Hazyjane, thank you so much, you have been extremely helpful. (up)

Thanks Hazyjane, your comments are very useful. I understand "mathematical epidemiology" is a field to model the spread of (infectious) diseases. Based on the articles I've read so far, it can be pretty heavy in maths and the PhD programme I would target are in Applied Mathematics departments. (see for example the following introductory article http://citeseerx.ist.psu.edu/viewdoc/download;jsessionid=0C0D83C1CC0041EA9A966720356DDC13?doi=10.1.1.130.1956&rep=rep1&type=pdf)

I was planning, as you suggested, to get in touch with potential supervisor (but wanted to test the water on forums first!). When you mention institution with strong epi programme/research, how can I see which one are the best? I mainly Google to find the relevant contacts but I'm wary I may miss good ones. Is there a (inter)national database of contacts?

Also, thanks to BilboBaggins for your encouraging post!

Hi, I am posting this to seek some advices on a very unusual career change I intend to do. Thanks in advance for your time and advice.

Let me first give you my background.

My education background is in applied mathematics. I own a DEA (Diplome d'Etudes Approfondies, a pre-PhD degree equivalent to a MPhil in France) in Probabilities Applied to Finance that I completed with honours in 1999. (I'm 35 and French living in the UK).
Then, I entered the financial corporate world as a quantitative analyst. The job is mainly designing and implementing financial models. After more than 12 years in this industry, I evolved through various positions which involved more and more management/finance and less mathematical stuff.

My choice for this career was mainly driven by its financial prospects. If I had not been in the need to work early, I would have most likely chosen an academic career to fulfil the desire I had when I was student to do some research in applied maths.

I have been contemplating switching to academia for some time already, without really knowing if i would do it and in which field. And recently I discovered and got interested in mathematical epidemiology. It's  been several weeks I'm reading research articles related to this topic to assess - and actually confirmed - my will to spend many years working in this area. Unfortunately, research in Quantitative Finance - a natural field given my experience - doesn't really motivate me.

The scientific component of my job is comparable to a "very applied engineering". Hence, I haven't practised daily high-level mathematics since I left University and least for the last 5 years where my role has been more about business building and management. Although I guess I have most of the academic background, I would have a steep catch up to come back to the level I had when I was student.

So, put simply, I would go from a corporate job where I did mathematical finance to academic research in mathematical epidemiology. I guess my experience is not completely irrelevant but is not obviously related either. The lack of intellectual challenge in my current and potential future jobs is the main motivation for me to switch to academia.

Fortunately, my job has been rewarding enough so that I can contemplate a significant career change now without taking a huge financial risk. My wife also supports me and is aware of the significant life change this would involve and we are pretty flexible in terms of location.

Obviously, I have some doubts about all this. Having your thoughts - even short ones - would be tremendously useful.
I wonder how realistic this career change is and how it would be received by a research lab/supervisor. Would I have a chance to enter directly into a PhD program (thanks to my DEA diploma) or would I be requested to sit again some exams beforehand? Would I be at a disadvantage for future jobs (post PhD)prospects? Has someone ever had a similar experience (switching to a "non-natura