MODEL RELEASED. AIDS baby. Baby boy born to a mother with AIDS (acquired immune deficiency syndrome). He is extremely thin, had recurrent diarrhoea and showed failure to thrive. He also had pulmonary tuberculosis. AIDS is a contagious disease caused by the human immunodeficiency virus (HIV). It causes progressive weakening of the immune system, making the patient susceptible to opportunistic infections, and making normally harmless infections life threatening. It can spread from an infected mother to her baby through the placenta, despite there being no contact between their blood systems.