Squirrels Packing Real Viral Heat, Not Just Nuts

Virtually no one thinks of squirrels as anything more than cute spastic creatures that are fun to watch. All animals harbor dangerous infectious disease that--in specific contexts--can pose a risk to humans. Accordingly, it has been well-established that squirrels are connected, via their lice, mites, and fleas, with plague, certain forms of typhus, and rickettsialpox (for example). 

A newly discovered virus (likely directly transmitted from squirrels) can now be added to these indirectly transmitted infections: variegated squirrel 1 bornavirus (VSBV-1).

What is interesting about this newly discovered fatal encephalitis-causing virus is that it appeared in 3 German squirrel breeders and how it was identified. 

Anyone who operates at the interface of humans and animals should be considered a sentinel or a canary in the coal mine for novel infections. Most human infections originated from animals and jumped into the human species at some point, so it is likely that animals will remain a major source of new infections. Such a fact underscores how important it is to be extremely vigilant when dealing with an unexplained illness in individuals who have unusual animal exposures and never being satisfied until an actual etiology has been established--something that happens all to rarely.

Additionally, the identification of this virus employed a metagenomic approach in which sequencing of nucleic acid was performed directly on squirrel samples with the aim of finding genetic material that could be linked a known microbe family. 

The paper is, to me, significant not just for the description of VSBV-1 but for highlighting the importance of viral discovery and the principles that should be applied. 

Thank You Louis Pasteur

Yesterday was the 130th anniversary of Louis Pasteur's rabies vaccination of Joseph Meister--a day that everyone should recognize and celebrate. Though Jenner's smallpox was the first vaccine and Pasteur's called his rabies version "vaccine" to honor Jenner, Pasteur--in my view--is on the highest echelon of our race. 

Why I elevate Pasteur to that level has to do with the fact that not only did he discover the rabies vaccine but his contributions to the germ theory of disease (I'm not even counting  his contributions to stereochemistry) gave the entire field a green light to hypothesize, innovate, and advance. Such an achievement's ramifications are incalculable. 

To put it simply, I just would like to say thank you to Louis Pasteur for his recalcitrant, intransigent pursuit of the truth and that I am embarrassed that some members of our species have returned to the primitive status that humans have wallowed in for most of our history by shunning vaccination and pasteurization. 

The debt we owe Pasteur is not something repayable. 

Measles Still Has A License to Kill

The news of the 1st acute measles death in the US in over a decade is an event that should serve to remind those who doubt the ability of this virus, which kills 145,000 people per year, to inflict damage in the developed world. However, I doubt it because if people can blow off the 20% hospitalization rate that occurred during the Disneyland outbreak, one immunosuppressed person's death isn't enough to crack through layers of evasion.

I am interested to learn the details of this unfortunate case that resulted in a fatal measles pneumonia to see how the diagnosis was made, when it was made, and what confounding variables were present (I know no rash was present, something that occurs in the immunocompromised).

To date there have been 178 cases of measles reported this year, with nearly half of the 50 states being affected. The numbers are largely driven by the Disneyland outbreak that began last year.

Letting our guard down against this plague carries dire consequences.

Infectious Disease: The Coolest Specialty in the World

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.

Mucormycosis.

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.

Cryptosporidium in the Pool: Don't Drink the Water

Swimming pools and hot tubs are well known centers for the exchange of bodily fluids since it is a setting in which people regularly consume the fecal matter of others. Though public pools routinely evacuate swimmers when visible feces are present, non-visible fecal matter is basically omnipresent. 

The recent alerts regarding cases of Cryptosporidium infections in recreational swimming facilities is such an example of occult fecal ingestion. Cryptosporidium is a protozoal organism that is basically found everywhere and is infamous for a 400,000+ person outbreak it caused in 1990s Milwaukee. Infection occurs when someone ingests the oocysts of the organism that then hatch in the intestine. Though usually a benign illness, it can be particularly severe in the immunocompromised or in the malnourished.

Cases of Cryptosporidium can sometimes produce little to no symptoms but still be contagious, a factor that may be responsible for some infections. Also, the organism's ability to tolerate chlorine makes it particularly successful.

So bottom line: don't drink the water in pools or hot tubs and be wary of pools with diaper-wearing creatures present as they are always leaking some sort of fecal matter.