Co-infection of highly pathogenic avian influenza and duck hepatitis viruses in Egyptian backyard and commercial ducks

Peer review under responsibility of Faculty of Veterinary Medicine, Cairo University.

Figures & data

able 1 Number of ducks in the backyard and commercial sector during outbreaks in Sharkia, Egypt during 2009–2017.

Breed	Housing system	No of house/farm	Total No of birds	No of sampled birds
Native	Backyard	14	365	17
Pekin	Backyard	4	41	6
Muscovy	Backyard	2	140	9
	Commercial	6	10,333	34
Mallard	Backyard	1	120	7
	Commercial	2	2895	31
Total		29	13,894	104

ig. 1 Phylogenetic analysis of HA gene nucleotide sequences of AIV isolated from ducks at Sharkia Province, Egypt and other sequences available in GenBank. The tree was constructed via multiple alignments of 1585-bp nucleotide sequence of HA gene from 43 isolates and analyzed by neighbor-joining analysis with 1000 bootstrap replicates. The viruses isolated in the study are marked with the solid circle.

ig. 2 Mortality rate among investigated ducks in Sharkia Province, Egypt according to the breed of birds, vaccination status against HPAIV, housing system and sampling years.

ig. 3 Duckling infected with HPAI subtype H5N1. (A) Torticollis and incoordination with staining of the feather with greenish diarrhea. (B) Brain, showing severely congested meningeal blood vessels with meningeal hemorrhage. (C) Brain showing vacuolation, spongiosis (asterisks), degenerated neurons (arrowheads), microglial cell infiltrations and perivascular lymphocytic cuffing (arrows). Haematoxylin and eosin, bar: 50 μm. (D) Brain and cerebrum showing a strong AIV antigen signal in the neurons and glial cells. Immunohistochemistry. Bar 20 µm. (E) Liver showing an intense signal in the hepatic and Küppfer cells. Immunohistochemistry. Bar 20 µm. (F) Intestine showing a positive AIV antigen signal in the neurons of the submucosal plexus (arrows). Immunohistochemistry. Bar 50 µm.

able 2 The details of GenBank-published HPAIV strains isolated from ducks in Sharkia province, Egypt.

Strain name	Year	Locality	Breed	Age/Month	Mortality % (No. of dead/Total No)^1	Accession number
A/duck/Egypt/SHMK-2203/2010(H5N1)	2010	Minet-ElKamah	Native	2	2.5 (1/40)	JX520633
A/duck/Egypt/SHZA-6504/2011(H5N1)	2011	Zagazig	Pekin	7	100 (12/12)	JX520634
A/duck/Egypt/SHZA-6605/2011(H5N1)	2011	Zagazig	Native	8	100 (27/27)	JX520635

All the above mentioned ducks were kept in backyard housing system and not-vaccinated against AIV.

% of mortality was recorded on the day of submission.

able 3 The clinical profile of HPAIV and DHV-1 co-infected ducks in Sharkia province, Egypt.

No	Breed	Year	Age	Mortality %	Clinical pictures/ lesions
1	Muscovy	2010	19 days	15.8%	Nervous signs, congested meningeal blood vessels, swollen and congested liver.
2	Mallard	2013	15 days	48%	Nervous signs, congested meningeal blood vessels, hemorrhages on brain, enlarged liver with sub capsular hemorrhages, and petechial hemorrhages on pancreas.
3	Muscovy	2015	4 days	62%	Nervous signs, congested meningeal blood vessels, hemorrhages on brain, enlarged liver with hemorrhages, severe congestion in pancreas, and petechial hemorrhage on coronary fat.

ig. 4 Correlation between the age of ducks and observed clinical symptoms/lesions. Spearman’s rank correlation coefficient revealed no correlation between the two examined datasets Rs = 0.363. *Correlation is significant at the level .05.