Polio-like Illness in California?

A few points regarding the cases of paralysis linked to enterovirus 68 in California:

--Enteroviruses are a large group of viruses that cause diseases ranging from the common cold to paralysis

--Polio itself is an enterovirus and in an era in which polio is almost eradicated, it is not surprising to see another enterovirus causing paralytic illness

--These cases are a rare manifestation of a rare virus

Overall, the identification of these cases is important because it illustrates the benefit of surveillance in combating infectious diseases. Future work should focus on understanding the true burden of this disease and determining what percentage of illness proceeds to paralysis.

I'm supposed to discuss all this on John Seigenthaler's show shortly. 

Lurking in Tap Water

An interesting case I was involved with over the past week illustrates the ubiquity of microorganisms and their ability exploit to any weakness to cause infection.

A guy falls off a ladder, tears his meniscus, and has surgery. Pretty routine until he develops a cystic mass at the surgical site. It's excised and grows Mycobacterium kansasii, a bacterium which is related to tuberculosis and merits aggressive treatment. 

How does one get such an organism at a routine surgical site? Tap water.

Of course, not everyone's wound gets infected by this relatively rare bacterium so there is likely a large amount of host susceptibility at play. In fact, M.kansasii really gained prominence during the early years of the HIV/AIDS pandemic. While untreated HIV/AIDS causes catastrophic immune collapse, subtle alterations in an individual's immune repertoire are likely all that is needed when a the bacterium comes into contact with a hospitable wound.

The fact that such a pathogen flourishes in tap water reinforces the fact that we live in a world populated by microbes and that sterility is only relative. So, when a new mother lunges after her toddler when he drops his binky so she can wash it in the sink her activity just replaces one set of microbes with another. 

Pittsburgh & San Francisco: Sister Measles Cities

Not to be outdone by San Francisco, Pittsburgh joined the 2014 measles club after atleast 1 case was diagnosed here.

The facts surrounding the case in Pittsburgh serves to reinforce some important points about measles:

1. Measles is extremely contagious: the case patient in Pittsburgh traveled on public buses. As measles can infect 90% of those exposed that are susceptible to infection, secondary cases are to be expected.

2. Measles is a world traveler the couldn't resist one of the nation's most livable city: the case patient traveled to New York and was exposed to someone who contracted the disease overseas.

3. High vaccination rates are needed for herd immunity: because of its marked contagiousness, communities need to have vaccination rates above 90% to halt transmission.  Children under 1 year of age are a group too young to be vaccinated and are reliant upon herd immunity for protection, as are those whose vaccine failed to provide full immunity.

Hopefully this case will prompt those who have deferred or declined vaccination to seal some holes in the Pittsburgh herd's immunity. Next up should be our potholes. 

Calling UTIs Mundane: A Privilege to Be Earned

Today I was the instructor/facilitator for a problem-based learning (PBL) session for 1st year medical students in their microbiology course. 

The "problem" we worked through was a urinary tract infection (UTI). As an infectious disease physician, I often find myself scorning at consultation requests for UTIs. UTIs are usually  e mundane and lack the excitement or intellectual change of, for example, a fever in a returned traveler.

By working through the case with the med students, however, I realized mundaneness  depends upon one's context of knowledge. That UTIs have become mundane is testament to the fact that I have internalized the principles of infectious disease management and UTIs, with minimal cryptic elements, allow all these principles to be apparent in a very concrete manner. Such principles that readily available include: host defense mechanisms, bacterial virulence, risks for resistance, alterations in host immunity, and iatrogenic risk factors. 

It was extremely fun to try and bring these principles alive in the mind of the students allowing them to internalize the principles. 

It is a privilege to be able to think of a UTI as mundane. 

Smallpox and Stage Fright

I'm currently listening to the audio versions of the multi-part Lyndon Johnson biography by Robert Caro and, especially for those who like the Netflix series House of Cards, it is a must read as it portrays naked power-lust and secondhandedness on a grand scale. 

One infectious disease tidbit that I found in the books is interesting. Describing Lady Bird Johnson, the books relate that as a child she was so afraid of public speaking that she hoped that if she ended up salutatorian or valedictorian of her high school and was required to give a speech at graduation, she would contract smallpox and be excused. She ended up 3rd in her class. 

That's a bad case of stage fright for a future First Lady. 

With a mortality rate that could reach 30%, wishing for chickenpox or influenza would be much more advisable than hoping for smallpox.

Today, modern stage fright sufferers don't have the "luxury" of wishing smallpox on themselves as DA Henderson has removed that option.