HIV/AIDS is caused by a virus that can be transmitted sexually, through sharing needles, from infected mother to child, or through contact with infected blood. While there is no cure, treatments can slow the progression of the virus and reduce symptoms, allowing those infected to live longer. Common early symptoms may include fever and rash, while later symptoms can include extreme fatigue, diarrhea, and infections. The virus is extremely contagious and safety precautions are important to prevent transmission.