Human Immunodeficiency Virus Residual Risk Research Articles

HIV incidence and compliance with deferral criteria over three progressively shorter time deferrals for men who have sex with men in Canada.

In Canada, the deferral for men who have sex with men (MSM) has been progressively reduced from a permanent deferral for MSM since 1977, to 5 years, 1 year, and, most recently, 3 months. We estimated human immunodeficiency virus (HIV) residual risk and compliance with the MSM time deferral after each change. Four anonymous online compliance surveys were carried out before and after each change. HIV incidence and prevalence were monitored from 2010 to 2021. Residual risk was estimated using the incidence-window period model. Human immunodeficiency virus prevalence, incidence, and residual risk did not change with incrementally shorter MSM deferrals. The residual risk per million donations post 3-month deferral was 0.05 (0.001-0.371). Men with temporally remote MSM history became eligible and, therefore, compliant as the deferral periods decreased (Cochran-Armitage p value=<.0001). However, the percentage of men with MSM history in the last 3 months with the indefinite deferral in place was similar to the percentage noncompliant, while the 3-month deferral was in place. MSM donors did not report high-risk behaviors for which they would otherwise be deferred in any survey. Following the change, an estimated 4467 MSM per year were eligible to donate, an increase from 2501 estimated eligible MSM donors following the change to the 1-year deferral. With progressively shorter MSM deferral periods, HIV residual risk was unchanged. The proportion of male donors with deferrable MSM history remained low, while those with temporally remote MSM history became eligible, increasing the number of eligible MSM donors.

HIV residual risk in Canada for apheresis source plasma donation without deferral for men who have sex with men.

In Canada, men having sex with men (MSM) are deferred for 3 months from last sexual contact to reduce human immunodeficiency virus (HIV) risk to recipients. The aim of this paper was to model the Canadian residual risk of HIV-positive source plasma incorporating pathogen inactivation (PI) under no MSM deferral scenarios for apheresis plasma donations. A combined Bayesian network (BN) and Monte Carlo approach were implemented to estimate the HIV residual risk under 3-month deferral compared with no deferral without quarantine scenarios for MSM donors. Models involve the stochastic generation of donation and its infection status based on its corresponding simulated donor profile. Viral load reduction conferred by PI used by source plasma fractionators was simulated. Model parameters were derived from Héma-Québec and Canadian Blood Services data, viral loads in a large sample of HIV-positive US blood donors, CSL Behring documentation and from published data. In the most likely scenario for the 3-month deferral model, there were 2.71 positive donations per 1,000,000 donations (95% confidence interval [CI] 2.63-2.78). For the no-deferral model, there were 3.01 positive donations per 1,000,000 donations (95% CI 2.94-3.09). For both scenarios, the risk of having an infectious pool was 0 in 300,000 pools (95% CI 0-0.0000123) after consideration of PI. Based on simulation results, there would be a negligible HIV residual risk associated with the removal of a time-based MSM deferral without quarantine for source plasma incorporating PI.

Incidence and Residual Risk of HIV, HBV and HCV Infections Among Blood Donors in Tehran.

Estimation of residual risk is essential to monitor and improve blood safety. Our epidemiologic knowledge in the Iranian donor population regarding transfusion transmitted viral infections (TTIs), is confined to a few studies based on prevalence rate. There are no reports on residual risk of TTIs in Iran. In present survey, a software database of donor records of Tehran Blood Transfusion Center (TBTC) was used to estimate the incidence and residual risk of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections, by applying the incidence rate/window period (IR-WP) model. A total of 1,207,155 repeat donations was included in the analysis and represented a mean of 8.4 donations per donor over 6years. The incidence amongst repeat donors was estimated by dividing the number of confirmed seroconverting donors by the total number of person-years at risk. The residual risk was calculated using the incidence/window period model. Incidence rate and residual risk for HBV, HCV and HIV infections were calculated for total (2005-2010) and two consecutive periods (2005-2007 and 2008-2010) of the study. According to the IR-WP model, overall residual risk for HIV and HCV in the total study period was 0.4 and 12.5 per million units, respectively and for HBV 4.57/100,000 donations. The incidence and residual risk of TTIs, calculated on TBTC's blood supply was low and comparable with developed countries for HIV infection but high for HCV and HBV infections. Blood safety may therefore be better managed by applying other techniques like nucleic acid amplification tests.

