A strain of poliovirus has been detected in a sample taken from sewage at the Viracopos International Airport in Sao Paulo state in March. Random samples are taken routinely and the positive results of polio strain have come after a very long time. Brazil has been Polio free since 1989 and also has a very aggressive vaccination program.
On Monday the WHO had released a statement that the virus strain which was akin to a recent strain isolated in a case in Equatorial Guinea was detected in the sample taken from the sewage at the Viracopos International Airport in Sao Paulo state in March. However there are no human cases as per the statement released by the WHO.
Experts say that the local population’s high immunity to the disease “appears to have prevented transmission”.
WHO also added that the virus was found in the sewage sample only and analysis of similar samples later was all either negative or positive for non polio enteroviruses. The UN health watchdog agency has described the risk of polio spreading from Equatorial Guinea as very high. It further added that the risk from Brazil remains pretty low.
Polio affects the nervous system and can cause irreversible paralysis within hours of infection. The damage is permanent but it can be prevented by immunization. Brazil has conducted the last nationwide immunization campaign last year and the coverage in Sao Paulo state has been higher than 95%.