This study will look at blood samples taken from 300 preterm babies and newborns admitted for inpatient care at Hopital Gabriel Toure in Bamako, Mali, and to gather information that will help the investigators verify the role of malaria in illness of very small babies. Blood samples will be taken from the mothers so that the investigators can find out if they have a malaria infection and how their body fights malaria. The investigators will also determine whether the mother and newborn baby are infected with the same malaria parasite. The information from this study may be used to improve malaria treatment in very small babies. Mothers and babies whose blood is tested will receive treatment for malaria as recommended by the National Malaria Control Program (NCMP).