Hospital authorities have confirmed that Thomas Eric Duncan, 42, the first patient to be diagnosed of Ebola in the United States died on October 8, in isolation at Texas Health Presbyterian Hospital.

Duncan flew from Liberia to Dallas International Airport, arriving on September 20. Five days later he went to Texas Health Presbyterian Hospital feeling ill but was released by the hospital after staff failed to see the signs of a potential Ebola case. On September 28, Duncan returned to the hospital after his illness worsened.

After his condition became critical, Duncan was treated with an experimental antiviral drug, brincidofovir, after the Food and Drug Administration approved its use for the treatment of Ebola virus disease on an emergency basis.

The hospital’s failure to spot the symptoms has raised questions about how prepared the West is to deal with the virus. Authorities in Dallas said they are confident that they have been able to prevent the spread of the disease and they are monitoring 48 people. So far none of them have shown any symptoms of Ebola.

Reports of Duncan being diagnosed in the US raised fears that the virus could soon spread to Western nations. Concerns grew when on October 6, a nurse in Spain became the first health worker to be infected by the virus outside of West Africa. The nurse contracted Ebola after treating a Spanish priest, Manuel García Viejo, who was infected in Sierra Leone and flown to Madrid’s Carlos III hospital, he later died on September 25.

Health officials have repeatedly reassured the public that if there is an outbreak of Ebola in Europe or in the United States, Western health care systems will be able to treat patients.

Following the infection in Spain and growing public concern about the spread of the virus, Prime Minister David Cameron will hold a meeting with the government’s emergency response committee on October 8 to discuss the threat and examine the country’s preparedness for an Ebola outbreak.

The World Health Organisation’s European director, Zsuzsanna Jakab, told Reuters on Tuesday that further cases of Ebola in Europe are “unavoidable”.