Severe Pneumonia Caused by Respiratory Syncytial Virus and Adenovirus in Children from 2 to 24 Months at Children's Hospital 1 in Ho Chi Minh City, Vietnam.

In Vietnam, due to the lack of facilities to detect respiratory viruses from patients' specimens, there are only a few studies on the detection of viral pathogens causing pneumonia in children, especially respiratory syncytial virus (RSV) and adenovirus (Adv). Here, we performed a cross-sectional descriptive prospective study on 138 children patients from 2 to 24 months old diagnosed with severe pneumonia hospitalized at the Respiratory Department of Children's Hospital 1 from November 2021 to August 2022. The number of patients selected in this study was based on the formula n = ([Z(1 - α/2)]2 × P [1 - P])/d2, with α = 0.05, p = 0.5, and d = 9%, and the sampling technique was convenient sampling until the sample size was met. A rapid test was used to detect RSV and Adv from the nasopharyngeal swabs and was conducted immediately after the patient's hospitalization. Laboratory tests were performed, medical history interviews were conducted, and nasotracheal aspirates were collected for multiplex real-time PCR (MPL-rPCR) to detect viral and bacterial pathogens. The results of the rapid test and the MPL-rPCR in the detection of both pathogens were the same at 31.9% (44/138) for RSV and 8.7% (7/138) for Adv, respectively. Using MPL-rPCR, the detection rate was 21% (29/138) for bacterial pathogens, 68.8% (95/138) for bacterial-viral co-infections, and 6.5% (9/138) for viral pathogens. The results showed few distinctive traits between RSV-associated and Adv-associated groups, and the Adv group children were more prone to bacterial infection than those in the RSV group. In addition, the Adv group experienced a longer duration of treatment and a higher frequency of re-hospitalizations compared to the RSV group. A total of 100% of Adv infections were co-infected with bacteria, while 81.82% of RSV co-infected with bacterial pathogens (p = 0.000009). This study might be one of the few conducted in Vietnam aimed at identifying viral pathogens causing severe pneumonia in children.

Monitoring of adenoviremia in pediatric patients undergoing hematopoietic stem cell transplantation: Is it alone sufficient to predict adenoviral disease?

BACKGROUND: We aimed to evaluate our pediatric HSCT recipients routinely monitored for adenoviremia and to determine the adequacy of this monitoring in predicting adenoviral disease (AD). METHODS: A retrospective cohort of patients who underwent allogeneic HSCT between January 2021 and August 2022, and routinely monitored for adenoviremia by real-time PCR was included in our survey. Demographic and clinical data of the patients were recorded. Incidence rates, risk factors, and mortality rates related to adenoviremia, and AD were analyzed. RESULTS: Among 104 HSCTs performed in 94 patients adenovirus (AdV) was revealed in 27 (26%) episodes and adenoviremia in 18 (17.3%) HSCT episodes. AD without adenoviremia developed in nine episodes (8.6%). Disseminated disease was significantly more frequently detected in episodes with adenoviremia (p = .008). GVHD was independent risk factor for AdV detection (OR: 8.6, 95% CI: 2.03-33.7, p = .001). Viremia developed within a shorter time interval after HSCT in isolated episodes of adenoviremia compared to those with concomitant AD (p = .006). Initial and peak viral loads were significantly higher in adenoviremia with AD (p < .001). Mortality was higher in the AdV-detected episodes (p < .001) than in the AdV-undetected episodes. AdV-related mortality was found to be 22.2%. Adenoviremia increased the risk of mortality (OR: 1.2, 95% CI: 0.22-1.33, p = .01). CONCLUSIONS: Adenoviremia monitoring is an important process in the detection of AD. Since some patients may develop AD without accompanying by adenoviremia, monitoring for AdV in blood samples should be supported with other monitoring methods in order to evaluate the probable involvement of different organs or systems.

Development of an ELISA for the detection of fowl adenovirus serotype -4 utilizing fiber protein.

