/cGVHD), and matched unrelated donor (MUD)/mismatched unrelated donor (MMUD)-HCT. The risk factor for death from viral infection were CMV-IgG seropositivity in acute lymphoblastic leukemia recipient, and MUD/MMUD-HCT. The incidence of EBV infection requiring pre-emptive treatment with rituximab in allo-HCT children was 19.3%. In 30.8% cases of EBV infection, these episodes were preceded by other viral infection and treated with antivirals, which did not prevent development of EBV-DNA-emia with need of rituximab treatment in 81.5% cases. In 47.7% of these cases, GVHD was a factor enabling development of significant EBV-DNA-emia during antiviral therapy of other infection.ConclusionWe have shown that antiviral drugs do not prevent EBV reactivation in allo-HCT pediatric patients.

Association of viruses causing acute respiratory infections with meteorological factors and air pollutants in hospitalised children in Macao: a retrospective analysis

BackgroundThe association of viruses causing acute respiratory infections with meteorological factors and air pollutants have been reported, but few studies have been done in children in the subtropical marine monsoon climate zone. We investigated the association of such viral infections with particular meteorological factors and air pollutants in infants and children in Macao. MethodsWe searched electronic health records at Kiang Wu Hospital in Macao to retrospectively identify all children aged up to 12 years admitted to the hospital for acute respiratory infection between Jan 1, 2014, and Dec 31, 2017, except for those with congenital respiratory disease, systemic chronic diseases, nosocomial infections, or chronic tuberculosis. All patient data collected were anonymised. Meteorological and pollutant data, including the monthly average of temperature, relative humidity, dew point, and air pollutants (PM10, PM2·5, and NO2) were obtained from the Macao Meteorological and Geophysical Bureau. The primary outcome was the association of the number of respiratory tract infections with these meteorological and pollutant factors. The secondary outcome was determining any lag patterns of such associations. Pearson's correlation and multivariate linear regression were used for data analysis, and multicollinearity between predictor variables was assessed using the variance inflation factor. FindingsOf all 4880 eligible children, 3767 (77·2%) children had tested positive for viruses. 2120 (56·3%) were male and 1647 (43·7%) were female. Their average age was 2·65 years (SD 1·92), with 673 (17·9%) younger than 1 year, 2870 (78·2%) aged from 1 to less than 5 years, and 225 (5·9%) aged 5–12 years. Out of all meteorological factors tested, only relative humidity was weakly associated with the number of viral infections (r=0·143, p=0·038), whereas monthly temperature (r=0·105, p=0·13) and dew point (r=0·131, p=0·059) showed no significant correlation. The overall pollution patterns of the three air pollutants were not similar, but all of them (PM10r=–0·281, p<0·0001; PM2·5r=–0·357, p<0·0001; NO2r=–0·182, p=0·0089) were negatively associated with virus detection. The multivariate linear regression analysis showed that one-week lags in temperature (β=–0·675, p<0·0001) and three-week lags in PM2·5 (β=–0·113, p=0·0059) were also negatively associated with the number of acute viral respiratory infections. InterpretationMeteorological factors could help to explain the prevalence of acute viral respiratory infections. However, air pollutants did not appear to be risk factors for viral infections. Our study warrants further investigation into the influence of the subtropical marine monsoon climate on acute viral respiratory infections in children. An improved understanding of how meteorological changes and exposure to air pollutants could affect respiratory viral infections could help clinicians to decide on diagnoses, prevention strategies, and therapeutic approaches. FundingNone.

PS1552 THE INCIDENCE RATES AND RISK FACTORS OF ATYPICAL INFECTIONS IN PATIENTS WITH LYMPHOMA WHO RECEIVED AUTOLOGOUS STEM CELL TRANSPLANTATION

Background:Autologous stem cell transplantation (ASCT) is an intermediate risk group for infections according to National Comprehensive Cancer Network (NCCN) guideline. Based on the risk of infection, experts recommend prophylaxis for fungal infections with fluconazole or micafungin if mucositis is accompanied, and prophylaxis for Pneumocystitis jirovecii (P. jirovecii) infection with trimethoprim‐sulfamethoxazole (TMP‐SMX) for 3 to 6 months after transplantation. For varicella zoster virus (VZV) reactivation, acyclovir or famcyclovir or valacyclovir is recommended as prophylaxis for 6 to 12 months after ASCT. However, there is a lack of evidence to support this guideline.Aims:In this study we performed a nationwide population‐based study to provide information regarding the incidence and risk factors of atypical infections such as fungal, viral or PJP in patients were performed ASCT in the South Korea.Methods:Using the Korean Health Insurance Review and Assessment Service database, the patients with lymphoma who received ASCT from 2003 to 2016 were retrospectively analyzed. Atypical infection is identified by international classification of disease (ICD) codes of each infection or ATC(Anatomical Therapeutic Chemical) codes of medicines for treatment. Oral Candidiasis, Herpes simplex virus (HSV), and Epstein‐Barr virus (EBV) infection were excluded because these are considered to non‐pathogenic in clinical field. The patients undergoing allogenic stem cell transplantation (AlloSCT) were excluded.Results:The total number of patients with lymphoma undergoing ASCT was 2147, median age was 48 years (range 2–70). The cumulative incidence of fungal infection is 10.4%, viral is 20.0% and PJP is 5.5% in lymphoma. In multivariate analysis, TBI (HR 1.702, p = 0.0390), and previous fungal infection (HR 1.701, p = 0.0398) were independent significant risk factors for fungal infection. The multivariate analysis showed that TBI (HR 2.524, p &lt; 0.0001), previous infection history (HR 1.351, p = 0.0046) and prophylaxis (HR 1.633, p = 0.0001) were independent risk factors for viral infection. The multivariate analysis showed that prophylaxis (HR 2.647, p = 0.0002) were independent risk factors for PJP infection.Summary/Conclusion:In this study, patients with lymphoma who underwent ASCT showed relative high risk of viral infection (CIR 20.0%) and previous viral infection, TBI conditioning and non‐prophylaxis were independent risk factors for viral infection. So patients with lymphoma who planed ASCT should be considered prophylaxis for 2years after ASCT. Especially, patient who treated with TBI conditioning and have previous viral infection should receive prophylactic anti‐viral agents.

