Before retiring, Dr. Mramba was the CEO of the Hester Biosciences Africa, which produces vaccines for large animals, small ruminants and poultry. Previously, she was the CEO of the Tanzania Veterinary Laboratory Agency (TVLA), an agency that is responsible for the diagnosis and surveillance of livestock diaseases. She was the overseer of 13 veterinary laboratories based in Tanzania. TVLA is also responsible for the production and distribution of veterinary vaccines, development of technologies which are used for validation, eradication, and control of animal diseases, and analysis of animal feeds (Government analysts). Dr. Mramba has supervised over 25 research projects both at national and international levels as the PI and Co-PI. She has more than 60 publications in both national and international peer reviewed journals.