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Letter
Hepatitis C Antibodies among
Blood Donors, Senegal, 2001
Jean-François Etard,* Pierre Colbachini,† Jacques-Albert Dromigny,‡
and Jean-David Perrier-Gros-Claude‡
*Institut de Recherche pour le Développement, Dakara, Senegal; †Hôpital
Principal de Dakara, Dakar, Senegal; and ‡Institut Pasteur de Dakar, Dakar,
Senegal
Suggested citation
for this article:
Etard J-F, Colbachini P, Dromigny J-A, Perrier-Gros-Claude, J-D. Hepatitis
C antibodies among blood donors, Senegal, 2001 Emerg Infect Dis [serial
online] 2003 Nov [date cited]. Available from: URL: http://www.cdc.gov/ncidod/EID/vol9no11/03-0191.htm
To the Editor: Prevalence of chronic hepatitis C virus (HCV) among
blood donors has been assessed in a few West African countries; most recent
estimates range from 1.1% to 6.7% (1–4). A recent meta-analysis
of studies, including a confirmation test, yielded an average prevalence
of HCV infection of 3.0% (5). Until 2001, no systematic
screening of HCV infection occurred among blood donors in Senegal, and
blood donation legislation is still pending. We report an assessment of
the proportion of blood donors from the Hôpital Principal de Dakar who
had HCV antibodies in 2001.
Blood donors were all volunteers, recruited independently from the hospitalized
patients and registered in a local donors association. We screened for
risk factors for bloodborne infections in potential donors through a clinical
examination and a confidential questionnaire. Persons with a history of
jaundice or a risk behavior were excluded. Serum samples collected from
blood donors from June to December 2001 were screened for HCV antibodies
by a third-generation enzyme immunoassay (EIA) (HCV Murex 4.0; Abbott
Laboratories, Abbott, IL). Confirmation was performed by a recombinant-immunoblot
assay (INNO-LIA HCV Ab III update; [Innogenetics, Gent, Belgium]). HCV
RNA was detected by a qualitative reverse transcription–polymerase chain
reaction (Roche Amplicor HCV test [Hoffman-LaRoche, Basel, Switzerland]).
Genotype was determined by the INNO-LiPA HCV II assay (Innogenetics).
Presence of hepatitis B surface antigen (HbsAg) and alanine-aminotransferase
(ALAT) level are routinely assessed, as well as HIV and human T-lymphotropic
virus type l infection.
The age of the 1,081 donors ranged from 18 years to 61 years (mean 35.6
years), and 81% were men. First-time donors accounted for 31% and were
younger than repeat donors (mean 30.5 years vs. 37.8 years; p < 10–4).
EIA HCV antibodies were found in 18 donors (1.6%). Immunoblot assay was
positive for nine, yielding an overall prevalence of 0.8% (exact 95% confidence
interval 0.4% to 1.5%). Eight of the nine were repeat donors, but the
difference in prevalence compared with first-time donors did not reach
statistical significance (1.1% vs. 0.3%). HCV-infected donors tended to
be older than uninfected donors (mean 42.3 years vs. 35.5 years, median
46.7 years vs. 34.6 years, Mann-Whitney test p = 0.04), and the trend
with age was significant (18–29 years 0.3%; 30–39 years 0.6%; 40–49 years
1.5%; >50 years 1.8%; chi-square trend = 4.39; p = 0.03). ALAT
levels of infected study participants were in the normal range (17–55
IU). One participant had an ALAT level above normal. Genotype 2ac has
been identified on line immunoassay–positive samples (three samples not
tested). HBsAg was detected in 13% of the new donors. No co-infection
with HCV and hepatitis B virus was found.
The prevalence of HCV antibodies in blood donors in Dakar in 2001 appears
to be one of the lowest in West Africa, close to published estimates for
Mauritania and Benin (1.1% and 1.4%, respectively) and lower than in other
West African countries such as Ghana or Guinea, where prevalence ranges
from 2.8% to 6.7% (1–4). This finding is in keeping with
results of a hospital case-control study on HCV infection and liver cirrhosis
or cancer, conducted in 1995 in Dakar. While that study did not identify
HCV infection in 73 controls, 2 of 73 case-patients (2.7%) had HCV antibodies
(6). Conversely, high HCV prevalence was found in groups
at risk: antibodies were present in 12 of 15 hemodialysis patients, and
HCV RNA was found in 6 of the 12 HVC antibody-positive patients (genotype
2ac, the same as in our study); 7% of a cohort of 58 HIV-1 patients receiving
highly active antiretroviral therapy had a positive HCV serologic result
(7,8).
In the urban setting of Dakar, HCV infection seems still to be confined
to groups at risk. The contribution of HCV to chronic liver diseases has
not been yet demonstrated. Approximately 15,000 blood donations are annually
made in Dakar. A systematic screening of HCV antibodies in blood donors
could prevent, on average, 120 bloodborne HCV infections each year. Given
these data and the price of EIA and LIA, the screening cost per HCV-positive
sample identified, and infection subsequently averted, is approximately
200,300 CFA (U.S.$305). This estimate is low since it includes only the
marginal cost of the reagent kits. This screening cost could be reduced
by discarding blood units that test positive after only one enzyme-linked
immunosorbent assay (156,000 CFA or U.S.$237), at the price of nearly
3% of blood units wrongly discarded. France has demonstrated that this
strategy has the best cost-effectiveness ratio, as long as the prevalence
remains below 8% (9). This cost compares favorably with
the cost per HIV infection averted through improvement of blood safety
(range U.S.$20–U.S.$1,000), assessed in some highly HIV-prevalent southern
African countries (Tanzania, Zambia, Zimbabwe) (10).
The HCV-positive discarded blood units will be added to the blood units
testing positive for hepatitis B surface (13%), HIV, and HTLV, which accounted
for nearly one third of all donations in 2001. These findings argue in
favor of maintaining a roster of regular, seronegative donors to save
numbers of blood units.
Acknowledgments
We thank Penda Ogo
Ly for her technical input.
This study was funded
by Institut de Recherche pour le Développement and Institut Pasteur
de Dakar.
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