PMID- 19166053
OWN - NLM
STAT- MEDLINE
DCOM- 20090224
LR  - 20090126
IS  - 0005-2086 (Print)
IS  - 0005-2086 (Linking)
VI  - 52
IP  - 4
DP  - 2008 Dec
TI  - Virulence of low pathogenicity H7N2 avian influenza viruses from the Delmarva 
      peninsula for broiler and leghorn chickens and turkeys.
PG  - 623-31
AB  - The virulence of low pathogenicity (LP) type A H7N2 avian influenza virus (AIV) 
      isolates recovered from chickens in Delaware and the eastern shore of Maryland in 
      2004 was evaluated. Three-week-old leghorn- and broiler-type chickens and turkeys 
      were inoculated via the conjunctival sac with 10(3.5)-10(4.0) 50% embryo 
      infections dose (EID50) of virus per bird with A/ chicken/Delaware/Viva/04, 
      A/chicken/Delaware/Hobo/04, and A/chicken/Maryland/Minh Ma/04. In broilers, the 
      viruses produced respiratory signs, airsacculitis, and microscopic lesions in the 
      trachea and lung. In contrast, signs and lesions were less severe in turkeys, and 
      they were rarely observed in specific-pathogen-free (SPF) leghorns. In broilers 
      and SPF leghorns, AIV peaked on day 3 postinoculation (PI), based on virus 
      isolation and real-time reverse transcription-polymerase chain reaction, and 
      antigen capture testing. Infection in turkeys peaked on day 7 PI. Serum 
      antibodies generally were detected earlier in broilers (day 7 PI) than in turkeys 
      or SPF leghorns (day 14 PI) using agar gel immunodiffusion, 
      hemagglutination-inhibition, and the enzyme-linked immunosorbent assay. A second 
      trial was performed to further examine the disease susceptibility of the leghorn 
      chicken given the comparatively mild responses noted in the first trial. A 
      10-fold higher dose of 10(4.5)-10(5.0)EID50 per chick given via the conjunctival 
      sac was used. In addition, commercial-type leghorns were tested as were chicks 
      from the SPF leghorn source. The higher AIV dose resulted in more rapid and 
      consistent rates of infection and higher serum antibody responses in both types 
      of leghorn chickens. However, as observed in the first trial, clinical signs and 
      microscopic lesions in both types of leghorns were infrequent and very mild. 
      These findings indicate leghorn-type chickens, which are commonly used for 
      pathogenicity assessments because of their availability, may not be the most 
      suitable host for evaluating the virulence potential of LP AIV.
FAU - Ladman, B S
AU  - Ladman BS
AD  - Avian Biosciences Center, University of Delaware, Newark, DE 19716-2150, USA.
FAU - Rosenberger, S C
AU  - Rosenberger SC
FAU - Rosenberger, J K
AU  - Rosenberger JK
FAU - Pope, C R
AU  - Pope CR
FAU - Gelb, J Jr
AU  - Gelb J Jr
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Avian Dis
JT  - Avian diseases
JID - 0370617
SB  - IM
MH  - Animals
MH  - *Chickens
MH  - Delaware/epidemiology
MH  - Influenza A virus/*pathogenicity
MH  - Influenza in Birds/epidemiology/*virology
MH  - Maryland/epidemiology
MH  - Specific Pathogen-Free Organisms
MH  - *Turkeys
MH  - Virginia/epidemiology
MH  - Virulence
EDAT- 2009/01/27 09:00
MHDA- 2009/02/25 09:00
CRDT- 2009/01/27 09:00
PHST- 2009/01/27 09:00 [entrez]
PHST- 2009/01/27 09:00 [pubmed]
PHST- 2009/02/25 09:00 [medline]
AID - 10.1637/8282-031208-Reg.1 [doi]
PST - ppublish
SO  - Avian Dis. 2008 Dec;52(4):623-31. doi: 10.1637/8282-031208-Reg.1.