Federal health officials are reporting an increase in the number of pregnant women in the U.S. infected with the Zika virus.

Fox's Gurnal Scott has the latest:

The Centers for Disease Control and Prevention in Atlanta reports 320 women are infected with Zika, 33 more cases than last week.

During a conference call, C.D.C. Director, Tom Frieden, says virus control means stopping mosquitoes carrying it. But roadblocks in congressional funding have slowed that process.

Frieden says in the meantime, those who are vulnerable must be careful:

(Frieden) "Four out of five of those infected don't have symptoms and those who do tend to have mild symptoms, but the silence does not indicate that it's not serious." 

Prevention delays come despite White House efforts to get bipartisan support on funding.

Gurnal Scott, FOX News.

Follow Gurnal Scott on Twitter: @GurnalScott