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Thursday, August 18, 2016

Mosquito Guns and Heavy Fines: How Cuba Kept Zika at Bay for So Long

Mosquito Guns and Heavy Fines: How Cuba Kept Zika at Bay for So Long
It is one of the last Caribbean countries to get hit
By Sara Reardon, Nature magazine on August 17, 2016

As soon as the rain stops, mosquitoes flood the guard house of an
upscale tourist resort near Cuba's Bay of Pigs. Without hesitation, one
of the guards reaches under his desk to pull out a device that looks
like a very large hair dryer. "Mosquito gun," he says. He walks around,
spraying a thick, white cloud of fumigant that engulfs the booth.
Slowly, the mosquitoes disappear.
It's not uncommon to see clouds of pesticide wafting through Cuba's
houses and neighbour­hoods. It is largely because of such intensive
measures by ordinary citizens that the country has been among the last
in the Caribbean to succumb to local transmission of Zika. As of Augus
11t, Cuba has recorded three people who were infected by local
mosquitoes rather than contracting the illness abroad, compared with
8,766 confirmed cases in nearby Puerto Rico (see 'Zika in the Caribbean').
Although scientists and public-health officials are disappointed that
Zika has finally arrived in Cuba, they are not surprised. "It's not easy
to avoid an introduction, because a lot of people are coming to Cuba
from a lot of places," says Maria Guzmán, head of virology at the Pedro
Kourí Tropical Medicine Institute in Havana. The country has recorded
about 30 confirmed imported cases.
Zika is especially insidious because most people who have it show either
no symptoms or only common ones such as fevers, which could be
attributed to other illnesses. Yet, with the exception of one locally
acquired case in March, Cuba mostly managed to keep Zika out until this
month.

ON THE BALL

That success was the result of its excellent health-care system and an
extensive surveillance programme for vector-borne diseases that the
government set up 35 years ago, says Ileana Morales, director of science
and technology at Cuba's public-health ministry.
In 1981, Cuba saw the first outbreak of haemorrhagic dengue fever in the
Americas, with more than 344,000 infections. "We turned that
epidemiological event into an opportunity," says Morales. The country
sent medical workers to affected areas and began intensively spraying
pesticides to eradicate the Aedes aegypti mosquito that carries the disease.
It also created a national reporting system, as well as a framework for
cooperation between government agencies and public-education campaigns
to encourage spraying and self-monitoring for mosquito bites, even among
children. One of the most effective measures was a heavy fine for people
found to have mosquitoes breeding on their property, says Duane Gubler,
an infectious-disease researcher at Duke–NUS Medical School in
Singapore. With all these measures in place, Cuba eliminated the dengue
outbreak in four months.
Now, when another outbreak threatens, "it's no problem for us to
reinforce our system" and intensify such efforts, says Morales.
In February, before any Zika cases had been detected in Cuba, the
government dispatched 9,000 soldiers to spray homes and other buildings,
while workers killed mosquito larvae in habitats such as waterways.
Airport officials screened visitors arriving from Zika-infected
countries and medical workers went from door to door looking for people
with symptoms. The health-care system already conducts extensive
prenatal examinations, so it is primed to detect Zika-caused birth
defects such as microcephaly.
Cristian Morales, head of the Cuba office of the Pan American Health
Organization (PAHO), says that it is probably unrealistic for other
countries to simply copy Cuba's mosquito-control programmes. The
country's health-care network is one of the best in the developing
world, and the decades-long stability of its government has ensured
policy continuity and enforcement of measures such as fines. He adds
that the most important aspects of a response, for any country, include
collaboration between government sectors and increased surveillance.

EVERYONE'S CHALLENGE

"Cuba probably does a better job of controlling mosquitoes than any
other country in the Americas, but it hasn't been totally effective,"
says Gubler. This is partly due to dips in funding. A resurgence of
dengue in 1997 was probably exacerbated by the fall of the Soviet Union,
Cuba's major trading partner, which decimated the economy and weakened
health funding.
Another disadvantage stems from the 56-year-old US trade embargo, which
prevents Cuba from acquiring drugs and medical supplies that include
components made in the United States. It must instead buy them from
other countries, such as China, often at higher cost.
Yet success has come despite these issues. According to PAHO, health
workers have intensified efforts to spray pesticides and eradicate
standing water—where mosquitoes can breed—within 150 metres of the homes
of each of the two most recent people to get Zika, in the southeastern
province of Holguin. Workers are also searching houses for infected
people and collecting mosquitoes for study. Guzmán adds that Cuban
researchers have begun to plan work on a Zika vaccine.
She says that international cooperation will be important in helping
Cuba and others to address Zika. "It's a problem of everybody. It's a
new challenge for the world."
This article is reproduced with permission and was first published on
August 17, 2016.

Source: Mosquito Guns and Heavy Fines: How Cuba Kept Zika at Bay for So
Long - Scientific American -
http://www.scientificamerican.com/article/mosquito-guns-and-heavy-fines-how-cuba-kept-zika-at-bay-for-so-long/
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