In pictures: 'Life Interrupted' by Don McCullin

Edith, right, visits Catherine, 33, and her two-year-old son, Kenan. As Catherine becomes increasingly ill, she worries about Kenan, whom she thinks might be HIV-positive. Although Zambia now provides drugs to help stop mother-to-child transmission, many mothers do not know that they are positive and pass on the virus in childbirth or while breastfeeding. Nkwazi compound, Ndola, Zambia 2004.