In the news this week is a story from New Zealand of a young girl suffering from leukemia who has also become infected with aspergillus.
This is a dreadful 'catch 22' situation where in order to treat the cancer the patient has to have their natural immune system completely wiped out. Of course as soon as the patient has no immune system then they have no resistance to infection, resulting in a wide variety of infections including one of the most deadly - aspergillosis.
Many of these infections are serious but are treatable using antibiotics, but even when antibiotics are used a lot of the 'work' needed to kill off an infection is still done by a healthy immune system. If there is no immune system then treatment becomes very difficult with a high chance of failure (90% in this case according to the news article).
If the infecting organism is the aspergillus fungus then things are very bad indeed as this can be far more resistant to treatment with antifungal 'antibiotics' than bacteria.
This becomes a deadly race between the fungal enemy and the recovering immune system. Leukemia patients have virtually no immune system for a fairly short period of time after treatment for the cancer. After treatment (e.g. transplant of bone marrow) the patients immune system gradually recovers - every day the immune system becomes better at fighting off infection. Past a certain point of recovery the patient can fight off even the worst infections (e.g. aspergillus) as long as the fungus has not got too great a foothold in the patients body.
All is not gloom and doom however. A few years ago there was only one drug to treat aspergillus infections, and that was very toxic. A weak patient could find the drug itself to be intolerable so it would not be possible to fight the infection aggressively. Nowadays there are several drugs available, most of which being far less toxic so treatment is less inhibited.
The Fungal Research Trust funds a lot of research into these drugs and their best use. Aspergillus infections are still very rare but as we have seen they are very deadly - much more research is needed as more and more transplants are carried out to treat a variety of illnesses.