A recent example of a strange headline for an interesting case report is “The Brief Case: A Fishy Tale Prevents Digital Doom following Polly’s Peck—the Importance of Pets in a Comprehensive Medical History” published in the Journal of Clinical Microbiology (Simpson et al. 2017).
I guess it’s a double zoonosis, as the infection described was linked to both a bird and fish. Birds are more commonly implicated in zoonotic infections but fish-tank associated infections occur, usually by the bug implicated in this report.
Here’s the short version of the story:
- A 68-year-old man was bitten by his pet African Grey parrot. He’d be in a high risk category for infections based on his age, as well as his medical history. He went to a physician the day after the bite and was given oral antibiotics because of inflammation at the site of the bite. Swelling persisted and some further testing (a couple of months later) showed likely infection of the bone.
- Over a year later, he went back to his doctor with worsening finger swelling, and the next month a rheumatologist injected one of the finger joints with steroids to reduce inflammation. The problem is, steroids reduce inflammation by suppressing the immune response, and when there’s an infection present, suppressing the body’s response often leads to badness. Consistent with that, things had worsened by the next month, more aggressive care was needed, and amputation was considered.
- Eventually (a long time later), a diagnosis of Mycobacterium marinum infection was made. This bacterium is associated with fish and fish tanks, and infection is often referred to as “fish tank granuloma.” The parrot bite set the scene for infection by damaging the skin and allowing the bacterium to access the site. The person’s age and health status reduced the ability to eliminate the bacterium, and the steroid injection blew things wide open.
- Fortunately, over many months of treatment, he responded and full function of the finger was regained.
An important part of this story is the statement that “A comprehensive medical history revealed that, in addition to the African gray parrot, the patient kept tropical fish and had cleaned the fish tank thoroughly following the parrot bite.” This only came out over a year after the onset of disease, when an infectious disease team was involved. It’s a common theme on this blog, but while pet-associated infections are uncommon, getting pet contact history when infection does occur is critical and unfortunately rare. Here, as in countless other cases, failure to get that information was a key part of the pathway that lead to complicated and prolonged disease.
As is stated in the paper, “Pet ownership is an often neglected part of a medical history with both patients and health care professionals sometimes being unaware of the potential risks of zoonotic diseases. In this case, eliciting multiple pet ownership—after an 18-month diagnostic delay— contributed to saving this gentleman’s M. marinum-infected finger from amputation”.