Hepatitis C virus prevalence and incidence estimates among Chinese blood donors.

BACKGROUND: Hepatitis C virus (HCV) is an important transfusion-transmitted virus with global significance. The objective of this study was to evaluate the HCV prevalence and incidence among Chinese blood donors from 2013 to 2016. STUDY DESIGN AND METHODS: Whole blood and apheresis platelet donations collected from five Chinese blood centers from June 1, 2013, to December 31, 2016, were screened in parallel by two different enzyme-linked immunosorbent assays for anti-HIV 1/2, hepatitis B surface antigen, anti-HCV, and syphilis. Screening-reactive samples were further confirmed by western blot. Confirmatory positive rates among first-time and repeat donors were used to estimate the prevalence and incidence rates. Multivariable logistic regression modeling was used to examine factors associated with HCV infection. RESULTS: A total of 1,276,544 donations were collected from five Chinese blood centers, of which an estimated 1203 were confirmed HCV positive. The overall HCV prevalence among first-time donors was 166.56 per 100,000 donors (95% confidence interval, 156.04-177.08). The HCV incidence rate was estimated to be 15.21 (95% confidence interval, 11.83-19.56) per 100,000 person-years among repeat donors. Multivariable logistic regression results showed that increased age, lower educational levels, ethnicity, and occupation were all important factors associated with HCV confirmatory status among first-time donors (p < 0.01). CONCLUSIONS: HCV infection is still an important concern for transfusion safety in China. Our findings indicate that continued strong efforts are needed to monitor and control the risk of transfusion-transmitted HCV infection in China. Moreover, to reduce unnecessary donor loss, HCV donor screening procedures should be improved by incorporating confirmatory testing into routine blood center operations.

Estimation of hepatitis B-positive rates in Chinese blood donors by combining predonation and postdonation screening results.

BACKGROUND: Chinese blood centers use Hepatitis B surface antigen (HBsAg) rapid test (RT) in pre-donation and two rounds of screening with different enzyme-linked immunosorbent assays in post-donation. Nucleic acid testing (NAT) on screening non-reactive (SC-) donations has been gradually implemented since 2010. Yet RT+ and SC-/NAT+ donors are seldom included in hepatitis B virus (HBV) positive rate estimates in Chinese blood donors. METHODS: We performed HBsAg neutralization test (NT) on whole blood (WB) with pre-donation RT+ results and post-donation screening reactive (SC+) samples from Mianyang and Chongqing in 2015. The annual totals of pre- and post-donation NT+ donors were combined with the annual totals of SC-/NAT+ donors to derive the estimated HBV positive rates. RESULT: In Mianyang and Chongqing, 59.4% and 68.2% of RT+ donors in Jan-Aug 2015 contributed for NT, 95.5% and 97.2% of which were NT+ respectively. In 2015, 422 and 667 donors from Mianyang and Chongqing respectively were HBsAg RT+, yielding estimated 403 and 648 pre-donation RT+/NT+ deferrals. 411 and 668 post-donation SC+ samples were NT tested from Mianyang and Chongqing, of which 249 and 323 were NT+ respectively. An estimated 63 donors in Mianyang and 88 donors in Chongqing were SC-/NAT+. The estimated HBV confirmed positive rate in blood donors are 1.59% in Mianyang and 1.01% in Chongqing. CONCLUSION: Pre-donation HBsAg RT effectively intercepts donations from HBV infected donors. Using NT confirmatory results from RT+, SC+ and SC-/NAT+ donors, this study provides a model for more accurate estimation for HBV positive rates in China.

Risk factors for hepatitis B and C infection among blood donors in five Chinese blood centers.

BACKGROUND: Few studies were conducted on hepatitis B and C virus (HBV and HCV, respectively) risk factors among Chinese blood donors in recent years since voluntary donors replaced commercial donors. STUDY DESIGN AND METHODS: A case-control survey was conducted in HBV- or HCV-positive and -negative donors from five blood centers in China between September 2009 and April 2011. Case status was defined by having a reactive result on Monolisa HBsAg Ultra (Bio-Rad) for HBV and Ortho anti-HCV EIA 3.0 (Johnson & Johnson) for HCV. Controls were randomly selected qualified blood donors matched to cases by donation month and blood center. Specific test-seeking, medical-related, and behavioral risk factors were compared by HBV and HCV status using chi-square tests or Fisher's exact tests with Bonferroni correction. RESULTS: A total of 364 HBV cases, 174 HCV cases, and 689 controls completed the survey; response rates were 66.2, 47.3, and 82%, respectively. HCV-positive donors were significantly more likely to report having a blood transfusion history (23.4% vs. 3.0%, p < 0.0001) and ever living with a person with illegal drug injection (6.0% vs. 0.5%, p < 0.0001) than controls. Having intravenous and intramuscular injections in the past 12 months and ever having a tattoo are marginal risk factors for HCV (p values < 0.01). No specific risk factor for HBV was identified. CONCLUSION: History of previous transfusion and living with illegal drug users are risk factors for HCV infection among Chinese blood donors from five regions. Test-seeking behavior is not associated with HBV or HCV infections.

