A forecasting model to estimate the drop in blood supplies during the SARS-CoV-2 pandemic in Italy.

OBJECTIVES: To estimate the number of actually Severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infected blood donors applying a statistical forecasting model. BACKGROUND: Following the outbreak of the SARS-CoV-2 epidemic, a drop in blood donation has been observed. It is crucial to determine the actual number of potential SARS-CoV-2-positive donors to define the measures and ensure adequate blood supply. METHODS: The cumulative incidence of SARS-CoV-2 positivity, calculated on the general population, was applied to the donor population by estimating the number of positive subjects. The calculation model was validated by the linear interpolation method. The number of blood units actually discarded based on post-donation information was also taken into account. RESULTS: Three months after the outbreak, 5322 donors were estimated to be positive for SARS-CoV-2 and were therefore potentially excluded from donation. A total of units of blood components were discarded following post donation information. The estimated number of donors deceased (180) and the number of clinically recovered individuals in the same period was also considered. CONCLUSION: This forecasting model can be used to obtain information on blood donors' involvement during future SARS-CoV-2 outbreaks, especially in case of changes concerning epidemiology, incidence by age bracket and geographical distribution and also for new outbreaks of emerging viruses.

The Antibiotic Polymyxin B Impairs the Interactions between Shiga Toxins and Human Neutrophils.

Hemolytic uremic syndrome (HUS) is the life-threatenig sequela of intestinal infections by Shiga toxin (Stx)-producing Escherichia coli (STEC) in children. Human neutrophils specifically bind Stx through TLR4, the receptor of LPS. The binding could be considered protective (Stx sequestration) or harmful (toxin delivery to target organs). The amount of Stx on neutrophils is in equilibrium with the amount of Stx present in the gut, and it is also related to renal and neurologic symptoms. The TLR4-mediated interaction of LPS with innate immune cells is hampered by the well-known antibiotic polymyxin B. In this study, we show that the same antibiotic impairs the binding of Stx to neutrophils, also blocking their functional effects (release of CXCL8, formation of neutrophil/platelet aggregates) involved in HUS pathogenesis. Controls for contaminating LPS in Stx-induced neutrophil responses inhibited by polymyxin B were performed. Stx interact with human neutrophils through their A chain, since these leukocytes do not express globotriaosylceramide, the specific receptor for Stx B chains. Consistently, polymyxin B blocked the enzymatic activity of Stx1, Stx2, Stx1 A chain, and the analogous plant protein gelonin, whereas the antibiotic did not show any protective effect on Stx-induced cytotoxicity in globotriaosylceramide-expressing Raji cells. Antibiotic administration is not recommended in human STEC infections during the prodromal intestinal phase, and the toxicity of polymyxin B could further discourage its therapeutic use. However, nontoxic, nonbactericidal polymyxin derivatives have been developed and might be used in animal models of STEC infection to study their efficacy in preventing the onset of HUS during the systemic blood phase of Stx.

HIV-1 gp120 impairs the differentiation and survival of cord blood CD34+ HPCs induced to the erythroid lineage.

Anemia is the most common hematological abnormality in human immunodeficiency virus (HIV)-infected patients. Besides chronic disease, opportunistic infections, nutritional deficiencies and antiretroviral drug toxicity, the direct role of HIV in the development of anemia has not yet been fully investigated. To explore the HIV-related mechanisms involved in the genesis of anemia, we used two experimental designs. In the first, HPCs purified from cord blood were challenged with HIV-1IIIb or recombinant gp120 (rgp120) and then committed to erythrocyte differentiation (EPO-post-treated HPCs). In the second, HPCs were first committed to differentiate towards the erythroid lineage and only afterwards challenged with HIV-1IIIb or rgp120 (EPO-pre-treated HPCs). Our results showed that HPCs and EPO-induced HPCs were not susceptible to HIV-1 infection. In addition, the two experimental designs (EPO post or pre-treated HPCs) independently showed that HIV-1IIIb or rgp120 were able to induce the impairment of survival, proliferation, and differentiation albeit differing in kinetics and extent. Interestingly, the gp120 interaction with CD4 and CXCR4 played a pivotal role in the impairment of erythrocyte differentiation by inducing TGF-b1 expression. These observations reveal an important additional mechanism involved in the genesis of anemia suggesting a complex competition between EPO-positive regulation and HIV-negative priming regarding erythrocyte survival, proliferation and maturation.

