Russia has confirmed its first polio case in 13 years in an infant visiting from Tajikistan, but there is no immediate threat of a wider outbreak, the country's main public health body said on Friday.

The 9-month-old girl was diagnosed with the disease after arriving in the Siberian region of Irkutsk from the Central Asian state, where at least 12 people have died from a polio outbreak, said Rospotrebnadzor spokeswoman Lyubov Voropayeva.

"All the necessary epidemiological measures have been taken. There is not currently any threat the disease will spread," Voropayeva said.

Tests in a Moscow hospital found that a second girl from Tajikistan, also 9 months old, was carrying the polio virus but had not developed the disease, Voropayeva said. The last case of polio was confirmed in Russia in 1997.

Polio, which spreads in areas with poor sanitation, attacks the nervous system and can cause irreversible paralysis within hours of infection. Children under the age of 3 are most vulnerable.

The disease was practically eliminated as a public health problem in industrialized countries in the 1960s, but remains endemic in seven countries, including India, Nigeria and Pakistan, according to the World Health Organization.