Nairobi sheep disease is a viral infection that primarily affects sheep, particularly in East Africa. It is caused by the Nairobi sheep disease virus, which is transmitted by ticks. The disease can lead to symptoms such as fever, swelling, and a decrease in wool production, ultimately affecting the health and productivity of the animals. The disease poses a significant threat to sheep farming in affected regions, as it can result in high mortality rates among infected animals. Control measures include managing tick populations and implementing vaccination programs to protect sheep from the virus.