Human Vascular Wall Mesenchymal Stromal Cells Contribute to Abdominal Aortic Aneurysm Pathogenesis Through an Impaired Immunomodulatory Activity and Increased Levels of Matrix Metalloproteinase-9.

BACKGROUND: The main histopathological features of abdominal aortic aneurysm (AAA) are tissue proteolysis mediated by matrix metalloproteinases (MMPs) and inflammation. This study aimed at verifying the presence and contribution of mesenchymal stromal cells (MSCs) to aneurysmal tissue remodeling. METHODS AND RESULTS: MSCs were successfully isolated from the AAA wall of 12 male patients and were found to express mesenchymal and stemness markers. MMP-2/-9 are involved in AAA progression and their mRNA levels in AAA-MSCs resulted higher than healthy MSCs (cMSCs), especially MMP-9 (400-fold increased). Moreover, MMP-9 protein and activity were pronounced in AAA-MSCs. Immunomodulation was tested in AAA-MSCs after co-culture with activated peripheral blood mononuclear cells (PBMCs) and revealed a weak immunosuppressive action on PBMC proliferation (bromodeoxyuridine incorporation, flow cytometry assay), together with a reduced expression of anti-inflammatory molecules (HLA-G, IL-10) by AAA-MSCs compared to cMSCs. MMP-9 expression in AAA-MSCs was shown to be negatively modulated under the influence of cMSCs and exogenous IL-10. CONCLUSIONS: MSCs with stemness properties are niched in human AAA tissues and display a dysregulation of functional activities; that is, upregulation of MMP-9 and ineffective immunomodulatory capacity, which are crucial in the AAA progression; the possibility to modulate the increased MMP-9 expression by healthy MSCs and IL-10 suggests that novel therapeutic strategies are possible for slowing down AAA progression.

Prevalence, incidence and residual risk of transfusion-transmitted hepatitis B virus infection in Italy from 2009 to 2018.

BACKGROUND: In Italy, the use of nucleic acid testing for hepatitis B virus (HBV) in donor screening has allowed the detection of infections in the window phase, as well as the presence of occult infections which could potentially be transmitted. The aim of this study was to analyse the trends of epidemiological data focused on HBV infection in blood donors and to estimate the residual risk of transmitting HBV from both the window phase and occult infection over a 10-year period in Italy. MATERIALS AND METHODS: Data were obtained from the Italian Haemovigilance System which includes the results of screening tests for transfusion transmissible infections. During the period of this survey (2009-2018), the molecular methods used for HBV screening were transcription-mediated amplification and polymerase chain reaction tests. Prevalence and incidence were calculated. The residual risk was estimated by applying the incidence-window period model for acute cases and a more recently reported model for estimating the risk due to occult infections. RESULTS: A total of 17,424,535 blood donors and 30,842,794 donations were tested for HBV. Altogether, 6,250 donors tested positive for HBV markers: 4,782 (175.6×105) were first time donors and 1,468 (10.0×105) were repeat donors. The prevalence of HBV markers in first time donors was 275.9×105 in 2009, declining to 143.6×105 in 2018. The incidence of new infections was 3.37×105 in 2009 and 2.17×105 in 2018. The overall residual risk for HBV amounted to 1 in 2,566,854 donations calculated as the sum of risks of both acute infections in the window period (1 in 5,835,306 donations) and occult infections (1 in 4,582,270 blood units). DISCUSSION: In Italy, the residual risk of transfusing a blood unit infected with HBV, both from window phase and occult infections, is currently very low, amounting to levels that can be considered tolerable.

Pathogen reduction of blood components during outbreaks of infectious diseases in the European Union: an expert opinion from the European Centre for Disease Prevention and Control consultation meeting.

Pathogen reduction (PR) of selected blood components is a technology that has been adopted in practice in various ways. Although they offer great advantages in improving the safety of the blood supply, these technologies have limitations which hinder their broader use, e.g. increased costs. In this context, the European Centre for Disease Prevention and Control (ECDC), in co-operation with the Italian National Blood Centre, organised an expert consultation meeting to discuss the potential role of pathogen reduction technologies (PRT) as a blood safety intervention during outbreaks of infectious diseases for which (in most cases) laboratory screening of blood donations is not available. The meeting brought together 26 experts and representatives of national competent authorities for blood from thirteen European Union and European Economic Area (EU/EEA) Member States (MS), Switzerland, the World Health Organization, the European Directorate for the Quality of Medicines and Health Care of the Council of Europe, the US Food and Drug Administration, and the ECDC. During the meeting, the current use of PRTs in the EU/EEA MS and Switzerland was verified, with particular reference to emerging infectious diseases (see Appendix). In this article, we also present expert discussions and a common view on the potential use of PRT as a part of both preparedness and response to threats posed to blood safety by outbreaks of infectious disease.

