Malaria question from an aspiring novelist

Hi!

I am 60, an editor & translator by trade, and am writing a novel, my first.

I have one of my characters (a German male born in 1915) picking up malaria while hiking in the Camarague around 1930 (maybe earlier) and then having a relapse in 1943. I need & would like some expert advice, particularly on the severity & duration of the 1943 relapse.

I thank everyone in advance for their time & consideration.