Mediaboss Marketing

London, Sept 20 : Many of us are infected with a virus we'll never clear. While we're healthy, it's nothing to worry about, but when our immune system is suppressed it could kill us.

To catch the herpes virus human cytomegalovirus (HCMV) you must be exposed to someone who has it. This isn't difficult: it is carried by around 65% of the population.

Once in the body, HCMV persists for life owing to its clever ability to avoid our immune system and to go into hiding inside our cells in a latent state. Now, research is identifying changes in these cells that could lead to a new route to eradicating the virus.

"HCMV can be acquired very early in childhood, and the number of people infected gradually rises throughout life," said Professor John Sinclair, a molecular virologist in the Department of Medicine, University of Cambridge.

"The active virus can not only be passed from an infected mother to her child in breast milk but can easily be transferred from child to child in saliva - one child puts a toy in their mouth, then it's passed to another child who does the same, and the virus is passed on.

"It's also a sexually transmitted disease, so there's another increase in infections when people become sexually mature."

Once acquired, the virus goes into a latent state in the body. If it reactivates in healthy people, their immune responses prevent it from causing disease. But when the immune system is suppressed, active HCMV becomes dangerous.

It is a major cause of illness and death in organ and bone marrow transplant patients, who are given drugs to deliberately suppress their immune system and prevent their body rejecting the transplant. With an increasing demand for transplants in the UK, HCMV is set to become a growing problem.

"If it's not treated well, or it develops resistance to antiviral drugs, HCMV can lead to pneumonitis - inflammation of the lung tissue - and, in the most extreme case, it replicates all over the body and the patient ends up with multiple organ failure," said Dr Mark Wills, a viral immunologist working alongside Sinclair in the Department of Medicine.

"Tissue from donors carrying the virus often has to be used for transplants because there are so few donors and so many people carrying the virus," said Sinclair. "By transplanting bone marrow, or an organ from someone with the infection, you're giving the patient the virus and you're immune-suppressing them. That's the worst of both worlds."

See the article here:
65% population carries 'silent killer' virus: Study