6.1 Background:
Influenza is a highly contagious, acute illness in humans. Influenza viruses have negative-sense RNA genomes and are placed in the Orthomyxoviridae family grouped into three types A, B and C on the basis of the internal nucleocapsid or the matrix protein. Droplet and airborne are the most common modes of transmission. In Humans infection appears to be direct or indirect exposure to infected live or dead poultry or contaminated environments, such as live bird markets.
6.2 Hypothesis:
Avian influenza virus is prevalent in poultry butchers working in live bird markets with domestic and pet, wild, exotic birds.
6.3 Parameter/Methodology:
A cross sectional survey of poultry butchers in Lahore was conducted in order to determine seroprevalence of avian influenza Disease. A target population was the poultry butchers/retailers in the District Lahore. A study population was the apparently healthy butchers in Lahore. A sample of 300 butchers was collected. Blood sample from apparently healthy butchers was collected from brachial veins as described in WHO (2010). Three ml blood was collected in the syringe and was allowed to clot to separate serum. Collected sera was stored in freezer at -70°C for further laboratory analysis. Data was gathered by simple random sampling technique. A total of 300 samples were collected. Haemagglutinationinhibition (HI) test applied to detect antibodies sensitivity. The test was followed as described by WHO (2013).
6.4 Statistical Design:
The weighted proportion estimate with 95% Cl (confidence intervals) of the overall seroprevalence was computed by using R-software. Logistic regression was conducted to estimate the effect of each study variable on the outcome.
6.5 Outcomes:
Out of 300 blood samples of butchers of sentinel live bird markets, 171 blood samples are sero positive for H9 virus after HI Testing. The sero prevalence of H9 virus in butchers of live bird markets is found to be 57 %. The results of H5 and H7 are found to be negative.
In univariable analysis, following risk factors which were significant as per criteria of selection in current study (p-value < 0.25); Education, Age, Smoking, Sticks smoke/day, Years of smoking, Having chronic disease, Birds sold/day, Keep birds at home, Access of stray dogs, Access of stray cats, Wash instruments after slaughtering, Do not clean cutting boards, Wearing of aprons.Multivariate analysis determined one factor i-e having birds other than broiler as significant factor having p-value < 0.001.