Prevalence and risk factors of malaria and human immunodeficiency virus co-infection among pregnant women at Sokoto, Nigeria oleh Chisom. E. Okechukwu, E. Okechukwu, Idris. N. Abdullahi, D. Aliyu, M. Kabiru, H. Aderisayo Adekola, Emeka. I. Ikeh, Thompson H.I. Spencer, Ngwoke. C. Chinedu