Adenovirus respiratory infection in hospitalized children in Hong Kong: serotype-clinical syndrome association and risk factors for lower respiratory tract infection

Seroprevalence of neutralizing antibodies to human mastadenovirus serotypes 3 and 7 in healthy children from guangdong province

Severe adenovirus pneumonia is becoming more common in children infected with human mastadenovirus (HAdV)-3 and HAdV-7 than in those infected with other types of adenoviruses. Recently, there has been a trend toward an increasing prevalence of pneumonia caused by HAdV-7, an important viral pathogen in Pediatric Intensive Care Unit infections. Children infected with HAdV-7 have more serious symptoms of acute respiratory infections and other complications than those infected with HAdV-3. No specific anti-adenovirus drugs or vaccines are available for treatment or prevention. Therefore, we investigated the seroprevalence and titer levels of neutralizing antibodies (NAbs) against HAdV-3 and HAdV-7 in healthy children in Guangdong Province. We found that the seropositivity rates and antibody titers for HAdV-3 NAb were higher than those for HAdV-7 NAb. In children between 6 and 12 months of age, the seropositivity rates and titers were significantly low against HAdV-3 and HAdV-7. The HAdV-7-positive rate was significantly higher in the HAdV-3-positive samples than in the HAdV-3-negative samples. The HAdV-7 NAbs carried by the 0-6-month age group were dominated by low titers. These results reveal a low level of herd immunity against HAdV-3 and HAdV-7 in children, clarifying the importance of monitoring these two highly virulent adenoviruses, developing prophylactic vaccines, and predicting potential outbreaks.

Analysis of mortality risk factors in children with severe adenovirus pneumonia: A single-center retrospective study

BACKGROUND

Human adenovirus (HAdV) is one of the most common viruses causing respiratory infections among young children. Most adenovirus infections are mild and self-limited; however, these infections may occasionally cause severe pneumonia and even death. The mortality risk factors for severe adenovirus pneumonia are not completely clear. This study aimed to evaluate the mortality risk factors in children with severe adenovirus pneumonia.

METHODS

A retrospective study of children with severe adenovirus pneumonia hospitalized in Guangzhou Women and Children's Hospital between July 2018 and January 2020 was performed. Binary logistic regression analysis was used to identify independent mortality risk factors for severe adenovirus pneumonia after univariate analysis.

RESULTS

Our study included 189 patients (123 males and 66 females). Among them, 13 patients did not survive with a mortality of 6.88%. In multivariate analysis, the independent mortality risk factors in children with severe adenovirus pneumonia were age less than 1 year (OR = 18.513, 95% CI: 2.157-158.883, p = 0.008), hypoxia (OR = 62.335, 95% CI: 2.385-1629.433, p = 0.013), and thrombocytopenia (platelet <100∗10ˆ9/L) (OR = 13.324, 95% CI: 1.232-144.075, p = 0.033).

CONCLUSIONS

In children with severe adenovirus pneumonia who are younger than one year old, hypoxia and platelet counts less than 100∗10ˆ9/L represent mortality risk factors.

Identified risk factors for co-infection in hospitalized children infected with adenovirus in Hangzhou

This study aimed to describe the clinical manifestations of adenovirus infections and identify potential risk factors for co-infection with chlamydia, viruses and bacteria in hospitalised children from Hangzhou, China. From January to December 2019, the characteristics of hospitalised children infected with adenovirus at Hangzhou Children's Hospital and Zhejiang Xiaoshan Hospital were collected. The clinical factors related to co-infection with chlamydia, viruses and bacteria were assessed using multivariate logistic regression analyses. A total of 5989 children were infected with adenovirus, of which 573 were hospitalised for adenovirus infection. The severity of adenovirus respiratory infection was categorised as follows: mild (bronchiolitis, 73.6%), moderate (bronchopneumonia, 17.6%) or severe (pneumonia, 8.8%). Of the 573 children who were hospitalised, 280 presented with co-infection of chlamydia, viruses or bacteria, while the remaining 293 had only adenovirus infection. Multivariate stepwise logistic regression analyses indicated that elevated ferritin was associated with an increased risk of chlamydia co-infection (odds ratio (OR) 6.50; 95% confidence interval (CI) 1.56–27.11; P = 0.010). However, increased white blood cell (WBC) count was associated with a reduced risk of viral co-infection (OR 0.84; 95% CI 0.75–0.95; P = 0.006). The study indicated that co-infection with chlamydia could be affected by elevated ferritin levels. WBC levels could affect viral co-infection in hospitalised children infected with adenovirus.

