An estimate of the current risk of transmitting blood-borne infections through blood transfusion in Italy

Prevalence of HIV infection among Chinese voluntary blood donors during 2010-2017: an updated systematic review and meta-analysis

BACKGROUND

Understanding the latest human immunodeficiency virus (HIV) epidemic in voluntary blood donors could be of great value to further increase blood safety in China, as transfusion-transmitted infection places a heavy burden on both infected individuals and the whole society. Therefore, we evaluated the national HIV prevalence of voluntary blood donors in China and characteristics of HIV-infected blood donors.

STUDY DESIGN AND METHODS

We searched literature in Chinese and English concerning the prevalence of HIV infections in Chinese voluntary blood donors from 2010 to 2017, yielding 97 eligible papers. We performed a meta-analysis to calculate pooled HIV prevalence, and characteristics of HIV-infected blood donors were also extracted.

RESULTS

The pooled sample consisted of 21,100,755 voluntary blood donors and 4,755 HIV-infected blood donors. Pooled HIV prevalence of China voluntary blood donors during 2010 to 2017 was 21.02 in 100,000. Pooled HIV prevalence varied in different provinces, showing greater severity in Southwest, Northwest, and South China. Subgroup analysis also showed a significantly increasing trend from 2010 to 2017. The majority of HIV-infected blood donors in China were male, young, unmarried, nonlocal residents, receiving 12 years or less of schooling, and first-time donors. Nearly 90% of HIV-infected blood donors acquired their infections through sexual contact.

CONCLUSION

The prevalence of HIV increased in China among voluntary blood donors during 2010 to 2017, highlighting the risk of HIV transmission by transfusion. Blood centers and public health services should improve screening and intervention programs targeting voluntary blood donors and expand education on blood safety in areas experiencing severe epidemics and among high-risk populations.

Prevalence, incidence and residual risk of transfusion-transmitted HBV infection before and after the implementation of HBV-NAT in northern Brazil

Background

Nucleic acid testing (NAT) for virus detection during blood screening has helped to prevent transfusion-transmitted infections worldwide. In northern Brazil, NAT was implemented in 2012 for HIV and HCV and more recently, in January 2015, the screening for HBV was included and currently used concomitant with serological tests (HBsAg and anti-HBc). This study aims to evaluate the prevalence and the incidence of HBV infection among voluntary blood donors at ten regional blood centers of HEMOPA Foundation in Pará state and to compare the residual risk of transfusion-transmitted HBV infection before and after the Brazilian HBV-NAT implementation.

Methods

The prevalence (restricted to first time donors- FT) and seroconversion rate (restricted to repeat donors- RP) of HBV were calculated based on rates of confirmed positive samples. Residual risk was based on the incidence and window period (WP) model described by Schreiber and coauthors. Logistic and Poisson regression were used in the statistical analysis by SPSS v20.0. A p value <0.05 was considered statistically significant.

Results

HBV prevalence in the periods before and after the implementation of HBV-NAT were 247 and 251 per 100,000 donations, respectively. Seroconversion rates were 114 and 122 per 100,000 donations in the two periods, respectively. The residual risk (RR) for HBV decreased significantly in the posterior period to the HBV-NAT implementation, when compared to RR before implementation, with a reduction of 1:144,92 to 1:294,11 donations (p <0,001).

Conclusions

The RR to HBV decreased after the implementation of HBV-NAT, increasing significantly the transfusional security in the North region of Brazil at HEMOPA Foundation.

A study on confidential unit exclusion at Shiraz Blood Transfusion Center, Iran

Background:

Confidential unit exclusion (CUE) system has been designed to enhance transfusion safety as an extra additive approach.

Aims:

This study was designed to survey demographic characteristics, prevalence of serologic markers, and reasons of opting CUE.

Materials and Methods:

The cross-sectional study was performed at Shiraz Blood Transfusion Center (Southern Iran). CUE is used for all individuals who refer for blood donation, and donors can choose their blood not to be used if they have any doubt about their blood suitability for transfusion. The prevalence rate of HIV, hepatitis B virus (HBV), and hepatitis C virus (HCV) was compared between the blood donors who opted into and out of CUE. Then, the donors were contacted to give another blood sample and the reasons of deferral. Researchers also determined whether their reasons were logical or not. Data were analyzed using comparison of proportions in MedCalc software 7.

Results:

Out of all the donors, 2365 ones (2.3%) opted for CUE. CUE was more frequent among men, singles, donors with low education levels, between 18 and 25 years old, and with history of previous donation (P < 0.05). The prevalence rate of HCV was higher among the donors who opted for CUE (P < 0.05), but it was not the case regarding HBV and HIV (P>0.05). Furthermore, 91.5% of the donors had opted for CUE by mistake and only 8% had chosen CUE logically.

Conclusion:

It is necessary to review the process of CUE, make some changes both in procedure and design, and then survey its effectiveness in blood safety.

Comparison between screening and confirmatory serological assays in blood donors in a region of South Italy

BACKGROUND

Screening assays are needed in order to guarantee safety of donated blood, but a significant number of safe donations are removed from blood supply because of reactive screening results. It is important to evaluate the positive predictive value (PPV) of screening assays in order to modulate confirmatory algorithm and implement an adequate counseling.

METHODS

An analysis of 17,912 blood donations has been conducted at Transfusion Medicine at Second University Naples, Italy, in 2009-2012. Serological screening for syphilis, hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) was performed by ARCHITECT (Abbott Diagnostics, Wiesbaden, Germany); repeatedly reactive (RR) samples were checked by respective confirmatory tests. The relationship between sample/cutoff and confirmed seropositivity were analyzed.

