Avian Influenza
Conditions
Keywords
Serology, Poultry, H5N1 virus, HPAI virus
Brief summary
The main focus of the study is: * To estimate seroprevalence of AI in poultry-exposed and non-exposed human populations. * To estimate the incidence of AI in poultry-exposed and non-exposed human populations. * To investigate risk factors associated with AI infections in occupationally-exposed poultry workers. The secondary objectives of the study: * To investigate patterns in transmission of AI to household contacts of AI clinical cases * To isolate AI viruses from acute cases * To monitor the pathogenicity and disease severity of AI viruses causing human infections
Detailed description
This 4-year prospective cohort study to compare individuals with occupational exposure to poultry with non-poultry exposed adult controls for evidence of incident and previous infections with AI viruses. At the start of this study, study staff will obtain informed consent, and a blood sample will be obtained from study volunteers to establish baseline levels of antibodies against avian influenza types H4-H12. Subjects will be interviewed regarding their exposures, medical history, and behaviors using a close-ended questionnaire specifically tailored for this study. After one year, study subjects will be interviewed again to note any changes in exposure variables. At this time, another blood sample will be obtained and tested for any changes in antibodies' levels. The same procedures will be repeated at the final visit after another year. Exposed individuals will be selected from rural areas where poultry is commonly raised. Non-exposed controls will be selected from urban neighborhoods in Cairo.
Interventions
None listed
Sponsors
National Institute of Allergy and Infectious Diseases (NIAID)
St. Jude Children's Research Hospital
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
2 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Be willing to participate by signing a consent/assent form, completing the study questionnaire, and permitting the withdrawal of blood. * Does not buy poultry from live bird markets (for controls only).
Exclusion criteria
* Any known immunosuppressive condition or immune deficiency disease (including HIV infection), or ongoing receipt of any immunosuppressive therapy. * Any individual with unknown poultry exposure status, or who was exposed to poultry more than 5 years ago. * Children who are less than 2 years old when baseline enrollment is performed.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Measure antibodies in sera collected from poultry-exposed and non-exposed individuals | 4 years | Prevalence rates will be measured by the presence of antibodies against AI viruses of types H4-H12 using a microneutralization assay. |
| Draw 3 annual serum samples from each individual and record any increase in the antibody titers against AI viruses. | 4 years | Incidence rates will be assessed based on a 2-fold increase of antibody titers between baseline and follow-up and between follow-up and the final visit. |
| Risk or protective factors correlated with infection will be measured using the enrollment questionnaire. | 4 years | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Obtain nasal and naso-pharyngeal swabs from subjects reporting ILI symptoms and confirm the presence of influenza by a rapid test. | 4 years | Obtain swabs from the household contacts of individuals with a confirmed influenza A infection and test them for the presence of influenza A viruses |
| To send RT-PCR positive specimens collected from subjects reporting ILI symptoms to the hospital in order to isolate and characterize the virus. | 4 years | — |
| Collect data on disease pathogenicity and severity of symptoms from subjects reporting ILI and obtain a blood sample to isolate and study peripheral blood mononuclear cells. | 4 years | — |
Countries
Egypt
Outcome results
None listed