Roche Diagnostics Symposium 2014
Current developm ents and challenges in the diagnosis and m anagem ent of congenital CMV infection Vincent Em ery Professor of Translational Virology Friday, 26 September 2014 2
Overview of presentation • Brief summary of congenital CMV infection • Symptomatic • Asymptomatic • Advances in diagnosis • Treatment options • Looking to the future • Benefits of universal screening • vaccines Friday, 26 September 2014 3
Congenital CMV infection • In resource rich settings CMV is: • the commonest non-genetic cause of childhood hearing loss • Important cause of neurodevelopmental delay Boppana et al (2001) NEJM 344, 1366-1371 Friday, 26 September 2014 4
Disability attributable to congenital CMV 6000 5000 Annual 4000 number of affected children in 3000 the USA 2000 1000 0 Reviews in Medical Virology RMV-2013-055.R1, 24 APR 2014 DOI: 10.1002/rmv.1790 http://onlinelibrary.wiley.com/doi/10.1002/rmv.1790/full#rmv1790-fig-0004
Disability attributable to congenital CMV 6000 5000 Annual 4000 number of affected children in 3000 the USA 2000 1000 0 Reviews in Medical Virology RMV-2013-055.R1, 24 APR 2014 DOI: 10.1002/rmv.1790 http://onlinelibrary.wiley.com/doi/10.1002/rmv.1790/full#rmv1790-fig-0004
Causes of Deafness at Birth and at Four Years Morton C, NEJM 354, 2151, 2006.
Congenital CMV infection • In resource rich settings CMV is: • the commonest non-genetic cause of childhood hearing loss • Important cause of neurodevelopmental delay • Primary infection most important risk but…… • Reinfection of seropositive women can lead to intrauterine transmission and congenital disease 1 • 8000 children with neurological disease per year (USA) • Estimated cost in 1990s $1.86 billion per annum (>$300,000 per child) 1 Boppana et al (2001) NEJM 344, 1366-1371 Friday, 26 September 2014 8
Risk of intrauterine transm ission: prim ary infection Friday, 26 September 2014 9
CMV seroprevalence in wom en of reproductive age Congenital infection rates ( ) Friday, 26 September 2014 10
Estim ates of congenital CMV – related disability Annual number of: Australia England and Wales United States (popul n ~ 22m) (popul n ~ 50m) (popul n ~ 307m) Live births 296,000 709,000 4,248,000 Congenital CMV 1,780 4,254 25,488 infections (0.6%) Symptomatic at birth 228 544 3,262 (12.8%) Symptomatic who 114 272 1,631 develop disability (50%) Asymptomatic at 1,552 3,710 22,226 birth (87.2%) Asymptomatic who 210 501 3,001 develop disability (13.5%) Total 324 773 4,632 Cannon et al Rev Med Virology 2014 10.1002/ rmv.1790 Friday, 26 September 2014 11
Congenital CMV in low and high seroprevalence settings Friday, 26 September 2014 12
Resource poor setting: estim ates of congenital CMV infection Parameter South Africa Thailand Annual birth rate 1,000,000 830,000 Antenatal HIV prevalence 30% 0.7% HIV perinatal transmission 3.5% 2.8% rate No of congenital CMV infections HIV unexposed (risk,1%) 700,000 (7,000) 824,190 (8,242) HIV exposed (risk, 3%) 265,000 (7,950) 5,647 (169) HIV infected (risk, 10%) 35,000 (3,500) 163 (16) Total no of congenital CMV 18,450 8,427 infections Manicklal et al Clinical Micro Rev 2013, 26, 86-102 Friday, 26 September 2014 13
Managem ent during pregnancy taken from, Lazzarotto et al 2011
Congenital CMV - outcom e n=1000 CCMV cases
Congenital CMV - outcom e n=1000 CCMV cases 2/3 of children with hearing loss are ‘asymptomatic’ at birth
Diagnosis of congenital CMV (CCMV) • Currently made by CMV positive PCR or culture before day 21 of life • Urine and saliva most common sample received DAY 21 Birth CCMV + + + + + + + + + + + + + + + + + + + + + + + Virus secretion Perinatal - - - - - - - - - - - - - - - - - - - - + + + infection • Differentiating congenital CMV from perinatal is important • perinatal infection much less likely to be associated with disease • Could other samples be used?
