A virus that spread via inhalation or blood. At first behaves just like HIV, and takes a bit to set in. However, what makes this virus unique is that the virus mutates the white blood cells into pseudo-tendons worms that pervade the entire body. When the body is injuries, the worms seek to reconnect the tissue. However, they will connect with another host body if possible. The worms connect themselves, via capillary sized webbing of nervous tissue.
Should the host die due to having a compromised immune system, the worms keep the tissue of the deceased alive, and will connect with other infected corpses.