Effectiveness of Flu Vaccination and Burden of Illness Among Community-dwelling Elderly With Influenza Like Illness in Brazil

Study Overview
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Brief Summary
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The purpose of this research study is to estimate how many elderly people who have symptoms that look like influenza (i.e. an influenza-like illness) actually have the disease and how effective influenza vaccines are in preventing influenza in elderly people. The study will also examine the severity of the disease (e.g. how long are people ill, were there any complications) and how it affects everyday life (e.g. cost, medications, care by family members).

Official Title
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An Observational Case Control Study of Effectiveness of Influenza Vaccination and Burden of Illness in Community-dwelling Elderly With Influenza-like Illness in Southern Brazil

Conditions
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Influenza

Intervention / Treatment
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* Other: Routine sample collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects who the investigator believes that they can and will comply with the requirements of the protocol. A male or female >= 65 years of age. Written informed consent obtained from the subject. Presenting within the first 72 hours of an influenza-like illness. Influenza-like illness is defined as the presence of: Fever measured by the patient or physician and at least one of the following symptoms: Sore throat. Coryza (runny nose) and/or nasal congestion. Cough. Availability to be followed up by phone or in person after an interval of approximately 14 - 21 days. Exclusion Criteria: Receipt of any experimental influenza vaccine within 6 months of the onset of the influenza-like illness. Terminal stage of disease. Subjects living in a nursing home. Use of any investigational or non-registered product planned during the study period. Subjects who have already been enrolled in this study.

Ages Eligible for Study
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Minimum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group 1<br>Subjects with influenza like illness | Other: Routine sample collection<br>* Collection of routine nasal/throat swab samples<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Laboratory-confirmed influenza status in patients presenting with influenza-like illness defined as positive for PCR for influenza A or B |  | At enrolment (day 0) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of days of illness since onset of influenza-like illness |  | At the follow-up contact (between day 12 and 28) | 
| Number of days of reduced activity since onset of influenza-like illness |  | At the follow-up contact (between day 12 and 28) | 
| Number of days off work of other family members or caregivers to provide patient care since onset of influenza-like illness |  | At the follow-up contact (between day 12 and 28) | 
| Number of medical visits related to influenza-like illness since Visit 1 |  | At the follow-up contact (between day 12 and 28) | 
| Use of medication since onset of influenza-like illness |  | At the follow-up contact (between day 12 and 28) | 
| Occurrence of complications since onset of influenza-like illness |  | At the follow-up contact (between day 12 and 28) | 
| Hospitalization since onset of influenza-like illness |  | At the follow-up contact (between day 12 and 28) | 
| Presence of non-influenza respiratory pathogens in patients presenting with influenza-like illness defined as positivity by PCR |  | At enrolment (day 0) | 
| Number of deaths |  | At the follow-up contact (between day 12 and 28) | 
| Clinical features related to influenza-like illness |  | At enrolment (day 0) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Influenza-like illness, vaccine effectiveness, elderly, Influenza