Adenovirus can be a serious, life-threatening disease, even in previously healthy children

AIM

Adenovirus infections are exceedingly common in childhood. However, little is known of the clinical characteristics of children admitted with severe infection to the paediatric intensive care unit (PICU).

METHODS

Clinical data on children hospitalised with adenovirus infection between January 2005 and March 2020 were collected. We compared data between children hospitalised in the PICU and those who were not in a 1:2 ratio.

RESULTS

During the study period, 69 children with adenovirus infection were admitted to the PICU, representing 5% of all hospitalised children with adenovirus. Thirty-four (49%) were previously healthy children. Mortality occurred in 5 patients, and all had an underlying illness. Cidofovir was used in 21 children, including 11 who were previously healthy. No side effects were attributed to the treatment. During 2005-2014, viral co-infection rates were 42% in the PICU group and 11% in the control group (p = 0.002). However, during 2015-2020, when the viral panel became widespread in our institution, the rates of co-infection were similar in the two groups (32% and 34%, p = 1.0).

CONCLUSION

Our findings suggest that adenovirus may present as a serious, life-threatening disease even in previously healthy children.

Serotype Identification of Human Adenoviruses Associated with Influenza-Like Illnesses in the Philippines from 2006-2012 by Microneutralization and Molecular Techniques

OBJECTIVES

Human adenoviruses (HAdV) are known to cause a wide range of diseases including acute respiratory infections, conjunctivitis, and acute gastroenteritis. In this study, we aimed to determine the serotypes of HAdV in patients with influenza-like illness (ILI) in the Philippines from 2006-2012 and to describe the demographic and epidemiological characteristics of patients who tested positive for HAdV.

METHODS

Between 2006 and 2012, the Philippine National Influenza Centre detected HAdV in 1294 samples of patients with ILI. Serotype determination was done in select samples using microneutralization, polymerase chain reaction (PCR), and sequencing methods.

RESULTS

A total of 8 serotypes were identified (HAdV 1-7 and 11), with HAdV-2 (27.8%), and HAdV-3 (27.8%) being the most prevalent. The majority of HAdV infections were found in children below 5 years of age (79.9%).

CONCLUSIONS

The identification of HAdV circulating serotypes may serve as guide for designing disease intervention and control strategies and will provide important information regarding the contribution of this virus to respiratory infections, particularly in children, which remain a public health burden in the Philippines.

The Epidemiology, Molecular, and Clinical of Human Adenoviruses in Children Hospitalized With Acute Respiratory Infections

Introduction

Human adenovirus (HAdV) is a common pathogen in children with acute respiratory infections (ARIs). The aim was to describe the epidemiology, molecular, and clinical characteristics of HAdV among children hospitalized with ARIs in Wenzhou in southeastern China.

Methodology

From January 2018 to December 2019, nasopharyngeal swab or sputum specimens were prospectively collected from hospitalized children with ARIs. HAdV was detected using direct immunofluorescence. We used a multiplex PCR assay combined with capillary electrophoresis targeting the hexon gene’s hypervariable region to identify HAdV types 1, 2, 3, 4, 5, 7, 14, 21, 37, 40, 41, and 55. We analyzed the epidemiological, molecular, and clinical data according to the HAdV type.

Results

HAdVs were detected in 1,059 (3.5%) of the total of 30,543 children tested. A total of 947 cases with monotype HAdV identified by the PCR assay were included in the analysis. HAdV-3 (415/947, 43.8%), HAdV-7 (318/947, 33.6%), HAdV-2 (108/947, 11.4%), and HAdV-1 (70/947, 7.4%) were the predominant types. Of the 550 (58.1%) cases detected from December 2018 to August 2019, HAdV-3, and HAdV-7 were the main types. The main diagnoses included 358 cases of pneumonia, 232 cases of tonsillitis, 198 cases of bronchitis, and 159 cases of upper respiratory tract infection (URTI). Among children with pneumonia the main types were HAdV-7 (51.1%), HAdV-3 (36.9%), and HAdV-1 (2.2%). Among children with bronchitis, the main types were HAdV-3 (48.0%), HAdV-7 (28.3%), and HAdV-2 (10.6%). Among children with URTIs, the main types were HAdV-3 (49.7%), HAdV-7 (22.6%), and HAdV-2 (13.2%). Among children with tonsillitis, the main types were HAdV-3 (47.4%), HAdV-2 (22.4%), and HAdV-7 (18.5%). In total, 101 (55.2%) patients required supplemental oxygen, 15 (8.2%) required critical care, and 1 child (0.5%) with HAdV-7 pneumonia died.

