How much should potential visitors to Israel be worried about polio?
November 16, 2013 7:25 AM   Subscribe

My family has planned, but have not purchased plane tickets for, a trip to see relatives in Israel a couple of months from now. We are concerned about the presence of wild polio virus there, apparently imported from Syria. The CDC is recommending that adults get a booster dose of IPV (the "killed" virus used in the countries, like the US, where polio infection has been essentially eradicated) and that kids are up to date with our vaccination; for our 3-year-old, this would mean getting her last dose of IPV early (though not so early as to violate any guidelines.) But Israeli children are getting OPV, the live vaccine. If I understand correctly, IPV is effective at preventing you from actually getting paralytic polio, but it does not prevent asymptomatic infection with poliovirus.

I don't think OPV is available in the US (and I would not be enthusiastic about giving it to my kids anyway, since it has a very small risk of inducing paralysis, which is why it's not used here anymore.) We would be mostly in Jerusalem, where according to the linked Ha'aretz story, polio "seems to have disappeared from the sewage system."

So my question: Am I correct that I'm not putting anyone in my family at risk of being paralyzed from polio if we go on this trip? Are there adverse health affects to being infected with polio (the possibility IPV leaves open) even if you don't suffer polio-related paralysis? If one of us is asymptomatically infected, are we permanent carriers, or does the infection pass with time? And finally, the global question: is it a ridiculous overreaction to think about annoying our relatives by canceling this trip?
posted by anonymous to Health & Fitness (6 answers total) 1 user marked this as a favorite
OK, so far no one in Israel has actually gotten polio. Even in Syria there are only 13 confirmed cases of polio. That is out of millions of people in a country that is actually at war, with serious disruptions in basic services like water and sewers (and presumably vaccinations).

Basically: this outbreak is important from a public health perspective, and it's scary, but the chance of it affecting your family is vanishingly small. I would get the boosters and go. (And maybe do a little obsessive handwashing while I was there.)
posted by mskyle at 8:10 AM on November 16, 2013

IANYD, but here's my understanding: if everyone is up to date with vaccinations, and has received his/her IPV, the health risks for yourselves are extremely low, practically null, and the risk of your transmitting the virus is slightly higher, but still pretty low.

The difference between IPV and OPV is that the OPV kills the poliovirus in your gut--so if you were infected with the virus, you would not be able to pass it to a non-immune person. The reason it is given to kids in areas of high prevalence is because the OPV will confer community immunity: because it kills virus in the gut, it can't exist in the kid's stool, so you protect everyone that's bathing in that lake/eating food cooked by unwashed, diaper-changing hands, etc. and hasn't been vaccinated.

The risk of vaccine-associated polio paralysis is 1 in 2.4 million, so the US stopped using it because we have such high vaccination rates that the risk outweighed the benefit. Compare that number with, say, the risk of a traumatic brain injury for a kid in the US (70 per 100,000)--clearly, the risk is extremely low. As you point out, you may not even be able to get it in the US, so I wouldn't sorry about it.

The CDC and WHO guidelines are pretty good on these things, and I wouldn't hesitate to gete the booster for the adults and complete the vaccine series for your kid, if it's in line with your ped's recommendation.

Happy travels!
posted by stillmoving at 8:19 AM on November 16, 2013 [4 favorites]

An Israeli's perspective: it feels like this story is being blown up in order to scare people into getting vaccinated, but I'm not a professional so bear that in mind. There have been no reported cases of polio, actually only stories of children suffering from paralysis because of the vaccine itself - stories which have been suspiciously quieted/ignored by the health ministry. My brother and his wife did not vaccinate their toddler.

Honestly, I don't think you have to worry about it at all. Israel is a very safe country in many ways people don't quite understand. Especially meteropolins like Jerusalem and Tel Aviv.
posted by alon at 8:50 AM on November 16, 2013 [3 favorites]

is it a ridiculous overreaction

It's never ridiculous to think about your family's safety, but you're in the clear here. Get your American shots on the schedule the pediatrician prescribes, and happy travels.
posted by fingersandtoes at 9:24 AM on November 16, 2013

Asymptomatic infection won't hurt you and it will pass. Even if you still had the infection upon your return to the US, it's unlikely you'd infect anyone here because of our high vaccination rates.

Aside on OPV - my understanding is that the community benefit isn't from killing the virus in the gut (if you already had the virus, the vaccine wouldn't help you) but rather from the fact that the live virus is shed in feces of people who get it and can be passed to other people. If you'd had wild-type polio, they would get that, but if what you've had is the vaccine strain, they effectively get vaccinated too. Not that anyone should or would plan on getting vaccinated by ingesting fecally contaminated water, but the fact that OPV turns what would otherwise be a source of infection into a source of immunity is pretty cool. IPV contains killed virus and doesn't provide this benefit. But it also can't revert to wild-type, as OPV can.
posted by lakeroon at 12:36 PM on November 16, 2013 [1 favorite]

Oh, I think I was reading too fast and misunderstood what stillmoving meant by "kills virus in the gut." Both mechanisms are helpful.
posted by lakeroon at 12:40 PM on November 16, 2013

« Older Ideas for a low powered home server running Linux....   |   Working as a petsitter Newer »
This thread is closed to new comments.