By Gonzalo Argandona
SANTIAGO (Reuters Health) - After a century, the mosquito responsible for the spread of dengue and yellow fever has been detected again in the continental area of Chile, a country traditionally proud of being free of the two illnesses.
The Chilean national surveillance program detected one female specimen of Aedes aegypti in the Huasco province, located in the northern part of the country. Aedes aegypti is a domestic, day-biting mosquito that prefers to feed on humans and is a known vector of the four serotypes of dengue virus, which produce a spectrum of illnesses ranging from "classical dengue" to the often-fatal hemorrhagic manifestations of the disease.
"This is the first observation of the insect in the area since its eradication at the beginning of the twentieth century," Cecilia Perret, director of the tropical diseases laboratory at the Catholic University, told Reuters Health.
She added that Chile was the only country in South and Central America free of the presence of the Aedes aegypti. "With the new detection, we can say that all the American countries face the threat of the Aedes aegypti," Perret said.
In North America, the mosquito is found in south Texas and the southeastern U.S. and in parts of Mexico, according to a U.S. Centers for Disease Control and Prevention surveys.
The first Chilean cases of dengue were detected last year, but in a remote place far from the continent: Eastern Island. In that outbreak, there were 672 patients in a period of just four months, equivalent to 20 percent of the entire population of the island.
The Chilean authorities said that despite the presence of the mosquito in the Huasco Province there are still no reports of patients with dengue. To prevent the viral infection, they launched a sanitary campaign, which includes the fumigation of houses and buildings.
"We are asking the people to collaborate on the elimination of the mosquito, which is our main task today," Yasna Provoste, head of the regional government, said.
The National Office of Emergencies is distributing water in the Huasco province, which is known for its dryness. Due to the scarceness of water, the villagers usually store it in containers that can facilitate the reproduction of the mosquito. Mosquitoes typically breed in standing water, including rainwater that collects in old tires or containers.