Health officials have positively identified the polio virus in an area of Brazil that will take part in hosting the World Cup. Water samples take from sewers in the Viracopos International Airport in Sao Paulo, Brazil were found to contain the wild poliovirus type 1 (WPV1).

The World Health Organization (WHO) has both confirmed the find and stated that transmission to humans is unlikely. The virus seems to be localized, as other samples from surrounding areas have tested negative. Also, the rate of immunization in the area is very high. 95 percent of individuals have received the proper immunization against the virus.

The WPV1 strain is similar to the one that has been identified in Equatorial Guinea this year. Equatorial Guinea has reported four cases of polio in 2014, the first cases the country has seen since 1999. The outbreak has been attributed to a reduction in the availability of vaccines in the areas as well as slow reactions by government and health officials to provide immunizations in light of the outbreak.

Other countries in Africa, Asia, and the Middle East have reported outbreaks as the result of reduced availability of vaccines in these areas. Health officials believe the virus found in Sao Paulo likely came from one of these sources. The virus appears to be completely isolated to this one area, but is being monitored closely nonetheless.

Due to herd immunity among the population, the virus is not considered to be a health threat at this time. Thanks to its aggressive immunization program and the population’s willingness to adhere to vaccination schedules, Brazil has not had a single case of polio infection among humans since 1998.

Though many people who are infected may never display any symptoms, the polio virus can ravage the nervous system. Paralysis is a major complication of infection with this virus that can result in lifelong impairment or even death.