Several new tests have been recently introduced by the United Kingdom Blood Services to improve safety. The frequency (or risk) of hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV infectious donations entering the UK blood supply during 1996-2003 has been estimated. These years span the introduction of nucleic acid testing (NAT) for HCV, HIV combination antigen and antibody test and NAT for HIV. The frequency of an infectious donation entering the blood supply due to i) the window period, ii) assay failures and iii) human and technical errors in testing and processing, was estimated. The window period risk was estimated using the incidence of infection in donors and the length of the window period for tests in use, with an adjustment for atypical inter-donation intervals in seroconverting donors. The estimated frequency of infectious donations entering the blood supply during 1996-2003 was 1.66, 0.80 and 0.14 per million for HBV, HCV and HIV respectively. HCV NAT resulted in an over 95% fall in the risk of HCV. Current usage of HIV combined antibody-antigen tests and of HIV NAT reduced the estimated risk of HIV by 10%. Since 1996, the risk of transfusion-transmitted HBV, HCV and HIV infection in the UK has been lowered by several improvements to donation testing, although the absolute reduction in risk has been small. Vigilance for errors and the affects of donor selection may be as or more important than further reductions to window periods of tests for improving blood safety with respect to HBV, HCV and HIV.
"Similar risk of 1 : 7,142.857 or 0.14 per million donors was reported for the 1996–2003 period for the whole of Great Britain . HBV incidence based on HBsAg IgM was halved between 1996 and 2008, with the first-time donors comprising most of the cases . "
[Show abstract][Hide abstract] ABSTRACT: Despite a considerable reduction of the risk of HBV-infected blood donation entering blood supply (residual risk) due to improved screening by HBV NAT in the developed countries, the bulk of the people with HBV living in the developing countries still needs to be screened by serologic tests such as HBsAg and anti-HBc. Many of these countries lack resources for implementing NAT and are likely to remain so in the next decade or longer, thus depending on the HBV residual risk monitoring based on serologic testing and corresponding estimation methods. This paper reviews main HBV residual risk findings worldwide and the methods based on serology used for their calculation with repeat donors, as well as their extension to the first-time donors. Two artificial datasets with high (4.36%) and low (0.48%) HBV prevalence were generated to test the performance of five methods: the original incidence/window-period model based solely on HBsAg, its modification by Soldan in 2003, the Müller-Breitkreutz model, the HBsAg yield model, and its extension to include anti-HBc seroconversions within a year. The last model was closest to the true values of residual risk and had smallest variation of the estimates in both high and low prevalence data. It may be used for residual risk evaluation in relatively small samples, such as regional blood banks data.
"In several studies conducted in Pakistan and in other countries of the world, prevalence of TTIs appears high among replacement blood donors compared to voluntary donors [6,7]. Prevalence of TTIs is highly uncommon in the developed countries due to a well-developed healthcare and blood transfusion system which follows stringent donor selection criteria, deferral on the basis of high risk behavior and sensitive screening tests . "
[Show abstract][Hide abstract] ABSTRACT: Objective: To determine the prevalence of Hepatitis-B, Hepatitis-C and Human Immunodeficiency infections in replacement blood donors.
Materials and Methods: From January 2004 to December 2011, 108,598 apparently healthy donors donated blood at our Blood Bank. Screening was done by Microparticle Enzyme Immuno Assay (MEIA) method on Axsym System (Abbott Diagnostic, USA) and in year 2011 by Chemiluminescent Immunoassay (CIA) method on Architect i2000 (Abbott Diagnostic, USA). From 2010 onward, HIV reactive donors were advised for confirmatory tests and reported back with the results.
Results: Of the 108,598 total donors, 108,393 (99.8%) were replacement donors with a mean age of 28.92 (17-55) years. Of this, only 164 (0.15%) were females. Among the replacement donors, 4,906 (4.5%) were found to be reactive for Hepatitis-B, C and Human Immunodeficiency Virus. All the reactive patients, except one, were males. HbsAg was positive in 2,068 (1.90%) and anti-HCV in 2832 (2.61%) donors, while 111 (0.10%) were positive for Human Immunodeficiency Virus. Co-infectivity was observed in 103 (0.09%) cases. The prevalence appeared to be higher in younger age group (17-30 yrs). Only 16.6% cases should be patients returned with results of the confirmatory tests for HIV and were found positive.
Conclusion: Hepatitis-B and C sero-prevalence in our series of replacement donors appears high compared to most studies from neighboring countries and relatively low in comparison to earlier studies from Pakistan. Prevalence of HIV, however, appears low and turn out of HIV positive cases for confirmatory tests is low.
Conflict of interest:None declared.
"More recently, however, HIV antigen tests that allow the diagnosis of HIV infection even in the pre-seroconversion phase and nucleic acid amplification tests (NATs) have become widely available, which made it possible to identify early HIV infection . In the UK, NATs were administered to acute retroviral syndrome patients and HIV risk-groups, which resulted in the diagnosis of early HIV infection . "
[Show abstract][Hide abstract] ABSTRACT: The detection of HIV seroconverters increased annually since HIV antigen/antibody testing kits have been available widely in South Korea. This study aimed to identify the epidemiological characteristics of HIV seroconverters and their immune level at HIV diagnosis.
We analyzed the epidemiological and immunological characteristics of 341 HIV seroconverters among 6,008 HIV-diagnosed individuals from 1999 and 2009. The analysis of immune level and epidemiological factors of HIV seroconverters was conducted by using chi-square test on SAS version 9.1.
The seroconverters among newly-identified HIV cases each year increased from 0.5% in 1999 to over 5% or in 2009. The sex ratio of seroconverters was 18:1 (male:female), and 33% were in their 30s, and 28% were in their 20s. Reasons for HIV testing were involvement in voluntary test due to risky behaviors (43%), and health check-up (36%). Discovery of HIV infection occurred primarily in hospitals (84%). Among seroconverters, 55 percent had a CD4 T-cell count of more than 350/μl.
Korean HIV seroconverters tended to be younger at diagnosis, diagnosed during a voluntary test, and their CD4+ T-cell counts at HIV diagnosis were higher than those of non-seroconverters aall HIV-infected individuals. This study of HIV seroconverters will be important foundational in future studies on HIV incidence, disease progress, and survival rate.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.