Dengue fever is on the rise in Mexico and elsewhere in the Americas.

By MARY CUDDEHE

Special to The Miami Herald

TECOMAN, Mexico -- Mayra Regidor knocked on the door of the little green house, asked to enter and walked straight to the kitchen, where she saw a tub filled with dishwater and took out measuring tools to figure how much insecticide powder should go inside.

''She's got to get just the right amount,'' explained her supervisor. ``Too little and it won't work; too much and the mosquitoes will develop resistance.''

Regidor and her boss, Pedro Santamaria, a biologist with Mexico's Public Health Department, were part of the team that recently conducted one of the largest anti-dengue mosquito sweeps in the state of Colima's history. The target was nearly 9,000 homes in the city of Tecoman.

So far this year, the central state on the Pacific Coast is leading the country in confirmed cases of dengue fever, the mosquito-borne illness that's on the rise in Mexico.

OTHER COUNTRIES

Climate change and global commerce have created ripe conditions for the disease to spread not just in Mexico but all over Latin America. Brazil and Argentina have reported record numbers of cases this year, and dozens of people have died.

The Atlanta-based Centers for Disease Control and Prevention considers dengue one of the most important mosquito-borne viral illnesses. Tens of millions of cases occur each year, and outbreaks have happened in at least 24 countries in the Americas.

While there's just a small risk of dengue outbreaks in the continental United States, there have been periodic outbreaks.

Other places, like Puerto Rico, are more threatened, say experts.

''At this point in time, we're keeping track of what's happening in Mexico and all of Latin America,'' said Dr. Fermin Arguello, acting chief of epidemiology in the CDC's Dengue Branch in Puerto Rico. Though the agency devotes its resources to diseases in the United States, ''we do our best to keep track of diseases globally,'' Arguello added.

ADAPTABILITY

An eradication program in Latin America that started in the 1950s all but vanquished the dengue mosquito, but it reappeared in the late 1970s and has slowly spread the virus since. Perhaps no factor is more to blame for the rise of dengue in the Americas than the impressive adaptability of the carrier mosquito, the Aedes aegypti.

In 2000, there were 1,781 reported cases of dengue fever in Mexico. Last year saw a total of 33,000, according to the Public Health Department. This year, the rate is up 15 percent. What's more, the prevalence of the deadly hemorrhagic form has also spiked. In 2000, hemorrhagic dengue represented one in about 26 cases; today, it's one in four.

`INTELLIGENT MOSQUITO'

Dubbed the ''intelligent mosquito,'' lately it has been showing up in colder climates and at higher altitudes than ever. This year for the first time, it has been detected in 21 of Mexico's 31 states. Entomologists say it is also reproducing year-round for the first time.

''In terms of statistics,'' said Miguel Angel Lezana, the director of epidemiology for the Public Health Department. ``It's more useful to talk about where it is not.''

The mosquito is so common in the capital city of Colima that everybody seems to have had dengue or at least know somebody who has.

In the central plaza, Maria Dolores Vazquez, a homemaker out for a sunset stroll with a girlfriend, said her entire family had it last winter. She got it first, then her husband, then two of their children. Only their 19-year-old daughter was spared.

`EVERYTHING CLEAN'

''Now we just make sure to keep everything clean,'' she said. ``I just hope it doesn't come back.''

Despite the increasing occurrence of the illness also known as ''breakbone fever,'' the Mexican government says it isn't particularly worried about an epidemic.

The majority of cases belong to the classic serotype, the mildest of the disease's four forms. Classic dengue can cause excruciating symptoms like severe joint aches, pain behind the eyes, high fever, rashes and nausea, but they generally last only about a week. And classic dengue is less likely than the other serotypes to develop into the hemorrhagic form. Mexico has reported 5,052 cases this year, of which 901 were hemorrhagic.

OTHER TOLLS

So far there have been no deaths. However, the illness's rise has brought other tolls.

Government studies of the economic impact have focused more on productivity than foreign spending. (Sickened Mexicans missed 150,000 days of work last year.) But officials are wary of what an outbreak could do to tourism after the recent swine-flu epidemic ravaged the $13 billion sector.

The same beach towns that draw tourists also happen to be ideal breeding grounds for mosquitoes.

''The majority of the important tourist destinations are right in the zones,'' said Lezana. ``It's something that we give special attention.''

The government has acted aggressively to kill mosquitoes in places where important industries like tourism, petroleum and agriculture are centered. The operation in Tecoman recently was a large-scale version of eradication programs taking place all over the country. Tecoman is an important exporter of limes, and it sits about an hour's drive from Manzanillo, the busiest port in Mexico.

`DEPENDS ON ... PEOPLE'

Under a scorching sun on a typically steamy day, 500 health-department workers in yellow vests swept through the town, doling out insecticide and lecturing residents to avoid havens for larvae by covering water containers and clearing waste.

''That doesn't guarantee that there won't be any mosquitoes,'' cautioned Juan Miguel Torre, the head of epidemiology for Colima's Public Health Department.

``It doesn't just depend on us; it depends on the people to do their part.''

Miami Herald staff writer Trenton Daniel contributed to this report from Miami.

http://www.miamiherald.com/news/americas/v-fullstory/story/1112810.html

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