The confirmation of more avian influenza cases in South America raised alarm bells in Brazil, which remains free of contagion even after its close neighbours Argentina and Uruguay confirmed cases there on Wednesday, reported Reuters. 

In a press conference to discuss the global sanitary hazard, Brazilian Agriculture Minister Carlos Favaro said Brazil, the world's biggest chicken exporter, would bolster measures to prevent outbreaks as the virus continued to spread.

Until now, avian influenza cases had been detected in commercial farms in Bolivia, which borders Brazil, and in Peru and Ecuador, Favaro said.

On Wednesday, cases in wild birds were confirmed in Uruguay and Argentina, sparking a health emergency in both.

In recent days, Brazil also investigated suspected cases of the highly pathogenic avian influenza.

The suspect cases occurred in wild birds in Rio Grande do Sul state, where many Brazilian meatpackers operate, and in domestic birds, ducks and chickens with bird flu symptoms in Amazonas state, according to the minister.

None of the suspect cases turned out to be avian influenza, he said.

Avian flu, which has reached new corners of the globe, has become endemic for the first time in some wild birds that transmit the virus topoultry, experts said.

The virus has spurred import bans in some countries and pushed egg prices to record highs in some parts of the world.

Brazil is home to some of the world's biggest meatpackers including BRF and JBS. It has never registered an avian influenza case.

But since late last year, the Brazilian meat industry has been on high alert. Most of Brazil's chicken processors operate in southern states, making the discoveries in Uruguay and Argentina worrisome.

"It should be remembered that the situation in Uruguay (affecting wild birds) is an example of a case that would not suspend trade and exports of poultry products, in accordance with recommendations established by the World Organization for Animal Health," Brazil's meat lobby ABPA said in a statement.

The Uruguayan government declared a state of national sanitary emergency after detecting avian influenza in five dead black neck swans between the departments of Maldonado and Rocha.

"It's very important to isolate wild birds from domestic birds, especially sources of food and water", Virginia Russi, a technician from the agriculture ministry of Uruguay told a news conference.

Argentina's Agriculture Secretary Juan Jose Bahillo also confirmed its first cases of avian influenza in wild birds, leading it to declare a sanitary emergency and reinforce measures against the disease.