A study of seroprevalence and rates of asymptomatic viremia of severe fever with thrombocytopenia syndrome virus among Chinese blood donors.

BACKGROUND: Severe fever with thrombocytopenia syndrome virus (SFTSV), an emerging tick-borne pathogen that can cause fatal severe fever with thrombocytopenia syndrome, was first identified in China in 2009. Limited evidence suggests that SFTSV can be transmitted between humans via blood contact, raising concerns over transfusion safety. A study of donor samples from three Chinese blood centers was conducted to investigate the seroprevalence and rate of SFTSV viremia among Chinese blood donors. STUDY DESIGN AND METHODS: From April 16 to October 31, 2012, a total of 17,208 plasma samples were collected from donors at Xinyang (located in an SFTSV-endemic area), Mianyang, and Luoyang Blood Centers. Assessment of anti-SFTSV total antibody was performed on all samples using enzyme-linked immunosorbent assay. Repeat-reactive samples were tested for SFTSV RNA using reverse transcription (RT)-real-time polymerase chain reaction (PCR) assay with Taqman probes. In addition, 9960 of the Xinyang samples were tested in pools of 4 by the same PCR method and each of the samples in a reactive pool was tested individually. RESULTS: Donor seroreactivity rates were as follows: Xinyang, 0.54% (80/14,752); Mianyang, 0.27% (3/1130); and Luoyang, 0.28% (3/1326). All seroreactive samples were negative on RT-PCR single-sample testing. Two RT-PCR-reactive donor samples were identified, both with estimated viral load of less than 20 plaque-forming units/mL. The RNA prevalence rate for SFTSV among donors in Xinyang was 0.02%. CONCLUSION: This was the first multiregion study of SFTSV sero- and viral prevalence among Chinese blood donors. Viral prevalence was low and no seroreactive sample was viremic, suggesting a limited impact of SFTSV on blood safety in China.

The persistence of hepatitis C virus transmission risk in China despite serologic screening of blood donations.

BACKGROUND: A total of 2%-2.9% of the population in China is infected with hepatitis C virus (HCV). This study estimated the prevalence and incidence of HCV among Chinese blood donors. STUDY DESIGN AND METHODS: We examined whole blood and apheresis platelet donations at five Chinese blood centers in 2008 to 2010. All donations were screened using two rounds of testing for alanine aminotransferase, antibody to human immunodeficiency virus Types 1 and 2, hepatitis B surface antigen, anti-HCV, and syphilis. Screening reactivity is defined by a reactive result in one or both rounds of screening tests. Confirmatory tests (Ortho third-generation HCV enzyme immunoassay, Johnson & Johnson) were performed on anti-HCV screening-reactive samples. Confirmatory positive rates among first-time donors (prevalence) and repeat donors (incidence) were calculated by blood center and demographic categories. Donor characteristics associated with HCV confirmatory status among first-time donors were examined using trend test and multivariable logistic regression analysis. RESULTS: Among 821,314 donations, 40% came from repeat donors. The overall anti-HCV screening-reactive rate was 0.48%. Estimated HCV prevalence was 235 per 100,000 first-time donors; incidence was 10 per 100,000 person-years in repeat donors. In multivariable logistic regression analysis, first-time donors older than 25 years displayed higher HCV prevalence than the younger donors. Less education is associated with higher HCV prevalence. Donors 26 to 35 years old and those above 45 years displayed the highest incidence rate. CONCLUSION: High prevalence and incidence in donors indicate high residual risks for transfusion-transmitted HCV in Chinese patients. Implementation of minipool nucleic acid testing in routine donation screening may prevent a substantial number of transfusion-transmitted HCV infections.

Long-term return behavior of Chinese whole blood donors.

