Dennis Kerr, 48, is a nurse living in Edinburgh who recently spent four weeks as a volunteer with Medecins Sans Frontieres (MSF), working in an ebola treatment centre in Monrovia, Liberia.

His main job while working in the West African country in late August and early September was to manage the ebola "suspect" team, which tested patients who were thought likely to be infected with the virus.

Kerr said: "When I was there 90% of the patients who were brought through were positive for ebola."

His work was not always so bleak, he said, adding: "Some of the patients were negative - one day I had around 20 results to give out and about six of them were negative that day. It was great telling people they were negative and seeing their face light up.

"There were three big blokes who just star jumped up and down when they heard.

"But there were also cases of patients who you really thought were going to survive - they didn't look too sick - but you would go home and come back the next day and find out they had died.

"There was also one health worker who worked in the suspect tent - he got infected with ebola, probably from running a health clinic from his home in the evening, and just after I left the country I heard he had passed away."

Kerr, who is originally from New Zealand, said he had volunteered to go to the country when he heard of the great need for health professionals in West Africa.

He said: "There is a minimal risk if you wear the personal protective equipment and follow the protocols. And, on the way to Monrovia, I had a two-day course in Brussels on the appropriate protection for ebola.

"It is a full protective suit - inside the suit the temperature rises to about 47 degrees - but that is only worn when you are working within certain high-risk areas."

He added: "I would love to go back to Liberia again - even though it is extremely challenging. This is a global public health crisis and we really need to hit it head on.

"They need more healthcare workers, but it is not just about setting up ebola treatment centres, it is also looking at issues such as safe burials, contact tracing, community sensitisation and understanding the epidemiology.

"The other thing is we really need to work on fast-tracking the vaccines and other treatments that appear to be on the horizon but are not quite ready yet. We are in uncharted waters and it needs an unprecedented response."