Conclusion

HAdV-3 -7, -2, and -1 were the predominant types identified in hospitalized children with ARIs in Wenzhou. From December 2018 to August 2019, there were outbreaks of HAdV-3 and -7. There were significant differences in HAdV types among children with pneumonia, tonsillitis, bronchitis, and URTI. HAdV-7 can cause more severe pneumonia in children than HAdV-3.

Study of the Etiology of Acute Respiratory Infections in Children Under 5 Years at the Dr. Agostinho Neto Hospital, Praia, Santiago Island, Cabo Verde

Background: Acute respiratory infections are one of the major causes of morbidity and mortality in children under 5 years in developing countries and are a challenge for the health system of these countries. In Cabo Verde, despite the lack of recent studies, data indicate that it affects thousands of children, being the fourth leading cause of infant mortality in 2013. The aim of this study was to identify and describe the etiological agents associated with acute respiratory tract infections in children under 5 years old, and their associated risk factors, such as clinical symptoms or socio-demographic characteristics. Methods: Naso-pharyngeal samples were collected from children under 5 years attending at Dr. Agostinho Neto Hospital (Praia, Santiago Island, Cabo Verde) with suspected ARI at different time-points during 2019. Samples were analyzed using FilmArray® Respiratory Panel v. 2.0 Plus to identify etiological agents of ARI. A questionnaire with socio-demographic information was also collected for each participant. Data analyses were carried out using the IBM SPSS version 25 (IBM Corporation, Armonk, NY) and R 3.5.1 statistical software. Results: A total of 129 naso-pharyngeal samples were included in the study. Seventeen different etiologic agents of respiratory infections were identified. HRV/EV was the most frequent agent detected, followed by FluA H3 and RSV. Coinfection with two or more pathogens was detected in up to 20% of positive samples. The results were analyzed in terms of age-group, sex, period of the year and other social and demographic factors. Conclusion: Viruses are the main causative agents of ARI in children <5 years attending at the pediatrics service at the Dr. Agostinho Neto Hospital in Praia city, Santiago Island, Cabo Verde. Some factors are described in this study as statistically associated with the presence of an infectious agent, such as having one or more children sharing the bedroom with an adult and the presence of some clinical symptoms. The data addresses the need for studies on respiratory tract infections in Cabo Verde.

Comparative analysis of clinical features of SARS-CoV-2 and adenovirus infection among children

BACKGROUND

The new emerging coronavirus disease 2019 (COVID-19) overall shares similar symptoms with other common respiratory viral infections. We aimed in this study to compare COVID-19 and human adenovirus (HAdV) infections in pediatric patients regarding the frequencies of major clinical symptoms and the potential disparities in laboratory and imaging parameters.

METHODS

Following a case-control-like design, we built 72 age-matched pediatric COVID-19 and HAdV patient pairs. Their early symptoms and laboratory and imaging characteristics were then retrieved and compared.

RESULTS

Fever and cough were the most common symptoms for both infections but were seen more often in HAdV than in COVID-19 patients (92% vs. 66% and 60% vs. 18%, respectively). Compared with COVID-19 patients, children with HAdV infection had statistically significantly higher values of neutrophil count, neutrophil percentage, activated partial thromboplastin time, prothrombin time, lactate dehydrogenase, C-reactive protein, procalcitonin but lower values of lymphocyte percentage, total bilirubin, potassium and sodium. Thoracic computed tomography also revealed more anomalies in HAdV patients than in COVID-19 patients (95% vs. 67%).

CONCLUSIONS

COVID-19 is an overall less symptomatic and less severe infection at admission compared to HAdV respiratory infection in pediatric population.