Hydropericardium syndrome (HPS), caused by the Fowl adenovirus 4 (FAdV-4) has led to significant financial losses for the poultry industry globally, including Pakistan over the past few years. Conventional serological methods are time consuming, laborious and less sensitive therefore, a rapid and sensitive ELISA kit is required for the reliable detection of FAdV-4 infection. In the current research, fiber proteins (1 &2) of FAdV-4 were successfully expressed in Escherichia coli and purified using metal affinity chromatography. Using these proteins as antigens, an indirect ELISA for detecting FAdV-4 infection was developed. The developed ELISA showed superior performances upon comparison with Serum neutralization test (SNT). This ELISA also showed reliable detection of FAdV specific antibodies in experimentally infected and vaccinated chickens. This assay produced good correlation on the samples collected from the field with SNT and found essential for large scale serology of the FAdV. No cross reactivity was observed in the ELISA following the testing of the serum samples of different other avian pathogens which showed that this ELISA is specific in detecting the FAdV infection. In conclusion, the developed Fiber protein ELISA is highly sensitive and specific in the detecting the FAdV infection and can be utilized for large scale sero-epidemiology of the disease.

A Fulminant Case of Adenovirus Genotype C108 Infection in a Pediatric Stem Cell Transplant Recipient with x-Linked Lymphoproliferative Syndrome Type 1.

A 3-year-old male with X-linked lymphoproliferative syndrome type 1 underwent an unrelated umbilical cord blood transplant (UUCBT). The week prior to transplant the patient tested positive for adenovirus (HAdV) with a viral load of <190 copies/mL and was started on cidofovir. UUCBT proceeded as scheduled, and the patient engrafted on day +19. The patient's HAdV load in serum continued to rise with resulting hepatic dysfunction, despite ongoing therapy with cidofovir and HAdV specific T-cell infusions. The patient died 6 months after transplantation having never cleared the virus. Next generation whole genome sequencing and sequence data analyses identified an intertypic recombinant HAdV-C P1H2F2 closely related (99.6% similarity) to genotype C108 in the isolates from three blood specimens obtained during the last week of life. Incidentally, the de novo assembly strategy enabled the detection of an adeno-associated virus type 2 (AAV2) genome in the DNA purified from the plasma isolates. Proteotyping analysis revealed minor differences in the predicted amino acid sequences for E1A, E1B 19K, E1B 55K, DNA polymerase, penton base, and fiber. None of the mutations previously described for HAdV-C5 variants resistant to cidofovir were identified. In silico restriction enzyme analysis revealed a distinct Sac I profile for the identified virus, supporting its designation as a C108 variant.

Cutaneous adenovirus infection in an immunocompromised child.

Adenoviruses are common viral pathogens in childhood; however, cutaneous manifestations are not well-documented. We present a rare case of cutaneous adenovirus infection in a 23-month-old boy with a background of CD40 ligand deficiency, post bone marrow transplant. The clinical morphology of the skin lesions in our patient, described as skin-colored papules with central crusting, has not been previously described and contributes to the growing literature of cutaneous adenovirus cases.

Visual detection of fowl adenovirus serotype 4 via a portable CRISPR/Cas13a-based lateral flow assay.

The widespread occurrence of fowl adenovirus serotype 4 (FAdV-4)-induced hepatitis-hydropericardium syndrome (HHS) has led to significant economic losses for the poultry industry. A sensitive, accurate, and practical FAdV-4 diagnostic approach is urgently required to limit the incidence of the disease. In the present study, a practical method for detecting FAdV-4 was developed using the CRISPR/Cas13a system and recombinase-aided amplification. The approach was based on 37°C isothermal detection with visible results being achieved. The detection limit of the target gene with this approach was only 101 copies/µl, making it very sensitive and specific. Clinical samples fared well when tested with the Cas13a detection method. For identifying FAdV-4, this novel detection approach was found to be sensitive, specific, and effective.RESEARCH HIGHLIGHTS First study using the CRISPR/Cas13a-based lateral flow detection assay for FAdV-4 detection.The results can be observed by the naked eye.The developed assay could provide an alternative tool for detection of FAdV-4 with minimal equipment.

