HIV positive Ziphi Mzila collects water outside her home near Msinga in the country's rural Kwa-Zulu Natal province on April 13, 2005. Mzila was diagnosed HIV positive in 2000 after AIDS-related illnesses forced her to quit growing and selling tomatoes, the main way which she fed her three children. AIDS will kill 20 percent of southern Africa's agricultural workers by 2020, researchers said on Thursday, possibly threatening food production in a region already facing frequent shortages. Picture taken April 13, 2005. REUTERS/Peter Apps/Handout IFAW/NL