Adenovirus type 21 bronchopneumonia in infants and young children

Human Adenovirus Subtype 21a Isolates From Children With Severe Lower Respiratory Illness in China

Human adenovirus type 21 (HAdV-21) is an important pathogen associated with acute respiratory infection (ARI), but it was rarely reported and characterized so far. In this study, 151 of 1,704 (8.9%) pediatric patients (≤14 years old) hospitalized with ARI in Guangzhou, China in 2019 were positive for HAdV which was the third most frequently detected pathogen. Two HAdV-21-positive patients presented with severe lower respiratory illness and had similar initial symptoms at onset of illness. Then two HAdV-21 strains were isolated and characterized. The two HAdV-21 strains were sequenced and classified as subtype 21a with genomes closely related to strain BB/201903 found in Bengbu, China in March 2019. Phylogenetic analysis for whole genome and major antigen proteins of global HAdV-21 strains showed that HAdV-21 could be classified into two branches, branch 1 including genotype 21p, branch 2 including all other strains dividing into genotype 21a and 21b. There was no significant difference in the plaque size, or the replication curves between the two HAdV-21a strains and the prototype strain HAdV-21p AV-1645. However, there were five highly variable regions (HVR1, HVR3, HVR4, HVR5, and HVR7) in the hexon protein that varied between two branches. Mice immunized with one branch strain showed 2-4-fold lower neutralizing antibody titers against another branch strain. In summary, this study firstly reported two HAdV-21a infections of children in China, characterized two isolates of HAdV-21a associated with severe lower respiratory illness; our results could be important for understanding the HAdV-21 epidemiology and pathogenic, and for developing HAdV-21 vaccine and drug.

Human adenoviruses associated with respiratory illness in neonates, infants, and children in the Sousse area of Tunisia

Background

The human Adenovirus (HAdV) is a common agent of acute respiratory infections (ARIs). Its clinical impact in immunocompetent children and in the context of coinfections remains unclear in Tunisia.

Material and methods

HAdV‐ARIs were studied in hospitalized patients from birth to the age of 5 years from 2013 to 2014. Clinical and demographic characteristics, coinfections, and molecular characterization of HAdV were established.

Results

HAdV‐positivity was detected in 114/583 specimens (19.6%) including 6.1% single infections and 93.9% coinfections. Adenoviral coinfections mostly comprised human Rhinovirus (50.9%), Streptococcus pneumoniae (34.2%), human Respiratory Syncytial virus A/B (29.8%), and human Coronaviruses (21.9%). HAdV infection was predominant in the pediatric population (25.0% vs 10.0% in neonates, P < .001) and peaked in February 2014 (21.1%). HAdV severity of pediatric cases is characterized by low saturation of oxygen (<94%, 33.8%, P = .05) and long duration of oxygen support (≥5 days, 32.7%, P = .02). Severe HAdV infections were described with S. pneumoniae coinfection, which seemed to increase the risk of death. HAdV genotyping identified HAdV‐C as the most common species. Severe ARIs were observed in all HAdV‐identified types. Phylogenetic analysis revealed that sequences were variable suggesting the circulation of different HAdV strains sharing more similarities to strains circulating in Europe or Asia than those from Africa.

Conclusion

This first molecular study of HAdV in Tunisia demonstrated that it has an important role in severe ARIs with HAdV‐C being the most common species. S. pneumoniae codetection seems to increase the severity of HAdV‐ARIs.

Severe acute respiratory distress syndrome (ARDS) induced by human adenovirus B21: Report on 2 cases and literature review

Severe pneumonia and ARDS caused by human adenovirus B21 infections (HAdV-B21) is a rare, but a devastating disease with rapid progression to multiorgan failure and death. However, only a few cases were reported so far.

Infections appear associated with increased disease severity and higher mortality in infected critically ill patients. Possible factors contributing to infection are underlying psychiatric disease resulting in institutionalization of respective patients, and polytoxicomania. Controlled data on the therapy of severe adenovirus infections are lacking and remains experimental.

In conclusion, data on HAdV-B21 infections causing severe pneumonia or ARDS are scarce. Controlled clinical trials on the therapy of adenovirus pneumonia are non existent and thus there is no established therapy so far. ICU physicians should be aware of this potentially devastating disease and further studies are needed.