Kawasaki disease, multisystem inflammatory syndrome in children, and adenoviral infection: a scoring system to guide differential diagnosis.

Children with Kawasaki disease (KD), Multisystem Inflammatory Syndrome in Children (MIS-C), and Adenovirus infections (AI) of the upper respiratory tract show overlapping features. This study aims to develop a scoring system based on clinical or laboratory parameters to differentiate KD or MIS-C from AI patients. Ninety pediatric patients diagnosed with KD (n = 30), MIS-C (n = 26), and AI (n = 34) admitted to the Pediatric Emergency Unit of S.Orsola University Hospital in Bologna, Italy, from April 2018 to December 2021 were enrolled. Demographic, clinical, and laboratory data were recorded. A multivariable logistic regression analysis was performed, and a scoring system was subsequently developed. A simple model (clinical score), including five clinical parameters, and a complex model (clinic-lab score), resulting from the addition of one laboratory parameter, were developed and yielded 100% sensitivity and 80% specificity with a score ≥2 and 98.3% sensitivity and 83.3% specificity with a score ≥3, respectively, for MIS-C and KD diagnosis, as compared to AI. CONCLUSION: This scoring system, intended for both outpatients and inpatients, might limit overtesting, contribute to a more effective use of resources, and help the clinician not underestimate the true risk of KD or MIS-C among patients with an incidental Adenovirus detection. WHAT IS KNOWN: • Kawasaki Disease (KD), Multisystem Inflammatory Syndrome in Children (MIS-C) and adenoviral infections share overlapping clinical presentation in persistently febrile children, making differential diagnosis challenging. • Scoring systems have been developed to identify high-risk KD patients and discriminate KD from MIS-C patients. WHAT IS NEW: • This is the first scoring model based on clinical criteria to distinguish adenoviral infection from KD and MIS-C. • The score might be used by general pediatricians before referring febrile children to the emergency department.

High rate of adenovirus detection in gastrointestinal biopsies of symptomatic stem cell transplant recipients.

OBJECTIVES: The gastrointestinal (GI) tract is a major human adenovirus (HAdV) replication site in patients undergoing hematopoietic stem cell transplantation (HSCT), yet the prevalence and correlates of HAdV GI infection in this setting have remained poorly recognized, especially among adult HSCT recipients. DESIGN OR METHODS: We retrospectively studied the prevalence and risk factors of HAdV GI-tissue infection in HSCT recipients (73 adults and 15 children) with GI symptoms who underwent GI-tissue biopsy between January-2012 and December-2017. The presence of HAdV in the GI tissues was determined by real-time PCR. RESULTS: HAdV GI-tissue infection was detected in 21 (23.9%) patients, with similar infection rates identified in adults and children. GI-tissue detection was more common at late (>100 days) compared to early times post-transplantation (50% vs. 12.9%, p < .001). The presence of bloody diarrhea, Arab ethnicity (p = .014) and concurrent cytomegalovirus GI-tissue detection (p = .025) were significantly correlated with HAdV GI-tissue infection, while chronic graft versus host disease was of borderline association (p = .055). CONCLUSIONS: Our findings reveal a high rate and new clinical-demographic correlates of HAdV GI-tissue infection in adult and pediatric HSCT recipients with GI symptoms. The findings highlight the need for future prospective studies to assess the relatedness of HAdV infection to the GI symptoms, and the prevalence, impact, and treatment of HAdV GI infection in HSCT recipients.

Adenovirus Infection in a Kidney-Pancreatic Transplant Recipient: Case Report.

