A fatal illness associated with two viruses: an intermediate adenovirus type (21-16) and influenza A2

Are adenoviruses zoonotic? A systematic review of the evidence

Adenoviruses (AdVs) are major contributors to clinical illnesses. Novel human and animal AdVs continue to be identified and characterized. Comparative analyses using bioinformatic methods and Omics-based technologies allow insights into how these human pathogens have emerged and their potential for host cross-species transmission. Systematic review of literature published across ProQuest, Pubmed, and Web of Science databases for evidence of adenoviral zoonotic potential identified 589 citations. After removing duplicates, 327 citations were screened for relevance; of which, 74 articles received full-text reviews. Among these, 24 were included here, of which 16 demonstrated evidence of zoonotic transmission of AdVs. These documented instances of AdV crossing host species barriers between humans and non-human primate, bat, feline, swine, canine, ovine, and caprine. Eight studies sought to but did not find evidence of zoonosis. The findings demonstrate substantial evidence suggesting AdVs have previously and will continue crossing host species barriers. These have human health consequences both in terms of novel pathogen emergence and epidemic outbreaks, and of appropriate and safe use of non-human adenoviruses for therapeutics. As routine human clinical diagnostics may miss a novel cross-species adenovirus infection in humans, next generation sequencing or panspecies molecular diagnostics may be necessary to detect such incursions.

A Zoonotic Adenoviral Human Pathogen Emerged through Genomic Recombination among Human and Nonhuman Simian Hosts

Genomics analysis of a historically intriguing and predicted emergent human adenovirus (HAdV) pathogen, which caused pneumonia and death, provides insight into a novel molecular evolution pathway involving "ping-pong" zoonosis and anthroponosis. The genome of this promiscuous pathogen is embedded with evidence of unprecedented multiple, multidirectional, stable, and reciprocal cross-species infections of hosts from three species (human, chimpanzee, and bonobo). This recombinant genome, typed as HAdV-B76, is identical to two recently reported simian AdV (SAdV) genomes isolated from chimpanzees and bonobos. Additionally, the presence of a critical adenoviral replication element found in HAdV genomes, in addition to genes that are highly similar to counterparts in other HAdVs, reinforces its potential as a human pathogen. Reservoirs in nonhuman hosts may explain periods of apparent absence and then reemergence of human adenoviral pathogens, as well as present pathways for the genesis of those thought to be newly emergent. The nature of the HAdV-D76 genome has implications for the use of SAdVs as gene delivery vectors in human gene therapy and vaccines, selected to avoid preexisting and potentially fatal host immune responses to HAdV.IMPORTANCE An emergent adenoviral human pathogen, HAdV-B76, associated with a fatality in 1965, shows a remarkable degree of genome identity with two recently isolated simian adenoviruses that contain cross-species genome recombination events from three hosts: human, chimpanzee, and bonobo. Zoonosis (nonhuman-to-human transmission) and anthroponosis (human to nonhuman transmission) may play significant roles in the emergence of human adenoviral pathogens.

Molecular characterization of an adenovirus 3-16 intertypic recombinant isolated in Argentina from an infant hospitalized with acute respiratory infection

An intertypic recombinant adenovirus with a serotype 3-like hexon gene and a serotype 16-like fiber (99% identical to that of the prototype strain of human adenovirus 16 [HAdV-16], Ch79) was isolated in Argentina from an infant admitted to the hospital with acute respiratory disease. Consistent with the results of molecular characterization, strain Arg827/04 was designated H3-F16.

Assessment of genetic variability among subspecies b1 human adenoviruses for molecular epidemiology studies