Emergence and re-emergence of respiratory adenoviruses in the United States

Human adenoviruses (HAdVs) are prevalent causes of acute respiratory disease (ARD) in military and civilian communities. Over the last 20 years, collaborative efforts between US public health, military and academic laboratories have gathered comprehensive data documenting the emergence and re-emergence of specific HAdV types in association with outbreaks and unrelated cases of ARD, which have attracted national attention. New or reemerging HAdVs have included genomic variants of HAdV-B14, HAdV-B7, and HAdV-E4. Detailed molecular characterizations of virus strains are essential to understand the etiology and epidemiology of HAdV infections. The continuation of such studies is important for ongoing assessment of the national and global evolution of respiratory HAdVs and to inform decisions regarding antiviral drug and vaccine development and implementation.

Adenovirus pneumonia complicated with acute respiratory distress syndrome: a case report

Severe adenovirus infection in children can manifest with acute respiratory distress syndrome (ARDS) and respiratory failure, leading to the need for prolonged mechanical support in the form of either mechanical ventilation or extracorporeal life support. Early extracorporeal membrane oxygenation (ECMO) intervention for children with ARDS should be considered if selection criteria fulfill.We report on a 9-month-old boy who had adenovirus pneumonia with rapid progression to ARDS. Real-time polymerase chain reaction tests of sputum and pleural effusion samples confirmed adenovirus serotype 7. Chest x-rays showed progressively increasing infiltrations and pleural effusions in both lung fields within 11 days. Because conventional ARDS therapies failed, we initiated ECMO with high-frequency oscillatory ventilation (HFOV) for 9 days. Chest x-rays showed gradual improvements in lung expansion.This patient was subsequently discharged after a hospital stay of 38 days. Post-ECMO and adenovirus sequelae were followed in our outpatient department.Adenovirus pneumonia in children can manifest with severe pulmonary morbidity and respiratory failure. The unique lung recruitment by HFOV can be a useful therapeutic option for severe ARDS patients when combined with sufficient lung rest provided by ECMO.

Molecular Epidemiology of Adenovirus Type 21 Respiratory Strains Isolated From US Military Trainees (1996-2014)

BACKGROUND

The circulation of human adenovirus type 21 (HAdV21) in the United States has been documented since the 1960s in association with outbreaks of febrile respiratory illness (FRI) in military boot camps and civilian cases of respiratory disease.

METHODS

To describe the molecular epidemiology of HAdV21 respiratory infections across the country, 150 clinical respiratory isolates obtained from continuous surveillance of military recruit FRI, and 23 respiratory isolates recovered from pediatric and adult civilian cases of acute respiratory infection were characterized to compile molecular typing data spanning 37 years (1978-2014).

RESULTS

Restriction enzyme analysis and genomic sequencing identified 2 clusters of closely related genomic variants readily distinguishable from the prototype and designated 21a-like and 21b-like. A-like variants predominated until 1999. A shift to b-like variants was noticeable by 2007 after a 7-year period (2000-2006) of cocirculation of the 2 genome types. US strains are phylogenetically more closely related to European and Asian strains isolated over the last 4 decades than to the Saudi Arabian prototype strain AV-1645 isolated in 1956.

CONCLUSIONS

Knowledge of circulating HAdV21 variants and their epidemic behavior will be of significant value to local and global FRI surveillance efforts.

A human adenovirus species B subtype 21a associated with severe pneumonia

Between 2005 and 2013 six severe pneumonia cases (all requiring mechanical ventilation, two fatal outcomes) caused by human adenovirus type 21 (HAdV-B21) were observed in Germany. So far, HAdV-B21 was mainly associated with non-severe upper and lower respiratory tract infections. However, a few highly virulent HAdV types, e.g. HAdV-B14p1, were previously associated with severe, fatal pneumonia. Complete genomic sequences of the German HAdV-B21 pneumonia isolates formed a single phylogenetic cluster with very high sequence identity (≥ 99.897%). Compared to the HAdV-B21 prototype (only 99.319% identity), all isolates had a unique 15 amino acid deletion and a 2 amino acid insertion in the RGD loop of the penton base which may affect binding to the secondary receptor on the host cells. Moreover, a recombinant E4 gene region derived of HAdV-B3 was identified by bootscan analysis. Thus, the highly virulent, pneumotropic HAdV-B21 was denominated as subtype 21a. Surprisingly, there was 99.963% identity with agent Y/SIBU97 (only 13.4 kb available in GenBank of the 35.4 kb genome) which was associated with 10 fatalities due to cardiopulmonary failure in Sarawak, Malaysia, in 1997. In conclusion, a HAdV-B21 subtype (21a) associated with severe pneumonia in Germany was phylogenetically linked to an adenovirus isolated in Malaysia.