RESULTS

RR rates were low as expected in blood donors: 0.47% for syphilis, 0.42% for HBV, 0.50% for HCV, and 0.15% for HIV. The specificity on RR + gray zone (GZ) was 99.67%, 99.79%, 99.77%, and 99.88%, respectively; due to the low prevalence, PPV value was 30.6% for syphilis, 50.7% for HBV, 42.2% for HCV, and 18.5% for HIV. These values increased substantially reaching a plateau of 89.3% for syphilis, 94.6% for HBV, 85.7% for HCV, and 100% for HIV at the threshold established by receiver operating characteristics curve analysis.

CONCLUSIONS

Supplemental testing on samples with high signal by screening assays seems to add little information. GZ settings and confirmatory testing for positive screening results should be designed taking in account several factors, including difference in the natural history among blood-borne infections, the characteristics of first- and second-level tests, and, when available, the results of nucleic acid amplification testing.

Intraoperative cell salvage in revision hip surgery

Allogenic blood is a finite resource, with associated risks. Previous studies show intraoperative cell salvage (ICS) can reduce allogenic transfusion rates in orthopaedic surgery. However, there are concerns regarding efficacy and cost-effectiveness of ICS. This study was carried out to review ICS use in revision hip arthroplasty. All patients who underwent ICS and re-infusion between 2008 and 2010 in the Southern General Hospital (SGH) were audited. The fall in haemoglobin (Hb), volume of blood re-infused and postoperative allogenic transfusion rates were recorded. This group was compared to a similar SGH cohort who underwent surgery by the same surgeons between 2006 and 2008, and a pre-2005 control group where no ICS was used. The proportion of patients receiving a postoperative allogenic transfusion fell by 55% in the 2008-2010 ICS cohort compared with the control, and by 40% compared with the previous ICS group. In both instances, there was a statistically significant (p < 0.001) reduction in mean units transfused per patient; in the 2008-2010 ICS cohort, a mean of 0.8 units was used per patient, while 1.4 were used in the 2006-2008 cohort. 3.5 units were used in the control group. There was no statistically significant difference in age or preoperative Hb between the groups, or in length of hospital stay. In this study, ICS has been shown to be effective in reducing rates and volume of postoperative allogenic transfusion in patients undergoing revision hip surgery at the SGH. However, further work is needed to establish the effect of changing anaesthetic technique on postoperative allogenic transfusion rates.

The risk of transfusion-transmitted viral infections at the Gabonese National Blood Transfusion Centre

BACKGROUND

Blood transfusions carry the risk of transmitting blood-borne infections. In contrast to the situation in the developed world, there is a limited number of studies examining this problem in sub-Saharan Africa. In this study we aimed to calculate the risks of acquiring human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) infection from units of blood issued by the Gabonese Blood Transfusion Centre between 2009 and 2011.

MATERIALS AND METHODS

All the donations were tested for infectious diseases and the seroconversion incidence rates of HIV, HBV and HCV were calculated. The residual risk of transfusion-associated transmission for each virus was calculated by multiplying the seroconversion rates by the window period expressed in fractions of a year.

RESULTS

The risks of becoming infected with HIV, HCV, and HBV in subjects receiving units of blood from the Gabonese Blood Transfusion Centre were 64.7, 207.94 and 534.53 per million donations, respectively.

CONCLUSIONS

This study, which is the first to quantify the true risks of transfusion-transmitted infections in Gabon, reveals and confirms the need to reinforce preventative and screening strategies to improve transfusion safety in sub-Saharan Africa.

Hepatitis C virus maintains infectivity for weeks after drying on inanimate surfaces at room temperature: implications for risks of transmission

BACKGROUND

Healthcare workers may come into contact with fomites that contain infectious hepatitis C virus (HCV) during preparation of plasma or following placement or removal of venous lines. Similarly, injection drugs users may come into contact with fomites. Hypothesizing that prolonged viability of HCV in fomites may contribute significantly to incidence, we determined the longevity of virus infectivity and the effectiveness of antiseptics.

METHODS

We determined the volume of drops misplaced during transfer of serum or plasma. Aliquots equivalent to the maximum drop volume of plasma spiked with the 2a HCV reporter virus were loaded into 24-well plates. Plates were stored uncovered at 3 temperatures: 4°C, 22°C, and 37°C for up to 6 weeks before viral infectivity was determined in a microculture assay.

RESULTS

The mean volume of an accidental drop was 29 µL (min-max of 20-33 µL). At storage temperatures 4°C and 22°C, we recovered viable HCV from the low-titer spots for up to 6 weeks of storage. The rank order of HCV virucidal activity of commonly used antiseptics was bleach (1:10) > cavicide (1:10) > ethanol (70%).

CONCLUSIONS

The hypothesis of potential transmission from fomites was supported by the experimental results. The anti-HCV activity of commercial antiseptics varied.

Residual Risk of Hepatitis-B-Infected Blood Donations: Estimation Methods and Perspectives

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.

Prevalence of serologic markers for hepatitis B and C viruses in Brazilian blood donors and incidence and residual risk of transfusion transmission of hepatitis C virus

BACKGROUND

We evaluate the current prevalence of serologic markers for hepatitis B virus (HBV) and hepatitis C virus (HCV) in blood donors and estimated HCV incidence and residual transfusion-transmitted risk at three large Brazilian blood centers.

