A report released Thursday by the Centers for Disease Control and Prevention in Atlanta says in 2009, all but one of the importation-related wild poliovirus outbreaks seemed to have been interrupted, but new importations occurred in 2010.
In 2010, the first wild poliovirus importation occurred in the World Health Organization European Region since the region was certified polio-free in 2002, the report says.
The importation of wild poliovirus resulted in a large-scale outbreak in Tajikistan that involved 458 cases, with 18 more polio cases in Kazakhstan, Russia and Turkmenistan, the report says.
"All polio-free countries are advised to maintain high vaccination coverage and sensitive surveillance systems at all times," CDC officials say in a statement. "Should wild poliovirus importation be recognized, health authorities need to rapidly institute supplementary immunization activities to limit wild poliovirus spread and interrupt outbreaks so that Global Polio Eradication is achieved."