Vaccine deniers are increasing in number in Canada and the US; countries that have not seen the major impact of preventable diseases in a couple of generations. In some parts of the world, people are not so fortunate. Polio was a scourge of the past that has been eradicated in most of the world. However, thanks to wars and superstition, it has been creeping back.
In 1988, when the Global Polio Eradication Initiative was formed, polio paralysed more than 350 000 people a year. Since that time, polio case numbers have decreased by more than 99% (with only 406 polio cases reported in 2013).
Polio has been creeping back in Guinea; it experienced new cases in January after being free of polio since 1999, one of many Africans countries where the disease has returned after being contained. The virus was carried into Guinea from Cameroon, which was infected by migrants from Chad, which redeveloped polio as a result of vaccine refusal in Nigeria more than 10 years ago.
Now the polio virus has been found in Brazil. Just in sewage so far, but the danger for infection is present.
The World Health Organization, which announced the finding on Monday, says the virus was discovered last week in a sample collected in March at Viracopos International Airport in Campinas, which is about 60 miles outside Sao Paulo, and is where many of the World Cup teams have been landing. The agency said no cases of polio have been identified and there is no evidence the disease has been transmitted.
Genetic sequencing of the virus — the WHO didn’t say, but probably done by the Centers for Disease Control and Prevention in Atlanta — revealed that it was closely related to a poliovirus that recently caused a case of the disease in Equatorial Guinea in West Africa. Humans are polio’s only host; so that probably means the virus was carried into Brazil by a traveler, likely someone who never knew he was harboring it.
Brazil is one of the countries that has a high rate of vaccination, so transmission is unlikely. However, it is troublesome to see the virus on the move. With the amount of global movement that continues to rise, the spread of relatively rare diseases will likely increase.
This is the danger of not-vaccinating your children. A trip to another country, or exposure to an immigrant or sports-fan could cripple your child. But you aren’t just risking yours, you are also risking everyone else’s children.
The anti-vax movement can pretend that measles and mumps are a normal part of growing up and aren’t dangerous, but polio is a different thing altogether. The effects are very visible and last a lifetime.