The anti-HHV-6 kits are intended for the serological diagnosis of diseases associated with Human Herpesvirus 6 infection, such as exanthema subitum, acute respiratory illnesses, diarrhea with fever and febrile seizures in infants, heterophile antibody-negative infectious mononucleosis in children, and interstitial pneumonia, encephalitis, meningitis, hepatitis, and aplastic anemia in immunodeficient patients. The presence of IgG anti-HHV-6 antibodies reveals the immune status of the patient. Seroconversion or 4-fold rise in antibody titer in paired serum samples, taken in acute and convalescent phase of the infection, is indicative of the active infection.