Human immunodeficiency virus type 1-infected blood donors: behavioral characteristics and reasons for donation. The HIV Blood Donor Study Group

Between May 1988 and September 1989, 829 human immunodeficiency virus type 1 (HIV-1)-seropositive donors were identified from 3,919,000 units of blood donated at 20 United States (US) blood centers. Of the 829,512 (62%) were interviewed to assess behavioral characteristics of the largest subgroup, men reporting sex with men, use of the confidential unit exclusion (CUE) and reasons for donation among all donors. Among 216 men reporting sex with men, 97 percent had male and 72 percent had female sexual contact since 1978. The majority identified themselves as bisexual (29%) or heterosexual (26%). Although 61 percent of 512 donors were aware of their risk behavior at donation, including 57 percent of those infected through heterosexual transmission, only 5 percent used the CUE. Reasons for donation included failure to read carefully (46%) or comprehend (15%) the deferral materials, pressure to donate (27%), a desire to be tested for HIV-1 (15%), and a reliance on screening to identify infected blood (10%). Reasons given for a perception of being at low risk included no recent risk behaviors, infrequent risk behaviors, or modification of risk behaviors. To reach high-risk donors, centers should assess whether referral materials provide necessary medical information and are clearly written for persons with diverse cultural and language backgrounds. Staff should be encouraged to avoid the use of culturally stigmatized terms and behaviors that may be perceived as high pressure.     

Human immunodeficiency virus type 1-infected blood donors: epidemiologic, laboratory, and donation characteristics. The HIV Blood Donor Study Group

Transmission of human immunodeficiency virus type 1 (HIV-1) by homologous blood transfusion in the United States (US) is minimized by the deferral of potential donors who are at risk for HIV-1 infection and by the screening of all donations for HIV-1 antibody. HIV-1-seropositive donors at 20 blood centers were studied for information to be used in evaluating the safety of the US blood supply and making recommendations to increase that safety. From June 1988 to August 1989, 829 (0.04%) of 2,192,000 donors were found to be seropositive; 512 were interviewed. Of 388 seropositive men, 56 percent had had sex with men, 10 percent had used drugs intravenously, 8 percent had had sex with intravenous drug users, and 27 percent had no identified risk. Of 124 seropositive women, 58 percent had had sex with men at risk for HIV (81% of whom used drugs intravenously), 5 percent had used drugs intravenously, and 41 percent had no identified risk. Racial and ethnic minorities made up 68 percent of seropositive donors (black, 38%; Hispanic, 30%) and approximately 14 percent of all donors. The 157 persons with no identified risk had demographic characteristics and serologic test results for syphilis and hepatitis B that were more similar to those of HIV-1-seropositive donors with recognized risk than to those of seronegative donors. Three health care worker-blood donors (from an estimated 93,100 health care worker-donors) had infection that was probably acquired occupationally.(ABSTRACT TRUNCATED AT 250 WORDS)     

Temporal trends in the prevalence of HIV and other transfusion-transmissible infections among blood donors in northern Thailand, 1990 through 2001

BACKGROUND: Thailand's epidemic of HIV infection, which began in 1988, has primarily involved heterosexual transmission of the virus. This study describes changes in prevalence of HIV and other infectious diseases among blood donors in northern Thailand from 1990 through 2001. STUDY DESIGN AND METHODS: Serologic screening results and demographic data were analyzed from 276,066 donors screened at two blood collection facilities in Chiang Mai, Thailand, from 1990 through 2001. RESULTS: The HIV prevalence peaked in 1991 to 1993 at 4.04 percent and then declined to 0.38 percent in 2001. The overall prevalence of HIV infection was 2.16 percent; HIV prevalence was higher among male (2.24%) than among female (0.64%) donors, in first-time donors, and in replacement volunteer donors. The majority of the donors were men and first-time donors throughout this study. The prevalence of antibodies to syphilis decreased significantly in both men and women. However, the prevalence of antibodies to HCV and HBsAg were stable. CONCLUSIONS: The declining HIV prevalence from 1990 through 2001 among blood donors in two large blood banks in northern Thailand indicates significant progress toward recruitment of a safer donor population in a developing country despite a major HIV and AIDS epidemic involving the general population.     