STUDY DESIGN AND METHODS

Data on whole blood and platelet donations were collected from January through December 2007, analyzed by center; donor type; age; sex; donation status; and serologic results for hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (anti-HBc), and anti-HCV. HBV and HCV prevalence rates were calculated for all first-time donations. HCV incidence was derived including interdonation intervals that preceded first repeat donations given during the study, and HCV residual risk was estimated for transfusions derived from repeat donors.

RESULTS

There were 307,354 donations in 2007. Overall prevalence of concordant HBsAg and anti-HBc reactivity was 289 per 100,000 donations and of anti-HCV confirmed reactivity 191 per 100,000 donations. There were significant associations between older age and hepatitis markers, especially for HCV. HCV incidence was 3.11 (95% confidence interval, 0.77-7.03) per 100,000 person-years, and residual risk of HCV window-phase infections was estimated at 5.0 per million units transfused.

CONCLUSION

Improvement in donor selection, socioeconomic conditions, and preventive measures, implemented over time, may have helped to decrease prevalence of HBV and HCV, relative to previous reports. Incidence and residual risk of HCV are also diminishing. Ongoing monitoring of HBV and HCV markers among Brazilian blood donors should help guide improved recruitment procedures, donor selection, laboratory screening, and counseling strategies.

Reducing the risk of hepatitis B virus transfusion-transmitted infection

Before 1970, approximately 6% of multi-transfused recipients acquired a transfusion-transmitted Hepatitis B virus (HBV) infection. The safety improvements since then have been tremendous. From a level of a few infections per 1000 donations, the risk today, depending on the screening algorithm and additional measurements performed, has decreased to around 1:500,000 to 1:1,000,000, an improvement greater than 1000-fold compared to 50 years ago. This enormous gain in safety has been achieved through many factors, including development of increasingly more sensitive Hepatitis B antigen (HBsAg) assays; the adoption in some countries of hepatitis B core antibody (anti-HBc) screening; an improved donor selection procedure; HBV vaccination programs; and finally the introduction of HBV nucleic acid testing (NAT). Because there is a tendency in transfusion medicine to add one safety measure on top of another to approach the ultimate goal of zero risks, costs become increasingly a matter of debate. It is obvious that any new measure in addition to existing methods or measures will have very poor cost effectiveness. Therefore each country needs to perform its own calculation based on the country’s own epidemiology, resources, political and public awareness of the risks, in order to choose the correct and most cost-efficient measures. Ideally, each country would make decisions regarding implementation of additional blood safety measures in the context of both the perceived benefit and the allocation of overall health care resources.

A systematic review of hepatitis C virus epidemiology in Europe, Canada and Israel

BACKGROUND AND AIM

Decisions on public health issues are dependent on reliable epidemiological data. A comprehensive review of the literature was used to gather country-specific data on risk factors, prevalence, number of diagnosed individuals and genotype distribution of the hepatitis C virus (HCV) infection in selected European countries, Canada and Israel.

METHODOLOGY

Data references were identified through indexed journals and non-indexed sources. In this work, 13,000 articles were reviewed and 860 were selected based on their relevance.

RESULTS

Differences in prevalence were explained by local and regional variances in transmission routes or different public health measures. The lowest HCV prevalence (≤ 0.5%) estimates were from northern European countries and the highest (≥ 3%) were from Romania and rural areas in Greece, Italy and Russia. The main risk for HCV transmission in countries with well-established HCV screening programmes and lower HCV prevalence was injection drug use, which was associated with younger age at the time of infection and a higher infection rate among males. In other regions, contaminated glass syringes and nosocomial infections continue to play an important role in new infections. Immigration from endemic countries was another factor impacting the total number of infections and the genotype distribution. Approximately 70% of cases in Israel, 37% in Germany and 33% in Switzerland were not born in the country. In summary, HCV epidemiology shows a high variability across Europe, Canada and Israel.

CONCLUSION

Despite the eradication of transmission by blood products, HCV infection continues to be one of the leading blood-borne infections in the region.

[Current status of acute hepatitis C]

Acute hepatitis C (AHC) is an increasing health issue. Despite the decline of blood-to-blood transmission of hepatitis C virus (HCV) through donor screening programs and a decline in intravenous drug use, the incidence of sexual transmission has now increased, particularly in HIV-infected homosexual patients. The presentation is almost always asymptomatic, which complicates diagnosis. Spontaneous clearance of the virus occurs in 25% of cases and usually, within the first three months after onset of symptoms and in symptomatic patients. If serum HCV-RNA remains detectable after this period, antiviral treatment should be started without delay, since sustained viral response rate in the acute phase is higher than that achieved with chronic liver disease. The optimal treatment regimen (interferon alone or combined with ribavirin) and its duration are not clearly established at the present time.

Positivity of HIV, hepatitis B and hepatitis C in patients enrolled in a confidential self-exclusion system of blood donation: a cross-sectional analytical study

CONTEXT AND OBJECTIVE

Selection of healthy blood donors is essential to ensure blood safety. A confidential self-exclusion (CSE) system was designed so that high-risk donors could confidentially exclude their blood from use in transfusions. This study aimed to compare the demographic characteristics and the results from human immunodeficiency virus (HIV), hepatitis B surface (HBS) and hepatitis C virus (HCV) screening tests on donors who opted to get into and out of CSE.

DESIGN AND SETTING

Analytical cross-sectional study on all volunteer donors at Shiraz Blood Transfusion Organization from March 21, 2006, to March 21, 2008.

