This week, the World Health Organization (WHO) confirmed wild poliovirus type 1 (WPV1) was detected in a sewage sample collected in March 2014 near São Paulo, home of this year’s World Cup. Brazilian authorities are conducting further investigations to rule out any local spread, but at this time no cases of polio have been reported in Brazil, which has been polio-free since 1989.
Genetic sequencing found the positive sample to be most closely related to a virus found in Malabo, Equatorial Guinea, in March. The risk of further exportation of polio from Equatorial Guinea remains high as Equatorial Guinea has already reported four cases of WPV1 in 2014, following an importation from Cameroon.
“The detection of poliovirus in sewage from Brazil underscores what Rotary and its partners have long known: in today’s global society, if polio exists anywhere, children everywhere are at risk,” says Rotary’s International PolioPlus Committee Chair Dr. Robert Scott. “However, Rotary emphasizes that there is no case of acute polio in Brazil at this time and going forward is monitoring the situation very closely.”
Despite the news, the risk of polio transmission in Brazil is low. World Health Organization’s International Travel and Health strongly advises that all travelers be vaccinated against polio, but the sample detected does not pose a specific threat to Brazilians or short-term visitors.
To prevent further international spread of the virus, Equatorial Guinea must fully implement the WHO’s Temporary Recommendations to vaccinate all residents and long-term visitors against polio prior to international travel.
Brazil’s most recent nationwide campaign was conducted in June 2013 and is reported to have reached 93 percent of children in São Paulo State. Routine immunization coverage rates are reported to be above 95 percent.