Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) causing coronavirus disease, Covid-19, has spread rapidly across the globe since its emergence in January 2020. As of January 2021, there are 87.6 million confirmed cases worldwide, with 1.9milion deaths. In conjunction with this high disease incidence, there have also been reports of Covid-19 related sleep disordered breathing, with up 18% in a Chinese study and 57% in an Italian study of individuals with Covid-19 reporting sleep disturbance.

Obstructive Sleep Apnea (OSA) is a common, chronic condition due to partial or complete upper airway collapse during sleep. OSA is more common in males & obese individuals, both of which are more adversely affected by SARS-CoV-2 infection. Furthermore, inflammation of the upper airway, or nasal passages leading to congestion could lead to a compromised upper airway during sleep and subsequently, obstructive sleep apnea.

We believe that's SARS -CoV-2 infection, and subsequent Covid-19 will lead to an altered microbiome in the upper airway. This is turn will lead to worsening nasal inflammation and congestion, which could predispose individual with previous Covid-19 disease to OSA.

Additionally, OSA is treated with Continuous Positive Airway Pressure (CPAP) a machine which delivers pressurized air into the upper airway via a face mask. This keeps the upper airway open during sleep. When CPAP is well tolerated by individuals, it works well to reduce the symptoms of OSA. Unfortunately, many patients find it difficult to tolerate CPAP. One reason often reported for poor tolerance is nasal congestion. We believe that an altered upper airway microbiome, due to previous SARS-CoV-2 infection, will affect treatment adherence to CPAP therapy. Secondly, we will investigate if treatment with CPAP therapy causes any change in the upper airway microbiome.

Inclusion Criteria:

• Symptoms of sleepiness, fatigue, loud snoring

Exclusion Criteria:

1. Gross skeletal alterations affecting the upper airway (eg.micrognathia)
2. Unstable chronic medical conditions known to affect OSA (CHF, stroke) 3.
3. Pregnancy or intent to become pregnant within the period of the protocol
4. Inability to sign informed consent form
5. Habitual snorer or previous diagnosis of OSA.
6. Less than 18 years of age.

Participants will be selected from the Sleep Clinic and Post-Covid Clinic in Beaumont Hospital. Participants with snoring and daytime somnolence requiring sleep assessment as part of routine clinical care will be selected.