METHODS

The results from the abovementioned tests were compared between donors who opted into and out of CSE.

RESULTS

100,148 donors in 2006 and 104,271 in 2007 gave blood. Among these donors, respectively, 829 (0.82%) and 592 (0.57%) opted for the CSE. The prevalence of HIV antibodies, HBS antigens and HCV antibodies in CSE donors was significantly higher than in donors who did not choose CSE (p < 0.05). The prevalence of at least one of these three infections among CSE donors was 3.12% in 2006 and 3.04% in 2007, and was significantly higher than the prevalence among non-CSE donors (0.58% and 0.57%, respectively).

CONCLUSION

Because of the higher prevalence of HBS, HCV and HIV positivity in blood donors who chose the CSE option, offering CSE to blood donors could be a potentially useful method for improving blood safety, since it could increase the detection of infected blood during the window period.

Transfusion-transmitted hepatitis B virus infection

Hepatitis B virus (HBV) remains a major risk of transfusion-transmitted infection due to the pre-seroconversion window period (WP), infection with immunovariant viruses, and with occult carriage of HBV infection (OBI). Reduction of HBV residual risk depends upon developing more sensitive HBV surface antigen (HBsAg) tests, adopting anti-HBc screening when appropriate, and implementing HBV nucleic acid testing (NAT), either in minipools or more efficiently in individual samples. HBV NAT combines the ability to significantly reduce the window period and to detect occult HBV carriage substantiating decades of clinical observation that HBsAg-negative/anti-HBc-positive blood could transmit HBV. Clinical observations suggest limited transmission rate of occult HBV compared to WP. Low transmission rate might be related to low viral load observed in OBIs or to the presence of mutants associated with occult carriage. OBIs carrying detectable anti-HBs ( approximately 50%) are essentially not infectious by transfusion. However, recent data suggest that the neutralizing capacity of low anti-HBs may be inefficient when overcome by exposure to high viral load. Anti-HBc blood units without detectable anti-HBs appear moderately infectious except in immunocompromised recipients. Immunodeficient elderly and patients receiving immunosuppressive treatments may be susceptible to infection with lower infectious dose even in the presence of anti-HBs. The immune status of blood recipients should be taken into consideration when investigating "post-transfusion" HBV infection. Pre-transfusion testing and post-transfusion long-term follow-up of recipients, and molecular analysis of the virus infecting both donor and recipient are critical to definitively incriminate transfusion in the transmission of HBV.

Identification of low HBV-DNA levels by nucleic acid amplification test (NAT) in blood donors

OBJECTIVE

To evaluate the presence of HBV-DNA in 22,765 consecutive blood donors, who donated blood in the period from January 2006 to August 2007 at a transfusion centre in Lazio, a region in central Italy with low HBV endemicity.

METHODS

Each donation was individually tested using immunoenzymatic assays and nucleic acid amplification technologies (NAT). Samples that were reactive to generic NAT, Procleix Ultrio Assay were tested for HBV-DNA, HCV-RNA and HIV1-RNA by Discriminatory Procleix Ultrio NAT Assay. In samples that were reactive to generic NAT and negative for HBsAg, HCV-RNA and HIV1-RNA, HBV-DNA was further tested using Cobas TaqMan and an in-house nested PCR following an ultracentrifugation step. Sequence analysis confirmed HBV-DNA positivity.

RESULTS

Generic NAT identified 31 (0.13%) reactive sera. HBV-DNA discriminatory NAT identified 15 positive sera; HBsAg was positive in 12 sera. Of the 5 generic NAT-reactive/discriminatory NAT-negative/HBsAg-negative sera and of the 3 HBsAg-negative/HBV-DNA discriminatory NAT-positive sera, 7 were positive to Cobas TaqMan or the in-house PCR after ultracentrifugation. The overall HBV-DNA positivity was 0.083% [19 of 22,765 donors: 12 HBsAg-positive (HBV-DNA range 10(2)-10(4) IU/mL), 7 HBsAg-negative/anti-HBc positive (HBV-DNA< 6 IU/mL)].

CONCLUSIONS

For blood transfusion safety, the significance of the finding of very low HBV-DNA levels should be further investigated. Our data indicate that in areas with a low HBV endemicity, single NAT assays may not always identify blood donations with very low HBV-DNA levels.

Acute hepatitis C: current status and remaining challenges

The acute phase of hepatitis C virus (HCV) infection represents a key point in the evolution of hepatitis C. In some patients, the infection resolves spontaneously, whereas in others it develops into chronic disease. However, because acute hepatitis C is often asymptomatic, detection and diagnosis are usually difficult. What is more, there are no established treatment guidelines, leaving physicians to make several challenging decisions, such as whether to treat, when to treat and what treatment regimen to use. Pegylated interferon alfa monotherapy is most commonly used to treat patients with acute hepatitis C; the role of ribavirin has yet to be established. In this review, we discuss the epidemiology of acute hepatitis C, its risk factors and routes of transmission and current treatment practices. We also discuss data from published clinical studies and focus on unresolved issues for which additional studies are needed in order to establish standardized treatment guidelines for the management of acute hepatitis C.

Treatment of acute hepatitis C: the success of monotherapy with (pegylated) interferon alpha

Early control in the acute phase of hepatitis C infection is an attractive therapeutic goal in order to shorten disease duration and infectivity, to prevent chronicity and progression to advanced liver disease and to avoid eventual therapeutic non-response in the later stages of chronic hepatitis C. Over the past decade, different interferon-based treatment options have been developed, which lead to sustained virological response rates of up to 98%. The present article summarizes the successful invention of immediate and delayed strategies in acute hepatitis C monoinfection, critically discusses potential limitations and illustrates the therapeutic challenges of the near future.