Adenovirus infection in transplant recipients may present from asymptomatic viremia to multisystemic involvement. Most frequently, it occurs in the first year after a kidney transplant, and it is secondary to the reactivation of latent disease. However, primary infection may occur, and disseminated disease is more common when related to primary infection. Kidney involvement may be confirmed by biopsy, although diagnosis may be presumptive. Reduction of immunosuppression and supportive care are important components of therapy. CASE DESCRIPTION: A 41-year-old female renal-pancreatic recipient 12 years before with chronic renal graft dysfunction and a functional pancreatic graft had a history of cytomegalovirus and polyoma virus infection 2 years after transplantation. She was taking tacrolimus, mycophenolate mofetil, and prednisolone. The patient was admitted after persistent uncharacteristic diarrhea 3 weeks before hospitalization without any relevant epidemiologic context. She was dehydrated, and the lab results showed worsened kidney function and leucocytosis. The viral culture revealed adenovirus. Vigorous hydration was implemented, and the mycophenolate mofetil dose was reduced. The patient was discharged, and renal function returned to previous values. DISCUSSION AND CONCLUSION: Adenovirus infection has a wide clinical presentation, and multisystemic involvement may occur in transplant recipients. Supportive care is paramount. The clinical features and viral culture confirm the diagnosis, although tissue samples and quantitative polymerase chain reaction may be required in more severe cases.

[Diagnosis and treatment of 26 cases of adenovirus infection after allogeneic hematopoietic stem cell transplantation].

Objective: To analyze the clinical characteristics and prognosis of adenovirus infection after allogeneic hematopoietic stem cell transplantation. Methods: A total of 26 patients with adenovirus infection admitted to the posttransplant ward of the First Affiliated Hospital of Soochow University from 2018 to 2022 were enrolled. Their data on baseline and clinical characteristics, treatment, and follow-up were analyzed. Results: The median patient age was 30 (22, 44) years. Twenty-two patients received related haploid stem cell transplantation, three received unrelated stem cell transplantation, and one received umbilical cord stem cell transplantation. Antithymocyte globulin was included in the conditioning regimen in 25 patients. The median time of adenovirus infection was +95 (+44, +152) days. The median peripheral blood lymphocyte count was 0.30 (0.11, 0.69) × 10(9)/L. Twelve patients had acute graft-versus-host disease. Twenty-four patients received antirejection therapies at diagnosis. Sixteen cases had combined infection with other pathogens with adenovirus infection. Eight cases were diagnosed as asymptomatic infection, and 18 were diagnosed as adenovirus disease, including pneumonia (38.89% ) , gastrointestinal disease (38.89% ) , encephalitis (33.33% ) , hepatitis (5.56% ) , and urinary tract inflammation (5.56% ) . The age of >30 years was a risk factor for adenovirus disease (P=0.03) . Eighteen patients received tapering of immunosuppression, and all 26 patients received at least one antiviral drug. Other treatments included high-dose gamma globulin and donor lymphocyte infusion. Adenovirus infection improved in 10 cases and progressed in 16 cases. The median follow-up time was 30 (7, 237) days. Twenty-two patients died. The all-cause mortality rate was (88.5±7.1) % , and the attributable mortality rate was 45.5% . There was no significant difference in the 100 d survival rate between asymptomatic infected patients and patients diagnosed with adenovirus disease (37.5% vs 22.2% , HR=1.83, 95% CI 0.66-5.04, P=0.24) . Conclusion: The age of >30 years was a risk factor for adenovirus disease. Mortality was high in patients with adenovirus infection after allogeneic hematopoietic stem cell transplantation.

An efficient and convenient Fiber -2- based latex agglutination test for the detection of antibodies against fowl adenovirus serotype 4 in clinical samples.

