The “Mwana” project in Zambia, launched in 2010 with support from the Ministry of Health and UNICEF, has reduced delays in transmitting results from HIV test laboratories to health facilities via instant SMS message from 66 days to 33 on average in the country’s rural and underserved communities. In addition to strengthening early infant diagnosis and improving the rate of postnatal follow-up, Mwana proved successful in engaging with local health workers and service users in the co-design of m-health information services.