HHV-6 Transmission
"Both intrauterine and sexual transmission of human herpesvirus (HHV)-6 and HHV-7 have been suggested."
http://www.ncbi.nlm.nih.gov/pubmed/17922393
"Transmission of this virus is believed to occur as a result of exposure to saliva."
http://www.emergingworlds.com/ch_viruses_detail.cfm?vPageid=41
"Human herpesvirus 6 (HHV-6) is transmitted from parent to child in an integrated form and characterization of cases with chromosomally integrated HHV-6 DNA."
http://www.ncbi.nlm.nih.gov/pubmed/15170644
"HHV-6 has a very high prevalence (close to 100% of the world’s population has been exposed). It is transmitted mainly by saliva. Transmission occurs usually within the first two years of life; primary infection is often associated with a febrile condition and sometimes with the onset of roseola (exanthem subitum). Two variants of the virus are known, HHV-6A and HHV-6B. HHV-6 is mainly lymphotropic, infecting a broad range of immune cells including T cells, monocytes, NK cells; however the virus can also infect many other tissues such as brain or liver."
http://www.redlabs.be/red-labs/our-science/viral-infections.php
"Virus replicated in the salivary glands and secreted in saliva is the epidemiologically proven source of transmission. Other routes of transmission have been suggested but remain to be proven."
http://wwwnc.cdc.gov/eid/article/5/3/99-0306_article
"Infection with human herpes virus 6 (HHV-6) occurs in infancy or early childhood. Primary HHV-6 infection accounts for 10-20% of all febrile illnesses in infants and children less than 3 years of age seen in pediatric emergency departments. Serious complications have been described such as meningitis, encephalitis, hepatitis (including neonatal hepatitis), disseminated infection and hemophagocytic syndrome. At least one case of verified transmission from mother to foetus has been described. HHV-6 is closely related to CMV, which is transmitted from mother to infant in 0.5-2.0 of all pregnancies, most often as a result of reactivation of the virus."
http://www.nature.com/pr/journal/v41/n4s/full/pr19971488a.html
"Respiratory transmission among persons with close contact with one another is the major route of primary infection."
http://www.nature.com/jidsp/journal/v6/n3/full/5640056a.html