Tatjana Tallo1,2, Valentina Tefanova1, Tatjana Plahhova3, Tatiana Kuznetsova1, Ljudmilla Priimägi1, Helene Norder2

1 - National Institute for Health Development, Tallinn, Estonia2 - Swedish Institute for Communicable Disease Control, Stockholm, Sweden

3 - North Estonia Medical Centre Blood Centre, Tallinn, Estonia

valentina.tefanova@tai.ee

 

HCV SUBTYPES DISTRIBUTION IN ESTONIAN BLOOD DONORS, 2007-2009

 

10th ANNUAL CONFERENCE OF NEW VISBY NETWORK ON HEPATITIS C RIGA, FEBRUARY 10-12, 2013

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

0

50

100

150

200

250

300

350

400

17 24

The number of acute hepatitis C cases in Estonia, 1993–2012

HC

V re

port

ed c

ases

, abs

367

Introduction of HCV registration

Increasing nr of IDUs

HAV outbreak

HIV epidemic

PegIFN + ribavirin treatment

Data source: Health BoardAdopted: Dept of Virology, NIHD

Chronic HCV infection, Estonia, 2004-2011

2004 2005 2006 2007 2008 2009 2010 2011

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100% Acute viral hepatitis

Chronic HCV

Chronic HBV

Data source: Health BoardCVH became a notifiable since 1998From 2004 – according to etiology

years

years

I

ncid

ence

per

100

000

pop

ulat

ion

2010 – 246 cases2011 – 190 cases

14.2

18.4

Up to now, the quality of donor’s blood is an issue of high importance.

The safety of the blood supply can be estimated by monitoring the prevalence of viral markers in the blood donor’s population.

The other approach to increase quality of donor’s blood is to improve the quality of blood donors and one of the solutions is the replacement of paid blood donation with free blood donation system.

WHO goal: Towards 100% voluntary non-remunerated blood donation by 2020

Blood donation in Estonia, 1998-2009Paid blood donation: before 1998Transitional period: from 1998 to 2004

• From 1998 – only Rh-neg (3.3-4.0%) apheresis donors were paid• From 2002 – only plasmapheresis donors (1.8-2.0%) remained paid • From 2004 – all blood donations became free

1999

2001

2003

2005

2007

2009

0

5000

10000

15000

20000

25000

30000

35000

DonationsDonorsFirst time donorsRepeated donors

- 340551

- 204559

- 57663

- 146896

Data source: North Estonia Medical Centre Blood CentreAdopted: Dept of Virology, NIHD

  

The total number of blood donors, donations, and the number of repeated donors increased, respectively, in 1.2, 1.1 and 1.4 timesThe ratio between males and females remained similar: M:F=0.9 in average

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Anti-HCV prevalence in blood donors, Estonia, 1995-2009

North Estonia Medical Centre Blood CentreAdopted: Dept of Virology, NIHD

Introduction of free donation

%

HCV RNA

Lack of data

1997-2001 = 0.80%

2002-2006 =0.34%

<0.1%

transitional period

No recent data has been reported on molecular epidemiology of HCV in Estonian blood donors

The study objectives

To investigate the distribution of HCV genotypes in anti-HCV positive blood donors diagnosed in 2007 to 2009

To compare the relative HCV genotypes distribution in blood donors before and after introduction of free donation

To determine genetic relatedness of isolates from Estonian blood donors with isolates from previously studied population groups in Estonia and other parts of the world

Material and methods

• 61 serum samples (47%) collected from 131 anti-HCV positive blood donors

during 2007-2009 at North Estonia Medical Centre Blood Centre, Tallinn, were used as a source of HCV RNA

• Sex distribution: 36 males, 25 females

• Mean age: 31.5±10.2 years; range: 18-57 years

• Detection of serum HCV RNA has been performed by PCR forwarded to the 5’-UTR region

• The HCV subtypes were determined by amplification sequencing within NS5B region and phylogenetic analysis

2k/1b 1,0%1a 1,0%

3a 21,4%

1b 76,7%

HCV studied population, n=103

HCV molecular epidemiology in Estonia, 1994-2004

T.Tallo, JMV, 2007

First 2k/1b recombinant strain outside Russia

Study population:• Infectious disease clinics, pts;• Hemodialysis pts;• Oncohematology pts (chidrens);• Health Care Workers

Similarity: mainly with strains from St.-Petersburg, Siberia and Uzbekistan

1b 69,1% 1a 5,5%

3a 20%

2a 3,6%2c 1,8%

Blood donors, n=61 (2007-2009)

Results: HCV subtypes distribution

All 1a subjects were isolated from first-time donors, males, mean age 28 yrs, from Tallinn

3a 24,6%

1b 68.2%

2a 1,5%2c 4,6%

Blood donors, n=100 (1998-2004)

Mean age 28yrs ; 69% males

85% - first time donors

Mean age 31.5yrs; 59% males

88% - first time donors

1b, 3a, 2a and 2c strains were intermixed with previously published Estonian strains and were similar to strains from Siberia and St.-Petersburg area

T.Tallo, JMV, 2007

Results: Phylogenetic analysis

1b, 3a, 2a and 2c strains were intermixed with previously published Estonian strains sharing, in general, similarity with strains from St.Petersburg and Siberia.

Three 1a starins have been found in 2 different clades: Two strains isolated from blood donors in 2007 were similar to strains from USA and Germany.

One strain obtained from blood donor in 2009 was similar to strains from Portugal.

1a strain from our previous study isolated from HCV patients with unknown risk factor in 2001 was similar to strains from St. Petersburg.

 

Conclusions

Subtype 1b is still the most prevalent HCV subtype found in Estonian blood donors.

The relative distribution of HCV subtypes in blood donors before and after the introduction of free donation was similar; two separate introduction of 1a HCV strains have been observed in Estonian blood donor’s population during study period.

Changes of the HCV subtype distribution in the Estonian blood donors reflected recent changes in relative distribution of the HCV subtypes in the Estonian IDUs reported previously.

We suggest that blood donors can be used as a representative part of “a general population” for study on HCV Molecular epidemiology in Estonia.

Acknowledgment

Health Board (former Health Protection Inspectorate) Jevgenia Epshtein, Chief Specialist, epidemiologist

National Institute for Health Development, Department of VirologyIrina Reshetnjak, scientist

Study was supported by grants from Swedish Institute, nr. 01348/2007 and nr. 00747/2010.

Thank you for attention!