Question about Encephalitis

[DahliaRW]

Purely out of curiousity.

I know one of the potential side effects of diseases like measles and varicella is encephalitis. I also know that there can be "breakthrough" cases of varicella and fever/rash with the measles vax. Anyone know what the rate of encephalitis is with these reactions compared to the rate of it from the diseases themselves?

I know it's exceedingly rare. But I know a mom whose 1 yo is having a vax reaction from the MMRV. And I know that encephalitis is a listed potential side effect of the vax. So just got wondering how it compares for curiousity sake (not something I plan to share with this mom, just spiked my curiousity).

Fwiw, we don't vax.

[Marnica]

I have no idea of the actual statistics. I'd find it interesting as well, BUT since a vast majority of vaccine reactions are not recognized for what they are (ie a parent calls the ped to tell them their 2 month old has been screaming for hours after a vaccine and they are told, "that's fairly normal" or they admit it might be a "side effect" from the vaccine but tell the parent it will go away soon and it is not reported by the doc and the parent may not know they have the option to report it themselves) I would not think whatever statistics that I come across would reflect actual numbers on the vaccine side so would be fairly meaningless to me.

[Otto]

A grab-bag of pre-coffee numbers:

Acute encephalitis, wild-type measles: 1:1000-2000 (here)
SSPE, wild-type measles: 1:100,000 (same)

Encephalitis, wild-type VZV: 1:2000 (e.g., here)

Encephalitis, MMR-II: <1:3,000,000 (causality unestablished; here)
SSPE, live measles vaccine: 1:1,000,000
Encephalitis, Varivax: Not well quantified, but it has happened (general review here)

[DahliaRW]

Thanks! And I agree that it's probably under reported. I'm sure the child I know hasn't been reported as a reaction (rash/fever), since it's not "serious", so I would think that that reaction is probably more common than the stats I'm finding as well...

[MountainMamaGC]

There is a high pitched wail my daughter had following her DTaP. SHe even wailed in her sleep. SHe had trouble nursing and would not look at me for 2 days. I look back and think it could have been cry enchephalitis. I was told her reaction was normal. Yeah right!

I bet this reaction is very much under reported as most doctors believe vaccines are 100% safe. They are trained to look for signs of encephalitis in people with measles/varicella infections so they find it more often, because they accept that as a very real complication.

[Otto]

Originally Posted by DahliaRW

And I agree that it's probably under reported.

Yah, I mean, comparing disparate sets of numbers is hard enough without really understanding the methodologies that led to each. Of course, if a condition is subject to underreporting, there's no a priori reason to think that it's not underreported on both sides of the ledger, which is just another variable to be quantified.

[carriebft]

Originally Posted by Otto

Yah, I mean, comparing disparate sets of numbers is hard enough without really understanding the methodologies that led to each. Of course, if a condition is subject to underreporting, there's no a priori reason to think that it's not underreported on both sides of the ledger, which is just another variable to be quantified.

definitely agree with the last part. A recent study on SSPE found it to be drastically underreported, esp when it came to infant infection that lead to SSPE 8 years or more later.

[Marnica]

Originally Posted by Otto

Yah, I mean, comparing disparate sets of numbers is hard enough without really understanding the methodologies that led to each. Of course, if a condition is subject to underreporting, there's no a priori reason to think that it's not underreported on both sides of the ledger, which is just another variable to be quantified.

I can think of a few reasons............

[Delicateflower]

I thought the MMRV had been withdrawn because there were more reactions (fevers)?
http://www.aafp.org/online/en/home/p...mmrv-updt.html

I'd quote, but a short enough quote to comply with MDC policy would be misleading and out of context. Basically yes, you get more fevers with MMRV than with separate vaccines (even given in different legs at the same time).

[DahliaRW]

I was surprised it was being given too, but apparently it is...