Adenovirus infection with serious pulmonary sequelae in Korean children

Molecular epidemiology of human adenoviruses in children with and without respiratory symptoms: Preliminary findings from a case-control study

Background

Human adenovirus (HAdV) is an important viral agent in children which can lead to severe acute respiratory infection (SARI). Reports on molecular epidemiology of HAdVs in Iran are limited. This case-control study is conducted to compare the HAdV infection rate and molecular epidemiology among two groups of children with and without respiratory symptoms in Tehran, Iran during 2018–2019.

Methods

Nested PCR was performed on 120 oropharyngeal swabs taken from children aged five and younger with SARI who were hospitalized as the case group, and 120 oropharyngeal swabs were collected from children of the same age without respiratory symptoms as the control group. For positive samples Sanger sequencing was done and a phylogenetic tree was drawn afterward.

Results

Out of 120 cases, 8 (6.6%) tested positive for eachHAdV types including 6 (75%) HAdV-B7, 1 (12.5%) HAdV-C2, and 1 (12.5%) HAdV-C6. Among the control group, out of 120 samples, 8 (6.6%) were positive comprising 5 (62.5%) HAdV-C5, 2 (25%) HAdV-F41, and 1 (12.5%) HAdV-C6.

Conclusion

The present study indicated a different viewpoint of HAdV molecular epidemiology in which the genotypes were compared in children with and without respiratory symptoms. HAdV prevalence was equally common in cases and controls but different genotypes were detected in these two groups. HAdV-B7 was the main type among children with SARI, dissimilar to children with no respiratory symptoms where HAdV-C5 was the predominant type. Detecting HAdV-F in oropharyngeal swabs was a rare finding, which requires further investigation.

A case of post adenoviral bronchiectasis being managed at home with humidified high flow nasal cannula (HHFNC)

Human adenovirus is an important cause of febrile illness affecting mainly respiratory system ranging from pharyngitis, coryza to fatal pneumonia. Though most of the infections are trivial and results in complete recovery but it may result in considerable morbidities and mortalities in selected patients who developed severe adenoviral infections especially Pneumonia(ADVP)/Lower respiratory tract infection(LRTI). Severe adenoviral pneumonia is notorious to produce long term sequelae in the form of post infectious bronchiolitis obliterans (PIBO) or even bronchiectasis. Here we present a case of a ten months old boy developed bronchiectasis as a sequela of severe adenoviral LRTI and needed prolonged and recurrent respiratory support in the pediatric intensive care unit(PICU) and ultimately discharged on home Humidified high flow nasal cannula(HHFNC).

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.

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.

Clinical and molecular features of adenovirus type 2, 3, and 7 infections in children in an outbreak in Taiwan, 2011

Objectives

We studied paediatric patients with human adenovirus (HAdV) infection during the 2011 outbreak in northern Taiwan to define the clinical features of different HAdV genotypes in children.

Methods

Between January and December 2011, 637 patients <19 years of age exhibited culture-confirmed adenoviral infection in Chang Gung Memorial Hospital, and provided specimens available for genotyping by multiplex real-time PCR. Clinical data were collected retrospectively.

Results

Excluding five cases with multiple genotypes, 632 cases were included for analysis. Three genotypes were identified, including HAdV-3 (429/632; 67.6%), HAdV-7 (144/632; 22.6%) and HAdV-2 (59/632; 9.8%). Median age was 4.58 years (range 2 months to 18 years), with children infected with HAdV-3 significantly older (82.9% >3 years; p <0.001). Of the 621 inpatients, 98.2% had fevers and all exhibited respiratory symptoms, 75 patients (12.1%) had lower respiratory tract infections, 20 (3.2%) required intensive care (HAdV-2: 1; HAdV-3: 8; and HAdV-7: 11), and three died (all HAdV-7-infected). HAdV-3-infected patients were significantly more likely to have upper respiratory symptoms and a high serum C-reactive protein level >100 mg/L, whereas leucocytosis (white blood cell count >15 000/mm³) was more common in HAdV-2-infected patients (p 0.007). HAdV-7 infections were significantly associated with a longer duration of fever, leucopenia (white blood cell count <5000/mm³), thrombocytopenia (platelet count <150 000/mm³), lower respiratory tract infections, a longer length of hospital stay, and requiring intensive care (all p <0.001).

Conclusion

Childhood HAdV-2, HAdV-3 and HAdV-7 infections may exhibit different clinical manifestations. Although HAdV-3 was the most prevalent genotype observed during the 2011 Taiwan outbreak, HAdV-7 caused more severe disease characteristics and outcomes.

