Argentina is on alert for dengue fever, with 1,100 cases nationwide and a situation of epidemic proportions in the country's northern border provinces.

Argentina already has passed from the "containment phase" to the "mitigation" phase, treating patients in hard-hit areas who traveled to neighboring affected countries or had contact with people who had done so, Health Ministry official Nestor Perez Baliño told EFE.

The northeastern provinces of Formosa and Misiones, which border on Brazil and Paraguay, have the most cases - 900, all told - while the rest are spread among other provinces although the situation is not one of an outbreak, he said.

The most common symptoms of the disease transmitted by the Aedes aegypti mosquito are high fever, back and joint pain, skin rash, head- and eyeache and occasional vomiting.

For Argentina, the good news is that there are still very few people who have become infected within the national territory.

The increase in rain and temperatures caused by the El Niño weather phenomenon has resulted dengue epidemics in Paraguay and Brazil, thus increasing the risks for Argentina.

Dengue generally spikes in four- to six-year cycles, said Perez, and the last epidemic occurred in 2009.

However, this year, the disease is hitting weeks earlier than its normal February-March appearance and experts don't know whether it will continue through the end of the Southern Hemisphere summer or will begin to abate before that.

"Under 12 degrees C (equivalent to 54 F), it's very difficult to find the Aedes (mosquito), and so I'm sure the epidemiological curve will start to fall off in May," he said. EFE