By Julie Steenhuysen
CHICAGO, June 17 (Reuters) - Zika infections in Puerto Rico
appear to be increasing rapidly, top U.S. health officials said
on Friday, raising concerns for dozens if not hundreds of cases
of microcephaly.
Puerto Rican health officials on Friday reported that 1,726
people in the U.S. commonwealth have been infected with Zika,
including a total of 191 pregnant women. That is up from a total
of 1,501 total infections and 182 infections in pregnant women a
week ago.
The numbers reflect the total number of confirmed Zika cases
since the start of the outbreak late last year, a number that
reflects largely symptomatic cases of Zika.
In new data released by the U.S. Centers for Disease Control
and Prevention on Friday, health officials have also seen a
sharp rise in the frequency in which Zika is detected in blood
donations.
The numbers are based on the use of a test from Swiss
drugmaker Roche Holding AG ROG.S in use since April 3 to
screen blood donations for Zika.
"This is a test that measures actual Zika virus in the
blood. It's highly sensitive and highly specific," CDC Director
Dr. Thomas Frieden told reporters in a conference call on
Friday.
As of April 3, 68 out of 12,777 blood donations have tested
positive for Zika, and the proportion of positive tests "has
steadily increased," Frieden said.
Testing in the most recent week ended June 11 showed 1.1
percent of donated blood was infected with Zika, the highest
proportion seen yet in Puerto Rico, Frieden said.
Although the blood donor population is not representative of
the general population, Frieden said the increasing prevalence
of Zika in blood donations likely reflects increases in the
population at large.
The Zika virus only remains present in the blood for about a
week after symptoms appear, and diagnostic tests also look for
signs of past infections. Frieden said analyzing Zika in blood
donations provides a snapshot of current infections in the
population at any given time, including asymptomatic cases.
Based on the findings, he estimates that as many as 2
percent of the population is infected with Zika each month.
The estimate suggests that over time, there is a
substantially higher risk that a pregnant woman would become
infected with Zika, putting her fetus at risk of birth defects.
That also means that in the coming months, "it's possible
that thousands of pregnant women in Puerto Rico could be
infected in with Zika," Frieden said, leading to "dozens or
hundreds of infants being born with microcephaly in the coming
year."
"The bottom line is we're seeing a steady increase," Frieden
said.
He stressed that pregnant women are the chief priority in
the fight against Zika. The virus has been shown to cause
microcephaly, a birth defect marked by small head size and
underdeveloped brains, as well as other malformations. It is yet
not clear whether babies exposed to Zika in the womb with no
obvious birth defects will have developmental issues later on.
In Brazil, authorities have confirmed more than 1,400 cases
of microcephaly in babies whose mothers were exposed to Zika
during pregnancy
Frieden said the test was highly sensitive, and all blood
donations that test positive are removed from the blood supply.
Donors who test positive for Zika, an infection that often has
no symptoms, are given information on how to avoid spreading the
infection to others.
Although Zika is largely a mosquito-borne virus, it can be
transmitted sexually and through blood donations.
Frieden said there have been no confirmed cases of Zika
spread through blood transfusions anywhere in the United States
or Puerto Rico or any other U.S. territory, although there has
been at least one report of Zika spreading through a blood
transfusion in Brazil.
The Obama administration has requested $1.9 billion in
emergency Zika funding. The Senate approved $1.1 billion of that
request, but the House of Representatives voted to allocate
$622.1 million financed through cuts to existing programs, such
as for Ebola, which U.S. health officials have called inadequate
and short-sighted.
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TAKE-A-LOOK on Zika outbreak
TIMELINE-Zika's origin and global spread
GRAPHIC: Spread of Zika virus http://reut.rs/1JwW4AT
GRAPHIC: Zika cases in the United States http://tmsnrt.rs/1QvaMW6
FACTBOX-Why the Zika virus is causing alarm
FACTBOX-Race to develop a Zika vaccine
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