Title: Development of a rapid, low cost Human Cytomegalovirus diagnostic
Funder: Department of Health and Social Care

Abstract: Human Cytomegalovirus (HCMV) causes substantial morbidity and mortality in transplant patients, and following congenital infection. Indeed, HCMV is the most common viral cause of congenital malformation. Infection can be lethal, or can result in major sequelae such as profound deficits in hearing, vision and mental capacity. Such infection occurs in around 5,000 babies every year in the UK, with a similar scale of problem worldwide. There is a major cost to healthcare systems of caring for these children, averaging >&pound;250,000 per child per year. There are also significant societal costs due to the impact of these disabilities. These burdens place HCMV as a vaccine candidate of highest priority, yet none is licensed. In the absence of a vaccine, multiple interventions can be effective following congenital infection. Antivirals can reduce disease severity, while behavioural and surgical interventions can have a major impact on symptoms. E.g. hearing loss is common, yet cochlear implants and speech therapy can result in learning outcomes comparable with unaffected peers. However, these benefits are only achieved if interventions are put in place early after infection. HCMV poses a unique problem, because >50% of neonates who go onto develop long-term sequelae will be asymptomatic at birth. A HCMV diagnosis may never be made, or may be significantly delayed. Thus the chance for treatment is missed, long-term clinical outcomes are worse, and the cost to healthcare systems is higher. The solution is to screen all newborns for HCMV, which is highly cost effective. However a lack of a suitable diagnostic has hampered its introduction. Diagnosis is currently performed by qPCR, but this too expensive and time-consuming to be used for screening. To address this significant unmet need, we developed a prototype low-cost, easy-to-use, label-free electrochemical impedimetric nanobiosensor for the direct quantitative detection of HCMV in clinical samples, via a previous i4i NIHR PDA. This device would significantly reduce the cost of routine diagnosis, while also enabling large-scale screening, along with the healthcare benefits and cost savings that this entails. The current proposal moves this device significantly closer to commercialisation and clinical uptake: The device was developed against urine since this is the current diagnostic standard, however testing of saliva is becoming the preferred option for population-level screening. We will therefore optimise the device against saliva, and use photonic annealing and antibody fragmentation to enhance sensitivity. Sensitivity and specificity of the device will be established using a cohort of clinical neonatal saliva samples. In addition to screening newborns, the device will also have a significant impact in the transplant setting. Here, treatment can be optimised by stratifying based on viral load, yet this is only possibly in large centres. The device will enable this stratification to be introduced to a wider range of centres. We will therefore determine sensitivity and specificity in this setting, compared to current standards of care. A prototype diagnostic kit suitable for clinical use will be developed. Analysis of the routes to healthcare adoption, and the economics of screening using the proposed device, will be performed.

Lay abstract: Cytomegalovirus (CMV) is a member of the herpes virus family and is spread through contact with saliva, blood, breast milk, semen and urine. Most adults will be infected by CMV during their life. Healthy individuals rarely show symptoms, however CMV can result in serious health complications and even death for those with weak immune systems, such as transplant recipients. CMV is also the leading viral cause of disease if it infects the fetus during pregnancy. This can cause permanent disabilities such as learning difficulties, blindness, deafness, or even death. Such infections occur in over 5,000 babies per year in the UK. However, many babies show no signs of disease at birth, with problems only appearing months or years later. As a result, diagnosis and treatment is delayed, leading to significantly worse outcomes for the patient, and greater overall cost to both the healthcare system and society. This problem could be addressed by screening all newborns for CMV infection, allowing early detection and treatment. Screening is already in place for diseases that are less common than CMV, such as Down syndrome. However, it has not been possible for HCMV due to the lack of a suitable diagnostic device. This project will develop a low-cost, easy-to-use diagnostic device that can rapidly detect CMV in saliva and urine with no sample processing. The proposal builds on a previously funded i4i project, where we developed a prototype device that successfully measured CMV in urine. The current project uses novel engineering techniques to improve detection of very low virus concentrations. Secondly, the existing device detected virus in urine, since urine is currently used for diagnosis. However, saliva is preferred for screening programs. The virus is present in saliva, we will therefore adapt the device to detect virus in saliva, before developing a complete commercial package, suitable for use by healthcare workers. Finally, this device will undergo extensive testing on saliva and urine from newborns and transplant recipients, to compare performance against current diagnostics. In parallel with laboratory development and clinical testing, a comprehensive plan for adoption of the device into the NHS will be produced. Ultimately this device will offer a cheaper, simpler and quicker diagnostic test, providing significant cost-savings to the NHS whilst improving the clinical management of CMV infection of both adults and newborns. It will also enable large scale routine screening of newborns, identifying babies at risk of future problems. In turn, this offers the opportunity to begin treatment earlier, which reduces the long-term impacts of the disease. Furthermore, the development of this technology platform will provide the basis for future sensors that can detect multiple diseases simultaneously.

Research activity codes: 4.2 EVALUATION OF MARKERS AND TECHNOLOGIES;4.1 DISCOVERY AND PRECLINICAL TESTING OF MARKERS AND TECHNOLOGIES
Health categories: INFECTION