Case-control Study of Pandemic A/H1N1 Influenza Risk Factors In Lebanon
The pandemic A/H1N1 virus was named "swine flu" when the current outbreak started. Although it is not yet confirmed that the index case acquired the virus from pigs, the nomenclature "swine flu" was due to the fact that the virus is triple-reassortant with genes from swine, avian, and human influenza origins. A total of 57,809 cases were reported in the WHO EMRO region, 693 of whom have died (1.2% case fatality). Lebanon had 1,838 confirmed cases with 5 deaths, it is estimated that 4% of these cases required hospitalization. Most cases of pandemic influenza presented with fever, cough, and sore throat. Other common symptoms included myalgia, headache, and rhinorrhea. The pandemic A/H1N1 virus appears to be very successful at human-to-human transmission. It is also causing infections beyond the traditional seasonal variation of previous human influenza viruses. Unlike seasonal influenza viruses that usually cause severe infections requiring hospitalization among the elderly and children under 5 years old, the pandemic A/H1N1 viruses are causing more severe illness among young adults. Several reports have associated certain underlying conditions with severe illness. Such conditions were pregnancy, asthma, diabetes, obesity, and heart disease.
|Study Design:||Observational Model: Case Control
Time Perspective: Prospective
|Official Title:||Case-control Study of Pandemic A/H1N1 Influenza Risk Factors In Lebanon|
- This study will investigate the risk factors with pandemic A/H1N1 virus by measuring the degree of exposure to virus; [ Time Frame: One (1) year ] [ Designated as safety issue: No ]This study hypothesize that certain factors make people more vulnerable to be infected with A/H1N1, such as traveling to H1N1 infected area, exposure to infected patients, no influenza vaccination, residency in nursing homes, attendance of daycares, poor health and etc.
- This study will characterize influenza viruses causing infection by using molecular and cultural techniques [ Time Frame: One (1) year ] [ Designated as safety issue: No ]Through these techniques, the study will isolate and characterize influenza viruses causing infection and morbidity severity of infection among the enrolled cases.
- This study will investigate the risk factors of severe illness or death associated with infection with the pandemic A/H1N1 viruses. [ Time Frame: One (1) year ] [ Designated as safety issue: No ]This study hypothesizes that certain factors make patients infected with A/H1N1 more vulnerable to severe illness or death, such as obesity, pregnancy, tobacco use, and other co-morbidities (pulmonary diseases, cardiovascular diseases, diabetes, and renal insufficiency).
Biospecimen Retention: Samples With DNA
Specimens collected from cases(ie positive for pandemic influenza by RT PCR) will be processed in order to isolate and characterize the viruses causing infection.
|Study Start Date:||October 2011|
|Study Completion Date:||June 2013|
|Primary Completion Date:||June 2013 (Final data collection date for primary outcome measure)|
H1N1 not exposed controls
For every enrolled H1N1 case, the study will enroll 2 sex matched controls. On the date of enrollment of a case, 2 sex-matched controls will be located from the same clinic from which the case was enrolled. Enrolled controls will then be verified to be free from influenza infection at the time of enrollment by RT-PCR.
H1N1 exposed Cases
A swab will be collected from cases to verify presence of pandemic influenza. Testing positive for influenza A/H1N1 by RT PCR to be enrolled will be confirmed as a case. The participant will be presented with a questionnaire that will capture exposure data through a group of variables assessing underlying health conditions, symptoms, use of influenza vaccine, travel, occupational setting, and other demographic variables. Cases will be contacted once during the study.
This study will measure risk and protective factors associated with pandemic A/H1N1 infection. This study will also be able to estimate risk factors for severe illness requiring hospitalization or leading to death. These factors are: travel history, exposure to other confirmed or suspected cases, obesity, pregnancy, influenza vaccination history, residency in nursing homes, attendance of daycares, tobacco use, and other comorbidities (pulmonary diseases, cardiovascular diseases, diabetes, renal insufficiency). Unlike other descriptive studies, this analytical case-control study will enable to accurately measure the strength of association between potential risk factors and outcome. By isolating viruses from specimens collected from cases, this study will be able to characterize these viruses and document any genetic mutations or antiviral resistance.
The main objectives of this study are:
- To investigate the risk factors of infection with the pandemic A/H1N1 viruses.
- To characterize influenza viruses causing infection.
- If enough severe cases were enrolled to make it statistically feasible, this study will investigate the risk factors of severe illness or death associated with infection with the pandemic A/H1N1 viruses.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01298206
|American University of Beirut|
|Beirut, Lebanon, 1107-2020|
|Principal Investigator:||Ghazi Kayali, Ph.D, MPH||St. Jude Children's Research Hospital|