WASHINGTON (AFP) - Ebola has infected few Americans, but it has gone viral on the US campaign trail, with politicians blaming one another for exacerbating the health crisis and feuding over how to contain it.

With 18 days until the nation's mid-term elections - which may well see Republicans seize control of the Senate from Democrats - Ebola is a political shuttlecock, battered around in campaign ads, in candidate debates, at congressional hearings and by presidential hopefuls past and future.

Republicans are slamming President Barack Obama for lack of leadership while Democrats attack rivals for seeking to slash funding for research on infectious diseases.

The blame game was on display on the campaign trail in several battleground states including Iowa, where Senate candidate Joni Ernst accused Obama - and her Democratic rival Bruce Braley - of dropping the ball.

"Unfortunately our administration, including congressman Braley, has been very reactive rather than proactive," she said in their recent debate.

"We have seen the threat from Ebola for the past several months, and I would encourage temporary travel bans and additional screenings for travellers" from Ebola-impacted West African nations.

Braley and another Senate hopeful, Colorado's Cory Gardner, broke from campaigning Thursday to join a House hearing on the US Ebola response, and Gardner used the opportunity to rap Obama for failing to implement a travel ban that many Republicans have called for.

Obama for his part said Thursday that closing US borders to citizens of Guinea, Liberia and Sierra Leone would not make Americans safer as it would only encourage people to skirt existing safety controls.

In North Carolina, Republican Thom Tillis linked the Ebola threat with a hot-button political issue: illegal immigration along the southern US border.

"We've got an Ebola outbreak, we have bad actors that can come across the border. We need to seal the border and secure it," Tillis said in an October debate with incumbent Senator Kay Hagan.

Campaign fear-mongering - always a powerful political tactic - over Ebola began in late August, when Senator Mark Pryor of Arkansas charged that his challenger Tom Cotton, a Republican congressman, "voted against preparing America for pandemics like Ebola."

Cotton dismissed the ad as "silly," and in a statement Thursday said Obama has failed to take appropriate action, leaving Americans "unnecessarily vulnerable."

Democrats lay some of that vulnerability at the feet of budget-slashing Republicans.

Congresswoman Jan Schakowsky told MSNBC Friday that containing and stopping Ebola requires boosted funding, but that "the preparedness budget, especially for hospitals, has been cut 44 per cent since 2006."

Several Republican potential White House hopefuls have delivered Ebola jabs. Senator Ted Cruz spoke of a potentially "catastrophic" outbreak on US shores unless Obama takes more decisive action.

"Hope is not a strategy," he warned in a Texas Tribune op-ed, urging a travel ban from West Africa.

Senator Rand Paul accused the administration of underplaying the Ebola threat and having a "bossy, arrogant attitude," while Louisiana Governor Bobby Jindal tweeted criticism of the president's efforts.

Even the 2012 Republican nominee Mitt Romney joined the fray, describing Ebola as yet another crisis bungled by the White House.

"Look, this administration couldn't run the IRS right, and it apparently is not running the CDC right. And you ask yourself, what is it going to take to have a president who really focuses on the interests of the American people?" Romney told NH1 News.

A survey this week exposed the partisan nature of much of the criticism.

The ABC News/Washington Post poll showed 76 per cent of Democrats have confidence in government's ability to respond effectively to Ebola, compared with 54 per cent of Republicans.

Back in 2006, when bird flu emerged during George W. Bush's presidency, those figures were reversed: an ABC/Post poll at the time reportedly found 72 per cent of Republicans confident the Bush administration could handle bird flu effectively, compared with 52 per cent of Democrats.