Human immunodeficiency virus prevalence, incidence, and residual transmission risk in first‐time and repeat blood donations in Zimbabwe: implications on blood safety

National Blood Service Zimbabwe human immunodeficiency virus (HIV) risk management strategy includes screening and discarding of first-time donations, which are collected in blood packs without an anticoagulant (dry pack). To evaluate the impact of discarding first-time donations on blood safety the HIV prevalence, incidence, and residual risk in first-time and repeat donations (wet packs) were compared. Donor data from 2002 to 2010 were retrieved from a centralized national electronic donor database and retrospectively analyzed. Chi-square test was used to compare HIV prevalence with relative risk (RR), and the RR point estimates and 95% confidence interval (CI) are reported. Trend analysis was done using Cochran-Armitage trend test. HIV residual risk estimates were determined using published residual risk estimation models. Over the 9 years the overall HIV prevalence estimates are 1.29% (n = 116,058) and 0.42% (n = 434,695) for first-time and repeat donations, respectively. The overall RR was 3.1 (95% CI, 2.9-3.3; p < 0.0001). The overall mean residual transmission risk of HIV window phase donations in first-time was 1:7384 (range, 1:11,308-1:5356) and in repeat donors it was 1:5496 (range, 1:9943-1:3347). The significantly high HIV prevalence estimates recorded in first-time over repeat donations is indicative of the effectiveness of the HIV risk management strategy. However, comparable residual transmission risk estimates in first-time and repeat donors point to the need to further review the risk management strategies. Given the potential wastage of valuable resources, future studies should focus on the cost-effectiveness and utility of screening and discarding first-time donations.

Prevalence, incidence, and residual risks for transfusion-transmitted human immunodeficiency virus Types 1 and 2 infection among Chinese blood donors.

There are little data on human immunodeficiency virus (HIV) prevalence, incidence, or residual risks for transfusion-transmitted HIV infection among Chinese blood donors. Donations from five Chinese blood centers in 2008 to 2010 were screened using two rounds of enzyme-linked immunosorbent assay for anti-HIV-1/2. A reactive result in either or both rounds led to Western blot confirmatory testing. HIV prevalence among first-time donors and incidence among repeat donors were examined. Weighted multivariable logistic regression analysis examined correlates of HIV confirmatory status among first-time donors. Residual risks were evaluated based on incidence among repeat donors. Among 821,320 donations, 40% came from repeat donors. A total of 1837 (0.34%) first-time and 577 (0.17%) repeat donations screened reactive, among which 1310 and 419 were tested by Western blot. A total of 233 (17.7%) first-time and 44 (10.5%) repeat donations were confirmed positive. Prevalence was 66 infections per 100,000 (95% confidence interval [CI], 59-74) first-time donors. Incidence was 9 of 100,000 (95% CI, 7-12) person-years among repeat donors. Multivariable logistic regression analysis indicates that first-time donors 26 to 45 years old were 1.6 to 1.8 times likely to be HIV positive than those 25 years and younger. Donors with some college or above education were less likely to be HIV positive than those with middle school education, odds ratios (ORs) ranging from 0.35 to 0.60. Minorities were 1.5 times likely to be HIV positive than Han majority donors (OR, 1.6; 95% CI, 1.2-2.1). HIV residual risk was 5.4 (95% CI, 1.2-12.5) infections per million whole blood donations. Despite the declining HIV epidemic in China, estimated residual risks for transfusion-transmitted HIV infection are still high.

Evolution of the Residual Risk of Transmitting HIV, HCV and HBV in the Blood Transfusion from 1998 to 2009 in Cote d’Ivoire

Prevention of viral contamination of blood from blood bags collected remains a concern finds strategies traceability of blood products and blood safety in Cote d’Ivoire. Thus, the authors have estimated the residual risk of transmission of human immunodeficiency virus (HIV), Hepatitis B virus (HBV) and Hepatitis C (HCV) among blood donors in four periods of three years, 1998-2000, 2001-2003, 2004-2006, 2007-2009 from data collected at the blood establishments in the national territory. The determination of HIV antibodies against the hepatitis C virus and the surface antigen of hepatitis B (HBsAg) were carried out by immuno-enzymatic techniques plate (ELISA) associated with the residual risk assessment. The results showed a gradual decrease of the residual risk of HIV to be the lowest in the period 2007-2009 with 12 per 100 000 or 1 per 8333 donations. Residual risk of hepatitis B and C have known an increase during the different periods to be respectively 219 to 100 000 or 1 457 and 1180 per 100 000 or 1 per 85 donations over the period 2007-2009. The residual risk of HCV is 98 times higher than HIV and 18 times that of hepatitis B. These results show that efforts must be continued in the steps of donor selection, confirmation of screening test for viral contamination and assessment of residual risk of viral transmission during blood transfusion