To detect the antibody against fowl adenovirus serotype 4 (FAdV-4) in clinical practice, the latex agglutination test (LAT) was developed by using the Fiber-2 protein of FAdV-4 as an antigen bound to sensitized latex microspheres. The concentration, time, and temperature of sensitization latex microspheres by the Fiber-2 protein were studied and optimized; the specificity, sensitivity, and repeatability of LAT were tested; and the method developed in the study was applied. The results showed that the optimum sensitization concentration of Fiber-2 protein was 0.8 mg/mL, the time was 120 min, and the temperature was 37 â„ƒ. Except for antiserum against FAdV-4 and FAdV-10, LAT developed in the study could not agglutinate antisera against FAdV-1, FAdV-2, FAdV-3, FAdV-4, FAdV-5, FAdV-6, FAdV-8a, FAdV-8b, FAdV-11, Newcastle disease virus, infectious bronchitis virus, egg drop syndrome virus and Clostridium perfringens. Compared with the commercial FAdV-4 ELISA Kit, the titers in 21 clinical samples were low when tested by the developed LAT method, but there was no significant difference. The coefficients of variation among different batches and the same batch of latex-sensitized particles were between 0 % and 13.3 % and 0-8.7 %, respectively. The critical value of immune protective antibody against FAdV-4 was 25, and the titers in 40.9 % of clinical samples were higher than the immune critical point. The results showed that the Fiber-2-based LAT developed in the study has the characteristics of high specificity, sensitivity and repeatability, has the advantages of free equipment, long shelf life, and fast and easy operation, and is an effective and convenient method for serological diagnosis of FAdV-4 infection and evaluating the efficacy of vaccines.

Rapid antigen test for adenovirus in children: Age and onset of symptoms are important.

INTRODUCTION: Respiratory infection is the most common human adenovirus (HAdV) disease accounting for 7-8% of viral respiratory diseases in children less than 5 years. Differentiation of bacterial infections and viral infections is a common clinical problem. MATERIAL AND METHODS: One hundred oropharyngeal swabs obtained from October 2019 to November 2020 from patients attending the paediatric emergency room with suspicion of upper respiratory tract infection and negative results in influenza and RSV tests were included. Oropharyngeal swabs specimens were rapidly processed with STANDARD™ F Adeno Respi Ag FIA and the results were confirmed by RealStar® Adenovirus PCR Kit 1.0 (Altona diagnostics). RESULTS: STANDARD™ F Adeno Respi Ag FIA had sensitivity and specificity values of 71.93% and 100% respectively. The performance of the test was higher in samples from children younger than 24 months and taken less than 72h since the beginning of symptoms. In this subgroup the test had 88.8% sensitivity and 100% specificity. CONCLUSION: STANDARD™ F Adeno Respi Ag FIA may improve the management of respiratory diseases in children younger than 24 months and less than 72h since the beginning of symptoms in paediatric emergency rooms.

TaqMan probe-based qPCR method for specific detection and quantification of fowl adenovirus 8b challenge from chickens inoculated with live attenuated or inactivated virus.

Background: Fowl adenovirus (FAdV) 8b and other serotypes cause inclusion body hepatitis (IBH) in chickens. Specific detection of aetiologic serotype in mixed infection and vaccine failure could be difficult. Aim: The objective of this study was to develop a TaqMan probe-based qPCR method for the detection and quantification of the FAdV 8b challenge virus. Methods: Forty-eight broiler chickens inoculated with live attenuated or inactivated FAdV 8b strains at day 1 of age either with or without booster at day 14 post-inoculation were used. The chickens were challenged with a pathogenic strain of FAdV 8b at day 28 of age. Liver and cloacal swabs were collected on days 7 and 14 post-challenge. Primers and probes were designed, specificity confirmed, and used to carry out qPCR amplification. Results: The assay amplified the FAdV DNA challenge virus, but not that of the live attenuated virus. It could detect FAdV 8b DNA as low as 0.001 ng/µl in liver and cloacal swab samples. Copy numbers obtained indicate virus load and shedding. Conclusions: It shows that a selective detection of FAdV 8b within serotype is possible. It can be useful for rapid detection and diagnosis of the disease, virus quantification and differentiation within species, determination of vaccination failure, and efficacy especially the virus load in the target organ and shedding.

