Please select the eligibility criteria that correspond to the clinical trial below.
Title: Incidence of Respiratory Illness in Outpatient Healthcare Workers Who Wear Respirators or Medical Masks While Caring for Patients
Brief Summary: Despite widespread use of respiratory protective equipment in the U.S. healthcare workplace, there is very little clinical evidence that respirators prevent healthcare personnel (HCP) from airborne infectious diseases. Scientific investigation of this issue has been quite complicated, primarily because the use of respirators has become "the standard of care" for protection against airborne diseases in some instances, even without sufficient evidence to support their use. The key question remains: How well do respirators prevent airborne infectious diseases? The answer to this important question has important medical, public health, political and economic implications.


Options:
A: Inclusion Criteria:

* Older than 18 years of age and without symptoms associated with corona-virus (or previously tested positive for corona).
* Participant is outside their home more than 3 hours a day. E.g.for work or for other activities among other people.
* Do not normally wear a facial mask for daily work (e.g. healthcare personnel)

Exclusion Criteria:

* Previously tested positive for corona-virus
* Wear facial mask for work
B: Inclusion Criteria:

* Clinical diagnosis of Covid-19 infection by the patient's general practitioner and hospital doctor
* Clinical signs started less than 8 days ago.
* Virological confirmation
* Understanding and acceptance of the trial.
* Written agreement to participate in the trial

Exclusion Criteria:

* Pregnancy
* Breastfeeding
* Inability to comply with protocol
* Lack of written agreement
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:

* Clinical site leadership has agreed to have one or more staff participate in the trial
* Subject meets the definition of "healthcare personnel"
* Subject able to read and sign informed consent
* Subject agrees to all requirements of the protocol, including fit testing and diary keeping
* Subject's age is 18 or greater
* Subject passes fit testing for one of the study supplied respirator models and agrees to use that model for the entire intervention period of the study (if in respirator arm).

Exclusion Criteria:

* Subject self-identified as having severe heart, lung, neurological or other systemic disease that one or more Investigator believes could preclude safe participation
* Known to not tolerate wearing respiratory protective equipment for any period
* Facial hair, or other issue such as facial adornments, precluding respirator OSHA-compliant fit testing or proper mask fit during the study period
* Advised by Occupational Health (or other qualified clinician) to not wear the same or similar respirator or medical mask models used in this study
* In the opinion of the Investigator, may not be able to reasonably participate in the trial for any reason
* Self-identified as in, or will be in the third trimester of pregnancy, during the study period.
* Subject rotating in 2 different ResPECT study clinic sites /clusters during the 12-week study period.
* Subject works less than 75% of the intervention period in that clinic.
* Subject is a previous participant of the ResPECT Study, but does not consent for data from previous flu season(s) to be linked.

Answer: D