Adenoviruses exhibit considerable intraserotypic genetic variability. Restriction enzyme analysis of the adenoviral genome is currently the most widely used procedure for the characterization of adenovirus isolates and has been extensively used for molecular epidemiological studies of subspecies B1 adenovirus infections. Comparison of restriction site maps between viral genomes is qualitatively consistent with DNA sequence homology providing that a sufficient number of sites are known. This technique is simple, sensitive, and can be adapted for screening numerous isolates and is therefore particularly useful for analysis of closely related genomes. Restriction enzyme analysis is still the only molecular approach that, at a reasonable cost, can give a "genome-wide" characterization of an adenovirus strain. Polymerase chain reaction (PCR) amplification followed by sequencing of the generated amplicon is the approach of choice for the detailed analysis of specific regions of the viral genome. Several laboratories have recently adopted PCR amplification of the hexon and/or fiber genes for the determination of adenovirus serotype identity, replacing identification by seroneutralization and hemmaglutination-inhibition. This approach permits rapid and objective type-specific identification of human adenoviruses and is especially useful for the characterization of serologically intermediate strains frequently identified among field strains of subspecies B1 adenoviruses.

Immunological and biochemical characterization of human adenoviruses from subgenus B. I. Antigenic relationships

47 adenovirus strains related to Ad11, 14, 16, 21, 34, and 35 (including all subgenus B prototypes) were studied in neutralization and hemagglutination-inhibition with 40 antisera, prepared against 16 virus strains, to determine their antigenic relatedness. Wild strains of Ad11-14 (14), Ad14, and a group of 16 strains related to Ad21 proved to be identical within their respective groups, whereas strains related to Ad11, 34, and 35 showed serological differences. Prototype strains of Ad11, 21, 34, and 35 fit the species definition (22) if selected antisera of known specificity are used. All virus strains with Ad16 hemagglutinin showed a bilaterial cross-neutralization either with Ad4, Ad14, Ad3, or Ad21. Doubly neutralizable strains with one hemagglutinin were Ad11 + 35/H11, Ad3 + 16/H16, Ad21 + 16/H16 (H stands for 'hemagglutinin'). Preliminary identification of subgenus B viruses (others than Ad3 and 7) may be performed by HI.

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.

Influenza A virus and Reye's syndrome in adults

We report fatal Reye's syndrome in two adults following proven influenza A viral infections. Reye's syndrome is, therefore, not confined to children but may also occur in adults. Many reported cases of postinfluenza A encephalopathy have clinical and pathological features of Reye's syndrome suggesting that they are not due to postinfectious perivenous demyelination.

Crippling lung disease after measles and adenovirus infection

Four children who developed severe lung disease after measles are described. One child died and three have been left with severe impairment of lung function. It is suggested that secondary infection with an adenovirus was responsible for causing the lung disease in these patients. The immune response to measles was abnormal. Measles virus may have rendered the children more susceptible to serious complications from infection with the adenovirus. The many deaths from 'measles pneumonia' in developing countries and the occasional occurence of post-measles bronchiectasis in this country may be due to secondary adenovirus infections. Further viral and serological studies are required to confirm this hypothesis.

Bronchiolitis obliterans, bronchiectasis, and other sequelae of adenovirus type 21 infection in young children

A remarkably high incidence of bronchiectasis and other pulmonary sequelae was observed in young children affected during an epidemic of severe lower respiratory tract infections apparently caused by adenovirus type 21. The histopathological findings are described in four cases in which one or both lungs were obtained for examination at intervals ranging from two months to three years after the acute infections. Widespread bronchiolar obliteration (bronchiolitis obliterans) was a striking finding in all four. The severity of bronchial inflammation and of bronchiectasis was proportional to the time elapsed since the acute infections. Bronchiolar obliteration is a likely sequel of the necrotizing bronchiolitis which may occur during acute adenovirus infections. The role of bronchiolar obliteration in the pathogenesis of bronchiectasis and other chronic lung disease is discussed. Adenoviruses may be a major cause of post-infectious bronchiectasis in childhood.

Neurological, electroencephalographic, and virological findings in febrile cheldren

Investigations were made of 78 febrile children, 53 with fits and 25 without fits. 53% of the children with fits had viral illnesses. Severe fits were commoner in these children than in those with negative viral findings. Permanent neurological damage and prolonged EEG abnormalities were found significantly more often in children with, than in those without, viral disease, whether or not fits had occurred. The long-term implications are discussed. In addition to viral agents already described as causing neurological complications, the following organisms were found in association with central nervous system disorder: adenovirus 7, respiratory syncytial virus, parainfluenza 2, and C. burnetii (Q fever).