Adenovirus infection diagnosed by metagenomic next-generation sequencing after haploidentical hematopoietic stem cell transplantation: A multicenter study in China.

OBJECTIVE: This study aims to observe and analyze the clinical characteristics and prognosis of adenovirus (ADV) infection diagnosed by metagenomic next-generation sequencing (mNGS) after haploidentical hematopoietic stem cell transplantation (Haplo-HSCT), which was performed following Beijing Protocol. METHODS: The clinical data of patients who developed ADV infection diagnosed by mNGS after Haplo-HSCT between January 2019 and March 2021, recorded in three transplantation centers, were retrospectively analyzed. Potential risk factors for infection and the clinical manifestations of ADV involvement in different end-organs were also studied. Additionally, the patient prognosis regarding the available treatment was observed. RESULTS: A total of seven patients were diagnosed with ADV infection by the mNGS technique after Haplo-HSCT of 976 patients enrolled. The risk factors for infection included antithymocyte globulin steroid-refractory graft-versus-host disease (GVHD) history, CD25 monoclonal antibody or ruxolitinib treatment history and <300 cells/µL of CD3+ T cells count in peripheral blood. The clinical manifestations of ADV infection included encephalitis, hepatitis, cystitis, and pneumonia. Six patients were treated with cidofovir (CDV) and intravenous immunoglobulin (IVIg), and one with CDV, ribavirin, IVIg, thymosin Alpha-1 for injection and low-dose donor lymphocyte infusion. One case showed negative ADV DNA results with improved conditions; however, the patient died of the relapse of the primary disease in the later stage. The remaining six died of ADV infection. CONCLUSION: mNGS can provide screening for ADV and information on ADV subtypes, helpful to understand tissue tropism. This technique could be useful in diagnosing patients at high risk for ADV infection. ADV infection can involve multiple organs, has difficulty in early diagnosis, and has a poor prognosis. Currently, effective treatments are inadequate.

Adenovirus Meningoencephalitis and Neurocysticercosis Co-infection: First Case from India.

BACKGROUND: Adenovirus generally causes upper and lower respiratory tract infections. It is common in children and occasionally in adults. Neurological involvement is rare, which may be mild aseptic meningitis to potentially fatal acute necrotizing encephalopathy. Recently, viruses have been reported increasingly to cause CNS infections. Viral aetiology typically varies with age. CASE PRESENTATION: Here, we report an unusual adenovirus meningoencephalitis with a co-infection of neurocysticercosis in an immunocompetent adult patient. An 18-year-old healthy female student was admitted with fever and headache for 11 days and progressive altered behaviour for 5 days, followed by altered sensorium for 3 days. This variable and unusual presentation of adenoviral infection involving CNS provoked diagnostic difficulties, but with the help of advanced diagnostics, especially molecular, exact aetiology was detected. Even with the neurocysticercosis infection in this patient, the outcome was not adversely affected. CONCLUSION: This unusual co-infection with a successful outcome is the first case of this type in literature.

Keratouveitis in juvenile dogs and its presumed association with canine adenovirus infection.

OBJECTIVE: We hypothesized that keratouveitis still occurs despite current widespread use of Canine adenovirus (CAV)-2 vaccinations and assessed the utility of CAV-1 and CAV-2 titers in elucidation of its etiopathogenesis. ANIMALS STUDIED: Nine dogs with unexplained keratouveitis (14 eyes) and nine control dogs. PROCEDURES: The Animal Health Trust clinical database was searched between 2008 and 2018 to identify cases of keratouveitis. Inclusion criteria included known vaccination status, interval from vaccination to development of clinical signs and availability of CAV titers. Cases were excluded if they were older than 1 year of age, or other causative ocular pathology for corneal edema was identified. Nine age-matched dogs without corneal edema but with CAV titers were included as controls. RESULTS: Mean CAV-1 and CAV-2 titers were not statistically different between dogs with keratouveitis and controls (p = .16 and p = .76, respectively). Three cases had CAV-1 titers >5000 and two of these cases had rising convalescence titers (greater than an 11-fold increase) suggesting infection with wild-type CAV-1. The six other cases did not appear to be associated with CAV infection or vaccination. CONCLUSION: Keratouveitis continues to occur despite the advent of CAV-2 vaccinations. While this study found no evidence to indicate CAV-2 vaccination causes keratouveitis, the data indicates that in a proportion of cases, contemporaneous wild-type CAV-1 infection is a possible cause.