Infectious disease markers in blood donors in northern Thailand

BACKGROUND: A major epidemic of human immunodeficiency virus type 1 (HIV-1) infections that are primarily due to heterosexual transmission has developed in Thailand since 1988. The epidemic has been most severe in northern Thailand. The blood banks in Chiang Mai began screening donors for HIV-1 antibodies in February 1988 and for p24 antigen in April 1992. STUDY DESIGN AND METHODS: The trends of HIV-1 antibody prevalence were analyzed by type of donor (i.e., paid, replacement, and voluntary) for the period of 1988 through 1993. In addition, the prevalence of HIV-1 p24 antigen and of antibodies to syphilis, hepatitis B surface antigen, and hepatitis C virus was evaluated among blood donors at Chiang Mai University Hospital and the Thai Red Cross blood banks in Chiang Mai. RESULTS: The prevalence of HIV-1 antibodies increased from 0.84 percent in 1988 to 4.04 percent in 1991. Seropositivity was highest in paid professional donors. After discontinuation of the use of paid donors in 1993, HIV-1 antibody prevalence decreased to 3.34 percent. Antibody prevalence in replacement donors increased from 0.56 percent in 1988 to 5.82 percent in 1991. Among 44,446 donors tested, 7 (0.016%) were HIV-1 p24 antigen positive but antibody negative. CONCLUSION: The exclusion of paid donors and the use of p24 antigen testing are justified in northern Thailand. Additional strategies to exclude donors at very high risk and to attract those at low risk for infection should be developed and evaluated to increase blood transfusion safety in this and other, similar populations.     

Epidemiologic characteristics of blood donors with antibody to human immunodeficiency virus

From March 1985 through July 1986, blood donors who were positive for antibody to human immunodeficiency virus (HIV) were evaluated at three major blood centers in the United States. Of 818,629 donations, 450 (0.05%) were HIV antibody-positive. The seroprevalence decreased from 0.07 to 0.04 percent during the study period, due perhaps to a decline in repeat donors. HIV-seropositive donors tended to be 20 to 29 years old (52%) and male (88%). HIV seroprevalence among white donors (2/10,000 donations) was less than that among Hispanic (9/10,000; p less than 0.0001) and black donors (31/10,000; p less than 0.0001). Of 152 seropositive men interviewed, 77 percent reported sexual contact with men; of this latter group, 53 percent were bisexual. Fifteen (44%) of 34 seropositive women had apparently acquired infection from heterosexual contact, and an equal number denied having any known risk factors for HIV infection. Educational efforts must address women and bisexual men who do not perceive themselves to be at risk for HIV infection and should be specifically designed for the mores of different racial and ethnic groups.     

Decreasing seroprevalence of human immunodeficiency virus type 1 in a regional blood donor population

Blood banks have intensified their efforts to discourage donations from individuals at risk for the human immunodeficiency virus (HIV-1). Since the onset of HIV-1 donor screening in April 1985, a marked reduction in seroprevalence has been seen at the authors' institutions: from 51 cases per 100,000 donors in 1985 to 13 per 100,000 in the first 6 months of 1988. Data from 3.5 years have been analyzed for temporal trends in the association of HIV-1 seroprevalence with donation site (urban vs. non-urban) and donor gender. The association of HIV-1 seropositivity with an urban donation site decreased through 1987 as the urban-to-nonurban donation odds ratio declined from 6.48 in 1985 to 2.54 in 1987. Despite this decrease, both men and women who donated in urban areas had a significantly higher seroprevalence than those in nonurban areas. Male donors had a higher overall HIV-1 seroprevalence than female donors. However, the male-to-female odds ratio declined from 2.94 in 1985 to 1.96 in 1988, and male gender was no longer significantly associated with HIV-1 seropositivity. This change in the donor profile appears to reflect declining numbers of seropositive men who acknowledge risk factors and greater numbers of women with no identified risks for HIV-1. This study documents a dramatic decrease in HIV-1-seropositive donors and suggests that the deferral of high-risk individuals has become increasingly successful.     

Human immunodeficiency virus-1 infection correlates strongly with herpes simplex virus-2 (genital herpes) seropositivity in South African and United States blood donations

