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 person or infected live or dead poultry or contaminated environments.Globally the annual attack rate with influenza viruses ranges between 5 to10% in adults and 20- 30 % in children. The WHO estimates that 3-5 million cases of severe influenza illness occur every year resulting in 250,000 to 500,000 deaths worldwide, with most influenza deaths occurring among adults over 65 years of age.
Influenza is the cause of outpatient visits and inpatient hospitalization among population of District Sheikhupura.
A prospective study for duration of 3 months (September to october) was performed in Tehsil Muridke District Sheikhupra. Population of Tehsil Muridke is 4, 52,009. We selected Tehsil headquarter hospital randomly as sentinel sites .Our Target population was cases of ILI and SARI. All cases of influenza like illness (ILI) or severe acute respiratory illness (SARI) who meets the inclusion & exclusion criteria was enrolled. Data was obtained by the face to face interview. A detail investigation form was filled after taking written consent form. Throat swab was collected from patient. The sample was stored at -70°C for further laboratory procedure. We will use Reverse transcriptase polymerase chain reaction (RT-PCR) for detection of type of the influenza virus. RT-PCR allows viral template RNA to be reversed transcribed producing complementary DNA (cDNA) which can then be amplified and detected. So in our Study we used RT-PCR for influenza virus detection.
Data analyzed by using SPSS software with 95% confidence interval. Chi-square test used to measure the association of risk factors (age, sex, occupation, exposure, healthcare worker, travelling etc) and the rate of morbidity and mortality was calculated by using standard formulae.
We identified ILI and SARI cases associated with outpatients and inpatients & also provided data to identify and monitor groups at high risk for influenza and will measure trends in morbidity and mortality attributable to influenza.