I would dig deep as possible into the cabinets, bath and kitchen areas to uncover possible mold or mildew growth. Mildew is not as serious a problem as mold and there are many types of each.
I sprayed three sides of a house with Oxyclean then pressure washed to remove a massive amount of mildew on latex paint
. Concrobium was a consideration but Oxyclean was on the shelf. Don't recall the details and correct me if I'm wrong, the method in which bleach, Concrobium and Oxyclean kills mold and mildew are similar. Oxy should be rinsed after use though if used on fabric imho.
If you paint
, there are products with mildewcide premixed, or additives you mix your self like Walla Walla. Kilz and Zinsser Bulls-Eye are the go-to primers.