Gastroenteritis, the multi-factorial nature of the disease, is the leading cause of death among infants and children worldwide. Similarly, diarrhea is the most important cause of disease in calves and is a major cause of economic loss to cattle producers. Although different bacteria and protozoa can cause diarrhea, more than 75% of cases are found to be caused by viruses. Rotaviruses have also been recognized as important agents of acute diarrhea in both humans and animals and are responsible for considerable economic losses worldwide including Ethiopia. Increasing evidence suggests direct transmission of rotavirus strains between animals and humans and nearly half a million children die from rotavirus infections each year worldwide. Recent studies in humans have suggested that simultaneous infection of a host by multiple pathogens might be important in the pathophysiology of gastrointestinal diseases. This work is proposed to determine the diversity of rotaviruses circulating in ruminants and children in central Ethiopia as well as to assess the transmission of rotavirus strains from diarrheic animals to humans and determine viral diversity and detection of noble virus in diarrheic humans and calves in central Ethiopia. Fecal Samples will be collected from diarrheic calves (< 6 months) in Debre-Birhan, Bishoftu, and Addis Ababa. Similarly, stool specimens of diarrheal patients (children < 5 years) will be collected from health posts in the corresponding area. The viral nucleic acid will be extracted from the fecal supernatant and then amplified by RT-PCR to identify viral pathogens and their variants. The genetic diversity and genotype will be determined using whole genome sequencing methods. Viral metagenomic will be performed to analyze the viral diversity and detection of noble viruses in diarrheic children and calves’ fecal sample