Hepatitis C seroprevalence in accepted versus deferred blood-donor candidates evaluated by medical history and self-exclusion form.
BACKGROUND
Hepatitis C virus (HCV) represents a viral pandemic that is five times as widespread as human immunodeficiency virus. Blood transfusion posed a major risk of HCV infection in developed countries before 1990, but the introduction of improved blood-screening measures has decreased the risk of transfusion-associated HCV infection, which may now be even lower since the introduction of screening of pooled samples by nucleic acid testing (NAT). Unfortunately, NAT is not affordable in most developing countries. The goal of this work is to assess the usefulness of both screening measures, the medical history, and the self-exclusion form to distinguish between high-risk and low-risk populations of HCV-carrier blood-donor candidates in Mexico.


METHODS
From February 2002 to April 2003, 4174 consecutive candidates were enrolled in a prospective, nonrandomized and comparative study. In total, 4158 candidates were included in the analysis and divided in two groups: Group A consisted of 3101 accepted donors and Group B consisted of 1057 deferred donors according to a complete medical history and self-exclusion form. The only exclusion criteria was the lack of a signed consent form to enter the study. All candidates from both groups underwent anti-HCV detection by third-generation enzyme immunoassay (EIA). Those who had either a positive or gray-zone signal-to-cutoff ratio underwent polymerase chain reaction and a second EIA test. If the second EIA test resulted in either a positive or gray-zone signal-to-cutoff ratio, a recombinant immunoblot assay test was performed. The chi-square test was used for statistical analysis, and a p value less than 0.05 was considered significant.


RESULTS
Anti-HCV prevalence by the EIA method was as follows: 0.61 percent for Group A and 1.32 percent for Group B (p = 0.0243); whereas with recombinant immunoblot assay the prevalence was 0.19 percent for Group A and 0.47 percent for Group B (p = 0.1265). When we analyzed the polymerase chain reaction test results, the prevalence in Group A was 0.10 percent (95% confidence interval, 0.089-0.110) and in Group B was 0.47 percent (95% confidence interval, 0.439-0.500) (p = 0.0159).


CONCLUSIONS
The medical history of blood donors in conjunction with serologic screening tests helps to improve blood transfusion safety. This measure is recommended in blood banks of those countries where NAT is still unaffordable.
National Center for Blood Transfusion, Mexico City, Mexico.
Rafael Antonio Marín y
RA
López
Sagrario
S
Romero-Estrella
Lilia
L
Infante-Ramírez
Jorge Saúl
JS
Méndez-Aquino
Patricia
P
Berrón-Ruiz
Norma Angélica
NA
Morales-Alfaro
Raúl
R
Vivar
Etelvina
E
Carrada
María del Refugio
Mdel R
Rivera-Rendón
Sergio Arturo
SA
Sánchez-Guerrero
D000328:Adult; D001782:Blood Donors / Q000523:psychology; D004279:DNA, Viral / Q000097:blood; D005260:Female; D006526:Hepatitis C / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D015151:Immunoblotting; D007124:Immunoenzyme Techniques; D007258:Informed Consent; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008499:Medical Records; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012650:Self Disclosure; D016036:Seroepidemiologic Studies; D011795:Surveys and Questionnaires; D014766:Viremia / Q000175:diagnosis / Q000453:epidemiology
D004279:DNA, Viral