At this time, it is not looking like Ava has a bacterial infection (if she has any infection). Nasal washes and cultures have come back negative.
The CT scan this morning looked much worse than the chest X-ray yesterday, though Ava's hydration status (e.g. if she was a little dehydrated) might affect what is seen on X-ray.
They are still working her up for any fungal infection. Apparently the procedure she will have only catches the presence of fungus 20% of the time, and it can also give a false negative. (Therefore, a "positive" result would be the most useful information, as it would confirm the presence of fungus).
There is also the possibility that Ava may be experiencing lung GVHD, which would be a big concern. If everything else gets ruled out, they will need to do a lung biopsy to evaluate the presence of GVHD.
Ava continues to be without fevers, but her oxygen saturation stays about the same (87-90%). This means that she's not quite getting enough oxygen just breathing on her own, so she continues to get supplemental oxygen.
That is the gist of what I understand at this point; I'll update more as I know.
Thank you for your continual prayers.