Hey guys..I took mudbone's timeline and tried to add most of the relevant quotes I found in this thread. I marked those not said by Froome himself.
2009 - Diagnosis (Possible mix-up)
"Back at...I think it was the end of 2009 actually...I was diagnosed for the first time with bilharzia" (Dec '12)
"You don't realize it is bilharzia unless you go for that specific test -- which I was lucky enough to detect at the end of 2009" (Dec '12)
("Since then I've...every 6 months I go for another check, and if there's any sign of it in the system then I'll just repeat the treatment" (Dec'12))
2009/2010 - Contraction
"I probably had it for year before I found it." (Sep '11)
"I found it 18 months ago and they had probably been in my system for a year before that." (May '12)
Dec/End of 2010 - Diagnosis (and presumably Treatment)
"Bilharzia – it’s a water-borne disease, which I found that I had it in December last year." (Sep '11)
"At the end of 2010, I was back home in Kenya visiting my family, and it was that time of year to do the UCI blood passport checks, so I went and had the tests done and at the same time I said to the doctors “I haven’t been great all year, can we just check a full screening for anything, and they came back immediately and said you have this parasite…” ('13)
May 2011 - Another diagnosis
"In the 2011 Tour of California, he was amazing one day and really bad the next. So we tested for Bilharzia again and sure enough he had it. And once he got treatment, he started progressing again." - Julich (Jul '12)
June 2011 - Feeling bad
"Yes, it's going well but I've been a bit unlucky with my health recently, picking up a chest infection which seems to be lingering. No regrets, though. I've had some great days and some not so great." (June '11)
July 2011 - Treatment
"I had to re-do the treatment after the Tour de Suisse this year. Since then, I have been a lot more consistent and good in my training" (Sep '11)
March/April 2012 - Treatment
"I took the treatment three weeks ago and I've got to wait six months to see if it's still active or not." (May '12)
“The bilharzia is not totally cleared up. I did repeat the treatment about three months ago in March. I am clear for now. I need to go check again in August-September." (Jul '12)
“I had a two week treatment in April last year, and have since been clear of the parasite. I have it checked every six months to make sure it hasn't returned.” (Dec '12)
"I was with Chris when he took the 7-day (NOT 6 week) course of medication (immediately following Criterium International) & while there was some mild nausea & fatigue it certainly wasn't anything like a chemo treatment." - Cound (Oct '12)
"He took it at the end of March after Criterium International, he had also taken two courses of praziquantel in the past but the parasites kept coming back. He was diagnosed back in 2010 if I remember correctly." - Cound (Oct '12)
January 2013 - Check-Up and Treatment
”I do go for a check-up every six months. The last was in January and it was still in my system. I take Biltricide. It kills the parasite in the system.” (Jul '13)
"He returns every six months to Africa for a course of treatment – the last was in January and the next will be straight after the Tour." - The Independent (June '13)
"In terms of that illness, I actually went for a check 10 days ago and found out that I did have to repeat the treatment again. It means these big pills that basically poison you and kill everything in your stomach and I took that in the last week. I am feeling much better now and hopefully I am in the clear for another six months or so." (Jan '13)