Immunocompromised Children with Severe Adenoviral Respiratory Infection

Purpose. To investigate the impact of severe respiratory adenoviral infection on morbidity and case fatality in immunocompromised children. Methods. Combined retrospective-prospective cohort study of patients admitted to the intensive care unit (ICU) in four children's hospitals with severe adenoviral respiratory infection and an immunocompromised state between August 2009 and October 2013. We performed a secondary case control analysis, matching our cohort 1 : 1 by age and severity of illness score with immunocompetent patients also with severe respiratory adenoviral infection. Results. Nineteen immunocompromised patients were included in our analysis. Eleven patients (58%) did not survive to hospital discharge. Case fatality was associated with cause of immunocompromised state (p = 0.015), multiple organ dysfunction syndrome (p = 0.001), requirement of renal replacement therapy (p = 0.01), ICU admission severity of illness score (p = 0.011), and treatment with cidofovir (p = 0.005). Immunocompromised patients were more likely than matched controls to have multiple organ dysfunction syndrome (p = 0.01), require renal replacement therapy (p = 0.02), and not survive to hospital discharge (p = 0.004). One year after infection, 43% of immunocompromised survivors required chronic mechanical ventilator support. Conclusions. There is substantial case fatality as well as short- and long-term morbidity associated with severe adenoviral respiratory infection in immunocompromised children.

Epidemiology of adenovirus respiratory infections among hospitalized children in Seremban, Malaysia

BACKGROUND

There is scarcity of data regarding epidemiology and clinical aspects of human adenovirus acute respiratory infection (ARI) among children in developing countries.

METHODS

Retrospective data on demographics, clinical presentation, outcomes and laboratory findings of 116 children admitted into Tuanku Jaafar Hospital in Seremban, Malaysia from 2012 to 2013 with documented diagnosis of community-acquired adenovirus ARI were collected and analyzed.

RESULTS

Male to female ratio was 1.70. Median age was 14 (1-107) months. The commonest symptoms were fever (94.8%; 110/116), cough (82.8%, 96), rhinorrhea (63.8%; 74), interrupted feeding (66.4%; 77), diarrhea (33.6%; 39) and conjunctivitis (21.6%; 25). Mean temperature on admission was 38.4°C±0.9°C. Among all 116 subjects, 20.7% (24) needed oxygen supplementation, 57.8% (67) required intravenous hydration, 11.2% (13) were admitted into the pediatric intensive care unit and 6.9% (8) required mechanical ventilation. Only 1% (1/87) had positive blood culture (Streptococcus pneumoniae) among 87 who received antibiotic treatment. Case fatality rate was 2.6% (3/116) and 1.7% (2/116) developed bronchiolitis obliterans. Median length of hospital stay was 4 (1-50) days.

CONCLUSION

Adenovirus ARI caused significant morbidity and substantial resource utilization among hospitalized Malaysian children. It should be considered in the differential diagnosis of infants below two years presenting with ARI associated with high fever. Antibiotics should not be prescribed as secondary bacterial infections are uncommon.

Risk Factors for Severe Adenovirus Infection in Children during an Outbreak in Singapore

BACKGROUND

Human adenoviruses (HAdVs) can cause a variety of human illnesses, with associated temporal and geographic changes in disease incidence. We report the emergence of an outbreak of HAdV infections in Singapore, presumably caused by a change of the predominating type to HAdV-7. We examined the clinical features of children admitted with HAdV infection to 1 institution and the risk factors for severe infection.

MATERIALS AND METHODS

This is a retrospective case-control study of all HAdV-infected children admitted during weeks 1 to 19 in 2013, as identified from laboratory records. A descriptive retrospective analysis of epidemiology, clinical data and the outcome of these children was also performed. Patients with severe infections were defined as cases, those with non-severe infections as controls, and the 2 groups were compared to find possible independent risk factors.

RESULTS

Eighty-five patients with HAdV infection were studied, including 11 (12.9%) cases and 74 (87.1%) controls. Binary logistic regression showed that cases were more likely to be <2 years old (adjusted OR 10.6, 95% CI, 1.8 to 63.2) and to have significant comorbidities (adjusted OR 19.9, 95% CI, 3.4 to 116.1) compared to controls. The predominant type in 2013 was HAdV-7, which differed from 2011 and 2012, when HAdV-3 was more common. There was a trend towards pneumonia being more common in patients infected with HAdV-7 than in patients infected with other types, although this did not reach statistical significance (OR 2.8, 95% CI, 0.9 to 8.7).