Impact of nucleic acid testing for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus on the safety of blood supply in Italy: a 6-year survey.

BACKGROUND: Nucleic acid testing (NAT) for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) has been implemented in several European countries and in the United States, while hepatitis B virus (HBV) NAT is still being questioned by opinions both in favor and against such an option, depending on the HBV endemicity, health care resources, and expected benefits. STUDY DESIGN AND METHODS: This survey was aimed to assess the NAT impact in improving the safety of blood supply in Italy, 6 years after implementation. The study involved 93 Italian transfusion centers and was carried out in 2001 through 2006. A total of 10,776,288 units were tested for the presence of HCV RNA, 7,932,430 for HIV RNA, and 3,405,497 for HBV DNA, respectively. RESULTS: Twenty-seven donations or 2.5 per million tested were HCV RNA-positive/anti-HCV-negative; 14 or 1.8 per million units tested were HIV RNA-positive/anti-HIV-negative; and 197 or 57.8 per million donations tested were HBV DNA-positive/hepatitis B surface antigen-negative. Of the latter, 8 (2.3/10(6)) were collected from donors in the window phase of infection and 189 (55.5/10(6)) from donors with occult HBV. Sixty-eight percent of the latter donors had hepatitis B surface antibody, 74.5 percent of whom with concentrations considered protective (>or=10 mIU/mL). CONCLUSION: NAT implementation has improved blood safety by reducing the risk of entering 2.5 HCV and 1.8 HIV infectious units per million donations into the blood supply. The yield of NAT in detecting infectious blood before transfusion was higher for HBV than for HCV or HIV. However, the benefit of HBV NAT in terms of avoided HBV-related morbidity and mortality in blood recipients needs to be further evaluated.

Prevalence, incidence and residual risk of transfusion-transmitted hepatitis C virus and human immunodeficiency virus after the implementation of nucleic acid testing in Italy: a 7-year (2009-2015) survey.

BACKGROUND: In Italy nucleic acid testing (NAT) became mandatory for hepatitis C virus (HCV) in 2002 and for human immunodeficiency virus (HIV) and hepatitis B virus in 2008. The aim of this study was to monitor the incidence and prevalence of HIV and HCV infections in Italian blood donors and the current residual risk of these infections after the introduction of NAT. MATERIALS AND METHODS: The Italian national blood surveillance system includes data from tests used to screen for transfusion-transmissible infections. During the period of this survey (2009-2015), the NAT methods used were the transcription-mediated amplification test, for individual donor testing, and polymerase chain reaction analysis, mainly for pools of six donors. Prevalence and incidence were calculated. Three published formulae were applied to estimate the residual risk (the window period ratio model and the formulae recommended by the European Medicines Agency and the World Health Organization). RESULTS: Overall, 12,258,587 blood donors and 21,808,352 donations were tested for HCV and HIV. The prevalence of HCV decreased from 110.3×105 to 58.9×105 in years 2009 and 2015, respectively, while that of HIV remained stable over time (15.5×105 vs 15.4×105). The incidence of HCV decreased from 3.19×105 in 2009 to 1.58×105 in 2015, while the incidence of HIV did not show any significant fluctuations (average incidence 4.39×105). The residual risk of a viraemic unit entering the blood supply was estimated to be 0.077×106 or 1 in 12,979,949 donations for HCV and 0.521×106 or 1 in 1,917,250 for HIV, according to the window period ratio model, and lower with the other two formulae. DISCUSSION: HCV infection has declined over time in both first-time and repeat donors, while the data for HIV infection are stable. All three methods employed in this study showed that the residual risk of transmitting HCV or HIV through an infected blood unit is currently very low in Italy, but there are considerable differences in estimates between methods. Thus, harmonisation of these methods is advisable.

Efficacy of 2-Month Treatment With Cord Blood Serum Eye Drops in Ocular Surface Disease: An In Vivo Confocal Microscopy Study.