Droplet Digital PCR Development for Adenovirus Load Monitoring in Children after Hematopoietic Stem Cell Transplantation.

Human adenovirus (AdV) reactivation after hematopoietic stem cell transplantation (HSCT) is associated with life-threatening clinical manifestations. Although real-tme quantitative PCR (qPCR) has been widely used to measure AdV loads, it has not been standardized for AdV. Droplet digital PCR (ddPCR) is a novel pathogen detection technology that enables the absolute quantification of viral loads. ddPCR would enable a more accurate AdV DNA detection compared with qPCR. In this study, ddPCR was developed for AdV DNA and its performance characteristics compared with those of qPCR. AdV DNAemia incidence during the first 12 weeks after allogenic HSCT was then retrospectively examined by qPCR and ddPCR in 97 HSCT procedures using the preserved 545 DNA samples. ddPCR exhibited better reproducibility and sensitivity, as well as equivalent quantifiability, compared with qPCR. AdV DNA among HSCT patients was detected in 11 (2.0%) and 49 (9.0%) of 545 samples by qPCR and ddPCR, respectively. AdV DNA levels >1000 copies/mL were observed in five cases by qPCR and/or ddPCR. However, two patients developed fulminant hepatitis and died; other patients remained asymptomatic with subsequently undetectable AdV DNA. In conclusion, ddPCR was more sensitive and reproducible in detecting AdV DNA among pediatric HSCT recipients than qPCR. ddPCR offers the potential to provide a more accurate DNAemia detection, determine cutoff values for treatment initiation, and enable antiviral efficacy assessment.

Construction and analysis of a nomogram prediction model for post-infectious bronchiolitis obliterans in children with adenovirus pneumonia after invasive mechanical ventilation.

BACKGROUND: Post-infectious bronchiolitis obliterans (PIBO) is the most common sequelae in children with adenovirus pneumonia (ADVP). However, there are few studies on the risk factors for PIBO occurrence. This study aims to investigate the risk factors for PIBO in pediatric patients with severe ADVP, especially after invasive mechanical ventilation (IMV), as well as to build a nomogram prediction model. METHODS: The clinical data, laboratory and imaging features, and treatment of 863 children with ADVP under 3 years old who were admitted to our hospital from January to December 2019 were retrospectively analyzed. Among them, 66 children with severe ADVP received IMV treatment. The situation and the influencing factors of PIBO in children with severe ADVP were explored, and a nomogram prediction model was constructed. RESULTS: Among the 863 cases of ADVP, 46 cases (5.33%) developed PIBO. Duration of fever, IMV, complications, and neutrophil percentage were independent risk factors for PIBO in children with ADVP. Among the 66 patients with ADVP who underwent IMV, 33 patients (50.0%) developed PIBO. Gender, duration of fever, adenovirus (ADV) load, and mixed fungal coinfections were independent risk factors for PIBO. In the nomogram prediction model analysis, the area under the curve (AUC) was 0.857; in addition, Hosmer‒Lemeshow (H-L) detection reflected good alignment (χ2 = 68.75, P < 0.01). CONCLUSIONS: A nomogram prediction model, which can be utilized to predict PIBO occurrence in pediatric patients with ADVP after IMV at an early time period, was successfully built.