BUENOS AIRES - Argentina's confirmed A(H1N1) flu cases jumped to 19 on Monday, with 13 of the cases linked to a student in the capital who had recently traveled to the United States, health officials said.

Authorities said they would shutter two schools in Buenos Aires and two just outside the capital for two weeks in a bid to halt the spread of the A(H1N1) virus outbreak.

The flu's spread in South America is being watched closely by health experts who warn that the virus could fade during the northern hemisphere's summer but reconstitute itself as a more virulent strain during winter that could kill in far greater numbers than the present epidemic.

Argentina's first case of the disease was confirmed on May 7 in a person who recently returned from Mexico, the epicenter of the outbreak.

Argentina, which soon faces legislative elections, was among the first countries to suspend flights to and from Mexico following the outbreak of the disease.

But authorities in Buenos Aires said on Friday they would not close the border with the country's western neighbour Chile, despite the spike in cases there.

The number of cases in South America remains relatively small compared to Mexico, where the Health Ministry has reported 83 deaths linked to swine flu and more than 4,000 confirmed infections from the virus. -- AFP