| | |  Health & Beauty | August 2009 
Mexico Fights Rise in Dengue Fever
 Mary Cuddehe - The Lancet
go to original
August 24, 2009
(Related: Dengue Quick Facts from Directors of Health Promotion and Education)
With an outbreak of H1N1 scarcely behind it, the Mexican Government is also fighting the spread of another viral illness: dengue fever. Mary Cuddehe reports from Mexico City.
The incidence of dengue fever in Mexico has been climbing steadily for a decade. In 2000, there were 1781 reported cases. Last year, the number totalled 33 000, according to Mexico's Public Health Department. And confirmed cases this year have already surpassed 2008 figures by 15%.
In many ways Mexico is an ideal place for dengue fever. It is a heavily populated country with 9300 km of coastline, vast tropical regions, and an economy based largely on foreign trade and tourism. Dengue fever most frequently occurs in urban and tropical areas, and the rise in global commerce and tourism is one of the main factors, along with climate change, that experts identify as a root cause of the disease's expansion.
Experts also point to the carrier mosquito itself, Aedes aegypti, to explain the growing incidence. Recently, A aegypti has appeared in more Mexican states and at higher altitudes than previously seen. It has been detected in 21 of Mexico's 31 states this year, and while entomologists once believed that it was not able to fly above 1500 m, they have discovered it buzzing around at 1700 m. What is more, the earliest cases of dengue fever were reported in January this year. That was months before the start of the summer rains that traditionally kick off peak breeding season, suggesting that A aegypti has begun to reproduce year-round. “Normally we start the year with zero cases”, said Juan Miguel Torre, the head of epidemiology for the Public Health Department in Colima, the central state on the Pacific Coast that leads Mexico in confirmed cases this year. “This year, we started with 80 cases.”
Worldwide, tens of millions of cases occur every year, and the disease has spread consistently throughout the western hemisphere for a quarter century, bursting on 3—5 year epidemic cycles. In 2002, a major outbreak swept the region, striking more than 1 million people, according to the Pan American Health Organization. 5 years later, the second worst outbreak on record left nearly another 1 million people ill in 11 countries, including Mexico.
The disease's widespread and increasing presence has incited world health organisations to develop novel approaches to mosquito eradication. In the 1950s, a programme to combat yellow fever, which A aegypti also carries, all but vanquished the mosquito from the Americas. (It returned in the late 1970s.) In those days eradication was synonymous with insecticide spraying. Today it means getting individuals involved. Health organisations reach out to community leaders who in turn mobilise citizens to clear out havens for larvae by dumping waste and covering standing water. “A crumpled-up cigarette pack thrown on the ground, even on a roadside, with rain will form enough of a little pool of water to give mosquitoes a breeding spot”, said Epstein. “Education is more important than spraying. Spraying is a one-time thing.”
Mexico is applying these measures aggressively. States like Colima have launched large-scale eradication and public-education programmes. A recent operation had 500 health workers in yellow vests sweep through a small town in a single day, knocking on the doors of nearly 9000 homes. They inspected, sprayed, and lectured residents on techniques for keeping their homes mosquito free. “The key to no dengue is no mosquitoes”, said Miguel Angel Lezana, the head of epidemiology for Mexico's Public Health Department. “We put insecticide around the house and inside, and work with people to eliminate standing water or at least guard it properly.”
This year Mexico has reported 5052 cases. Classic dengue, or serotype 1, the least severe of the four dengue viruses, has made up the majority of those, with haemorrhagic cases totalling 901. Experts remain especially wary of an outbreak this year, though, because the recent H1N1 epidemic devastated the country's US$13 billion tourism industry and the same beach towns that draw tourists are also breeding grounds for the disease vectors. But so far they say that this year's numbers square with the Public Health Department's predictions for 2009. “The serotype that's circulating is serotype 1”, said Torre. “That gives us, not cause for calm exactly, but it tells us that the resources we have may be sufficient.” |
|
| |
Vallarta Weddings
Tell a Friend
Site Map
Print this Page
Email Us