Treat the situation calmly, don't panic
Anxiety will cause more harm than good.
Look at things from helicopter view.
Treat it as a project issue, have a temporary workaround to resolve the situation.
1. If project team member(s) is/are affected. Please seek the team member to seek medical assistance and be quarantined for 10 days or more. Leave all office work behind and stay at home. Work is important but health is even more important.
2. Re-examine & analyse all project progress, are there any impact to project schedule if affected team member is absent from project. Can other non-affected team member act as backup and support the affected team member work.
3. Seek medical protection for all unaffected project team members such as put on surgical masks, frequent hands wash with soap etc.
At least achieve the above pointers to avoid any tension, stress.
Will seek assistance from higher management / client.