Rob C
2007-09-26 08:09:57 UTC
DETECTION OF HIV-1 INFECTION IN BLOOD DONORS DURING THE
IMMUNOLOGICAL WINDOW PERIOD BY THE IMPLEMENTATION OF
NUCLEIC ACID AMPLIFICATION TECHNOLOGY (P-018)
P.S.P. Scuracchio1, A.G. Oliveira Filho2, M.M.M. Lemos2, M.C.C. Poli2, R. Colella2, M.M.C. Magri3,
N.J.F. Cavalcanti3, E.C. Sabino4, N.A. Salles4, D.A.F. Chamone5
1 Banco de Sangue de Sao Paulo, Sao Paulo, Brazil
2 Banco de Sangue de Sao Paulo, Sao Paulo, Brazil
3 Centro de Referencia e Treinamento AIDS, Sao Paulo, Brazil
4 Fundaçao Pró-Sangue Hemocentro de Sao Pa, Sao Paulo, Brazil
5 Universidade de Sao Paulo, Sao Paulo, Brazil
Background: Individual Nucleic Acid-Amplification Testing (NAT) has been recently introduced in blood banks
in the city of São Paulo, Brazil, in attempts to reduce the transfusion transmission risk of HIV and Hepatitis C
viruses. This screening test can identify donations made during the immunological window period before
seroconversion.
Aims: To investigate the impact of this technology in our blood donors and transfusion routine.
Methods: From March 2004 to November 2005, when the NAT testing has been implanted, 64,248 donations
were tested using two approved enzyme immunoassays (EIA) for HIV antibodies (Abbott Murex and Biomérieux),
although 47,866 were also tested for individual NAT (Procleix by Chiron Healthcare). Confirmatory tests: Western
blot (Genelabs Diagnostics), p24 antigen (Vironostica) and quantitative PCR-HIV-1 (Roche).
Results: Among the samples screened, two were non-reactive in enzyme immunoassays but positive for HIV-1
RNA with negative confirmatory p24 antigen, as described: Donor A, male, 34 years old, married, was a repeat
donor with a previous blood donation on 06/21/04. After the results of the index donation on 11/17/05, he was
recalled to collect a new blood sample in order to confirm the HIV-1 positivity. The sample was collected 25 days
after the index donation and confirmatory tests showed quantitative PCR-HIV 16,800 cp/ml, reactive antibody
detection and negative p24 antigen. During interview with the infectious diseases specialist, the donor admitted,
between the two donations, many occasions of male homosexual intercourse without using a protective. Two
weeks before the index donation, he had low grade fever, sore throat, myalgia and malaise. Donor B, male, 30
years old, single, first time donor on 10/01/05. Four days after the blood donation, a new sample was collected
remaining serological tests non-reactive, negative p24 antigen and quantitative PCR-HIV showing 122.000 cp/ml.
The donor developed fever and diffuse body pain one week after the donation. He was recalled many times for
counselling and testing. Unfortunately, he has never returned again.
Conclusions: Although serologic analysis for HIV is a primary tool for diagnostic testing, the introduction of
NAT has made possible the identification and preventing of transfusion of two HIV-positive blood donations in a
18 months period. Interesting to note that while the prevalence of HCV is higher than HIV, in Brazil HIV incident
cases are more common than HCV using NAT technology. The screening of donors reduced the immunological
window period, permitting the identification of very early stage HIV infections. In addition, these case reports
emphasized the fact that the risk of HIV transmission is not limited to the first time donors.