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

Lower respiratory tract infections (LRTI) caused by adenovirus can be severe with resultant chronic pulmonary sequelae. More than 50 serotypes have been recognized; however, the exact association of serotype with clinical phenotype is still unclear. There have been no reports on the adenovirus serotype pattern in Hong Kong, and their relationships with disease manifestations and complications are not known. Clinical and epidemiological data on 287 children (<6 years old) admitted with adenovirus respiratory infections from 2001 to 2004 were reviewed. Common presenting symptoms included fever (97.9 %) and cough and rhinitis (74 %). Extra-pulmonary manifestations were present in 37.3 %. The clinical picture mimicked bacterial infection for its prolonged high fever and neutrophilic blood picture. Forty-two patients (14.6 %) had LRTI, either pneumonia or acute bronchiolitis, but none had severe acute respiratory compromise. Children aged 1 to 2 years old were most at risk for adenovirus LRTI (adjusted p = 0.0165). Serotypes 1 to 7 could be identified in 93.7 % of the nasopharyngeal specimens, with serotypes 2 and 3 being the most prevalent. Different serotypes showed predilection for different age groups and with different respiratory illness association. The majority of acute bronchiolitis (71.4 %) were associated with serotype 2 infection, and this association was statistically significant (p < 0.0001). Serotype 3 infection accounted for over half of the pneumonia cases (57-75 %) in those aged 3-5 years old. Only one patient developed mild bronchiectasis after serotype 7 pneumonia. Children aged 1 to 2 years old were the at-risk group for adenovirus LRTI, but respiratory morbidity was relatively mild in our locality. There was an apparent serotype-respiratory illness association.

Prolonged mechanical support in children with severe adenoviral infections: a case series and review of the literature

Adenovirus infections occur primarily in infants and children less than 5 years of age, accounting for 2% to 5% of respiratory illnesses in the pediatric population and 4% to 10% of childhood pneumonias. Although the majority of children with adenovirus disease develop mild upper respiratory tract disease, more severe disease may occur with involvement of the lower respiratory tract characterized by pneumonitis and/or small airways disease. The authors present a case series of 3 high-risk children with severe lower respiratory tract adenoviral infections. These cases demonstrate the potential for the development of severe respiratory involvement from adenovirus in infants and children with comorbid conditions and illustrate that there may be a rapid progression of the disease as well as the need, in selected circumstances, for prolonged mechanical support. We review the role of adenovirus in lower respiratory tract infections in infants and children, its potential to result in life-threatening complications in pediatric patients with comorbid conditions, and the potential life-saving role of mechanical ventilation and extracorporeal life support (ECLS) in these children.

Postinfectious bronchiolitis obliterans in children: clinical and pulmonary function findings

AIM

Postinfectious bronchiolitis obliterans (PIBO) is an infrequent yet potentially severe disorder following acute lower pulmonary infection (ALRI) in children. In infants and young children PIBO have been strongly associated with Adenovirus (Ad). The purpose of this study was to analyze the clinical features and pulmonary function findings in children with PIBO. Cases caused by Ad were compared with cases in which no viral agent was identified.

METHODS

Fifty-eight children with PIBO were prospectively studied. Clinical data and pulmonary function tests (spirometry and plethysmography) were evaluated. Patients were divided in two groups according to the identification of the causal agent. Group 1 (G1): Adenovirus (+) Group 2: No etiologic agent identified.

RESULTS

Fifty-eight patients (male/female ratio 3.4:1); median age 8 years; mean age at initial injury 11 months; median time of hospitalization at acute stage of disease 60 days. Spirometry: FVC 68 ± 13%, FEV1 40.5 ± 11%, FMMF(25-75%) 16.7 ± 7.5%. Pletysmography: TLC 136 ± 22%, FRC 208 ± 50%, RV 343 ± 102%, RV/TLC 59 ± 10, SGaw 0.05 ± 0.02. When clinical, spirometric and plethysmographic data were compared, no statistically significant difference was found between the two groups.