Clinical manifestations and risk factors of adenovirus respiratory infection in hospitalized children in Guangzhou, China during the 2011-2014 period

To evaluate epidemiology and risk factors of severe adenovirus respiratory infection in hospitalized children in Guangzhou, China.A retrospective review study was conducted, and 542 children hospitalized for adenovirus respiratory infection, were included from January 2011 to December 2014. Patients were younger than 14 years. Disease severity was classified into severe and mild. Laboratory tests and clinical characteristics were analyzed for risk factors of adenovirus respiratory infection by multivariable logistic regression.Among these 542 children, 92.1% were aged < 6 years. Clinical diagnoses were upper respiratory infections in 11.6%, bronchiolitis in 16%, and mild pneumonia in 62.0% of children. Severe pneumonia rate was 10.3% (56/542) with a mortality rate of 0.9% (5/542). The cohort comprised 542 patients; 486 patients with mild adenovirus respiratory infection and 56 patients with severe adenovirus respiratory infection. Multivariable logistic regression was used to confirm associations between variables and adenovirus respiratory infection, after age and gender adjustment. Hospital stay, still significantly associated with adenovirus respiratory infection. Patients with longer hospital stay (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.13-1.28, P < .001), lower LYMPH (OR = 0.73 95% CI: 0.55-0.99, P = .039), and increased LDH (OR = 1.002, 95% CI: 1.001-1.003, P =  .001) had a higher risk of severe adenovirus respiratory infection.Adenovirus is a major pathogen in hospitalized children with respiratory infection. High serum LDH level and low lymphocyte count could be used as predictors of adenovirus respiratory infection severity in children.

Comparative study of clinical and epidemiological characteristics of major pediatric adenovirus epidemics in southern Taiwan

Background

Human adenoviruses (HAdV) are important pathogens of pediatric respiratory tract infections in Taiwan. There were two major HAdV epidemics in southern Taiwan in 2011 and 2014, respectively.

Methods

The demographic, clinical characteristics, and risk factors for hospitalization of pediatric patients with HAdV infection in the two outbreaks were retrospectively compared. The epidemic was defined as > 7% HAdV detection rate for six consecutive weeks. HAdV infection was defined as positive HAdV isolates from respiratory tract specimens. HAdV genotype was determined by PCR-based hexon gene sequencing.

Results

A total of 1145 pediatric patients were identified (635 cases in 2011; 510 cases in 2014). HAdV genotype 3 and 7 contributed to both epidemics, although the proportion of HAdV3 decreased significantly (64.7% in 2011 to 25.5% in 2014, p < 0.001) and was replaced by other genotypes (type 1, 4, and 6) in the 2014 epidemic. Among the hospitalized patients, there were more patients hospitalized with bronchopneumonia/or pneumonia in the 2011 epidemic (10.6% vs 5.1%, p < 0.001), while more patients hospitalized with acute pharyngitis/pharyngoconjunctival fever (63.9% vs. 38.6%, p < 0.001) in the 2014 epidemic. In both epidemics, hospitalized patients had higher WBC and C-reactive protein (CRP) levels than non-hospitalized patients. Using multivariate regression analysis, underlying disease and elevated CRP levels were independent risk factors for hospitalization in both epidemics.

Conclusion

There were significant differences in clinical, viral characteristics and risk factors of hospitalization between the 2011 and 2014 epidemics. Understanding changes in the epidemiological and clinical characteristics of HAdV epidemics is important from a public health perspective.

New and Emerging Infections of the Lung

In this era of rapid globalization and frequent travel, emerging viral infections have gained an immense potential to spread at an unprecedented speed and scale compared with the past. This poses a significant challenge to coordinated international efforts in global surveillance and infection control.

Significantly, respiratory viral infections, spread mostly via droplet transmission, are extremely contagious and have caused significant morbidity and mortality during outbreaks in the last decade. Molecular diagnostics via reverse transcriptase polymerase chain reaction (RT-PCR) have been key in the rapid diagnosis of most of these viral infections. However, a high index of suspicion and early institution of appropriate isolation measures remain as the mainstay in the control and containment of the spread of these viral infections. Although treatment for most of the viral infections remains supportive, efficacious antiviral agents against influenza infections exist.

The infections discussed in this chapter include those first described in the 2000s: Middle East respiratory syndrome coronavirus (MERS-CoV) and metapneumovirus and rhinovirus C as well as those that have been described in the past but have reemerged in the last decade in outbreaks resulting in significant morbidity and mortality, including adenovirus, influenza virus, and enterovirus D68 (EV-D68).

