WASHINGTON — A dysfunctional Senate split along party lines on Tuesday and left a $1.1 billion proposal to fight the Zika virus in limbo, despite growing fears and more than 800 cases of Zika infection in the continental United States.

Democrats blocked the GOP-drafted measure by a 52-48 vote Tuesday — short of the 60 votes required to advance it. The party faulted Republicans for packing the bill with provisions designed to deny new funding for Planned Parenthood clinics in Puerto Rico and ease rules on pesticide spraying.

What happens next is unclear. Neither side is looking forward to leaving Washington next month for a seven-week vacation without having acted to address the health threat, but hard feelings seemed to harden in the immediate aftermath of the vote, leaving any path forward in doubt.

Zika is spread mainly by a tropical mosquito and is causing an epidemic in Latin America and the Caribbean. The virus can cause horrible birth defects and is likely to spread further this summer. So far, there’s been no transmission by mosquitoes in the continental United States.

The more than 800 cases include almost 300 pregnant women at risk of delivering children with severe deformities.

Democrats pressed to resume negotiations while Republicans insisted, for now at least, that the measure negotiated by House and Senate Republicans is the best the Obama administration is going to get.

The administration had requested $1.9 billion in emergency funds in February.

Associated Press