PURPOSE: To investigate the morphological changes of corneal epithelium and subbasal nerves by in vivo confocal microscopy in patients with ocular surface disease (OSD) treated with cord blood serum (CBS) eye drops. METHODS: Twenty patients with OSD (mean age 61.1 ± 12.6 years) were included in this prospective 1-arm study and treated with CBS eye drops for 2 months. Corneal sensitivity, Schirmer test score, breakup time, subjective symptoms [Ocular Surface Disease Index (OSDI) and Visual Analogue Scale (VAS)], and corneal staining were evaluated before (T0) and after (T1) treatment. In vivo confocal microscopy analyzed giant epithelial cells, subbasal nerve number and tortuosity, neuromas, beading, and dendritic cells (DCs) in the central cornea. RESULTS: OSDI, Visual Analogue Scale, and Oxford grading values significantly decreased at T1 versus T0 (respectively, 44.1 ± 18.9 vs. 74.2 ± 13.9; 3.7 ± 1.5 vs. 8.9 ± 0.9; and 2.4 ± 1.1 vs. 3.3 ± 1.3; P < 0.0001), whereas corneal sensitivity, Schirmer test score, and breakup time significantly increased (respectively, 49.5 ± 2.6 vs. 47.9 ± 2.9; 3.2 ± 2.0 vs. 2.4 ± 2.2; 4.6 ± 3.1 vs. 3.8 ± 2.1; P < 0.0001). Corneal nerve morphology improved at T1 versus T0 with a higher total nerve number (3.4 ± 1.6 vs. 2.5 ± 1.6 per frame) and lower tortuosity (3.0 ± 0.7 vs. 3.5 ± 0.6) (P < 0.01). The number of patients presenting with giant epithelial cells, beading, and neuromas decreased at T1. DC density did not change after treatment. The detection of neuromas and higher DC density at T0 were associated with greater OSDI reduction at T1 (P < 0.001). CONCLUSIONS: CBS eye drops significantly improved corneal nerve morphology and subjective symptoms in patients with severe OSD. The presence of neuromas and higher dendritic cell density at baseline were associated with greater reduction of discomfort symptoms after treatment.

Persistence of immunity 18-19 years after vaccination against hepatitis B in 2 cohorts of vaccinees primed as infants or as adolescents in Italy.

This study was aimed at assessing the anti-HBs persistence and immune memory 18-19 y after vaccination against hepatitis B in healthy individuals primed as infants or adolescents. We enrolled 405 teenagers (Group A) vaccinated as infants, and 409 young adults (Group B) vaccinated as adolescents. All vaccinees were tested for anti-HBs and anti-HBc antibodies; those found anti-HBc positive were further tested for HBsAg and HBV DNA. Eight individuals belonging to Group B were positive for anti-HBc alone, and were excluded from analysis. Individuals with anti-HBs concentration ≥ 10 mIU/ml were considered protected while those with anti-HBs concentration <10 mIU/ml were offered a booster dose and re-tested 2 weeks later. Overall, 67.9% individuals showed anti-HBs concentrations ≥ 10 mIU/ml (48.9% in Group A vs 87.0% in Group B, p < 0.001). The antibody geometric mean concentration (GMC) was higher in Group B than in Group A (102.5 mIU/ml vs 6.9 mIU/ml; p < 0.001). When boosted, 94.2% of vaccinees with anti-HBs <10 mIU/ml belonging to Group A and 94.7% to Group B showed an anamnestic response. Post-booster GMCs were similar in both groups (477.9 mIU/ml for Group A vs 710.0 mIU/ml for Group B, p = n.s.). Strong immunological memory persists for at least 18-19 y after immunization of infants or adolescents with a primary course of vaccination. Thus, booster doses are not needed at this time, but additional follow up is required to assess the long-life longevity of protection.

Changing patterns of hepatitis B infection in Italy and NAT testing for improving the safety of blood supply.

In Italy, as in most industrialized countries, the burden of hepatitis B has progressively declined in recent decades as a consequence of general improvements in hygiene and standard of living, the introduction of several public health measures, refinement in blood screening and the implementation of specific vaccination programmes. Universal hepatitis B vaccination for all infants and adolescents as well as individuals at increased risk has resulted in considerable progress towards prevention and control of HBV infection. The residual risk of transmitting blood-borne viruses through transfusion is currently very low. Nucleic acid testing can shorten the window period and, consequently, further reduce the risk of viral transmission. Blood donor screening for HCV by NAT was initiated in Italy in 2001 and became mandatory in June 2002. NAT for HIV is currently mandatory in four regions, not mandatory but almost universally performed in another thirteen regions, and not yet introduced in the remaining four regions. NAT for HBV is currently mandatory in four regions and under evaluation in the remaining. NAT for HBV may be a useful tool in detecting acute viral infections in the window phase as well as the occult infections. Its efficacy in improving the safety of blood supply is expected to be higher in countries with intermediate/high endemicity, where anti-HBc antibody screening cannot be routinely performed. There is agreement that, at present, the implementation of HBV DNA testing will not allow for discontinuation of screening for HBsAg.