Acute hepatitis B 14 years after the implementation of universal vaccination in Italy: areas of improvement and emerging challenges

BACKGROUND

Italy had intermediate-level endemicity for hepatitis B virus (HBV) infection in the 1970s and 1980s. In 1991, vaccination of infants and adolescents became mandatory. We report the impact of universal vaccination 14 years after its beginning.

METHODS

We performed a case-control study within a population-based surveillance for acute viral hepatitis. The incidence of acute hepatitis B (AHB) was estimated for the time since 1991, and the association between AHB and the considered risk factors was analyzed for the period 2001-2005.

RESULTS

The incidence of AHB progressively decreased from 1991 to 2005, mainly for persons in the age groups targeted by the universal vaccination campaign: there was a 24-fold and 50-fold decrease in the 15-24-year and 0-14-year age groups, respectively; for the > or =25-year age group, the incidence halved. Owing to the persons' ages, approximately 3% of total AHB cases should have been the target of vaccination campaign. In 2004-2005, foreigners accounted for 14% of total cases and for 57% of persons who should have been targets for vaccination. Missed opportunities for immunization were documented for approximately 50% of patients with AHB who reported cohabitation with HBV carriers and for 70% of those who reported injection drug use. The strongest associations with AHB were found for blood transfusion (adjusted odds ratio [OR(adj)], 8.4; 95% confidence interval [CI], 2.7-26), cohabitation with HBV carriers (OR(adj), 5.3; 95% CI, 3.6-7.7), injection drug use (OR(adj), 3.8; 95% CI, 2.5-5.8), and unsafe sexual practices (OR(adj), 2.8; 95% CI, 1.9-4.2).

CONCLUSION

Universal vaccination has contributed to a decreasing AHB incidence in Italy, especially by reducing the risk of infection among persons aged 15-24 years. Most infections occur in persons aged > or =25 years in association with injection drug use, unsafe sexual activity, percutaneous treatment, and iatrogenic exposure. Improvement of vaccine coverage in high-risk groups and adherence to infection control measures during surgery and percutaneous treatment are needed. The high risk still associated with blood transfusion needs to be further investigated, with consideration of occult HBV infection in blood donors. The potential spread of HBV infection from the immigrant population deserves adequate health policy prevention programs.

Nucleic acid testing (NAT) for HCV RNA in Italian transfusion centres: an external quality assessment

BACKGROUND

We conducted an external quality assessment of the results obtained in Italian transfusion centre laboratories employing nucleic acid testing (NAT) for detection of HCV RNA in donated blood.

STUDY DESIGN

Of 110 transfusions centres in Italy, 101 voluntarily participated. Each laboratory received seven separate shipments of samples for HCV RNA testing by NAT. Each shipment contained 8 plasma samples for a total of 23 negative and 33 positive samples with viral loads ranging from 25 to 1000 IU/mL.

RESULTS

Of the 2080 HCV RNA-negative samples, 14 (0.7%) were reported as positive. The highest percent of false-negative results (6.9%) was found on samples from the first shipment with viral loads from 75 to 100 IU/mL. In subsequent shipments, the highest false-negative percentage ranged from 0.6% for samples with viral loads of 170-1000 IU/mL to 3.4% for samples with viral loads of 35-50 IU/mL. A false-negative rate of 4.9% occurred in samples in the sixth shipment with the lowest viral load (25IU/mL). Five (4.9%) centres were identified as having laboratories with low-performance. There were no significant differences among genotypes 1b, 2c and 3a with respect to percent of false-negative results reported.

CONCLUSIONS

Overall, the accuracy of NAT observed in this study of Italian transfusion centre laboratories was excellent for all HCV genotypes tested, even for samples with low HCV RNA titres.

Seroprevalence of hepatitis B and C virus markers among blood donors in Rio de Janeiro, Brazil, 1998-2005

The prevalence of infection by hepatitis B (HBV) and C (HCV) viruses varies among geographical regions. In order to determine the prevalence of HBV and HCV infection in voluntary blood donors we evaluated the prevalence of HBsAg, anti-HBc, and anti-HCV markers of 128,497 blood donor samples collected from 1998 to 2005 in the state of Rio de Janeiro. These markers were analyzed by immunoenzymatic tests, as determined by the Ministry of Health. Data were obtained from the Sorology Laboratory of the Hemotherapy Service of the Instituto Nacional de Câncer, Rio de Janeiro. Overall prevalence estimates were: 0.27% for HBsAg, 3.68% for anti-HBc, and 0.90% for anti-HCV. There was a significant decrease in the overall prevalence of HBsAg (from 0.36 to 0.14%) and anti-HBc (from 6.12 to 2.05%) in the period encompassed between 1998-2005. Similarly, there was a decline in anti-HCV prevalence rates in Brazilian blood donors, from 1.04% in 1998 to 0.79% in 2004, with an increase of HCV prevalence to 1.09% in 2005. These prevalence estimates were higher than those found in other countries, indicating high rates of infection by HBV and HCV and a persistent risk of HBV and HCV transmission by transfusion.

Sensitivity of hepatitis B virus DNA transcription-mediated amplification testing in hepatitis B surface antigen-positive blood donations

BACKGROUND

The objective was to evaluate the performance of nucleic acid testing (NAT) in the detection of hepatitis B virus (HBV) infection in hepatitis B surface antigen (HBsAg)-positive blood donations.

