Justina Kabuli and her 12-year-old son Andrew, both HIV-positive, remove weeds from their field of sweet potato crops during a visit by a home-based care team to their home in Chiyobola village, close to the town of Chikuni in the south of Zambia February 21, 2015. The caregivers on the Jesuit-run home-based care team at Chikuni run a capacity building and empowerment project at household level, offering training and assistance in crop-growing and animal rearing, as well as offering companionship, pastoral care and monitoring antiretroviral treatment compliance of HIV-AIDS patients. Picture taken February 21, 2015.
REUTERS/Darrin Zammit Lupi (ZAMBIA - Tags: HEALTH DRUGS SOCIETY AGRICULTURE) 

Zimbabwe President Robert Mugabe (R) and his Zambian counterpart Edgar Lungu step out of State House in Harare, February 6, 2015. The recently elected Zambian president is in the country for a day's official visit and held a four hour meeting with Mugabe as the head of both Southern African Development Community (SADC) and African Union (AU). REUTERS/Philimon Bulawayo (ZIMBABWE - Tags: BUSINESS POLITICS) 

The new Zambian head of state President Edgar Lungu attends the opening ceremony of the 24th Ordinary session of the Assembly of Heads of State and Government of the African Union (AU) at the African Union headquarters in Ethiopia's capital Addis Ababa, January 30, 2015. REUTERS/Tiksa Negeri (ETHIOPIA - Tags: POLITICS HEADSHOT) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: ELECTIONS POLITICS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Election officials count ballot papers at a voting station in Lusaka, January 20, 2015. Zambians voted for their next leader on Tuesday in a tight race between a populist lawyer and a wealthy economist after the former president died in office. Edgar Lungu, leader of the ruling Patriotic Front (PF), is seen having a slight edge over Hakainde Hichilema, a businessman whose United Party for National Development (UPND) has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) Presidential candidate Hakainde Hichilema casts his ballot at a voting station in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) Presidential candidate Hakainde Hichilema casts his ballot at a voting station in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu's name appears on a shop wall in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS TPX IMAGES OF THE DAY) 

United Party for National Development (UPND) Presidential candidate Hakainde Hichilema speaks to members of the media before casting his ballot at a voting station in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu leaves after casting his ballot at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. Lungu is seen having a slight edge over main rival Hakainde Hichilema, a businessman whose United Party for National Development has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu leaves after casting his ballot at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. Lungu is seen having a slight edge over main rival Hakainde Hichilema, a businessman whose United Party for National Development has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu casts his ballot at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. Lungu is seen having a slight edge over main rival Hakainde Hichilema, a businessman whose United Party for National Development has wooed the middle-class and investors. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS TPX IMAGES OF THE DAY) 

Voters queue in the rain at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Voters queue at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Voters brave the rain as they walk to a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Voters queue in the rain at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Voters queue at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Voters queue at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

An election official checks a voters identity documents against the voters roll at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Voters queue at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

A voter marks his ballot at a voting station in John Howard township in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

An election official marks a voter's thumb nail at a voting station in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

A Zambian voter casts his ballot at a voting station in Lusaka, January 20, 2015. Zambians flocked to the polls on Tuesday to choose the next leader of one of Africa's most promising frontier markets, in what shaped up as a tight race between a populist lawyer and a wealthy economist. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu and his wife Esther Lungu leave a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Supporters of the Patriotic Front (PF) listen to Presidential candidate Edgar Lungu speak at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu speaks at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS HEADSHOT) 

Patriotic Front (PF) Presidential candidate Edgar Lungu speaks at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS HEADSHOT) 

Patriotic Front (PF) Presidential candidate Edgar Lungu (R) sings and dances with Acting President Guy Scott at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu (R) speaks with Acting President Guy Scott at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu looks on during a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Supporters of the Patriotic Front (PF) react to Presidential candidate Edgar Lungu at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS TPX IMAGES OF THE DAY) 

Patriotic Front (PF) Presidential candidate Edgar Lungu speaks at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS HEADSHOT) 

Patriotic Front (PF) Presidential candidate Edgar Lungu speaks at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu dances at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Patriotic Front (PF) Presidential candidate Edgar Lungu (C) dances at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Supporters of the Patriotic Front (PF) celebrate the arrival of Presidential candidate Edgar Lungu at a rally in Lusaka January 19 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

A supporter of the Patriotic Front (PF) awaits the arrival of Presidential candidate Edgar Lungu at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Supporters of the Patriotic Front (PF) await the arrival of Presidential candidate Edgar Lungu at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Supporters of the Patriotic Front (PF) arrive ahead of Presidential candidate Edgar Lungu at a rally in Lusaka January 19, 2015. Lungu's rapid rise from backroom politician to presidential front-runner in one of Africa's most promising frontier markets has revealed tactical nous and a steely determination that few knew lay beneath his quiet exterior. Zambians go to the polls on January 20, 2015 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

Supporters of the Patriotic Front (PF) await the arrival of Presidential candidate Edgar Lungu at a rally in Lusaka, January 19, 2015. Zambians go to the polls on January 20, 2015, following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: ELECTIONS POLITICS) 

Supporters of the Patriotic Front (PF) await the arrival of Presidential candidate Edgar Lungu at a rally in Lusaka, January 19, 2015. Zambians go to the polls on January 20, 2015, following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: ELECTIONS POLITICS) 

United Party for National Development (UPND) presidential candidate Hakainde Hichilema (C) greets supporters as he leaves a rally in Lusaka January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) Presidential candidate Hakainde Hichilema looks on during a rally in Lusaka January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) supporters react to presidential candidate Hakainde Hichilema (not in picture) at a rally in Lusaka January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) presidential candidate Hakainde Hichilema dances during a rally in Lusaka January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) presidential candidate Hakainde Hichilema dances during a rally in Lusaka January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) presidential candidate Hakainde Hichilema speaks at a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) supporters listen to presidential candidate Hakainde Hichilema (not in picture) speak during a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) supporters react as presidential candidate Hakainde Hichilema (not in picture) arrives at a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) presidential candidate Hakainde Hichilema smiles during a rally in Lusaka January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) supporters react as presidential candidate Hakainde Hichilema (not in picture) arrives at a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) presidential candidate Hakainde Hichilema speaks at a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) supporters react as presidential candidate Hakainde Hichilema (not in picture) arrives at a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS) 

United Party for National Development (UPND) supporters react as presidential candidate Hakainde Hichilema arrives at a rally in Lusaka, January 18, 2015. Zambians go to the polls on January 20 following the death of President Michael Sata in October 2014. REUTERS/Rogan Ward (ZAMBIA - Tags: POLITICS ELECTIONS)