Electron micrograph of HHV-6 There are nine known human herpesviruses. Of these,<unk>  has been linked to two: human herpesvirus 6 (HHV-6) and human herpesvirus 7 (HHV-7), which are sometimes referred to collectively as<unk> virus. These viruses are of the Herpesviridae family and the Betaherpesvirinae subfamily, underwhich Cytomegalovirus is also classified. HHV-6 has been further classified into HHV-6A and HHV-6B, two distinct viruses which share 88% of the same DNA makeup, with HHV-6B the most common cause of<unk> . After infection, these viruses enter a latent phase.<unk>  caused by HHV-7 has been linked to the ability of HHV-7 infection to reactivate latent HHV-6. Spread After exposure to<unk> , the causative virus becomes latent in its host but is still present in saliva, skin, and lungs. HHV-6 is thought to be transmitted from previously exposed or infected adults to young children by the shedding of virus through saliva. Even so, most cases of<unk>  are transmitted without known exposure.
Roseola
Rubella
Ebola
Scarlet fever
Measles
Mumps
Smallpox
Chickenpox