STUDY DESIGN AND METHODS

A total of 253 HBsAg- and anti-hepatitis B core antigen (HBc)-positive samples (50 hepatitis B e antigen [HBeAg]-positive and 203 anti-HBe-positive) from blood donations collected in France were studied. The samples were investigated with a blood screening assay (Procleix Ultrio, Chiron/Gen-Probe) in minipool (MP; x8) and in individual-donation (ID) testing. All nonreactive samples were retested once, and nonreactive MP samples were assayed for viral load (VL).

RESULTS

All 50 HBeAg-positive samples were reactive in MP-NAT and ID-NAT. Of the 203 anti-HBe-positive donations, 80.3 percent were MP- and ID-reactive, 17.2 percent were MP-nonreactive and ID-reactive, and 2.5 percent were nonreactive in ID-NAT. Overall the sensitivity of ID-NAT was 98 percent versus 84 percent for MP-NAT. After retesting, 16 of the 35 MP-nonreactive and/or ID-reactive donations became MP-reactive and 2 of the ID-nonreactive donations became NAT-reactive. The capacity of Procleix Ultrio to detect HBV DNA was not related to HBsAg subtype, but correlated with the VL: the mean VL in the group of MP-nonreactive samples was 1,420 copies per mL vs. 17,000 copies per mL in the group of 40 MP-reactive samples.

CONCLUSION

These results demonstrate that HBV-NAT in ID format is far more effective in detecting viremia in chronic HBsAg carriers than in MP-NAT. The sensitivity of the NAT assay needs to be improved to be considered for replacing the current HBsAg assays, especially when anti-HBc testing is not performed.

Risk factors and outcome among a large patient cohort with community-acquired acute hepatitis C in Italy

BACKGROUND

The epidemiology of acute hepatitis C has changed during the past decade in Western countries. Acute HCV infection has a high rate of chronicity, but it is unclear when patients with acute infection should be treated.

METHODS

To evaluate current sources of hepatitis C virus (HCV) transmission in Italy and to assess the rate of and factors associated with chronic infection, we enrolled 214 consecutive patients with newly acquired hepatitis C during 1999-2004. The patients were from 12 health care centers throughout the country, and they were followed up for a mean (+/- SD) period of 14+/-15.8 months. Biochemical liver tests were performed, and HCV RNA levels were monitored.

RESULTS

A total of 146 patients (68%) had symptomatic disease. The most common risk factors for acquiring hepatitis C that were reported were intravenous drug use and medical procedures. The proportion of subjects with spontaneous resolution of infection was 36%. The average timespan from disease onset to HCV RNA clearance was 71 days (range, 27-173 days). In fact, 58 (80%) of 73 patients with self-limiting hepatitis experienced HCV RNA clearance within 3 months of disease onset. Multiple logistic regression analyses showed that none of the variables considered (including asymptomatic disease) were associated with increased risk of developing chronic hepatitis C.

CONCLUSIONS

These findings underscore the importance of medical procedures as risk factors in the current spread of HCV infection in Italy. Because nearly all patients with acute, self-limiting hepatitis C--both symptomatic and asymptomatic--have spontaneous viral clearance within 3 months of disease onset, it seems reasonable to start treatment after this time period ends to avoid costly and useless treatment.

Hierarchy of baby-linked immunogenetic risk factors in the vertical transmission of hepatitis C virus

Mother-to-infant transmission of Hepatitis C Virus (HCV) represents the major cause of pediatric HCV infection today. Immunogenetic influence has been poorly investigated and mainly confined to HLA-class II serological polymorphisms. Among 290 parities, 135 from Pavia and 155 from Bergamo, of HCV-RNA-infected Italian women, 21 babies (7.24%) were HCV-RNA positive at birth and steadily positive over 20 months of life. All the 21 infected babies and 44 randomly selected uninfected ones, born to HCV-RNA+ mothers but steadily negative for HCV-RNA during a follow-up of 2 years, and their mothers were investigated for HLA-G, -C, -DRB1, -DQA1 and -DQB1 genomic polymorphisms. Among the different covariates, HLA-Cw*07, -G*010401, -DRB1*0701, -DRB1*1401 and homozygosity for HLA-G 14bp deletion can be considered as risk factors for HCV vertical transmission. On the contrary, protection was conferred by the HLA-DQB1*06, -G*0105N, -Cw*0602, DRB1*1104 and -DRB1*1302 alleles. Our initial question was: has the immunogenetic profile any role in the protection of the fetus growing in an infected milieu and, if so, is it independent from the other non-immunogenetic parameters? The answer to both questions should be yes.

Kidney transplantation from anti-HBc+ donors: results from a retrospective Italian study

BACKGROUND

The risk of transmitting a hepatitis B virus (HBV) infection from donor kidneys with a past HBV serological profile may be negligible. Data on HBV transmission to kidney transplant recipients from donor organs that were anti-HBc/HBsAg in Italy has not been previously reported. Anti-HBc testing in cadaver organ donors has been mandatory in Italy since 2002, when anti-HBc determinations were included in the National Guidelines for donor evaluation. Therefore, prior to that date kidney recipients from anti-HBc/HBsAg donors can be identified retrospectively where stored serum is available for testing.

