LAUSR

The ink was barely dry on my editorial for the previous issue of Reviews in Medical Virology than another piece of information was published that is relevant to screening for congenital CMV infection. Gantt and colleagues have calculated the potential cost effectiveness of screening in the USA, divided into two major parts: selective testing of those neonates who fail national screening programmes for hearing loss; universal screening of all newborns. To begin with, they estimated the costs associated with congenital CMV, based on the known natural history. A strength of their article is that they used the costs accepted by Medicare when reimbursing current expenditure. They allowed $10 per PCR test, one ophthalmology examination and cranial ultrasound in all neonates with congenital CMV with an estimate that 20% would require an MRI scan in addition. A course of valganciclovir would be given to those born with symptoms, so they included the cost of the drug plus monitoring for neutropenia. Audiology assessments would be performed every 6 months to the age of 6 years, and they assumed that 50% of babies with bilateral, severe sensorineural hearing loss would need cochlear implants. They did not include administrative costs for running the programme, assuming that the current system could cope. They next looked at the monetary value of benefits that would accrue to society through screening, broken into two broad categories. First, it is well known that the young brain develops according to the stimuli it receives. This means that neonates who are profoundly deaf will have underdeveloped speech receptive areas so that, even if their perception of sound is subsequently improved through cochlear implantation, the brain will have impaired ability to process the signals received. Compensation for early diagnosis of hearing loss of any cause leads to a 24% improvement in scores for language, so this is the figure they used in the calculations of benefits for CMV. For those children whose hearing is intact at birth but subsequently deteriorates, an estimate of a 12% improvement in language was used. Second, they estimated the benefits attributable to treatment with ganciclovir or its prodrug valganciclovir. Two randomised controlled trials provide evidence; 6 weeks of intravenous ganciclovir compared to controls randomised to no treatment, which led to a 6‐week course of this drug being adopted as the standard of care. A later study gave valganciclovir for 6 weeks to all followed by valganciclovir or placebo to complete 6 months of therapy. The longer course provided a better clinical outcome with significantly improved hearing measured 12 months and 24 months after study entry and so is now the standard of care for neonates born with symptoms. Because the clinical progression of sensorineural hearing loss caused by CMV fluctuates with time, Gantt and colleagues subtracted the improvements seen in the control