Malaria (Lusaka)

Hey all!
I'm moving to Lusaka in the end of this month for a year. I'm really excited about this adventure but my main concern at this point is Malaria. Ill be glad if you guys-other expats or locals, here in this forum, can share from your own experience...is that a real issue in Lusaka? Should i take pills everyday for the whole year around (as my doctor suggested)??? should i take the pills only in the hot and wet season?? does taking preventive medicine is necessary? or can i just use net and not going out in the evening?
Cheers!