Authorities in the South of Brazil fear that the yellow fever outbreak reported along the Paraguayan and Argentine border could spread to the state of Rio Grande do Sul and are taking special precautions.
The disease seems rampant in the tropical heartland of South America, particularly during the rainy season.
Rio Grande do Sul state's Health Secretary, Osmar Terra, said that yellow fever (transmitted by certain types of monkeys) "which has already killed four people and cattle in different countries has become the major threat; we've learned how to cope with endemic dengue."
Terra said one of the biggest mistakes committed by farmers who feed their cattle close to jungle areas is to kill them at the slightest symptoms of yellow fever. "Cattle acts as a sentinel for humans, it's only when we take blood samples that we know the virus is around and could "jump" to humans."
Actually yellow fever is transmitted by the bite of the female Aedes aegypti mosquito which bites monkeys and then again bitten can pass the disease to cattle and humans.
Argentine sanitary authorities have found dead monkeys in the jungle area close to the border with Paraguay and Brazil, and in most cases yellow fever virus was present. Several deaths have occurred in the Argentine province of Misiones and neighboring Paraguay among labour working in the jungle area.
Terra also admitted that homes in urban areas in the vicinity of reported cases of dengue, and therefore exposed, has dropped from 4 to 1% of households, "which is positive but not sufficient because it means the Aedes aegypti larvae are still around in stagnant waters."
The minister said that one city which has been targeted for fumigation is Livramento, just across the border from Uruguay's Rivera. The twin cities are only separated by a fictitious line since residents (and shoppers looking for bargains) choose to make their daily shopping wherever the exchange rate is more favorable. (Uruguayan peso, Brazil's Real).
Livramento's mayor Wainer Machado has declared a "municipal state of emergency," after the city was declared "infected," because of the Aegypti larvae density discovered, and thus entitled to federal aid.
Machado has contracted extra personnel for fumigation and expects to have the whole city "de-contaminated" in 45 days.
An additional problem is the number of tires that have accumulated for months. Brazilian motorists cross over to Uruguay where tires are significantly cheaper and change the whole set, but since they can't take them back, unless they show documents for the new ones, thousands of tires have become an excellent and protected breeding nest for mosquito larvae.
In Brazil with a long history of mosquito diseases used tires, by law, must be destroyed, but not in Uruguay. Thousands of tires have been shipped to Montevideo for recycling but there are always stocks building up in Rivera.
Uruguay is the only country of South America, so far, free of dengue epidemics. This does not mean the odd case of visitors or tourists returning from Brazil or other tropical areas have been cared for.
Meanwhile in Asunción, capital of Paraguay the government launched a campaign "let's keep home clean" to create awareness of the need to have clean surroundings and eliminate stagnant water where mosquito larvae can breed.
President Fernando Lugo, Health Minister Esperanza Martinez and other officials participated in the first day by in a symbolic act cleaning and clearing stagnant water from different exposed spaces of Government House, mainly gardens and plants.
"This is an awareness and keep clean campaign, and today we've shown that even Government House is exposed to mosquito larvae," said President Lugo.
The several stages campaign begun in schools, and every Friday a thorough inspection of all education centers will take place. Finally there will be an aggressive educational campaign to make people aware of the dangers, said Minister Martinez.
Earlier in the day President Lugo met with a delegation of next of kin of dengue victims who requested legislation emphasizing on civil responsibility for public or private areas infested with the disease transmitting mosquito.