Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest are simple/rapid tests for the detection of antibodies to HIV-1 and HIV-2 in human whole blood, serum and plasma samples. The assay is one step and the result is read visually within 15 minutes. Using 92 known HIV-1 reactive sera and 108 known HIV-1 negative sera, the 3 HIV tests correctly identified all the known HIV-1 reactive and negative samples. The results indicated that Determine HIV-1/2, Chembio HIV-1/2 STAT-PAK and PenTest HIV are as sensitive and specific (100% concordance) as Microparticle Enzyme Immunoassay. The data indicated that these 3 HIV tests are effective testing systems for diagnosis of HIV infection in a situation when the conventional Enzyme Immunoassay is not suitable.
HIV-1 antibody patterns in two groups, those infected by the intravenous route (IV drug users) and those infected by the sexual route (prostitutes, male homosexuals and sexually transmitted disease patients) were compared using the Western blot technique. A total of 160 cases were studied. The intravenous drug user (IVDU) group appeared to respond to fewer antibody markers than the sexually infected group, the difference being significant for markers p31, p51, p55, p66, gp41 and gp120. Furthermore, a higher proportion (63%) of the sexually infected group carried antibodies to all Western blot markers as compared to the IVDU group (49%).
OBJECTIVES: To estimate the risks of seroconversion of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency viruses (HIV) in children with multitransfused thalassaemia at a thalassaemic clinic in Kuala Lumpur, Malaysia.
METHODS: Seventy-two children (39 males, median age 11.3 years, 2.5th-97.5th centile: 1.4-19.2 years) with thalassaemia major were studied. The risks of seroconversion of HBV, HCV and HIV were estimated by comparing the seroprevalences of hepatitis B surface antigen (HBsAg), anti-HCV and anti-HIV between a defined starting point and an end point. The end point was the point when latest serological results were available while the starting point was when regular transfusion was commenced, or approximately 5 years before the end point when the duration of transfusion was longer.
RESULTS: The median duration of the study was 49 months (range 8-69 months, total 2953 patient-months). There were 2605 transfusion episodes and 4154 units of blood transfused (0.88 transfusion episode/patient per month, 1.41 units of blood transfused/patient per month). There were three new seroconversions for anti-HCV but none for HBsAg and anti-HIV. The risk of seroconversion for HCV was one in 1384 units of blood transfused (95% CI: 4000-472). The seroprevalence rates at the starting and end points were: HBsAg (1%, 1%), anti-HCV (10%, 13%) and anti-HIV (0%, 0%), respectively.
CONCLUSIONS: The estimated risk of acquiring HCV infection in children receiving multiple blood transfusions in this study is surprisingly higher than the generally accepted estimated risk. Other routes of transmission may be important. A prospective, multicentre study to estimate such risks more precisely is needed.
INTRODUCTION: Dried blood spot (DBS) collection is an appealing alternative to whole blood or plasma sampling, as it has technical and economic advantages over the latter.
MATERIALS AND METHODS: A prospective cross-sectional study was conducted at a Malaysian tertiary referral hospital from November 2009 to March 2010. One hundred and fifty paired specimens of DBS and plasma were analysed by the standard assays for HIV Ag/Ab, HBsAg, anti-HBS and anti-HCV, separately (total 600 paired specimens). DBS sample titres were then compared to the results of plasma testing, which was used as the gold standard.
RESULTS: For the HIV Ag/Ab assay with a cut-off point of 0.35 Relative Light Units (RLUs), the sensitivity and specificity were both 100%. For the HBsAg assay, the sensitivity was 96.5% and the specificity was 97.8%, with a cut-off point of 1.72 RLUs. Sensitivity for the anti-HBs test was 74.2% and the specificity was 86.9%, using a cut-off point of 0.635 RLUs. For the anti-HCV assay, the sensitivity was 97.3% and the specificity was 100%, with a cut-off point of 0.10 RLUs.
CONCLUSION: DBS is an ideal choice to be used as a screening tool for the detection of HIV, Hepatitis B and Hepatitis C virus infections. However, different cut-off values need to be used for the validation of test positivity in DBS samples because the small amount of blood in the DBS specimens leads to lower assay titres.