Epidemiology of human adenovirus infection in children hospitalized with lower respiratory tract infections in Hunan, China

To investigate the current genotypes of circulating human adenovirus (HAdV) strains, we molecularly genotyped HAdV in the nasopharyngeal aspirates (NPAs) of patients with acute lower respiratory tract infections (ALRTIs) and attempted to determine their associations with clinical symptoms. A total of 4751 NPA samples were collected from 4751 patients admitted to Hunan Provincial People's Hospital from September 2007 to March 2014, of which 447 (9.4%) samples were HAdV positive. Fourteen different HAdV types were identified; HAdV types 1 to 7 (HAdV 1‐7) were identified in 95.7% of the 447 NPA samples with HAdV‐7 and HAdV‐3 being the most prevalent. In addition, 93.3% (417 of 447) of patients were younger than 5 years. The incidence of HAdV infection peaked in summer. Different HAdV types showed a predilection for different age groups and different seasonal distribution patterns. Coinfection of HAdVs and other respiratory viruses was detected in 63.3% (283 of 447) of the HAdV‐positive samples. The most common clinical diagnosis was pneumonia and the most common symptoms were fever and cough. In comparison with children infected with HAdV‐3 alone, those infected with HAdV‐7 alone had an increased frequency of severe pneumonia involvement (11.6% vs 32.4%; P = 0.031), higher intensive care unit admission rates (7.0% vs 26.5%; P = 0.019), and a longer length of hospital stay (P = 0.03). Mixed infections in younger children were associated with a longer hospital stay (P = 0.023). Our results demonstrate the recent changes in the trends of circulating HAdV genotypes associated with ALRTIs in Hunan China.

Etiology and clinical features of viral bronchiolitis in infancy

BACKGROUND

Bronchiolitis is a common lower respiratory tract infection in infancy. The aim of this review is to present the clinical profile of viral bronchiolitis, the different culprit viruses and the disease severity in relation to the viral etiology.

DATA SOURCES

Databases including PubMed and Google Scholar were searched for articles about the clinical features of bronchiolitis and its viral etiology. The most relevant articles to the scope of this review were analyzed.

RESULTS

Currently there are two main definitions for bronchiolitis which are not identical, the European definition and the American one. The most common viral pathogen that causes bronchiolitis is respiratory syncytial virus which was identified in 1955; now many other viruses have been implicated in the etiology of bronchiolitis such as rhinovirus, adenovirus, metapneumovirus, and bocavirus. Several studies have attempted to investigate the correlation of bronchiolitis severity with the type of detected virus or viruses. However, the results were not consitent.

CONCLUSIONS

For the time being, the diagnosis of bronchiolitis remains clinical. The isolation of the responsible respiratory pathogens does not seem to confer to the prognosis of the disease severity.

Clinical Impact of Mixed Respiratory Viral Infection in Children with Adenoviral Infection

Background

Although adenovirus (ADV) infection occurs steadily all year round in Korea and the identification of respiratory viral coinfections has been increasing following the introduction of multiplex real-time polymerase chain reaction tests, the clinical impact of viral coinfection in children with ADV infection has rarely been reported.

Materials and Methods

Medical records of children diagnosed with ADV infection were retrospectively reviewed. The enrolled children were divided into two groups based on the identified respiratory viruses: ADV group and coinfection group. Clinical and laboratory parameters were compared between the two groups.

Results

In total, 105 children (60 males and 45 females) with a median age of 29 months (range: 0-131 months) diagnosed with an ADV infection were enrolled. Fever (99.0%) was by far the most frequent symptom, followed by respiratory (82.9%), and gastrointestinal (22.9%) symptoms. Upper and lower respiratory tract infections were diagnosed in 56 (53.3%), and 32 (30.5%) children, respectively. Five (4.8%) children received oxygen therapy, and no child died due to ADV infection. Coinfection was diagnosed in 32 (30.5%) children, with rhinovirus (46.9%), and respiratory syncytial virus (21.9%) being the most frequent. The proportions of children younger than 24 months (P <0.001), with underlying medical conditions (P = 0.020), and diagnosed with lower respiratory tract infection (P = 0.011) were significantly higher in the coinfection group than in the ADV group. In a multivariate analysis, only the younger age was significantly associated with coinfection (P <0.001). Although more children in the coinfection group received oxygen therapy (P = 0.029), the duration of fever and hospitalization was not significantly different between the two groups.

