Detection of parvovirus B19 and novel human parvoviruses in high-risk individuals

Detection of parvovirus B19 and novel human parvoviruses in high-risk individuals

Ashleigh Manning1, Kate Templeton2, Ed. Gomperts3, Peter Simmonds1,2

1Centre for Infectious Diseases, University of Edinburgh2Specialist Virology Laboratory, Royal Infirmary of Edinburgh

3Hospital for Sick Children, Los Angeles

Human parvovirus infections Human parvovirus B19

Widespread in human populations 3 genotypes, limited genetic heterogeneity Acute, resolving infections, associated with intense

viraemia Recent evidence for long term persistence

Frequent detection in autopsy tissue, despite lack of persistent viraemia

Strong, life-long CTL reactivity to B19 antigens, suggests ongoing low-level replication

Novel human parvoviruses Genome-based Virus discovery Based on molecular methods to detect non-host DNA

or RNA sequences within samples Recent description of novel human parvoviruses

(Allander et al., 2005; Jones et al., 2005)

Novel Parvoviruses in

humans

Parvoviridae Wide range of diverse viruses

infecting mammals Highly host-specific Acute resolving infections Highly transmissible, stable in

environment Human Parvoviruses

Human Erythrovirus (B19) PARV4 (Jones et al., 2005)

Acute infection syndrome Little known about epidemiology

Human Bocavirus (Allander et al., 2005)

Study Aims Human Growth and Development Cohort

NIH-supported prospectively collected cohort Recipients of non-virally inactivated factor VIII and IX

concentrates 6-monthly assessment and sample archiving. Prospectively collected samples for > 10 years Subject to several clinically-based and virological

natural history studies Edinburgh Respiratory Archive

LREC approval for construction of anonymous archives Clinical and epidemiological information recorded,

incapable of identifying specific patient Sample type and month, donor code, age band, location

codes, Supplied clinical information, Results of other diagnostic

tests (viral and bacteriological)

Study Methods PCR-based Parvovirus Detection

Highly conserved region identified in NS Nested PCR with B19, PARV4 and HBoV-specific primers

Calibration and Run Controls NIBSC Run control, calibrated to B19 International

Standard Quantified plasma samples containing PARV4 variant,

PARV5 Cloned, full length pre-quantified HBoV plasmid

All assays detected single copies of target sequence

Virus Screening Nucleic acid extracted by Qiagen MinElute 50 ul effective test volume for plasma

Primers 1000 100 10 1 0.1Neg

PARV4(5) 8/8 16/16 16/16 8/16 1/16 0/8

HBoV 12/12 12/12 12/12 5/12 1/120/25

Haemophilia Screen

Single samples from 59 haemophiliacs Test sensitivity 20 DNA copies / ml All sample negative for B19 and HBoV

Primers Positive Tested Frequency

Parvovirus B19 0 59 0%Human Bocavirus 0 59 0%PARV4/5 2 59 3.4%

Two samples positive for PARV4/5 One haemophiliac HIV+/HCV+, one HCV+ only Relatively high viral load, positive in 1st round Genetic characterisation

One identical to PARV4 over 216 bases One showed 14 substitutions, all synonymous (6.5%)

Respiratory Screen 942 respiratory samples from 589 individuals Human Bocavirus

53 positive from 37 individuals for HBoV Almost invariably non-persistent, short period of excretion Generally confined to infants and young children Three adults with immunosuppression (transplant) showed persistent infections (2 from 3 with multiple samples), high titres

Parvovirus B19 4 positive from 3 individuals for B19 1 persistent infection in an immunosuppressed adult

PARV4/5 All samples negative

HBoV Epidemiology

Closely resembles RSV in epidemiology Peak incidence December/January Infections largely confined to < 2 years of age

Strongly associated with lower respiratory tract infections Frequent HBoV / RSV or adenovirus coinfections

Potential exacerbating role in LRTIs

Specialist Virology Laboratory, Royal

Infirmary of Edinburgh

Kate Templeton

Centre for Infectious Diseases, University of

Edinburgh

Ashleigh ManningPeter Simmonds

Detection of parvovirus B19 and novel human parvoviruses in high-risk individuals

Sick Children’s HospitalLos Angeles

Ed Gomperts

ACKNOWLEDGEMENTS

HGDS CoordinatingGroupSally Baylis

Tobias Allander