Liberia faced a nationwide walkout by healthcare workers demanding danger money to care for Ebola patients, in an epidemic that has killed dozens of their colleagues.
The strike threat came as the United States scrambled to find out how a Texan healthcare worker contracted the tropical virus, in the first case of contamination on US soil.
The new infection dealt a blow to global efforts to stem an outbreak that has claimed more than 4,000 lives, most of them in the west African countries of Guinea, Sierra Leone and the hardest-hit, Liberia.
Monday's strike call in Liberia came in defiance of an official request to avoid industrial action during the Ebola crisis, which has killed more than 2,300 in Liberia and overwhelmed its skeletal health service.
The chairman of the Liberian health workers' union, Joseph Tamba, said the walkout concerned "every hospital and every health centre including ETUs (Ebola Treatment Units)".
Healthcare workers are on the frontline of the worst outbreak on record of Ebola, which spreads through contact with bodily fluids, with 95 killed in Liberia alone, according to the World Health Organisation.
With monthly salaries said to be as low as $250 (200 euros) a month, calls are mounting for pay commensurate to the acute risk of dealing with Ebola, for which there is no vaccine or widely-available treatment.
Liberian President Ellen Johnson Sirleaf acknowledged as much last week, telling a World Bank crisis meeting there was an urgent need for "compensation to healthcare workers who, for fear of the risk involved, have refused or are reluctant to return to work".
Staff at Island Clinic, the largest government-run Ebola clinic in the Liberian capital Monrovia, have been on a "go slow" since Friday for extra pay.
Dozens of patients at the clinic have died since then, according to Alphonso Wesseh, a staff representative.
Liberia has banned reporters from Ebola clinics, making the claim impossible to verify.
- 'Breach in protocol' -
Both cases of contamination reported so far outside Africa -- in Spain last week and now in the United States -- have involved health workers, who fell ill despite the stringent safety protocols surrounding Ebola.
Authorities in the United States blamed a safety breach as they confirmed the first case of transmission at the weekend, in an unidentified female caregiver who treated a Liberian Ebola patient in Dallas.
Dan Varga, chief clinical officer for Texas Health Resources, said the woman was "following full CDC precautions" -- which would have included wearing a mask, gown and gloves.
But the head of the US Centers for Disease Control and Prevention (CDC), Thomas Frieden, insisted that "at some point there was a breach in protocol".
As the CDC investigates, President Barack Obama told federal authorities to take "immediate additional steps" to ensure hospitals were ready to follow Ebola protocols.
National Nurses United, the largest US nurses' organisation, is demanding protective equipment, including hazardous materials suits, and special Ebola training.
"The time to act is long overdue," said executive director RoseAnn DeMoro.
- 'Highly-connected world' -
The latest US Ebola sufferer, who worked at Texas Health Presbyterian Hospital in Dallas, is currently in isolation and said to be in a stable condition.
CDC chief Frieden said she had "extensive contact" with Liberian patient Thomas Eric Duncan, who is thought to have been infected while still in Liberia and who died on Wednesday.
While the CDC was working to track down other carers who may have been exposed in Dallas, it said any spread into the community "can be prevented with proper public health measures."
World Health Organisation chief Margaret Chan also voiced confidence that developed nations would be able to contain the virus.
"We are living in a highly connected world, it shouldn't come as a surprise that some cases of contamination are happening, like it happened in the USA," she told reporters.
However, she said, "we do not expect the countries with a good system of health to experience a situation like in the three countries of west Africa."
The official reassurances were unlikely to calm global jitters about Ebola, whose rampage through west Africa has defied all efforts to contain it so far.
JFK in New York Saturday became the first of several US air hubs to launch health screenings for travellers from west Africa, to be checked for signs of illness and quizzed about possible exposure. Other nations have instituted similar checks.
Leading Italian football club AC Milan "categorically denied" reports that a Ghanaian player, former Chelsea midfielder Michael Essien, had contracted Ebola. Essen posted a photograph of himself giving a 'thumbs-up' pose.
- 'Many more cases' -
In Spain, the crisis cell set up after a Madrid nurse fell sick said there was "reason to hope" she could recover.
Teresa Romero, 44, the first person infected with the haemorrhagic fever outside Africa, is thought to have contracted it while caring for a Spanish missionary.
Romero has said she thought she might have developed Ebola after brushing her face with a glove -- pointing to possible gaps in protocol. Fifteen other people are under observation in Madrid.
Ebola causes fever, diarrhoea, vomiting and bleeding. It is spread by contact with bodily fluids or exposure to contaminated objects.
The United Nations says aid pledges to fight the epidemic have fallen well short of the $1 billion needed, leading Chan to warn Monday of far worse to come for Guinea, Sierra Leone and Liberia.
"If nothing is done by the international community we will and we should expect many more cases happening in these countries," she said.