Maternofetal transmission of human parvovirus B19 genotype 3

in Ghana, West Africa

D Candotti, K Danso, A Parsyan, A Dompreh, J-P Allain

National Blood Service, England

Div. Transfusion Medicine, University of Cambridge, UK

Dept. Obstetrics & Gynaecology and Dept. Microbiology, Komfo Anokye

Teaching Hospital, Kumasi, Ghana

B19 infection in Ghana

• 82% seroprevalence in adults

• B19 DNA prevalence:- 1.3% in blood donors- 11.5% in children (average age: 23 months)

• 0.9% persistent infections:- IgG only- low viral load ( 102- 105 IU/ml)

• Endemic region for B19 genotype 3

Phylogenetic tree of full length human parvovirus B19 genomes

0.005 substitutions/site

Genotype 2

Genotype 1

Genotype 3

3A

3B

100

100

100

100

100V9

D91.1

Study design

Pregnant women plasmas(n=885)

B19 DNA screeningMultiplex QPCR assay

Single QPCR & nested PCR confirmation

Specific QPCR & nested PCR

Cord blood plasmasNewborn whole blood

Anti-VP2 IgG

SequencingGenotyping

Serological and viral markers in pregnant women

Anti-VP2 IgG reactive 144/177 (81%)

Confirmed DNA pos. 16/885(1.8%)

DNA load (IU/ml) Median Range

1.3E+0346 - 3.6E+06

IgM reactiveIgG reactive

3/1616/16

Maternofetal transmission

19642005

16551956177419412246202921061818219614472409224221431577

Mother Cord blood Newborn

Viral load(IU/ml)

IgMtiter

IgGtiter

Viral load(IU/ml)

IgMtiter

Viral load(IU/ml)

SampleID

Type

1.1E+041.2E+06

3.6E+065.9E+034.2E+032.1E+031.5E+031.3E+031.2E+031.1E+036.5E+025.6E+023.3E+025.8E+014.6E+014.6E+01

1:10001:1000

1:100<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10

1:10001:1000

1:1000001:10000

1:10001:10000

1:1001:10001:10001:100

1:10001:10001:10001:10001:1001:100

1.1E+032.1E+06

00000000000000

<1:101:1000

<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10<1:10

1.7E+03-

0-------0-0---

33

33333133333333

Conclusions

• B19 genotype 3 is dominant in Ghana and is characterised by high genetic variability

• 2/3 cases of primary maternal B19 infection resulted in vertical transmission

• No evidence that maternal persistent B19 is vertically infectious

Acknowledgements

Pr J.-P. AllainDr A. Parsyan

Div. of Transfusion MedicineUniversity of Cambridge

Cambridge, UK

Dr K. DansoDept. of Obstetrics & GynaecologyKomfo Anokye Teaching Hospital

Kumasi, Ghana

Mr A. DomprehSerology laboratory

Dept. of MicrobiologyKomfo Anokye Teaching Hospital

Kumasi, Ghana

Mr C HornPlasmacute

Norway

National Blood ServiceEngland