The Ebola epidemic in Guinea led to a refocus, from bacteria and parasites, to viruses.

"All the work I did was exciting.

Meanwhile, the outbreak of Ebola virus disease fell on Guinea. This is my home country. I was working in Senegal. I was on bacteria, I was on parasites and I did everything, except what I could do to help my country, which was to work on viruses.

In September 2014, I was returning in Senegal, after some holiday in France, where my wife and children live.

I have been retained at Dakar airport. I am told: "The border is unfortunately closed between Senegal and Guinea, and everyone holding a Guinean passport must be quarantined in a transit zone."

I said, "But I haven't been to Guinea in over a year. I do not present any more risk than a tourist with a French passport coming from France. So you can let me pass because I come to work." And the gendarmes told me, "No, that's not possible."

I had to make a phone call to one of my managers in the unit, Dr. Cheikh Sokhna, who came and justified the fact that I work at the French Institute of Research for Sustainable Development. And I was let through.

So I arrived in Senegal. But since that day, I have never removed from my head that I could no longer stay in Senegal to work.

I stayed a few more months, and in February 2015 I returned to France. I managed to change my research unit. I came to work in Eric Delaporte's team, which was developing projects in Guinea on Ebola.

I came to see him and said, "I want to take action on the outbreak of Ebola virus in Guinea". But I didn't know how to do it.

One of the ideas he gave me was to volunteer.

There was EPRUS, the French health emergency preparedness institution, which sent people at the time to work on Ebola virus disease, help with patient management, help with diagnosis. So I volunteered with EPRUS, as a microbiologist to diagnose Ebola virus disease."