LIMA, April 25 (Xinhua) -- Public health authorities of South American countries took precautionary measures to fend off a possible pandemic after a deadly swine flu virus claimed dozens of lives in Mexico and infected at least 11 people in the United States.

    In Peru, experts with the Health Ministry said the ministry had initiated a nationwide precautionary plan to deal with potential threats, though no suspicious cases have been reported so far in the country.

    The Chilean Health Ministry expressed concern over the situation and drafted a contingency plan for epidemic prevention. It also ordered a public health alert that included health quarantine for all passengers entering the country at Santiago International Airport.

    The Guatemalan government convened a meeting of the health, interior and agriculture ministries to discuss the situation and ways to deal with the disease. Meanwhile, the Nicaraguan Health Ministry announced measures to enforce tighter epidemic prevention and urged the public to be alert for influenza-like respiratory illness.

    The Health Ministry of El Salvador also issued an early warning against a possible outbreak and strengthened surveillance over health quarantine in its border crossings.

    On Saturday, Mexican Health Minister Jose Angel Cordova raised the country's probable death toll from swine flu to 81. In the United States, 11 people were also confirmed to be infected with the virus.

    The World Health Organization announced Saturday that the outbreak in Mexico and the United States constituted a "public health emergency of international concern" and urged all countries to boost their surveillance for any unusual outbreaks of influenza-like illness and severe pneumonia.