Donor NKG2C Copy Number: An Independent Predictor for CMV Reactivation after Double Cord Blood Transplantation

Cytomegalovirus (CMV) is a member of the herpesviridae family and remains latent in the host cells after primary infection. The virus reactivates in the immunosuppressed host and is a leading cause of morbidity following allogeneic hematopoietic stem cell transplant (allo-HSCT). Natural killer (NK) cells provide the first-line defence against viruses and a subset of NK cells expressing NKG2C have been shown to play a role in the immune surveillance of human CMV. Deletion of the NKG2C gene has been reported as a risk factor for viral infections including CMV and HIV, but current data on the influence of NKG2C gene-copy number variations in the donor graft on the risk of CMV reactivation after allo-HSCT is limited. Following cord blood transplantation (CBT), where the T-cell compartment is functionally naïve, the NKG2C genotype may have an even more pronounced impact on the risk of CMV reactivation. Therefore, we studied NKG2C copy number in the donor graft and the risk of CMV reactivation after double umbilical cord blood transplantation (DUCBT) in 100 CMV seropositive DUCBT recipients and their corresponding cord blood grafts (n=200). The gene encoding NKG2C is present at different copy numbers in the genomes of different individuals, with possible genotypes including 2 copies (wt/wt), 1 copy due to heterozygous deletion (wt/del) or 0 copies due to homozygous deletion (del/del). Among the donor CB units, approximately 2/3 had both copies of the gene (wt/wt), 1/3 had only one copy (wt/del) and only a minority of units had 0 copies with both alleles deleted (del/del). In the setting of DUCBT, the combined graft may contain 0 to 4 functional copies of NKG2C gene. In our cohort, patients whose combined grafts contained only 1 or 2 NKG2C gene copies had a significantly higher probability of CMV reactivation than patients whose combined grafts had 3 or 4 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the 4 groups was 100%, 92.9%, 60.5% and 55.9% respectively (p=0.005). No patient received a graft with zero gene copies. For the rest of the analysis we divided the patients into two groups, namely the 84 patients who received a combined graft with 3 or 4 NKG2C copies and the 16 patients who received two units with 1 or 2 NKG2C copies. The 6-month cumulative incidence of CMV reactivation for the two groups was 58.4% and 93.7% respectively (p=0.0003). In a multivariate analysis, receiving a combined graft with low NKG2C copy number (1 or 2 copies) (HR=2.72, CI=1.59-4.64; p<0.0001) and reduced intensity conditioning (RIC) (HR=0.59, CI=0.35-0.99, p=0.046) were the only independent predictors for CMV reactivation. Interestingly, the NKG2C copy number of the dominant cord was not predictive for CMV reactivation, suggesting that both cord blood units contribute to the antiviral response early post-DUCBT. Our study points to an important role for donor NKG2C in protection against CMV reactivation after DUCBT. If confirmed in larger numbers of CBT recipients, NKG2C genotyping of the CB graft may be a useful biomarker for predicting the risk of CMV infection after CBT, thus guiding the intensity of CMV prophylaxis for individual patients. Moreover these novel findings may provide a compelling rationale for considering NKG2C genotype as a criterion in the algorithm of CB selection for DUCBT. DisclosuresOran:ASTEX: Research Funding; AROG pharmaceuticals: Research Funding; Celgene: Consultancy, Research Funding. Champlin:Sanofi: Research Funding; Otsuka: Research Funding. Shpall:Affirmed GmbH: Research Funding.

Clinical course of human herpesvirus 6 infection in pediatric living donor liver transplantation.

Differentiation between active and latent viral infection is critical for analysis of HHV-6-associated disease. HHV-6 infection has been associated with several clinical manifestations; however, the precise role of HHV-6 in pediatric LDLT remains unclear. This retrospective cohort study included 33 pediatric patients who received LDLT. All of the recipients were monitored for HHV-6 infection using viral isolation and real-time PCR. HHV-6 infection was observed in 14 of 33 (42.4%) recipients, and HHV-6B infection occurred within 2weeks after LDLT in 10 of 14 (71.4%) recipients. HHV-6 was isolated from 10 of 33 (30.3%) recipients. Multivariate analysis showed that independent predictors of HHV-6B infection were age (OR 0.975; 95% CI 0.943-0.999; P=.041), PELD (OR 1.091; P=.038), and biliary atresia (OR 16.48; P=.035). The occurrence of unexplained fever was significantly higher in recipients with HHV-6B infection (11/14) compared with uninfected recipients (6/19) (P=.013). Additionally, ALT levels at 8 and 9weeks after transplantation were significantly higher in the recipients with HHV-6B infection. Younger age, high MELD/PELD score, and biliary atresia as an underlying disease were identified as risk factors for viral infection.