CONCLUSION

The emergence of HAdV-7 in a population where other HAdV types had circulated previously may have caused the outbreak in Singapore, and this was associated with more serious infections in children. Young age (<2 years) and significant comorbidities were associated with more severe HAdV infection.

Postinfectious bronchiolitis obliterans in children: the South American contribution

Postinfectious bronchiolitis obliterans (PIBO) is an infrequent chronic lung that causes irreversible obstruction and, or, obliteration of the smaller airways. This review particularly focuses on more than 30 studies from South America.

CONCLUSION

The initial PIBO event occurs in the early years of life and is strongly associated with adenovirus infection and the need for mechanical ventilator support. Treatment requires a multidisciplinary strategy. Multicentre studies are needed to determine progression, optimal management and long-term follow-up.

Adenovirus serotype 3 and 7 infection with acute respiratory failure in children in Taiwan, 2010-2011

Objective

Increased incidence of adenovirus infection in children was noticed since September 2010 in Taiwan and severe cases requiring intensive care were noted later. We did this study to find the clinical characteristics and risk factors associated with severe adenovirus infection.

Patients and Methods

We collected cases of severe adenovirus infection between November 2010 and June 2011 to analyze their clinical characteristics in two medical centers in northern Taiwan. Severe adenovirus infection was defined as laboratory-confirmed adenovirus cases with required intensive care. Hexon gene sequencing was performed for molecular genotyping.

Results

45 patients were included, 22 cases (49%) were infected with serotype 7, 19 (42%) with serotype 3, and 4 with serotype 2. The median age (range) was 2.75 years (0.08–15.43 years); 87% were below 5 years. Male to female ratio was 1.65 (28 to 17). Of these patients, 56% had underlying neurological diseases, 50% experienced fever higher than 40°C and 69% suffered fever longer than one week. The clinical diagnosis included pneumonia in 40 (89%) patients, bronchopneumonia in 5 (11%), and encephalitis in 7 (16%). At least 22 patients had pleural effusion. They had complications of respiratory failure (53%), acute respiratory distress syndrome (24%), hypotension (40%), and 6 (13%) patients needed extracorporeal membranous oxygenation. Ten (22%) patients died, all with underlying major systemic diseases and 7 (70%) infected with serotype 7.

Conclusions

Adenovirus serotype 7 and 3 can cause severe disease–even death–in children, especially those with underlying neurological diseases. Patients infected with adenovirus serotype 7 tended to have a higher case-fatality rate.

Molecular typing of adenoviruses in pediatric respiratory infections in Buenos Aires, Argentina (1999-2010)

BACKGROUND

The human adenovirus (HAdV) types most commonly found in respiratory samples belong to HAdV species C (HAdV-C1, -C2, -C5, and -C6) and to HAdV species B (HAdV-B3 and -B7). Several studies in South America have shown the association between severe respiratory infections and subspecies B1.

OBJECTIVES

The aim of this study was to identify the adenovirus types associated with acute lower respiratory tract infections in children, found as single or coinfections, throughout a 12-year period.

STUDY DESIGN

All samples that tested positive for adenovirus by immunofluorescence assay from January 1999 to December 2010 were typed by evaluating a set of four viral genes (E1A, VA, hexon and fiber). Quantitative PCRs for HAdV-B and HAdV-C species were performed to compare the viral load found in single infections and coinfections.

RESULTS

From a total of 743 HAdV, 654 (88%) were single infections and 89 (12%) coinfections. From the 654 single HAdV infections, members of four species were present: species B (n=492, 75.23%), species C (n=138, 21.1%), species E (n=19, 2.91%), and species D (n=5, 0.76%). Only members of species B (n=109, 57.67%) and species C (n=80, 42.33%) were detected in coinfections. HAdV-B7 and HAdV-B3 were the most prevalent types (n=308, 36.54%; n=230, 27.28% respectively) and HAdV-C1, -C2, -E4, -C5, -C6, -D8, -B11, -B14 and -B21 were also detected. Viral loads for species C viruses were higher in single infections than in coinfections (p<0.01), whereas the opposite was observed for species B viruses (p<0.0001).

CONCLUSIONS

This study provides a thorough description of adenovirus circulation and diversity in Buenos Aires in a 12-year period. The high proportion of coinfections found in this work shows that this phenomenom might be more common than expected.