Please select the eligibility criteria that correspond to the clinical trial below.
Title: Tolerability and Measurability of the Efficacy of Non Pharmaceutical Measures to Prevent Seasonal Influenza
Brief Summary: With this study the investigators will try to assess the tolerability and measurability of the efficacy of non pharmaceutical measures to prevent seasonal influenza in individual households. Households with an identified index case of influenza will be randomised into one of three intervention arms: 1. group, where the household will receive general information about transmission of influenza virus and means to prevent it (Controls); 2. group, which will receive surgical masks and be asked to wear them whenever they are in close contact with the index case or other persons of the household that became ill during the observation period; 3. group, which will be given and asked to wear surgical masks as well as to execute intensified hand hygiene.

In addition to assessing the secondary attack rate as our primary outcome measure, the investigators will also try to evaluate compliance to those interventions by questionnaires.


Options:
A: Inclusion Criteria:

* Current or part-time student at McMaster University
* 17 year of age or older
* Currently living:

  i. In residence or, ii. Off-campus with at least one student housemate
* Willing and able to sign an informed consent

Exclusion Criteria:

* Students who do not meet the inclusion criteria
* Currently living at home with parents
* History or diagnosis of hypercalcemia
* Diagnosis of parathyroid disorder (hyper or hypo)
* Diagnosis of chronic kidney disease
* Use of anticonvulsants
* Malabsorption syndromes
* Diagnosis of sarcoidosis
* Currently pregnant or planning a pregnancy
* Inability to swallow capsules
B: Inclusion Criteria:

* Age 18 years or older
* Negative RT-PCR test at the beginning of the study.
* Negative SARS-CoV-2 serological Elecsys Anti-Sars-CoV-2 test at the beginning of the study.
* Living in a geographic area with active COVID-19 transmission (number of
* cases reported locally).
* Living in a geographic area that has been determined by the Colombian National Statistics Department (DANE) to have a medium, medium-high, and high vulnerability index (higher prevalence of comorbidities and social and economic vulnerabilities.
* Working outside the home for at least two days a week, during the last week.
* Acceptance to participate in the study regardless of the trial arm assignment through verbal informed consent.

Exclusion Criteria:

* Retired adults or unemployed
* Adults referring previous diagnosis of COVID-19 confirmed by RT-PCR tests or serological antibody tests.
C: Inclusion Criteria:

* influenza like illness symptoms
* positive rapid test for influenza
* inclusion within 48h of symptom onset
* inclusion of at least 3 members of a household (including index case)

Exclusion Criteria:

* severe illness
* other cases of similar symptoms within 14 days before onset of symptoms in index patient
* severe asthma or COPD
* pregnancy of index
D: Inclusion Criteria:

* Persons ≥ 5 years old: Influenza-like illness (ILI), defined as history of fever and either cough or sore throat with fever onset within the previous 24 hours
* Persons \< 5 years old: any child with acute fever with onset within the previous 24 hours
* Return to home within 24 hours of presentation to Upazilla Health Complex, Jahurul Islam Medical College Hospital or the local pharmacies; i.e., the index case cannot be admitted for treatment. If admitted, the patient would not be eligible.
* No fever in any bari resident during the 7 days preceding the patient's presentation to hospital (see definition below)
* At least two persons (in addition to the index case-patient) who intend to reside in the bari during the subsequent 20 days
* Residence within 30 minutes travel time (one-way) from the Upazilla Health Complex or Jahurul Islam Medical College Hospital or the local pharmacy.

Answer: C