CONCLUSIONS

PIBO is an extremely crippling lung disease with significant obstructive pattern in PFT. Both analyzed groups shared similar characteristics in the acute phase of the disease and in the severity of the sequelar pulmonary disease.

Lower respiratory infections by adenovirus in children. Clinical features and risk factors for bronchiolitis obliterans and mortality

Adenovirus (Ad) respiratory infections have a profound impact in Argentina. Severe chronic disease and a high mortality rate are observed in children after acute lower respiratory infections (ALRI) by Ad.

METHODS

A retrospective observational study was performed to describe clinical characteristics and to analyze risk factors for bronchiolitis obliterans (BO) and death in 415 children hospitalized with ALRI caused by Ad from March 1988 to May 2005.

RESULTS

Mean age of patients was 10.7 months (+/-9.2) Overall 80% of patients were healthy before ALRI. Forty-nine percent recovered, sequelae were observed in 36% and 15% died. Independent risk factors for BO were: >30 days of hospitalization (odds ratio (OR) 27.2, 95% confidence interval (CI) 14.6-50.9), multifocal pneumonia (OR 26.6, 95% CI 5.3-132) and hypercapnia (OR 5.6, 95% CI 3.5-9). Independent risk factors for death in acute stage of disease were: mechanical assistance (OR 121, 95% CI 18.2-814), multifocal pneumonia (OR 102, 95% CI 9.5-31.1), hypercapnia (OR 42.6, 95% CI 10.2-177.1), coagulation disorders (OR 17, 95% CI 8.25-35), neurological symptoms (OR 12.7, 95% CI 3.5-6.6) and co-infection with measles (OR 9.6, 95% CI 2.1-44.2).

CONCLUSIONS

High incidence of sequelae and mortality in previously healthy children after Ad infection was observed in a population of children from Argentina.

Nitric oxide levels and ciliary beat frequency in indigenous New Zealand children

New Zealand children's morbidity from respiratory disease is high. This study examines whether subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. A prospective study enrolled a group of healthy children who were screened for respiratory disease by questionnaire and lung function. Skin-prick tests were performed to control for atopy. Exhaled and nasal NO was measured online by a single-breath technique using chemiluminescence. Ciliary specimens were obtained by nasal brushings for assessment of structure and function. The ciliary beat frequency (CBF) (median CBF, 12.5 Hz; range, 10.4-16.8 Hz) and NO values (median exhaled NO, 5.6 ppb; range, 2.3-87.7 ppb; median nasal NO, 403 ppb; range, 34-1,120 ppb) for healthy New Zealand European (n=58), Pacific Island (n=61), and Maori (n=16) children were comparable with levels reported internationally. No ethnic differences in NO, atopy, or CBF were demonstrated. Despite an apparently normal ciliary beat, the percentage of ciliary structural defects was 3 times higher than reported controls (9%; range, 3.6-31.3%), with no difference across ethnic groups. In conclusion, it is unlikely that subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. The high percentage of secondary ciliary defects suggests ongoing environmental or infective damage.

Type-specific identification of human adenovirus 3, 7, and 21 by a multiplex PCR assay

Human adenovirus (Ad) serotypes 3, 7, and 21 of DNA cluster B:1 are often associated with severe respiratory illness, particularly in infants and young children and, in addition to Ad4, are among the most important causes of acute respiratory disease syndrome in new military recruits. To address the inherent problems associated with classic typing methods, we developed a multiplex PCR assay for the rapid, specific identification of Ad3, Ad7, and Ad21 field isolates. To design type-specific primers for our assay, we sequenced the Ad21 hexon gene and compared this sequence with previously published sequences of Ad3, Ad7, and Ad16. The overall nucleotide (nt) and amino acid (aa) identities between Ad21 and Ad3, Ad7, and Ad16 were similar (ranges 78.3-80.8% nt; 84.1-86.2% aa), with significantly greater variability in the regions of the hexon that encode surface loops 1 and 2. Type-specific primers designed to the hypervariable regions correctly identified Ad3, Ad7, and Ad21 prototype strains and 53 previously typed Ad field isolates. No cross-reactions with other Ad serotypes were identified. Our multiplex PCR assay for type-specific identification of Ad3, Ad7, and Ad21 isolates will provide a rapid and convenient tool for the epidemiologic investigation of Ad-associated respiratory illness.

