Decades past, when tuberculosis was a scourge, one of the first things done, after dust removal, was sealing all surfaces with fresh new non-permeable
paint.
In modern times this would be a gloss of semi-gloss, two coats. This will seal in bacteria, eggs from parasites, and fungi. Wooden floors should be sealed with polyurethane. Use good ventilation.
Paint the rooms a light color to insure good reflectivity of incoming sunlight. Keep windows wide open, if possible.