Effect of interventions on influenza A (H9N2) isolation in Hong Kong's live poultry markets, 1999-2005.
Live poultry markets (LPMs) are a recognized source of influenza viruses. Since 2001 and 2003, respectively, a first and second monthly "rest-day" has been implemented in Hong Kong's LPMs, when stalls are cleared of unsold poultry and disinfected. We assessed the incremental effectiveness of each rest-day and the banning of live quail sales in 2002 in reducing (H9N2) subtype isolation rates for chickens and minor poultry, by using a multivariable Poisson generalized linear model. There was a 58% reduction (p = 0.001) in virus isolation after 1 monthly rest-day in minor poultry compared with 27% (p = 0.22) in chickens. Combining 1 rest-day with the removal of quails further reduced virus isolation in chickens but not in minor poultry. However, an additional rest-day each month did not appear to affect isolation rates for either species.
Lau
Eric H Y
EH
The University of Hong Kong, Hong Kong Special Administrative Region, People's Republic of China.
Leung
Y H Connie
YH
Zhang
Li Juan
LJ
Cowling
Benjamin J
BJ
Mak
Sin Ping
SP
Guan
Yi
Y
Leung
Gabriel M
GM
Peiris
J S Malik
JS
D000818:Animals; D005243:Feces / Q000821:virology; D006723:Hong Kong; D006920:Hygiene; D053127:Influenza A Virus, H9N2 Subtype / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000517:prevention & control / Q000821:virology; D011200:Poultry / Q000821:virology*; D011784:Quail; D013997:Time Factors