This means that the share of under-five deaths occurring during the neonatal period is increasing. Still, of the 5.9 million under-five deaths in 2015, almost half were caused by infectious diseases and conditions such as pneumonia, diarrhoea, malaria, meningitis, tetanus, measles, sepsis and AIDS. Pneumonia and diarrhoea remain leading causes of death in the three regions with the highest under-five mortality: Eastern and Southern Africa, South Asia and West and Central Africa.