METHODS

The prevalence of anti-HBc Italian organ donors, the incidence of HBV transmission according to the recipients' HBV status (vaccinated, recovered, or naive), and the clinical impact (5-year graft and patient survival rates) in the North Italy Transplant program was evaluated by retrospectively screening for anti-HBc antibodies in the sera of cadaver kidney donors used in transplants from 1997 to 1999.

RESULTS

Two hundred and ten donors were found to have been anti-HBc. At the time of the study, no active infection was observed in any of the 344 HBsAg recipients, but 4/140 (2.86%) of the vaccinated recipients were found to have been anti-HBc/HBsAg. None of these patients, however, had any biochemical or clinical history of HBV infection. Patient and graft survival rates of anti-HBc or anti-HBc kidney recipients did not differ statistically.

CONCLUSION

Kidney grafts from anti-HBc donors should be considered in all recipients because the benefit obtained from the transplantation out weighs the negligible risk of HBV transmission.

Residual risk of transfusion-transmitted human immunodeficiency virus, hepatitis C virus, and hepatitis B virus infections in Italy

BACKGROUND

Estimating the risk of transfusion-transmitted infections (TTIs) is essential for monitoring blood safety. The residual risk of TTI was estimated for nearly 90 percent of the blood supply in Italy.

STUDY DESIGN AND METHODS

Data were analyzed from 1,079,281 repeat donors, corresponding to 5,361,000 donations made in blood transfusion centers throughout Italy in the period 1999 through 2001. The residual risk of transfusion-transmitted human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) infections was estimated with the incidence rate-window period model. The denominator for the incidence rate (i.e., the number of person-years at risk) was estimated on a sample of 5850 donors.

RESULTS

The risk of an infectious donation entering the blood supply, per 1 million donations, was 1.91 (probable range, 0.52-3.32) for HIV, 16.74 (9.57-24.01) for HCV, and 69.16 (43.12-102.70) for total HBV (adjusted for vaccination and hepatitis B surface antigen transience).

CONCLUSION

In Italy, the estimated residual risk of TTI is apparently low, particularly for HIV infection. Although the estimated risks are higher for HCV and HBV, the introduction of mandatory viral detection tests for HCV in 2002 should account for an 80 percent reduction in the HCV risk. Moreover, the ongoing HBV vaccination program will contribute to reducing the risk of transfusion-transmitted HBV.

Behavior Assessment of Blood Donors Facing the Risk of HIV Infection, Abidjan, Côte D'Ivoire, 2001-2002

Despite precautions taken to guarantee blood safety, in the National Blood Transfusion Center (CNTS) of Abidjan, about 30 regular blood donors are detected with HIV seroconversion each year, two-thirds of them men. A survey through face-to-face interviews was carried out at the CNTS of Abidjan from September 2001 to March 2002 among HIV-positive and HIV-negative regular blood donors, informed about their serologic status. HIV-negative regular blood donors informed about their serologic status since a median time of 67 months (n = 50) disclosed more risky behaviors such as multiple sexual partners (68%) than HIV-positive blood donors informed about their status (n = 112) since a median time of 35 months (41%) (P < 0.001). Condoms were systematically used by 17% of HIV-negative blood donors and 55% of HIV-positive blood donors (P < 0.001). Enhanced counseling and awareness could reduce in the future the number of cases of seroconversion among regular blood donors and improve their subsequent behavior. Blood donors who have unprotected sex with partners of unknown HIV serologic status and especially with casual partners are strongly exposed to HIV transmission and should be discouraged to continue giving blood, after adequate counseling.

Safety of the blood supply in Latin America

Appropriate selection of donors, use of sensitive screening tests, and the application of a mandatory quality assurance system are essential to maintain the safety of the blood supply. Laws, decrees, norms, and/or regulations covering most of these aspects of blood transfusion exist in 16 of the 17 countries in Latin America that are the subject of this review. In 17 countries, there is an information system that, although still incomplete (there are no official reports on adverse events and incidents), allows us to establish progress made on the status of the blood supply since 1993. Most advances originated in increased screening coverage for infectious diseases and better quality assurance. However, in 2001 to 2002, tainted blood may have caused infections in 12 of the 17 countries; no country reached the number of donors considered adequate, i.e., 5% of the population, to avoid blood shortages, or decreased significantly the number of blood banks, although larger blood banks are more efficient and take advantage of economies of scale. In those years, paid donors still existed in four countries and replacement donors made up >75% of the blood donors in another eight countries. In addition, countries did not report the number of voluntary donors who were repeat donors, i.e., the healthiest category. In spite of progress made, more improvements are needed.

Use of the minimum spanning tree model for molecular epidemiological investigation of a nosocomial outbreak of hepatitis C virus infection

The minimum spanning tree (MST) model was applied to identify the history of transmission of hepatitis C virus (HCV) infection in an outbreak involving five children attending a pediatric oncology-hematology outpatient ward between 1992 and 2000. We collected blood samples from all children attending since 1992, all household contacts, and one health care worker positive for antibody to HCV (anti-HCV). HCV RNA detection was performed with these samples and with smears of routinely collected bone marrow samples. For all isolates, we performed sequence analysis and phylogenetic tree analysis of hypervariable region 1 of the E2 gene. The MST model was applied to clinical-epidemiological and molecular data. No additional cases were detected. All children, but not the health care worker, showed genotype 3a. On six occasions, all but one child had shared the medication room with another patient who later seroconverted. HCV RNA detection in bone marrow smears revealed, in some cases, a delay of several months in anti-HCV responses. Sequence analysis and phylogenetic tree analysis revealed a high identity among the isolates. The MST model applied to molecular data, together with the clinical-epidemiological data, allowed us to identify the source of the outbreak and the most probable patient-to-patient chain of transmission. The management of central venous catheters was suspected to be the probable route of transmission. In conclusion, the MST model, supported by an exhaustive clinical-epidemiological investigation, appears to be a useful tool in tracing the history of transmission in outbreaks of HCV infection.

