[SANTIAGO] Insects whose bite can transmit a deadly parasite to people could be completely eradicated from six South American nations within five years, said scientists last week.
By 2010, Argentina, Brazil, Bolivia, Chile, Paraguay and Uruguay should all be free of the 'assassin bugs', which transmit the parasite that causes Chagas disease, they said.
According to the World Health Organization (WHO), Chagas disease affects 13 million people in Latin America. Each year, about 21,000 of them die, usually from heart failure caused by the chronic form of the disease.
Scientists from the region reported significant reductions in its impact at a meeting to discuss advances against the disease, held in Santiago, Chile on 6-8 October.
The reduction is due in part, they said, to international initiatives launched in the 1990s. These were coordinated by the Pan American Health Organization and intergovernmental committees of technical staff from health ministries in the affected countries.
Techniques included spraying pesticides and making homes less appealing to assassin bugs by replacing mud walls and palm roofs with plastered walls and zinc roofs.
Myriam Lorca of the Chilean Chagas Disease Surveillance Programme, who organised the meeting, says assassin bugs were so abundant in Chile in the 1980s that people used shovels to remove them from their houses.
Today, she says, only 300 specimens are caught each year.
In 1999, the WHO said that Chagas disease was no longer being transmitted in Chile by either assassin bugs or by another potential route of infection — blood transfusions. Uruguay was certified free of transmission two years earlier, and Brazil is likely to be certified free by 2006, says Lorca.
But for the WHO to consider a country totally free of assassin bugs, none must have been found for three years.
Lorca says the six 'southern cone' countries should achieve this by 2010, followed shortly by Andean countries and some years later by those in Central America.
A new weapon expected to play a role in this fight was unveiled at the Santiago meeting.
British and Paraguayan scientists have developed a way to eliminate assassin bugs by luring them to a trap with chemicals the insects use to attract mates.
"This strategy has never been used before, as it would only be useful in areas where the number of assassin bugs has already been greatly reduced," Lorca told SciDev.Net."We plan to start distributing the traps in Chile by November and some months later in Uruguay".