Proportional mouse model for aerosol infection by influenza.
OBJECTIVE
The aim of this study was to demonstrate a prototype tool for measuring infectivity of an aerosolized human pathogen - influenza A/PR/8/34 (H1N1) virus - using a small-animal model in the Controlled Aerosol Test System (CATS).


RESULTS
Intranasal inoculation of nonadapted H1N1 virus into C57BL, BALB/c and CD-1 mice caused infection in all three species. Respiratory exposure of CD-1 mice to the aerosolized virus at graduated doses was accomplished in a modified rodent exposure apparatus. Weight change was recorded for 7 days postexposure, and viral populations in lung tissue homogenates were measured post mortem by DNA amplification (qRT-PCR), direct fluorescence and microscopic evaluation of cytopathic effect. Plots of weight change and of PCR cycle threshold vs delivered dose were linear to threshold doses of ~40 TCID(50)  and ~12 TCID(50) , respectively.


CONCLUSIONS
MID(50)  for inspired H1N1 aerosols in CD-1 mice is between 12 and 40 TCID(50) ; proportionality to dose of weight loss and viral populations makes the CD-1 mouse a useful model for measuring infectivity by inhalation.


CONCLUSIONS
In the CATS, this mouse-virus model provides the first quantitative method to evaluate the ability of respiratory protective technologies to attenuate the infectivity of an inspired pathogenic aerosol.
Applied Research Associates, Inc, Panama City, FL, USA.
R S
RS
McDonald
A R
AR
Sambol
B K
BK
Heimbuch
T L
TL
Brown
S H
SH
Hinrichs
J D
JD
Wander
D000280:Administration, Inhalation; D000281:Administration, Intranasal; D000336:Aerosols / Q000009:adverse effects*; D000818:Animals; D001273:Atmosphere Exposure Chambers; D004195:Disease Models, Animal; D005260:Female; D053118:Influenza A Virus, H1N1 Subtype / Q000472:pathogenicity*; D019570:Inhalation Exposure; D008168:Lung / Q000473:pathology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL
D000336:Aerosols