Sewage soaks into anything porous - drywall, carpet, pad, subfloor - and those materials usually have to be removed and disposed of, not cleaned. Surface wiping just spreads contamination and leaves pathogens behind in the material.
Air quality is part of the hazard. Sewer gases and, within a day or two, mold make an unventilated backup unsafe to occupy. Professionals contain the area, run HEPA air scrubbers, and use EPA-registered antimicrobials before the space is reoccupied.
If you carry a sewer or drain backup endorsement, document everything first with photos and video, because that documentation is what the claim pays against.