World Bulletin / News Desk
A strain of the polio virus has been found at an international airport in Brazil, but there are no human cases, the World Health Organization has said.
On Monday, a WHO statement released said the virus was found in samples taken from sewage at Viracopos International Airport in Sao Paulo state in March.
It is said that the local population's high immunity to the disease "appears to have prevented transmission".
Brazil has been polio-free since 1989 and has high vaccination coverage.
The organization said that the virus was found in "sewage only" and subsequent analysis of similar samples have either been negative or only positive for "non-polio enteroviruses".
The WHO said the sample was a close match with a recent strain isolated in a case in Equatorial Guinea.
The UN agency described the risk of the polio virus spreading from Equatorial Guinea is “high”, but it said the risk from Brazil remained "very low".
Polio invades the nervous system and can cause irreversible paralysis within hours. There is no cure for the disease but it can be prevented by immunization.
The WHO said, Brazil's last national immunization campaign was conducted a year ago and coverage in Sao Paulo state has been higher than 95%.Last Mod: 24 Haziran 2014, 14:11