CMV load in congenital infection Symptomatic congenital infection CMV titer (log 10 -TCID 50 /0.2 ml urine) 10 6 Asymptomatic Natal infection 10 5 Standard error of the mean 10 4 10 3 10 2 42 Birth 15 24 30 36 12 18 3 6 9 Age (months) Stagno et al (1975) J Infect Dis, 132, 568
Viral load thresholds and disease Griffiths PD. The Lancet Infectious Diseases, Volume 12, Issue 10, 2012, 790 - 798
Dried blood spots (DBS) • DBS are routinely collected for neonatal screening for metabolic and hereditary diseases • Heel prick taken in the first few days of life is used • Cards are stored for up to 18 years depending on the Health Authority
CCMV: Diagnosis using DBS DAY 21 DBS taken day 5-8 Birth CCMV + + + + + + + + + + + + + + + + + + + + + + + Virus secretion Perinatal - - - - - - - - - - - - - - - - - - - - + + + infection • Dried blood spots (DBS) taken on every child born in the UK
Why diagnose congenital CMV? • To retrospectively diagnose CCMV in asymptomatic infants • Allows follow up and early intervention • Early intervention minimises the impact of SNHL on language and social development • Recruitment to cochlear implant programme • Treatment: ganciclovir reduces hearing deterioration and CNS involvement in symptomatic CCMV
Dried Blood Spot testing 1/2 Dried Blood Spot cut from card Nucleic acid extracted • Real Time PCR for CMV, gB target. • Positive result confirmed with 2 nd RT PCR for different region of CMV (UL69) • Normalised against beta- globin gene
Screening algorithm - retrospective diagnosis with DBS • Screening algorithm for retrospective diagnosis of CCMV in children with SNHL Child With SNHL (Consider testing mother for HCMV IgG if negative exclude CCMV ) <1 year old Urine/ Saliva x2 Urine / Urine or saliva saliva negative positive exclude CCMV Obtain parent ’ s written permission to test DBS DBS HCMV DNA detected: Consistent with congenital HCMV
Screening algorihm - retrospective diagnosis with DBS • Screening algorithm for retrospective diagnosis of CCMV in children with SNHL Child With SNHL (Consider testing mother for HCMV IgG if negative exclude CCMV ) <1 year old >1 year old urine/Saliva Urine/ Saliva x2 (+/ - HCMV IgG ) Urine /saliva Urine / Urine or Urine, saliva negative saliva saliva or IgG negative positive positive exclude IgG CCMV IgG negative positive exclude CCMV Obtain parent’s written permission to test DBS DBS HCMV DNA detected: DBS HCMV DNA not Consistent with congenital detected: SNHL unlikely HCMV to be caused by HCMV
Is there potential for national screening? • Sensitivity of assay found to be ~70% • Not all CCMV babies are born viremic • However viremic babies may be at higher risk of developing disease • Screening would identify these individuals • Ganciclovir reduces hearing deterioration and CNS involvement in infants with symptomatic CCMV • Potential harms must be investigated – 80% of children with CCMV do not develop disease • BEST Study (stopped recruiting Nov 2012, 400 infants tested, currently in data analysis)
To Screen or not? Paul D Griffiths Burden of disease associated with human cytomegalovirus and prospects for elimination by universal immunisation The Lancet Infectious Diseases, Volume 12, Issue 10, 2012, 790 - 798 http://dx.doi.org/10.1016/S1473-3099(12)70197-4
DBS vs saliva testing for CCMV • 20,448 babies screened using both methods • CCMV confirmed in 92 infants (0.45%) • DBS sensitivity found to be poor compared to saliva (34%) • Other groups show much better sensitivity in CCMV cohorts • Barbi et al 100% (nested PCR) • Could nested PCR be adapted for screening to improve assay sensitivity? Boppana et al, JAMA, 2010 April 14 :(1375-82)
Saliva for screening newborns Boppana SB et al. N Engl J Med 2011;364:2111-2118.
Boppana SB et al. N Engl J Med 20 11;36 4:2111-2118 . • Real-Tim e Polym erase-Chain-Reaction (PCR) Assays of Liquid- and Dried- Saliva Specim ens, vs. Rapid Culture, in 5276 Newborns Who Underwent All Three Assays Used to Screen for Congenital Cytom egalovirus Infection. Boppana SB et al. N Engl J Med 2011;364:2111-2118.
Perform ance of the saliva assay Boppana SB et al. N Engl J Med 2011;364:2111-2118.
Why DBS for CCMV? • Established sample collection route on every child in the UK • Only sample taken at correct time point • Cost and logistics of setting up a additional sample collection • Can we improve current methods…......... • A novel single tube nested PCR for enhanced detection of HCMV from dried blood spots developed 1 1. Atkinson, Emery and Griffiths (2014) J Virol Methods 196:40-44
Evaluation a nested PCR approach DBS Samples • 3 clinical DBS cohorts were tested • The Quality Control Molecular Diagnostic (QCMD) 2011 CMV DBS panel • 20 DBS samples from newborns with CCMV infection obtained from an earlier published study (17th BPSU Annual Report 2002). • DBS samples received as part of an ethically approved study (Benefits of Extended Screening Testing (BEST Study) from 6 children who failed their newborn hearing screen and were proven to have CCMV 1 1. Williams, Kadambari et al., 2014
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