Medical Fun Facts Episode 79: Enteroviral infections II

Medical Fun Facts Episode 79: Enteroviral infections II

It’s Monday 14 August 2017.

Some browsers do not render the embedded YouTube video. The link is at

Thanks for subscribing and listening to Medical Fun Facts.

Show notes for every episode are available at

Last week I did part I of enteroviral infections. I'm recording parts I and II on the same day because I'm going to be busy on the weekend 13 and 14 August. So, to recap, enteroviral infections are caused by enteroviruses, or viruses in the genus Enterovirus. These are very small RNA viruses in the family Picornavirdidae (pico=small so small RNA viruses). There were traditionally four major groups with polioviruses being in a single group, but now each enterovirus serotype is given a number, e.g., EV71. Apart from the polioviruses you may have heard about coxsackieviruses, echovirsues, and rhinoviruses. Within the genus Enterovirus there are 12 species, viz., Enterovirus A to Enterovirus J and Rhinovirus A to Rhinovirus C. The polioviruses PV1, PV2 and PV3 are found in Enterovirus C. Common clinical syndromes caused by enteroviruses include: Poliomyelitis Polio-like disease Aseptic meningitis Nonspecific febrile illness Hand foot and mouth disease Pericarditis and/or myocarditis Acute conjunctivitis Herpangina Encephalitis Diabetes Mellitus type 1

Last week I briefly described hand, foot and mouth disease. Tonight I want to describe aseptic meningitis. Aseptic meningitis is an old fashioned term used before we really knew a lot about the causes of meningitis and when most serious meningitis was caused by bacteria like pneumococci, meningococci, Hæmophilus influenzæ and Streptococcus agalactiæ. With the advent of HIV infection and AIDS, fungal meningitis also became more common and better described.

The term aseptic effectively means bacteria-free rather than microorganism-free. Unlike the bacterial causes of meningitis mentioned before, viral and fungal meningitis is mostly subacute as well. By that, I mean, rather than fulminating in less than 24 hours, aseptic meningitides tend to take longer than 24 hours to develop. Patients tend to feel unwell with a fever and a slowly worsening headache. They may also take longer to develop the signs of inflammation of the meninges, such as neck stiffness or nuchal rigidity and pain when looking into the light or photophobia.

The other reason why the term aseptic is used is because traditional bacterial culture methods will not reveal the ætiological agent. Even in 2017, viral culture is not commonly performed. My clinical virology friends like to point out that they pioneered molecular microbiology well before simple bacteriologists like me thought about using genetic techniques let alone whole genome sequencing.

So the most common cause of viral or what we used to call aseptic meningitis are enteroviruses. The clinical illness progresses over a few days to a really severe headache and body aches and pains. You'll want to keep the doors and windows covered to prevent sunlight hurting your eyes and you will not want to make any sharp movements because your head and body feels so delicate. So long as you rest and keep your fluids up, most of the time you will recover with no sequelæ. Unfortunately, some patients will progress to more severe meningitis and even to encephalitis or inflammation of the brain.

Next week I may discuss one more enteroviral infection.

And so, ends another episode of Medical Fun Facts. If you have suggestions or requests for future shows please let me know. You can find the show notes for every episode at my blog

You can find updates in the Facebook page. Medical Fun Facts is available in the iTunes podcast store. If you think more people would enjoy this show, please head over to iTunes and give Medical Fun Facts a five-star rating and please leave a comment. By doing so iTunes will rank the show higher and make it easier to find. Medical Fun Facts is also on Stitcher so if you use an Android device, you can download the Stitcher app and listen to the show in Stitcher. Android users should be able to find the Stitcher app in the Google Play store. The Stitcher link is Like iTunes, if you visit the show on the Stitcher website and leave a review, the Stitcher algorithms will improve the show’s ranking and more people will be able to find it. Feel free to share the link via Facebook, Twitter, Google+ and any other social media platform. If you disagree with anything in these podcasts or if you would like to voice a different view, please feel free to write a comment. If I have said something incorrect I welcome correction. Please also feel free to share your comments on social media. Just remember, for shows with video I go off script for good portions so please listen or watch to catch everything not written in the blog post. The video can be found at Tweet me at Send me a comment on Facebook at E-mail me at