LOUISVILLE, Ky. (WDRB) -- The number of pregnant woman with the Zika virus in the U.S. has tripled. 

There are currently 157 cases in the U.S., up from the 48 last week. 

The increase comes from how the government is counting cases. Previously, officials had reported pregnant woman that had both symptoms and positive blood test. 

But now the C.D.C. is counting all women who test positive, regardless of symptoms. 

The agency is worried one test is too prone to giving a false positive.

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