During the last 6 years Zanzibar has undergone a dramatic change in malaria epidemiology and burden of disease, with a marked decline of Plasmodium falciparum malaria among febrile children from approximately 30% to 1% or below and a reduction of crude child mortality of 50%. Millions of children in Africa die of neonatal disorders, acute respiratory tract infections (ARI), diarrhea, malaria, measles, HIV and malnutrition. A majority of these illnesses are also a common cause of febrile illness in out-patient departments. However, most of the few fever studies made in Africa are hospital based Very few studies on etiology of childhood febrile disease have been conducted on first level health facilities in the least developed countries in Africa. This study will therefore focus on children between 2 months to 5 years of age that have been diagnosed with a negative rapid diagnostic test (RDT) for malaria and their causes of fever at the first referral level in out-patient clinics in Zanzibar.