AISF-SIMTI position paper: the appropriate use of albumin in patients with liver cirrhosis.

The use of human albumin is common in hepatology since international scientific societies support its administration to treat or prevent severe complications of cirrhosis, such as the prevention of post-paracentesis circulatory dysfunction after large-volume paracentesis and renal failure induced by spontaneous bacterial peritonitis, and the treatment of hepatorenal syndrome in association with vasoconstrictors. However, these indications are often disregarded, mainly because the high cost of human albumin leads health authorities and hospital administrations to restrict its use. On the other hand, physicians often prescribe human albumin in patients with advanced cirrhosis for indications that are not supported by solid scientific evidence and/or are still under investigation in clinical trials.In order to implement appropriate prescription of human albumin and to avoid its futile use, the Italian Association for the Study of the Liver (AISF) and the Italian Society of Transfusion Medicine and Immunohaematology (SIMTI) nominated a panel of experts, who reviewed the available clinical literature and produced practical clinical recommendations for the use of human albumin in patients with cirrhosis.

Targeting growth factor supply in keratopathy treatment: comparison between maternal peripheral blood and cord blood as sources for the preparation of topical eye drops.

BACKGROUND: Epitheliotrophic growth factors (GF) can be supplied topically to patients with severe keratopathy through a variety of blood-derived products. We compared GF content in adult peripheral blood serum (PB-S) and cord blood serum (CB-S) as potential sources of GF. To limit inter-individual variability the assessment was performed in maternal-child pairs at the time of delivery. MATERIAL AND METHODS: The amounts of epidermal GF (EGF), insulin-like GF (IGF), transforming GF-beta (TGF-ß), vascular endothelial GF (VEGF) in CB units collected from the umbilical vein and PB from mothers (each group n=30) were estimated by enzyme-linked immunosorbent assays. Obstetric characteristics and haematological data were recorded from the archives of the Emilia Romagna Cord Blood Bank. Statistical evaluations were performed by Wilcoxon's test and correlations between variables were determined using Spearman's (ρ) coefficient; p-values <0.05 were considered statistically significant. RESULTS: EGF, TGF-ß and VEGF levels were significantly higher in CB-S than in PB-S (median 1,254.4 vs 646.0 pg/mL, 51.3 vs 38.4 µg/mL and 686.8 vs 30 pg/mL, respectively; all p<0.0001) whereas IGF content was significantly higher in PB-S than in CB-S (159.9 vs 53.5 pg/mL, respectively; p<0.0001). In CB-S, the CD34(+) cell concentration appeared to be related to EGF, IGF and TGF-ß levels whereas white blood cell count appeared to be related to EGF and TGF-ß levels. VEGF levels showed no relation to the haematological parameters considered. Platelet counts were not related to GF level in either CB or PB. DISCUSSION: The GF content in the two blood sources was different, with CB containing larger amounts. Each GF selectively regulates cellular processes involved in corneal healing, so the use of PB or CB should be targeted to supply specific GF on the basis of the type and severity of the keratopathy.

Mutations of the hemochromatosis gene in Italian candidate blood donors with increased transferrin saturation.

The aim of this study was to analyze the role of HFE mutations in blood donors with iron parameters suggesting iron overload, taking into account the regional distribution of HFE mutations in Italy. We studied 5880 subjects undergoing evaluation for blood donation eligibility, from different areas of Italy. Abnormal iron parameters were defined as transferrin saturation (TS) >50% or >45% and serum ferritin (SF) >300 or >250 microg/ml in males and females, respectively. Subjects with increased TS and/or SF were re-tested and typed for HFE mutations C282Y and H63D. A total of 548 individuals had increased iron parameters at first testing. In total, 179/548 were available for retesting, and in 109 increased TS and/or SF were confirmed. Increased TS was confirmed in 25 individuals, among whom three were C282Y homozygotes and six were compound heterozygotes for C282Y and H63D. Increased TS was more frequent in northern Italy than in southern regions. In individuals with increased TS and/or SF, the frequency of C282Y and H63D was 0.13 and 0.21 in northern-Italy versus 0.05 and 0.45 in southern Italy (P=0.004 for H63D). Nine out of 10 individuals carrying hemochromatosis-associated genotypes (including compound heterozygosity for C282Y and H63D) originated from northern regions. Among controls, the allelic frequencies of C282Y and H63D were 0.037 and 0.16 in the northern regions and 0.015 and 0.16 in the southern regions. In conclusion, over one-third of individuals with persistently altered TS carried hemochromatosis-associated genotypes, confirming that a diagnostic approach based on TS and genotyping of selected cases may represent a viable screening procedure.