Conclusion

Respiratory viral coinfection with ADV occurred more frequently in children younger than 24 months of age compared with children aged 24 months or older. Respiratory viral coinfection may increase the severity of ADV infection, however, appropriate therapy prevented prolonged hospitalization and poor prognosis due to coinfection.

Molecular epidemiology of respiratory adenovirus detection in hospitalized children in Shenzhen, China

OBJECTIVE

This study aimed to understand the molecular type of respiratory adenovirus in hospitalized children in Shenzhen and the relation to clinical diagnoses.

METHODS

Nasopharyngeal swab specimens were obtained from 6,479 hospitalized children younger than 14 years with respiratory tract diseases in Shenzhen Children's Hospital from December 2012 to November 2013. Nasopharyngeal swabs were routine examined by direct immunofluorescence assay to detect respiratory agents including seven respiratory viruses. Multiplex PCR of adenovirus types 3, 7, 11 and 21 in a single tube based on the sequence of the encoding gene for hexon was used to type for adenovirus positive specimens. For those strains that could not be typed by multiplex PCR, the gene fragment was amplified by a universal primer pair for all adenovirus types and the PCR products were sequenced directly.

RESULTS

A total of 1,066 of 6,479 (16.45%) specimens were positive for at least one of the seven viruses and 228 of 6,479 (3.52%) specimens were positive for adenovirus. 86.4% of children with adenovirus infection occurred less than 5 years of age and just over half of the children (54.4%) less than two years old. There was no significant difference in infection rates between males and females. AdV3 (46.3%) and AdV7 (36.3%) were the genotypes most commonly found followed by AdV1 (6.0%), AdV4 (5.0%), AdV2 (3.0%), AdV6 (1.5%), AdV5 (1.5%) and AdV3/7 (0.5%). No type 11, type 21, and other types of adenovirus were detected. Seven children had type 3 or type 7 and one had type 3/7 mixed infection in 15 severe pneumonia cases.

CONCLUSIONS

Our study demonstrated that respiratory adenovirus infection is an important cause of hospitalizations in children in Shenzhen, China. Types 3 and 7 were the most common followed by types 1 and 4. AdV3 and AdV7 were similarly contributed to the severe cases.

Risk factor analysis and molecular epidemiology of respiratory adenovirus infections among children in northern Taiwan, 2009-2013

BACKGROUND/PURPOSE

Respiratory infections caused by human adenoviruses (HAdV) are worldwide, and have significantly increased recently in Taiwan. This study aimed to clarify the molecular epidemiology and risk factors of HAdV severe infections and pneumonia among Taiwanese children.

METHODS

Patients with HAdV infections and hospitalized in a medical center between 2009 and 2013 were divided into severe or nonsevere HAdV infections based on whether or not they received intensive care. HAdV pneumonia was identified for comparison. The HAdV genotype was determined by sequencing the partial hexon and fiber genes. The nucleotide sequences were compared by phylogenetic analysis.

RESULTS

The 176 patients (97 boys, 79 girls) had a median age of 3.7 years. The HAdV infections circulated year-round. HAdV B3 (54.5%) was the most common genotype, followed by HAdV C2 (21%), HAdV E4 (8%), and HAdV B7 (6.8%). Thirty-two patients needed intensive care. In multivariate analysis, the risk factors for severe HAdV infections were underlying neurologic diseases [odds ratio (OR): 164.9; p < 0.001], prematurity (OR: 10.9; p = 0.042), and HAdV B7 (OR: 39.5; p = 0.011). Twenty-nine patients had HAdV pneumonia. Patients with underlying neurologic diseases (OR 76.8; p < 0.001), airway anomaly (OR 15.1; p = 0.033), chronic lung diseases (OR 12.5; p = 0.047), weight < 3^rd percentile (OR 5.5; p = 0.027), and HAdV B7 (OR 4.2; p = 0.002) had higher incidences of pneumonia. Four with underlying neurologic diseases died of acute respiratory distress syndrome.

CONCLUSION

HAdV infections circulate all year-round. HAdV B7 is strongly related to severe infections and pneumonia. Underlying neurologic diseases and prematurity are risk factors for severe HAdV infections.