Polio: Past, Present, and Future

It took a lot of will power not to title this article “Marco! Polio!” I’d hate to make light of such a devastating infection, but I think it’s one of those overlooked topics that could really use a good attention-getter.

There are only a few areas where wild polio virus lives. This is a problem, because it can still be transmitted into other areas. Case-in-point: a recent outbreak in China, imported from Pakistan. Cases of polio have nearly doubled in Pakistan this year, and there have been some cases in China, too. 10 people in China have been infected, and one has already died. With international travel, the virus could easily end up in almost any country.

Poliomyelitis, or polio, for short, is a disease affecting the central nervous system, resulting in symptoms from fever and fatigue, to painful limbs. About 1 in 200 cases of polio results in paralysis, according to the World Health Organization (WHO).

Polio is transmitted by the oral-fecal route. Even for that small fraction of Americans who don’t regularly ingest their neighbors’ poo, it can still be transmitted easily. In its heyday, before the development of a vaccine, there were nearly 60,000 cases of polio annually in the United States. Some of these outbreaks were connected to public swimming pools. It makes sense- right? You normally don’t completely sanitize your bottom after every BM. You go into the pool with some virus attached to you. It floats off happily. A young child jumps in, his or her mouth open. And presto, the virus has found a new host.

Nowadays, there are only about 10 cases of polio per year in the US, none of which are from indigenous virus. These cases are either imported from areas where polio has not been eradicated, or are vaccine related. Because the vaccine is a live, attenuated virus given orally, live virus particles can be passed out from some individuals. Vaccine related cases are caused when the vaccine virus, a live, attenuated strain, reverts back to wild-type virus. This normally occurs only when wild type virus is around- the two strains recombine. This also makes it extremely important to vaccinate everyone.

Another valuable reason to vaccinate everyone? Like smallpox, polio could easily become a disease of the past.

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