Lower respiratory tract infections due to adenovirus in hospitalized Korean children: epidemiology, clinical features, and prognosis

On occasion, outbreaks of infection with adenovirus types 3, 7, and 21 cause severe lower respiratory tract infections (LRTIs) in children. From 1990 to 1998, all cases of LRTI due to adenovirus at the Seoul National University Children's Hospital, Seoul, Korea, were reviewed. Adenoviruses were recovered from nasal aspirate specimens of 87 (5.9%) of 1472 children with LRTI. The principal adenovirus serotypes were type 2 (13 [15%] of 87 strains), type 3 (13 [15%]), and type 7 (36 [41%]). Of the 87 infections, 62 (71%) occurred in children <2 years of age, and 81 (94%) occurred in children <5 years of age. Infections due to types 3 and 7 occurred during epidemics, whereas infections due to type 2 occurred sporadically. For patients who were infected with types 3 and 7, extrapulmonary abnormalities were more common and homogeneous consolidation and pleural effusion were frequently identified on radiographs. The mortality rate was 12% overall and 19% among patients who were infected with type 7. Residual sequelae were identified in 6 (50%) of 12 patients who were infected with type 3 and in 9 (25%) of 36 who were infected with type 7. The data confirm that adenovirus types 3 and 7 can cause epidemics of severe LRTI in young children. Epidemics of LRTIs caused by adenovirus types 3 and 7 in Korea have not been described in reports published elsewhere.

Adenovirus 7a: a community-acquired outbreak in a children's hospital

BACKGROUND

Adenoviruses produce many illnesses in children, particularly respiratory and gastrointestinal disease. The most common adenoviral respiratory infections in children are caused by types 1, 2, 3 and 5. Adenoviruses spread rapidly in closed environments often causing epidemic disease. Serotype 7a has been responsible for outbreaks of respiratory disease in children living in close proximity with one another. This report describes a large community-acquired adenovirus 7a epidemic in hospitalized children.

METHODS

Evaluation of all patients with cultures positive for adenovirus from a children's hospital-based virology laboratory during a recognized adenovirus outbreak. All such adenovirus isolates were typed, and patients with adenovirus 7a are described by review of medical records.

RESULTS

Between March 1 and July 26, 1997, 47 children admitted to the hospital were identified as infected with adenovirus. Of these 47 patients 26 (55%) were infected with adenovirus 7a. Twenty-four (92%) infections were community-acquired. The age range was 11 days to 10 years with a median of 9.5 months. Twenty-two patients (84%) had respiratory symptoms, and 21 (8%) had fever, making these the most common symptoms. The mean durations of fever and hospitalization were 5.5 and 7 days, respectively. One of 26 patients died.

CONCLUSIONS

Adenovirus 7a can cause large community epidemics affecting children. The disease produced by adenovirus 7a in children is almost exclusively of the respiratory tract, and in some individuals it may be very severe and possibly fatal.

Mixed infection is common in children with respiratory adenovirus infection

The presence of concomitant viral or bacterial infection was evaluated in 20 patients hospitalized for adenovirus infection of the middle or lower airways by using new serological methods for detection of both antigens and antibodies. Adenovirus infection was identified by measurement of antibodies with complement fixation test or by direct detection of viral antigen in nasopharyngeal aspirates. Mixed infection was present in 11 (55%) of the 20 patients. Viral coinfection was demonstrated in five (25%) and bacterial in nine (45%) patients. Bacterial coinfection was common, 67%, in children with an infection focus, pneumonia or acute otitis media, but rare, 13%, in those without it. Seroconversion to nontypable Haemophilus influenzae was indicated in six children; four of them were infants, four had pneumonia and three acute otitis media. Pneumococcal infection was indicated in two patients with pneumonia, both aged over two years. Chlamydia trachomatis was involved in one case. The results indicate that bacterial coinfection is common in respiratory adenovirus infection affecting lower airways, especially if pneumonia is present.

Disseminated adenovirus (type 19) infection in a neonate. Rapid detection of the infection by immunofluorescence

A case of fatal disseminated adenovirus infection in a neonate who suffered from severe keratoconjunctivitis and pneumonitis is reported. The diagnosis was made seven days after the onset of illness based on the detection of adenovirus antigen in the smears of the tracheal suction and conjunctival swab by immunofluorescence. Viral antigen was detected in the frozen or formalin-fixed autopsy specimens of the lungs, kidneys, spleen, liver and lymph nodes. Typical crystal arrangement of adenovirus virions was observed in the alveolar epithelial cells by electron microscopy. The isolated virus was identified to be of type 19 by a neutralization test. The IF examination using adenovirus group specific immune reagents on the smears of clinical specimens appears to be useful for rapid diagnosis of viral infections.