BACKGROUND: It is important to understand donor return behavior to maintain sufficient numbers of blood donors in developing countries where blood supplies are often inadequate. STUDY DESIGN AND METHODS: A total of 54,267 whole blood (WB) donors who donated between January 1 and March 31, 2008, at the five blood centers in China were followed for 2.5 years. Logistic regression was conducted to identify factors associated with their return behavior. A recurrent-event Cox proportional-hazard model was used to evaluate the overall effect of demographic variables and return behavior among first-time donors. RESULTS: Donors with previous donation history were more likely to return and the number of previous returns was positively associated with future return (odds ratios, 3.31, 4.82, and 8.16 for one, two to three, and more than three times compared to none). Thirty-four percent of donors (first-time donor, 21%; repeat donor, 54%) made at least one return donation, with 14% returning in the first 9 months. The multivariable logistic regression model for all WB donors and the Cox proportional hazard model for first-time donors showed consistent predictors for return: female sex, older age (≥ 25 years), larger volume (300 or 400 mL), and donating in satellite collection site. CONCLUSION: Encouraging first-time donors to make multiple donations is important for keeping adequate blood supply. The finding that first-time and repeat donors shared the same predictors for return indicates that retention strategies on repeat donors may be effective on first-time donors. Studies on motivators and barriers to return are needed, so that successful retention strategies can be tailored.

An analysis of risk factors for human immunodeficiency virus infection among Chinese blood donors.

BACKGROUND: Information regarding the risk factors for human immunodeficiency virus (HIV) infection among Chinese donors is important for understanding the trend of HIV transmission routes and for developing effective donor behavioral screening policies. STUDY DESIGN AND METHODS: In 2009 to 2011, a total of 77 HIV-positive and 649 HIV-negative consented donors who screened nonreactive for hepatitis B virus, hepatitis C virus, syphilis, and alanine aminotransferase in four Retrovirus Epidemiology Donor Study-II Chinese regions received and completed a questionnaire by mail regarding their recent and past medical procedures, drug use, and sexual behaviors, etc. Exploratory and confirmatory factor analyses grouped questions into three risk factors. Multivariable logistic regression analysis examined the relationship between risk factors and HIV status adjusting for center, age, sex, and education. RESULTS: The three risk factors were test-seeking tendency, medical-related risks, and behavioral risks. In multivariable logistic regression analysis, greater test-seeking tendency and behavioral risks were associated with HIV infection, with the adjusted odds ratios (ORs) being 2.2 (95% confidence interval [CI], 1.2-4.1) and 3.8 (95% CI, 1.8-7.9), respectively, but medical risks were not (OR, 1.2; 95% CI, 0.6-2.2). In comparison to less high school education, high school and more education was associated with lower risks for HIV infection, with the ORs being 0.35 (95% CI, 0.17-0.70) and 0.17 (95% CI, 0.09-0.33), respectively. CONCLUSIONS: Test-seeking tendency and high-risk sexual behaviors are important predictors of HIV infection in Chinese blood donors, suggesting that the health history inquiry used in donor selection process needs improvement to defer high-risk donors more effectively.

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

BACKGROUND: There are little data on human immunodeficiency virus (HIV) prevalence, incidence, or residual risks for transfusion-transmitted HIV infection among Chinese blood donors. STUDY DESIGN AND METHODS: 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. RESULTS: 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. CONCLUSION: Despite the declining HIV epidemic in China, estimated residual risks for transfusion-transmitted HIV infection are still high.

Demographics of apheresis platelet donors in five blood centers in China.

BACKGROUND: Blood component donations by apheresis has become more common in modern blood transfusion practices. However, apheresis donation still remains less common in China. This study describes the demographic profile and transfusion-transmissible infection (TTI) prevalence among donors making apheresis platelet (AP) donations compared to those making whole blood (WB) donations and the differences among five geographically diverse blood centers in China. STUDY DESIGN AND METHODS: This is a descriptive study using data from all successful donations at the five blood centers in 2008 and 2009. Donor demographic and TTI screening reactive rates were collected for WB and AP donations and blood centers. Logistic regression was used to identify independent factors associated with AP donations. RESULTS: From January 1, 2008, to December 31, 2009, there were 512,594 WB and 26,199 AP donations at five blood centers. AP donations accounted for 4.9% of all donations. AP donations have lower reactive rate than WB donations for hepatitis B virus surface antigen, hepatitis C virus antibodies, human immunodeficiency virus antibodies, and syphilis screening testing. Males, donors older than 25 years old, non-Han donors, and donors with below high school educational level were more likely to make AP donations. The characteristics of AP donations differed among the five Chinese blood centers. CONCLUSION: Our analysis suggests that the characteristics of AP donations in China are different from WB donations and differ among the five Chinese blood centers. Some of the differences are likely due to different recruitment policies. Further studies should be conducted to understand what motivates Chinese blood donors to participate as AP donors.

