<p><b>OBJECTIVE</b>To analyze the results of
avian influenza surveillance program in Guangzhou from 2006 to 2012 and to evaluate the
risk of
infections with H5, H7 and H9 subtypes
avian influenza viruses .</p><p><b>
METHODS </b>
Avian influenza surveillance system in Guangzhou consisted five components
serum surveillance on occupational
population , environmental specimen
surveillance of
avian influenza virus ,
avian flu emergency surveillance ,
influenza viruses surveillance on ILI
patient and
surveillance on
pneumonia of unknown causes.
Hemagglutination inhibition test was conducted to detect the
antibodies against H5, H7 and H9 while RT-PCR was used to test the
nucleic acid of H5, H7 and H9
viruses .</p><p><b>RESULTS</b>From 2006 to 2012, 4103
serum specimens were collected from occupational
populations and the overall positive rate of H5/H7/H9
antibodies was 3.82% . The antibody positive rates for H5, H7 and H9 were 0.22% ,0.00% and 3.70% respectively. 4
serum specimens for H5 and H9 simultaneously showed antibody positive. The positive rate of H9 among occupational
populations (4.21%)appeared higher than that from the control
population (2.16%). 2028 specimens were collected from
poultry sites and 55 samples found positive for H5
nucleic acid (positive rate2.71%), 14 samples positive for H9
nucleic acid (positive rate0.69%), 5 specimens, simultaneously positive for H5 and H9
nucleic acids . However, none of the samples showing H7
nucleic acid positive. From 2006 to 2012, all the tested H5/H7/H9
virus were negative from the respiratory/
serum specimens among those close contacts of
patients or high
risk groups through the
avian flu emergency surveillance program,ILI
patient influenza virus surveillance programs or
pneumonia of unknown causes
surveillance program.</p><p><b>CONCLUSION</b>
Contamination of H5/H9
avian influenza virus did exist in the
poultry sites in Guangzhou, especially in the wet Markets. The H5/H9
avian influenza virus caused
asymptomatic infection was proved to be existed within the
population exposed to the
poultry , suggesting that the
poultry occupational
population in Guangzhou was under the
risk of
avian influenza virus infection .</p>