Hepatitis B virus infection among first-time blood donors in Italy: prevalence and correlates between serological patterns and occult infection.

BACKGROUND: A prospective, 1-year study was performed among Italian first-time, volunteer blood donors, who account for 12% of all donations, in order to assess the frequency and serological patterns of hepatitis B virus infection and the presence of occult infection. MATERIALS AND METHODS: Consecutive donors (n=31,190) from 21 blood transfusion centres, from age classes not subjected to universal HBV vaccination, were tested for HBsAg and anti-HBc by commercial immunoassays. Other HBV serological markers were searched for and qualitative and quantitative assessments of HBV-DNA were made in HBsAg and/or anti-HBc-positive individuals. RESULTS: Of the 31,190 donors studied, 100 (0.32%) were positive for both HBsAg and anti-HBc, 2 for HBsAg (0.01%) alone, and 2,593 (8.3%) for anti-HBc. Of these last, 86.7% were also positive for anti-HBs (with or without anti-HBe), 2.9% were positive for anti-HBe without anti-HBs and 10.4% had no other HBV markers (anti-HBc alone). A general north-south increasing gradient of HBV prevalence was observed. Circulating HBV-DNA was found in 96.8% of HBsAg-positive subjects as compared to 0.55% (12/2,186) of anti-HBc-positive/HBsAg-negative subjects, with higher frequencies among anti-HBs-negative than among anti-HBs-positive ones (1.68% vs. 0.37%; p <0.01) and among the 57 cases positive for both anti-HBc and anti-HBe (7%). HBV-DNA levels were significantly higher in HBsAg-positive subjects than in HBsAg-negative ones (median: 456 IU/mL vs. 38 IU/mL). CONCLUSIONS: The prevalence of HBV infection among Italian first-time blood donors is much lower than in the past. The presence of occult infections in this group was confirmed (frequency: 1 in 2,599), supporting the hypothesis of long-term persistence of HBV infection after clearance of HBsAg. HBsAg and nucleic acid amplification testing for blood screening and vaccination against HBV are crucial in order to further reduce the risk of transfusion-transmitted HBV towards zero.

Changing blood donor screening criteria from permanent deferral for men who have sex with men to individual sexual risk assessment: no evidence of a significant impact on the human immunodeficiency virus epidemic in Italy.

BACKGROUND: In 2001, the criteria for blood donor eligibility in Italy were modified by a ministerial decree from a permanent deferral for "men who have sex with men" to an individual risk assessment of sexual behaviours. The aim of this study was to evaluate the impact of this change in donor screening criteria on the human immunodeficiency virus epidemic among blood donors in Italy. MATERIALS AND METHODS: We used the data obtained from the Italian blood donor epidemiological surveillance system. We compared data collected in 2009 and 2010, when the individual risk assessment policy was applied, with data collected in 1999 when permanent deferral was applied for men who have sex with men based on a declaration of sexual orientation. We evaluated the change over time in the relative proportion of HIV antibody-positive donors who likely acquired the infection from men who have sex with men vs heterosexual sexual exposure; the relative risk was calculated using 1999 as the reference year. RESULTS: In all 3 years, the majority of HIV antibody-positive donors reported sexual exposure as a risk factor for HIV infection; this proportion increased over time, although not statistically significantly. Heterosexuals always accounted for at least 40% of all HIV antibody-positive cases. The rate of HIV antibody-positive donors increased similarly in men who have sex with men and heterosexuals; specifically, the rate of HIV antibody-positive cases per 100,000 donors was more than 2-fold higher among men who have sex with men in 2009-2010 than in 1999 (2009-2010 vs 1999, RR =2.8; P =0.06), and that among heterosexuals was 1.5 fold higher (P =0.18). DISCUSSION: When comparing the period before (1999) and after (2009-2010), the implementation of the individual risk assessment policy in 2001, no significant increase in the proportion of men who have sex with men compared to heterosexuals was observed among HIV antibody-positive blood donors, suggesting that the change in donor deferral policy did not lead to a disproportionate increase of HIV-seropositive men who have sex with men.