Hepatitis B virus nucleic acid testing in Chinese blood donors with normal and elevated alanine aminotransferase.

BACKGROUND: Nucleic acid testing (NAT) is currently not a routine donor test in China. The aim of this study was to evaluate the current residual risk of hepatitis B virus (HBV) transmission and the value of ALT testing in preventing HBV infection. STUDY DESIGN AND METHODS: From January 2008 to September 2009, a total of 5521 qualified donations by routine screening and 5034 deferred donations due to elevated ALT alone were collected from five blood centers. Samples were tested for HBV DNA by triplex individual-donation (ID)-NAT (ULTRIO assay, on the TIGRIS system, Novartis Diagnostics). HBV NAT-reactive samples were further analyzed by HBV serology, alternative NAT, and viral load and were diluted to simulate if they could be detected in a minipool-NAT. RESULTS: There was no significant difference in the HBV NAT-yield rate between the qualified donations group (5/5521) and the deferred donations group (4/5034). Of these nine potential HBV-yield cases, one donor (11%) was a possible HBV window-period donor, one (11%) was a chronic HBV carrier, and seven (78%) had probable or confirmed occult HBV infections. Of seven potential HBV-yield cases quantified, the viral loads were less than or equal to 70.0 IU/mL. Minipool testing (minipools of 4, 8, and 16 donations) would miss 43% to 79% of the nine HBV-yield donations. CONCLUSIONS: Based on our findings in qualified donations, we estimate that the nationwide implementation of ID-NAT testing for HBV DNA in China would detect an additional 9964 viremic donations per year. ALT testing seems to have no significant value in preventing transfusion-transmitted HBV infection. ID-NAT versus simulated minipool-NAT using the ULTRIO test demonstrates the benefit to implement a more sensitive NAT strategy in regions of high HBV endemicity.

Analysis of Chinese donors' return behavior.

BACKGROUND: It is important to understand donor return behavior. Converting first-time donors to become repeat donors is essential for maintaining an adequate blood supply. STUDY DESIGN AND METHODS: Characteristics of 241,552 whole blood (WB) donations from first-time and repeat donors who donated in 2008 at the five blood centers in China were compared. A subset of 54,394 WB donors who donated between January 1 and March 31, 2008, were analyzed for their return behavior in 2008 after the index donation using logistic regression. RESULTS: Of all donations, 64% were from first-time donors. Donors with self-reported previous donations tended to be male, older, and married; donated larger volume (≥ 300 mL); and were heavier in weight. Among donors who donated from January to March 2008, 14% returned for subsequent WB donations by the end of 2008. The number of previous donations and blood collection location were the two strongest predictors for making subsequent donations. Donors with one, two to three, and more than three previous donations were 3.7, 5.7, and 11.0 times more likely to return than first-time donors. Those who donated in a blood collection vehicle were four times more likely to return than those who donated at a blood center. Being female, younger, and of a lower education level (middle school or less) were positively associated with subsequent return blood donation during the follow-up period observed in this study. CONCLUSION: Most of the Chinese blood supply is from first-time donors. Strategies aimed at encouraging current donors to become repeat donors are needed.

Impact of the May 12, 2008, Earthquake on blood donations across five Chinese blood centers.

BACKGROUND: On May 12, 2008, a severe earthquake struck China's Sichuan Province. The nationwide outpouring of charity resulted in a surge of subsequent blood donations. The quantity and quality of these donations were examined in comparison with routine donations. STUDY DESIGN AND METHODS: Whole blood and apheresis donations from five geographically different blood centers collected within 1 week postearthquake were compared with those collected during the rest of the year. Regional differences, demographic characteristics, first-time and repeat donor status, and infectious disease screening markers associated with these donations were compared by earthquake status using chi-square statistics. Poisson regression analysis examined the number of daily donations by earthquake status after adjusting for center, day of week, and seasonal variations. RESULTS: The number of daily donations across five blood centers increased from 685 on a typical day to 1151 in the postearthquake week. The surge was observed in both sexes and across different education levels, age, and ethnicity groups and three blood centers and was significant after adjusting for confounding covariates. The influx of first-time donors (89.5%) was higher than that of repeat donors (34%). There was a significant change in the overall screening reactive marker rates excluding alanine aminotransferase (2.06% vs. 1.72%% vs. 4.96%). However, when the individual screening test was analyzed separately, no significant differences were found. CONCLUSION: Timely donations in response to a disaster are crucial to ensure emergency blood transfusion. The dramatically increased postearthquake donations suggest that Chinese blood centers are capable of handling emergency blood needs. Measures to maintain blood safety should be taken in times of emergency.