Donor Testing and Risk: Current Prevalence, Incidence, and Residual Risk of Transfusion-Transmissible Agents in US Allogeneic Donations

Over the past 20 years, there has been a major increase in the safety of the blood supply, as demonstrated by declining rates of posttransfusion infection and reductions in estimated residual risk for such infections. Reliable estimates of residual risk have been possible within the American Red Cross system because of the availability of a large amount of reliable and consistent data on donations and infectious disease testing results. Among allogeneic blood donations, the prevalence rates of infection markers for hepatitis C virus (HCV) and hepatitis B virus have decreased over time, although rates for markers of human immunodeficiency virus (HIV) and human T-cell lymphotropic virus did not. The incidence (/100 000 person-years) of HIV and HCV among repeat donors showed apparent increases from 1.55 and 1.89 in 2000 through 2001 to 2.16 and 2.98 in 2007 through 2008. These observed fluctuations confirm the need for continuous monitoring and evaluation. The residual risk of HIV, HCV, and human T-cell lymphotropic virus among all allogeneic donations is currently below 1 per 1 million donations, and that of hepatitis B surface antigen is close to 1 per 300 000 donations.

Progress in monitoring blood safety

Progress in monitoring blood safety

Quantitative estimate of the risks and benefits of possible alternative blood donor deferral strategies for men who have had sex with men

Implementation of sensitive screening methods for human immunodeficiency virus (HIV) and hepatitis viruses prompts the question of what quantitative risks may result from altered deferral strategies for donation of blood by men who have had sex with men (MSM). Quantitative probabilistic models were developed to assess changes in the residual risk of transfusion-transmitted HIV and hepatitis B virus (HBV) associated with blood testing and quarantine release errors (QREs) in the initial year of two hypothetical policy scenarios that would allow donations from donors who have abstained from MSM behavior for at least 5 years (MSM5) or at least 1 year (MSM1). The MSM5 and MSM1 models, respectively, predicted annual increases in units of HIV-infected blood of 0.5% (0.03 mean additional units; 95% confidence interval [CI], 0-1) and 3.0% (0.18 mean additional units; 95% CI, 0-1) over current estimated HIV residual risk using recent, nationwide biologic product deviation reports to estimate QRE rates. These estimates are approximately 10-fold lower than estimates based on New York State QRE data from the previous decade. The models predicted smaller increases in infectious HBV donations. QREs remain the most significant preventable source of risk. More accurate inputs, including the percentage of MSM in the population, the percentage of MSM who have abstained from MSM activity for 1 or 5 years, the prevalence of HIV and HBV in MSM who have abstained from MSM activity for 1 or 5 years, the rate of self-deferral, and QRE rates, are required before making more precise predictions.

Current incidence and estimated residual risk of transfusion‐transmitted infections in donations made to Canadian Blood Services

New testing methods such as nucleic acid amplification testing (NAT) and chemiluminescent serologic assays have been introduced, more precise estimates for infectious window periods are available, and a new method for estimating the residual risk (RR) of transfusion-transmitted infections (TTIs) has been developed. Thus, available RR estimates for Canada need to be updated. Incidence rates for known TTI markers were determined for all allogeneic whole-blood donations made to Canadian Blood Services between 2001 and 2005; they were derived from NAT conversions or seroconversions of repeat donors with at least two donations in a 3-year period. RR estimates for human immunodeficiency virus (HIV)-1 and hepatitis C virus (HCV) derived from the classical incidence/window-period model were compared to those obtained by the new method that estimates incidence from NAT-positive, antibody-negative donations (NAT-yield cases) from all donors divided by person-years. With the classical method, the RR of HIV (1 per 7.8 million donations) and HCV (1 per 2.3 million) were low; HBV RR was higher (1 per 153,000). HCV RR was significantly lower when estimated with the new method (1 per 13 million). Eleven HCV NAT-yield cases were predicted by applying the classical method to our seroconversion data but only 2 were observed (p = 0.011). Observed HIV-1 NAT-yield cases (n = 1) matched those predicted (n = 0.7). New tests have reduced an already low risk of TTI in Canada. HCV RR estimates by two different methods differed but both were low.