Infection with human herpes virus type 8 in an area at high prevalence for hepatitis C virus infection in southern Italy

The Campania Region is a geographical area of southern Italy characterized by high incidence rates of hepatocellular carcinoma and of classic Kaposi's sarcoma. Epidemiological investigations carried out among different population groups in this region have found high prevalence rates of both hepatitis C virus (HCV) and human herpesvirus type 8 (HHV-8). To assess co-infection rates of HCV and HHV-8, we carried out a cross-sectional seroepidemiological study prevalence in Pomigliano d'Arco, a Health District of Campania located 20 km away from Naples. The overall rate of HCV/HHV-8 co-infection was 3.1%, 3.5% among men and 2.7% among women. No difference emerged in the HCV/HHV-8 co-infection rates according to seropositivity for HCV infection, either overall (Mantel Haenszel odds ratio = 1.2, 95% CI: 0.6-2.6) or when the analysis was stratified by gender. These findings support the hypothesis that in Campania common routes of transmission are rarely shared by HCV and HHV-8 infections. Local factors may result in different epidemiological patterns for these two viral infections. However, our findings have important public health implications, especially in Mediterranean countries where HCV and HHV-8 infections are endemic.

Epidemiological and clinical burden of chronic hepatitis B virus/hepatitis C virus infection. A multicenter Italian study

BACKGROUND/AIMS

This study assess prevalence, risk factors, and clinical and virological features of dual hepatitis B virus (HBV)/hepatitis C virus (HCV) infection.

METHODS

We evaluated 837 hepatitis B surface antigen positive patients, prospectively enrolled in 14 Italian units.

RESULTS

Anti-HCV was present in 59 cases (7%); age specific prevalences were 4.5% (0-30 years), 4.4% (>30-50) and 14% (>50). Independent predictors of dual infection were age >42 years, history of I.V. drug use (IDU), blood transfusion and residence in the South of the country. The strength of the association with IDU was high, but this exposure accounted for five coinfection cases only. Cirrhosis was present in 107 of the 709 patients with HBV alone (15.1%), in 30 of 69 with hepatitis D virus coinfection (43%) and in 17 of 59 with HCV coinfection (28.8%); a light alcohol use was marginally associated with cirrhosis. Of 36 B/C coinfected patients, 16 (44.4%) had only HBV-DNA in serum, (median age=47.5 years) five (13.9%) had both HBV-DNA and HCV-RNA (age=53), nine (25%) had HCV-RNA alone (age=59) and six (16.7%) tested negative for both.

CONCLUSIONS

This study depicts the epidemiological and clinical burden of dual HBV/HCV infection in Italy.

Health and economic impact of posttransfusion hepatitis B and cost-effectiveness analysis of expanded HBV testing protocols of blood donors: a study focused on the European Union

BACKGROUND

Residual risk of posttransfusion hepatitis B (PT-HB) may be reduced through implementation of HBV NAT or the new, enhanced-sensitivity HBsAg assays in routine donor testing. However, there are some doubts about the cost-effectiveness of these new safety measures, because hepatitis B acquired in adulthood is not regarded as a severe disease in western countries.

STUDY DESIGN AND METHODS

A computer model was designed to estimate the health outcomes and associated costs of patients with PT-HB. Results from this model and estimations of the residual risk of HBV transmission, the risk reduction yielded by the new assays, and their cost were used to calculate the cost-effectiveness of including the new HBsAg assays or single-sample HBV NAT in the routine screening of blood donors.

RESULTS

The model predicts that 0.97 percent of patients with PT-HB die of liver disease (54% of them due to fulminant hepatitis). The mean loss of life expectancy was 0.178 years per patient, and the present value of the lifetime costs of treating PT-HB was 4160 euros per patient. Single-donor HBV NAT or the new HBsAg assays would increase the life expectancy of blood recipients by 16 (95% CI, 8-40) or 14 (95% CI, 7-28) years, respectively, per every 10 million donations tested. The projected cost per life-year gained was 0.79 (95% CI, 0.15-1.85) million euros for the enhanced-sensitivity HBsAg assays and 5.8 (95% CI, 1.9-13.1) million euros for single-donation HBV NAT, both compared with current HBsAg assays. If single-donation HBV NAT is compared with the new HBsAg assays, its cost- effectiveness ratio increases to 53 (95% CI, 16-127) million euros.

CONCLUSION

PT-HB has few health or economic repercussions. Single-donation HBV NAT would provide a small health benefit at a very high cost. Instead, in some circumstances, the cost-effectiveness of enhanced-sensitivity HBsAg assays would be within acceptable ranges for new public health interventions.

Transmission of viral hepatitis by blood and blood derivatives: current risks, past heritage

For more than 40 years in the history of transfusion medicine, transmission of viral hepatitis from infected donors to recipients has been a frequent and serious adverse effect of the administration of blood components and plasma derivatives. This epidemic is now over, at least in developed and resource-rich countries. Hence, the attention of clinicians and investigators now focuses mainly on the measures to reduce the residual risk, on the possible emergence of novel or undiscovered agents causing post-transfusion hepatitis, and on the long-term outcome of patients who became infected more than ten years ago. The present article reviews these issues.