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Infectious agent that have been described but have not been approved as species by
the International Committee on Taxonomy of Viruses (ICTV),
Classification for example psittacine adenovirus 1 and pigeon adenovirus 2
Adenoviruses belong to the family Adenoviridae and are grouped (Teske et al., 2017). FAdV-1 (strain CELO virus) is the prototype
into five genera: Mastadenovirus, Aviadenovirus, Atadenovirus, virus species for the genus Aviadenovirus.
Siadenovirus and Ichtadenovirus. Mastadenoviruses and aviadeno- Duck adenovirus 1 (DAdV-1) or egg drop syndrome virus
viruses infect mammals and birds, respectively. Atadenoviruses (EDSV) is in the sole avian species Duck atadenovirus A of the
have high A + T content and have been isolated from mammals, genus Atadenovirus.
birds and reptilian species. Siadenoviruses infect avian, amphib- Viruses in the genus Siadenovirus are serologically and phylo-
ian and reptilian species, whilst ichtadenoviruses infect fish genetically distinct from members of the other adenovirus genera.
(white sturgeon) (Harrach et al., 2011). In addition to other differences, the presence of a putative gene
The majority of avian adenoviruses are in the genus Aviadeno- at the left end of the genome encodes a protein that is related to
virus (Harrach et al., 2011). Members of this genus are grouped sialidases. Large numbers of known siadenoviruses infect birds,
into 12 species, based on phylogenetic distance, genome organi- such as the great tit adenovirus 1 (GTAdV-1), raptor adenovirus
zation, restriction fragment length polymorphism, host range, 1 (RAdV-1), South Polar skua adenovirus (SPSAdV) and turkey
pathogenicity, cross neutralization and ability to recombine adenovirus 3 (TAdV-3, or haemorrhagic enteritis virus/marble
(Table 10.1). These species are Fowl aviadenovirus A to Fowl avia- spleen disease virus, HEV/MSDV) belong to species Great tit
denovirus E (FAdV-A, FAdV-B, FAdV-C, FAdV-D and FAdV-E), siadenovirus A, Raptor siadenovirus A, Skua siadenovirus A and
Duck aviadenovirus B (DAdV-B), Falcon aviadenovirus A (FaAdV- Turkey siadenovirus A, respectively (Pitcovski et al., 1998; Kovács
A), Goose aviadenovirus A (GoAdV-A), Pigeon aviadenovirus A and Benko, 2011; Park et al., 2012). In addition, there are related
(PiAdV-A), Turkey aviadenovirus B (TAdV-B), Turkey aviadenovi- viruses that probably belong to the genus Siadenovirus but have
rus C (TAdV-C) and Turkey aviadenovirus D (TAdV-D). The 12 not been approved, such as budgerigar adenovirus 1 (BuAdV-1)
serotypes of FAdVs are grouped into the five species: FAdV-1 is and psittacine adenovirus 2 (PsAdV-2).
in species FAdV-A; FAdV-5 is in species FAdV-B; FAdV-4 and Virus taxonomy is not constant; it only follows the discovery
FAdV-10 are in species FAdV-C; FAdV-2, FAdV-3, FAdV-9, and analysis of new and not so new viruses. Probably we will see
FAdV-11 are in species FAdV-D; and FAdV-6, FAdV-7, FAdV-8a, changes even within a single family, such as Adenoviridae in the
FAdV-8b are in species FAdV-E. There are other aviadenoviruses coming years.

Table 10.1 Aviadenovirus species and their genomes (sequences)
Species Abbreviation Serotype (strain or isolate) GenBank accession(s) Genome size (kb)
Duck aviadenovirus B DAdV-B DAdV-2 (GR) KJ469653 43.7
Falcon aviadenovirus A FaAdV-A FaAdV-1* AY683541 –
Fowl aviadenovirus A FAdV-A FAdV-1 (CELO) U46933, AC_000014 43.8
Fowl aviadenovirus B FAdV-B FAdV-5 (340) KC493646 45.7
Fowl aviadenovirus C FAdV-C FAdV-4 (ON1) GU188428, NC_015323 45.6
FAdV-10 (C-2B)* DQ208710, EF458162 –
Fowl aviadenovirus D FAdV-D FAdV-2 (685) KT862805 44.3
FAdV-3 (CR49) KT862807 43.3
FAdV-9 (A-2A) AF083975, AC_000013 45.0
FAdV-11 (ON-P2) KU310942 44.4
Fowl aviadenovirus E FAdV-E FAdV-6 (CR119) KT862808 43.8
FAdV-7 (YR36) KT862809 43.5
FAdV-8a (HG) NC_014969 44.0
FAdV-8b (764) KT862811 43.6
Goose aviadenovirus A GoAdV-A GoAdV-4 (P29) JF510462 43.3
GoAdV-5 (D1036/08)* JQ178217 –
Pigeon aviadenovirus A PiAdV-A PiAdV-1 (IDA4) FN824512 45.4
Turkey aviadenovirus B TAdV-B TAdV-1 (D90/2) NC_014564 45.4
Turkey aviadenovirus C TAdV-C TAdV-4 (TNI1) KF477312 42.9
Turkey aviadenovirus D TAdV-D TAdV-5 (1277BT) KF477313 43.6
Only partial genome sequences are available for these viruses.