Tracking the stealth virus: diagnosis and treatment of CMV infection

Basic and translational research undertaken since 1993 by UCL Virology has defined the natural history and pathogenesis of cytomegalovirus (CMV) infection and disease. Rapid diagnosis and pre-emptive therapy are now available worldwide for this important infection, and a national reference service provided for strains of CMV resistant to current antiviral drugs and for diagnosis of congenital CMV infection.

CMV is a very common virus that affects over 60% of the world's population. In healthy individuals it usually goes unnoticed because the body's lymphocytes keep the virus under control. However it can be fatal for some groups, particularly those with weakened immune systems such as organ transplant recipients, people with HIV and unborn babies. It is the most frequent cause of intra-uterine infection, and causes permanent disability in 1-2 live births per thousand. It is also the commonest infectious agent to affect transplant patients, and is implicated in causing death in other at-risk populations, in particular elderly patients and those with HIV infection.

Research led by Professor Paul Griffiths (UCL Virology) developed assays to measure CMV DNA in infected humans. These have been licensed to Public Health England and allow rapid diagnosis of CMV viral load and inform the initiation of pre-emptive therapy in transplant patients.

During my professional working life it has been a privilege to help take CMV from a poorly understood virus that frequently killed transplant patients to one that is now routinely controlled through rapid diagnosis and early treatment. Having got rid of most disease caused by this virus, the next stage of our research is to get rid of the virus itself through universal immunisation using prototype vaccines which are currently undergoing evaluation. - Professor Paul Griffiths

Further work has developed tests of dried blood spots collected routinely at birth which are now used to provide a national service for retrospective diagnosis of congenital CMV infection when children present with sensorineural hearing loss or developmental delay.

Thousands of both of these tests have now been carried out across the UK, and the tests are recommended in guidelines on both transplant and hearing loss.

The work has also stimulated investment by several pharmaceutical companies in prototype CMV vaccines which are currently entering clinical trials. The research provided much of the scientific basis for its current control by means of antiviral therapy and what is hoped will be its ultimate elimination by means of routine immunisation.

Major funders were the Wellcome Trust and the National Institutes of Health (USA).

Related links

• CMV Action
• AHSC Immunology and Transplantation Programme
• The Stealth Virus, by Professor Paul Griffiths