Bacterial infections contribute significantly to high child mortality rates in Africa, and non-typhoidal Salmonellae (NTS) are consistently amongst the most common invasive isolates. Whilst NTS rarely cause severe illness in the western world, they are a frequent cause of major illness in the tropics. Understanding of how NTS infections are acquired and estimations of NTS disease burden in these settings are limited and strategies for NTS control are non-existent. Goals: 1) establish signifi cant risk factors for NTS acquisition in the community in Nairobi 2) determine estimates for NTS carriage in the general population. I propose a case-control study of children with microbiologically-proven NTS disease with controls from hospital out-patients to investigate risk factors for acquisition of NTS. I will measure the duration of stool carriage and estimate population NTS carriage prevalence. The study will take place in an urban African setting in conjunction with a well-establish ed microbiology laboratory inside a Wellcome Trust MOP. The strain structure of isolates obtained will be explored by MLST. I will prepare for this project by studying the LSHTM MSc in epidemiology. My work will be supervised by two experienced epidemiologists and a Kenyan NTS microbiology expert.