👉 Kelleziovirus is a type of virus that causes a condition called encephalitis, which can cause inflammation and swelling in the brain. It primarily affects people aged between 18 and 30 years old, but it can also infect children under 5 years old. Symptoms may include fever, headache, confusion, loss of appetite, and difficulty breathing. Treatment typically involves supportive care, including fluids, pain management, and possibly antibiotics if the infection is severe.