Sewage samples collected in March at the Viracopos International Airport in Brazil have shown the presence of the polio virus, the World Health Organization revealed Monday.

So far, no human cases in Brazil have been reported, the WHO said.

Viracopos Airport is in Campinas, which is a part of the Sao Paulo State and is the home camps for the Portuguese and Nigerian national teams for the FIFA World Cup.

"The strain of the virus, wild poliovirus type 1, is a close match to one recently isolated in Equatorial Guinea," according to a report from Time. The WHO is stressing that the virus has been detected in sewage only and that "no case of paralytic polio has been reported."

Brazil's last case of polio was in 1989 and the Americas have been declared free of wild polio transmission since 1991, according to a Fox News report based on WHO data.

According to the WHO, polio is a highly infection disease that can cause total paralysis in a matter of hours. The virus is transmitted person-to-person or by contaminated food or water. Polio mainly affects children under five years of age. The disease currently doesn't have a cure once contracted, but can be prevented by vaccination.

Brazilian health officials are looking for any un-immunized people, as well as any evidence of paralytic polio, the Time report said. Immunization in the Sao Paulo state is higher than 95 percent and the last national vaccination was in June 2013, according to Time.

"This detection does not mean any change in the epidemiological situation of Brazil or a threat to the elimination of the disease," the Brazilian Health Ministry told Time.

Polio cases have decreased by over 99 percent since 1988, the WHO says. There were 406 reported polio cases in the world in 2013. This year, just three countries -- Afghanistan, Nigeria and Pakistan -- remain polio endemic.