MONROVIA, Liberia (AP) — Liberian officials faced a difficult choice yesterday: deciding which handful of Ebola patients will receive an experimental drug that could prove life-saving, ineffective or even harmful.

ZMapp, the untested Ebola drug, arrived in the West African country late Wednesday. A day later, no one had yet received the treatment, which officials said would go to three people.

The Government had previously said two doctors would receive the treatment, but it was unclear who else would. Information Minister Lewis Brown said yesterday it would probably be another health care worker.

These are the last known doses of ZMapp left. The San Diego-based company that developed it has said it will take months to build-up even a modest supply.

The Ebola outbreak was first identified in March in Guinea. It has since spread to Liberia, Sierra Leone and Nigeria, killing more than 1,060 of the 1,975 people sickened, according to the World Health Organisation. There is no licensed treatment for Ebola, a virus transmitted by contact with bodily fluids like blood, sweat, urine, diarrhoea and vomit.

The outbreak has overwhelmed the already strained health systems in West Africa and raised questions about whether authorities are doing enough to respond.

The outbreak has sparked an international debate over the ethics of giving drugs that have not yet been tested to the sick and of deciding who should get the drugs. So far, only two Americans and one Spaniard have received ZMapp. The Americans are improving — but it is unclear what role the drug has played. The Spaniard died within days.