Optimizing the role of ‘lead mothers’ in seasonal malaria chemoprevention (SMC) campaigns: formative research in Kano State, northern Nigeria oleh Ekechi Okereke, Helen Smith, Chibuzo Oguoma, Olusola Oresanya, Kolawole Maxwell, Chinedu Anikwe, Lawrence Chijioke Osuji, Obianuju Ogazi, Jamila Musa, Ashiru Rajab, Emmanuel Shekarau, Festus Okoh, Erica Viganò, Laura Donovan, Charlotte Ward, Kevin Baker