As I always preach, infectious diseases can be an exhilarating field full of all kinds of challenges that may be lurking in each patient on whom you're consulted. Mixed amongst the mundane cases of infected pressure ulcers, cellulitis, and urinary tract infections is where you find the zebras--if you look hard enough or, in Pasteur's immortal words, have a prepared mind.
The latest zebra spotting occurred this week. The patient was an injection drug user who presented with an alteration in consciousness and ultimately was diagnosed with an encephalitis of unknown cause. Encephalitis has a variety of causes, many of which are infectious. Herpes and West Nile Virus are two common causes in the US, but many other viral causes go unidentified because of lack of easy diagnostics. Not all encephalitis, however, is infectious in origin and there are autoimmune forms as well. Treatment is different for infectious vs. autoimmune encephalitis with immunosuppression being the mainstay of management of autoimmune forms.
This patient's diagnostic workup was completely unrevealing--no virus was found and suspicion turned to an autoimmune form of encephalitis. Brain biopsy results were forthcoming when the patient's clinical course took a terminal course and the patient unfortunately died.
Now here come's the twist.
Since this was a young patient there was a major impetus for organ donation. However, it is a very dangerous proposition to transplant organs from a person who has died of an unknown encephalitis as both rabies and West Nile have been transmitted that way. His organs were deemed not suitable for donation.
Another twist then occurred when the brain biopsy results returned.
Many people outside of infectious disease may never have heard of Mucormycosis but it is an aggressive fungal infection that leaves most of its victims dead. It is often seen in the immunosuppressed or diabetics and occasionally has been seen in injection drug users (I saw a fatal case previously with horrible skin lesions) and was interestingly seen in Joplin tornado victims.
To transplant organs from someone who died of an invasive fungal infection, which Mucormycosis is par excellence, would be a death sentence for organ recipients. What likely occurred in this case is that heroin contaminated with fungal spores from the environment were injected and the process begun.
So hoofbeats can belong to zebras sometimes.