Is an interventional cardiologist at the Uganda Heart Institute.  He performs percutaneous mitral commissurotomy for patients with severe mitral stenosis. He completed his PhD training at Makerere University in 2015. His research was on the burden, risk factors and outcome of rheumatic heart disease (RHD) in Uganda. His findings showed that there is big burden of RHD in Uganda which is associated with high morbidity and mortality.

He also found genetic susceptibility to RHD related to the major histocompatibility complex (MHC) class II Human Leucocyte Antigens(HLA)- DR 11.As a THRIVE postdoctoral Fellow, Dr. Okello will look at the epidemiology and pathogenesis of acute rheumatic fever in Lira District, Northern Uganda, based on the problem that very few cases of ARF are currently being diagnosed reported, to explain the very prevalent cases of clinical rheumatic heart disease seen in hospitals around the country.

This study is expected to improve the diagnosis of acute rheumatic fever diagnosis and contribute to the reduction of morbidity and mortality associated with RHD, the long term consequence of rheumatic fever.His PhD work enabled him to join international research groups on rheumatic heart disease and rheumatic fever. He is mentored by Professor James Tumwine (Makerere), Dr. Andrea Beaton (Washington), Dr. Tom Parks (LSHTM) and Professor Jonathan Carapetis (Australia).