Molecular epidemiology of adenoviruses: global distribution of adenovirus 7 genome types

Abstract

Adenovirus 7 (Ad7) is the adenovirus species that most frequently has been associated with severe illness. Seven distinct genome types of adenovirus 7, Ad7p, Ad7a, Ad7b, Ad7c, Ad7d, Ad7e, and Ad7f, can be identified by using restriction endonucleases BamHI and SmaI. We analyzed the distribution of the different Ad7 genome types among 314 isolates from patients and healthy shedders. The Ad7b and Ad7c genome types accounted for 90% of the isolates from patients and appeared to be mutually exclusive. A shift from Ad7c to Ad7b genome types occurred in 1969 in Europe and in 1975 in Australia. During the last decade, Ad7b genome types predominated in Australia, Europe, and North America. Ad7c was detected in South Africa, Ad7d was detected in China, Ad7e was detected in Brazil, and Ad7f was detected in Australia. The Ad7p and Ad7a genome types dominated among isolates obtained from healthy shedders and appeared scattered through the years and the geographical areas. The prevalence of Ad7 infections is high in Japan as judged by the herd immunity. However, the low percentage (2%) of Adi isolates among all adenovirus isolates chiefly from patients, coupled with 30 to 50% antibody prevalence, argues for a high proportion of inapparent infections and, hence, Ad7 strain(s) of low pathogenicity.

Adenovirus type 7 infections in children in new South Wales, Australia

“…At present, the predominant circulating virulent Ad7 genome types are Ad7b in Australia, Europe, and the United States, Ad7c in Africa, and Ad7d in China. [Wadell et al, 1985;Kannemeyer et al, 1988;Li and Wadell, 19861. Our findings confirm the importance of adenovirus type 7b in childhood infections in New South Wales. Overall, the impact of this virus clinically and epidemiologically resembles that described previously elsewhere [Straube et al, 1983;Wadell et al, 19801.…”

“…Since the isolation of the prototype strain Gomen of Ad7 (Ad 7p) by Berget et al [19551, a total of 15 Ad7 genome types designated Ad7p, Ad7a, Ad7al to Ad7a5, Ad7b, Ad7c, Ad7d, Ad7d1, Ad7e, Ad7f, and Ad7g have been described by Li and Wadell [19861 and their distribution worldwide reported recently [Wadell et al, 19851. Overall, during the last decade, Ad7b predominated in Australia, Europe, and North America and Ad7c was detected in South Africa, Ad7d in China, Ad7e in Brazil, and Ad7f in Australia [Wadell et al, 1985;Kannemeyer et al, 1988;Li and Wadell, 19861. The present report describes our own experience of infection due to Ad7 in New South Wales, Australia. It confirms the above-mentioned data relating to Ad7b [Sutton et al, 1976;Straube et al, 1983;Wadell et al, 1981 I, thus emphasising the importance of this genome type in epidemic Ad7 infection in Australian children as well.…”

Current research on respiratory viral infections: Fifth International Symposium1

“…Moreover, the impact of genetic variability on adenovirus virulence is poorly understood. A shift from Ad7c to Ad7b occurred in Europe in 1969and in Australia in 1975(Wadell et al, 1985. A shift from Ad7b to Ad7d occurred in China between 1965and 1980(Li et al, 1996, and a shift from Ad7c to Ad7h took place in the South America (Argentina, Chile and Uruguay) in 1986 (Kajon and Wadell, 1994).…”

Enteric Adenovirus Type 41 Isolates: Cloning, Physical Maps and Diversity in Restriction Enzyme Cleavage Pattern

“…These facts suggest that Ad41 and Ad40 may have different infectious route or clinical features, perhaps depending on the process of genome evolution. Since Ad7 (33,34) and Ad21 (28) show successions of DNA variation with time, further genomic analysis of clinical samples of enteric Ads would be required.…”