Search

A self-deferral form has been used to screen Chiang Mai University Hospital blood donors and was improved in 2005. It has never been evaluated. The study aimed to assess the self-deferral form procedures in detecting infected donors. Sera from 5,083 donors, who passed the self-deferral screening form, were tested with the routine immuno-assays (serology) for HIV 1 and 2 antibodies, P24 antigen, HCV antibodies, HBV surface antigen, and syphilis. Antibody negative sera were also tested individually with the the Procleix Ultrio Assay for HIV-1 DNA, HCV RNA, and HBV DNA. The donors who had discrepant results between serology and NAT were evaluated with additional tests, including a more sensitive Alternative Nucleic Acid Test, AntiBcore IgM, AntiBcore IgG, HBsAg and Anti HBs. Among 5,083 donors, 331 (6.5%) had at least one positive marker. In multiple logistic regression analysis, the statistically significant factors (adjusted odds ratio and 95% CI) for infection were age 30 years or below [1.45 (1.03, 2.03)], male gender [2.73 (1.64, 4.56)], primary school or lower education [1.56 (1.09, 2.23)], first-time donation [1.82 (1.25, 2.67)], and frequent donation [0.80 (0.70, 0.92)]. The safest donors were females, older than 30 years, with an education more than primary school, and frequent donation. Because of missing responses to some sensitive questions, there remains a need for further improvement of the self-deferral form.

Background: Qualitative HIV-1 proviral DNA PCR tests have three main diagnostic applications. These include direct detection of viral sequences in the pre-seroconversion window period which may be positive up to 8 days prior to the development of HIV specific antibodies; resolution of indeterminate HIV serological tests and in the diagnosis of neonates born to seropositive mothers where maternal antibodies may be detectable for up to 15 months past partum., Methods: A total of three serial specimens from a single patient following symptomatic primary HIV-1 infection were assessed by commercially available serological assays for antibodies to HIV and HIV-1 antigen and nucleic acid amplification assays for proviral DNA (Amplicor HIV-1 test, Roche Molecular Systems, CA, USA) and RNA (HIV MONITOR ver1.5, Roche Molecular Systems) according to manufacturers recommendations. A subsequent modified PCR protocol for HIV proviral DNA was performed which included modified primers (SK145/SKCC1B) and altered thermal cycling parameters., Results: We describe a case of HIV infection acquired in Thailand by heterosexual transmission, where a commercially available HIV proviral DNA PCR assay remained negative despite a typical evolving serological profile consistent with seroconversion., Conclusion: These data support the use of HIV DNA PCR tests only as a second line supplemental test to licensed standard HIV diagnostic testing strategies, and should be used with care in cases where non-B subtype infection is a possibility., (Copyright 2002 Elsevier Science B.V.)

The antibody patterns of HIV-1 IgG3, IgG and IgA and of HIV-1 p24 antigen were investigated in Thai infants born to mothers infected with HIV-1. In the 17 HIV-1 infected infants, anti-HIV antibodies were detected continuously over a period of 15-18 months and a high level of specific IgG3 subclass was observed. Anti-HIV IgA could be detected at 6 months of age whereas p24Ag was detected at 2 months. In 79 uninfected infants, maternal anti-HIV IgG gradually decreased over 9 months whilst specific IgG3 decayed rapidly during the first 6 months. Both p24Ag and anti-HIV IgA were not found in these uninfected infants. Thus, the disappearance of anti-IgG3 subclass antibodies within 6 months can predict whether infants are uninfected whereas the persistence of anti-HIV IgG and IgG3 subclass antibodies, the production of anti-HIV IgA antibody and the presence of p24Ag appear as an adjunct to the diagnosis of HIV vertical transmission. The necessary assays are relatively simple and could be performed individually.

Background: A major epidemic of human immunodeficiency virus type 1 (HIV-1) infections that are primarily due to heterosexual transmission has developed in Thailand since 1988. The epidemic has been most severe in northern Thailand. The blood banks in Chiang Mai began screening donors for HIV-1 antibodies in February 1988 and for p24 antigen in April 1992., Study Design and Methods: The trends of HIV-1 antibody prevalence were analyzed by type of donor (i.e., paid, replacement, and voluntary) for the period of 1988 through 1993. In addition, the prevalence of HIV-1 p24 antigen and of antibodies to syphilis, hepatitis B surface antigen, and hepatitis C virus was evaluated among blood donors at Chiang Mai University Hospital and the Thai Red Cross blood banks in Chiang Mai., Results: The prevalence of HIV-1 antibodies increased from 0.84 percent in 1988 to 4.04 percent in 1991. Seropositivity was highest in paid professional donors. After discontinuation of the use of paid donors in 1993, HIV-1 antibody prevalence decreased to 3.34 percent. Antibody prevalence in replacement donors increased from 0.56 percent in 1988 to 5.82 percent in 1991. Among 44,446 donors tested, 7 (0.016%) were HIV-1 p24 antigen positive but antibody negative., Conclusion: The exclusion of paid donors and the use of p24 antigen testing are justified in northern Thailand. Additional strategies to exclude donors at very high risk and to attract those at low risk for infection should be developed and evaluated to increase blood transfusion safety in this and other, similar populations.