Lung volumes in Polynesian children

Polynesian (Maori and Pacific Island) children account for approximately one quarter of the children in New Zealand, but good data for lung function in this group are not available. In this review, we report lung volume measurements in 571 healthy children 5 to 13 yr of age: 270 Polynesians (139 boys and 131 girls) and 301 Europeans (177 boys and 124 girls). All measurements were made in a body plethysmograph. Polynesian boys had significantly larger VC, FVC, FRC, TLC, and expiratory reserve volume than did Polynesian girls. Polynesian and European children generally showed different slope and intercept relationships for the prediction of lung volume from height. Racial differences are not adequately explained by differences in body proportions or social factors including parental smoking. Possible explanations include racial differences in lung growth and maturation.

Clinical considerations in the diagnosis of viral respiratory infections

Recent advances are allowing the transfer of sensitive and precise rapid viral antigen detection technology from sophisticated research laboratories to standardly equipped clinical diagnostic facilities. It is now possible to identify many viral respiratory pathogens directly from clinical specimens in less than 1 hr. Rapid antigen detection promises to be of the most value in the identification of respiratory viruses 1) for which antiviral therapy is available, 2) which can be prevented by employing isolation precautions, chemoprophylaxis, and/or immunization, 3) whose presence usually is associated with acute respiratory disease, not just asymptomatic colonization, and 4) which ordinarily are not associated with concomitant bacterial infection, and thus, whose early detection may allow withholding or withdrawing antibiotics. Based on these considerations, the relative usefulness of rapid viral antigen detection of commonly encountered respiratory pathogens will be discussed. In addition, the role of rapid viral detection in diagnosis of respiratory infections in high risk versus otherwise healthy individuals will be explored.

Fatal adenoviral (type 7) respiratory disease in neonates

Two cases of fatal neonatal adenoviral type 7 respiratory disease are described. The clinical, laboratory, x-ray, and pathological features of these two neonates and those reported in the literature are highlighted. Suggestions are made regarding how to diagnose this disease early so that the patients can be isolated and further spread of the disease prevented.

Adenovirus bronchiolitis in Manitoba: epidemiologic, clinical, and radiologic features

We reviewed our experience with 41 children hospitalized from 1974 to 1978 for adenovirus (ADV) bronchiolitis. Thirty-two patients (78 percent) were native Indians between four and 12 months old. In 18 of the 41 patients (43.9 percent) acute complications developed. The five fatal cases (12.2 percent) were confined to native children. The initial chest roentgenograms showed lobar consolidation in 35 patients (85.4 percent). Atelectasis developed in five (12.2 percent) during hospitalization. Sixteen of 25 patients (64 percent) with adequate radiologic follow-up examination had subsequent pneumonias or showed residual chronic changes. The reasons for the predilection of ADV bronchiolitis in native Indian children and the precise effect on subsequent airway function in survivors are unknown and require further study. We emphasize the importance of ADV as a cause of bronchiolitis in native Indian children. Furthermore, this report focuses attention on the contribution of this disease to the spectrum of chronic pulmonary disorders in the pediatric group.

Chronic lung damage caused by adenovirus type 7: a ten-year follow-up study

Twenty-seven children aged 0.6 to 7.0 (mean 2.1) years were admitted to the hospital in 1967 and 1968 with type 7 adenoviral pneumonia. All ran a prolonged course. Type 7 adenovirus was isolated from 14 children, and in the other 13, the rise in the titer of complement-fixing antibodies to adenovirus was fourfold or greater. The outcome of the disease in these 27 children was reassessed in 1979, 9.6 to 12.1 (mean 10.7) years after the adenovirus type 7 pneumonia. Twenty-two were examined clinically and roentgenographically and all had lung function tests. Twelve had abnormal chest roentgenograms, and of these, six had bronchiectasis. Six of the ten children with normal chest x-ray films and ten of the 12 with abnormal chest roentgenograms had abnormal pulmonary function tests. Of the six patients with bronchiectasis, four showed no discernible cause of bronchiectasis other than the antecedent type 7 adenoviral infection. The other two patients had bronchial asthma, which can be a risk factor for bronchiectasis.