SÃO PAULO, Brazil — A little-known virus spread by mosquitoes is causing one of the most alarming health crises to hit Brazil in decades, officials here warn: thousands of cases of brain damage, in which babies are born with unusually small heads.
Many
pregnant women across Brazil are in a panic. The government, under
withering criticism for not acting sooner, is urging them to take every
precaution to avoid mosquito bites. One official even suggested that
women living in areas where mosquitoes are especially prevalent postpone
having children.
“If
she can wait, then she should,” said Claudio Maierovitch, director of
the department of surveillance of communicable diseases at Brazil’s
health ministry.
The
alarm stems from a huge surge in babies with microcephaly
(my-kroh-SEF-uh-lee), a rare, incurable condition in which their heads
are abnormally small. Brazilian officials have registered at least 2,782
cases this year, compared with just 147 in 2014 and 167 the year
before.
At
least 40 of the infants have recently died, and some Brazilian
researchers warn that cases could multiply in the months ahead. Those
babies who survive may face impaired intellectual development for the
rest of their lives.
Brazilian
researchers say that an obscure mosquito-borne virus that made its way
to the country only recently — Zika — is to blame for the sudden
increase in brain damage among infants.
But
other virologists caution that more testing is needed to prove the
dangerous link between the virus and brain damage, leaving the full
extent of the threat to the country, and the hemisphere, unclear.
“Why
this may have happened in Brazil and not elsewhere is at this stage
difficult to answer,” said Alain Kohl, a virologist at the University of
Glasgow who studies Zika.
“Perhaps
it was never properly registered in other areas, or the situation in
Brazil is indeed different,” he added, citing the possibility that the
link between Zika and microcephaly could be related to particular
strains of the virus.
The Zika virus has already reached several countries in Latin America, including Mexico, and the Centers for Disease Control and Prevention
warns that it could spread in parts of the United States as well. There
have already been cases diagnosed in the United States, in travelers
who visited affected countries, and the C.D.C. expects these instances
to increase.
“I
cried for a month when I learned how God is testing us,” said Gleyse
Kelly da Silva, 27, a toll road attendant in the city of Recife in
northeast Brazil, describing how an ultrasound exam had detected
microcephaly in the seventh month of her pregnancy with her daughter,
Maria Giovanna, born in October.
Just
a few months earlier, Ms. da Silva had sought medical attention after
experiencing some of Zika’s symptoms: fever, joint pain and a red rash.
“I
had never heard of Zika or microcephaly,” said Ms. da Silva, the mother
of three other children. “Now I just pray that my daughter can endure
life with this misfortune.”
No one knows precisely when the Zika virus made the leap to Brazil from its place of origin
in Africa. Some researchers say it could have arrived during the 2014
World Cup, when Brazil welcomed travelers from around the globe. Others
think the virus may have come during a canoe race weeks later, when paddlers from French Polynesia, the site of a recent Zika outbreak, arrived in Rio de Janeiro.
Researchers,
alert to the rapid increase in cases, say that Zika’s spread to Brazil
reflects how easily viruses are jumping from one part of the planet to
another.
They
are particularly worried that the disease is wreaking havoc in a region
where the population has not encountered it before, and that climate change may be allowing viruses like Zika to thrive in new domains.
The
Brazilian government has stopped short of officially advising women not
to get pregnant, but confusion and fear are spreading along with the
virus.
“The
situation is incredibly frightening,” said Andreza Mireli Silva, 22, a
worker in a shoe factory in Sergipe State in northeast Brazil who is
seven months pregnant. She said she was trying to avoid mosquito bites
by wearing long pants despite the heat of the Southern Hemisphere summer
and applying insect repellent every three hours.
Zika,
named for the forest in Uganda where scientists discovered it in the
1940s, often goes unnoticed in the people it infects and was not
considered especially life-threatening before spreading to Brazil. But
the advance of the virus here is focusing scrutiny on the resilience of a
worrisome pest: Aedes aegypti, the mosquito that carries Zika and other
diseases, among them yellow fever and chikungunya.
“Brazil
offers the ideal conditions for Zika to spread so quickly,” said Ana
Maria Bispo de Filippis, a leader of the research team that has linked
Zika to microcephaly. The country, she added, has “a susceptible
population in which the majority of people never had contact with the
disease.”
Before
Zika’s arrival, Brazil was already grappling with a much deadlier
epidemic of dengue, another virus transmitted by Aedes mosquitoes.
Brazil had nearly 1.6 million cases of dengue in 2015, according to
estimates from the health ministry, up from 569,000 in 2014. At least
839 people have died from dengue in Brazil this year, an 80 percent
increase from the previous year. Some health officials say that changes
in weather and rainfall may be behind the surge.
Brazil waged war
on the Aedes aegypti mosquito for decades during the 20th century
before a vaccine was developed for yellow fever. Health agents deployed
across the country to destroy habitats like water barrels and other open
water sources where the mosquitoes thrive. The authorities even
declared victory against the pest in 1955.
But
the mosquito re-emerged in Brazil in the late 1960s, outpacing
eradication campaigns. Now, at a time when President Dilma Rousseff’s
beleaguered government is under fire over corruption, an economic crisis
and its handling of the surge in dengue cases, the spread of Zika is
unleashing even more criticism.
After
virologists identified a Zika outbreak in May in northeast Brazil, the
health minister at the time, Arthur Chioro, played down the discovery.
“Zika virus doesn’t worry us,” he told reporters, calling it a “benign disease.”
After that dismissive response, public health experts say that the political upheaval
in Brazil — in which Ms. Rousseff is fighting impeachment proceedings —
weakened efforts to respond to Zika. Ms. Rousseff overhauled her
cabinet in October, dismissing various ministers from her own Workers
Party, including Mr. Chioro.
In
doing so, she ceded more power to the centrist Brazilian Democratic
Movement Party, or P.M.D.B., which controls both houses of Congress.
While Zika was raging, she named as her health minister Marcelo Castro, a
psychiatrist from that party who stopped practicing medicine years ago
to focus on his own business interests and politics.
“The
health minister, a politician dedicated to the business of ranching,
has a profile that’s the opposite of what’s required to lead the effort
to deal with microcephaly,” Ligia Bahia, a specialist on Brazil’s public
health system at the Federal University of Rio de Janeiro, said in a column in the newspaper O Globo.
Researchers
warn that they are only just starting to understand Zika’s impact on
Brazil and the potential for it to spread t other countries in the
Americas. The federal authorities do not yet have a precise estimate on
the number of Zika cases because reporting such figures is not
compulsory.
Some
researchers emphasize the role that climate change may play in Zika’s
spread. As temperatures increase in some areas, they argue, mosquitoes
can multiply more quickly, potentially enhancing their collective
ability to transmit diseases.
Additionally,
increased precipitation in some areas creates places where mosquitoes
can breed. And droughts, like those that recently afflicted parts of
Brazil, can cause people to hoard water in containers, providing
additional mosquito habitats.
“The
mosquito is exquisitely adapted to human hosts, living in close
proximity to humans and feeding repeatedly,” said Maria Diuk-Wasser, a
scholar at Columbia University.
Neither
the Zika outbreak in Latin America nor its possible link to
microcephaly in infants has led to changes in travel advice from the
C.D.C. or the Pan-American Health Organization, the regional office of
the World Health Organization.
Because
Zika is spread by the same mosquito species linked to dengue and
chikungunya, both agencies are sticking with the advice they gave for
those outbreaks: that all travelers, including pregnant women, do
everything they can to avoid mosquito bites, like using insect repellent
day and night, wearing long pants and long sleeves, and staying in
places that are screened and air-conditioned.
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