BACKGROUND: In South Africa, human immunodeficiency virus-1 (HIV-1) infection correlates with herpes simplex virus-2 (HSV-2; genital herpes) seropositivity in genitourinary disease clinic attendees. HSV-2 infection may be a marker for risk behavior and/or directly facilitate HIV-1 transmission. The rate of HSV-2 infection in HIV-infected South African and US blood donations was assessed, and whether the infections were correlated in donors screened and found negative for high-risk behavior by predonation interview was questioned. STUDY DESIGN AND METHODS: A total of 625 South African and 393 US HIV-1-infected repository samples previously characterized for longstanding or recent HIV-1 infection were tested with two commercially available HSV-2-specific assays. The prevalence of HSV-2 antibodies in South Africa was further assessed in 106 HIV-1-infected and 106 HIV-1-negative donors matched for sex, race, and donation history, as well as 200 random HIV-1-negative donors. RESULTS: A total of 52.2 percent of US and 69.3 percent of South African HIV-1-infected donations were HSV-2-seropositive. Age, race, and sex were independent risk factors for HSV-2 antibody prevalence in HIV-1-infected South African donors, who were more likely to be HSV-2 antibody-reactive than random HIV-1-negative donors (72.6% vs. 8.5%: odds ratio [OR], 28.6; 95% confidence interval [CI], 14.5-55) or matched donors (71.6% vs. 19.6%: OR, 10.3; 95% CI, 5.4-19.8). HIV-1 infection and HSV-2 seropositivity correlated in white and black populations when analyzed by age group. CONCLUSIONS: HIV-1 infection correlates strongly with HSV-2 seropositivity in US and South African blood donors. Our data describe the characteristics of HSV-2 antibody testing as a surrogate marker for HIV-1 infection and support a facilitating role for HSV-2 infection in HIV-1 transmission.     

Estimating the risk of blood donation associated with HIV risk behaviours

summary .  A blood donor questionnaire and declaration, with deferral of potential donors at a higher risk of blood-borne infections, was introduced in Australia in the mid-1980s to reduce the risk of donation of HIV-infected blood. However, the absolute risk of HIV transmission through blood donation from high-HIV-risk donors has not been estimated. This study presents a new method of assessing the risk posed to the blood supply by selected HIV risk behaviours. A model was developed to estimate the probability of blood donation during the window period for HIV infection. Five scenarios for blood donors were considered: (1) men who have sex with men (MSM), (2) men who have sex with women in Australia, (3) women who have sex with partners from countries with a high HIV prevalence, (4) men who have sex with commercial sex workers in Australia and (5) people injecting drugs used once in a year. Those estimated to be at highest risk of becoming infected and donating in the window period were MSM. Women who have sex with men from countries of high HIV prevalence are at greater risk than men who have sex with female sex workers from Australia. These three groups under current Australian guidelines are deferred from donating blood for 12 months. In Australia, a single episode of injecting drug use is associated with very low risk of HIV transmission. The model presented in this study can be used to assess the impact of selected individual risk behaviours on the safety of the blood supply.     

韶关市无偿献血人群10年HIV检测结果与感染者调查分析

目的了解韶关市无偿献血者近10年人类免疫缺陷病毒(HIV)感染状况及分布特征,明确血站需要采取有效防控措施,进一步减少或杜绝经输血途径传播获得性免疫缺陷综合征(AIDS)的风险。方法对2005～2014年韶关市无偿献血者265 771人份献血标本,采用2种不同厂家的试剂对抗-HIV初筛试验,初筛阳性标本送韶关市疾控中心确认。结果韶关市10年无偿献血者初筛抗-HIV阳性310例,确认阳性35例;确认阳性率为1.317/万;2012年HIV确认阳性率最高为2.867/万,与其他年份HIV确认阳性率比较差异有统计学意义(P0.05)。采血区域中新丰县HIV确认阳性率最高为5.369/万,与其他区域HIV确认阳性率比较差异有统计学意义(P0.05)。HIV确认阳性者流行病学调查发现,性别以男性30例占85.71%,明显多于女性;年龄分布以18～35岁青壮年感染26例占74.29%为主;已婚和未婚感染者分别占28.57%和71.43%;感染者职业分散,其中以农民、企业职员、服务业、机关干部居多;低学历HIV确认阳性率相对高,说明与文化高低有一定关系;该市户籍和外地户籍感染分别占71.43%和28.57%;首次献血者占68.57%,再次献血者占31.43%,两者感染比率有明显不同;合并感染其他病毒分别是乙型肝炎病毒2例,丙型肝炎病毒1例,梅毒3例;传播途径主要通过性传播,其中以异性性传播33例(94.58%)为主。结论韶关市无偿献血者HIV减染者呈上升趋势,以男性青壮年通过异性性传播为主。应引起政府、社会和血站高度重视,加强AIDS防控排查措施的宣传工作,最大限度降低经输血传播HIV的风险,确保临床输血安全。     

Duration of time from onset of human immunodeficiency virus type 1 infectiousness to development of detectable antibody. The HIV Seroconversion Study Group

Background : For persons newly infected with the human immunodeficiency virus type 1 (HIV-1), the time from the onset of infectivity to the development of detectable HIV-1 antibody is unknown. Persons who donate blood during this period account for nearly all instances of HIV-1 transmission from HIV-1 antibody-screened blood transfusions. Study Design and Methods : To estimate the window period from infectivity to HIV-1 antibody positivity, 701 HIV-1-seropositive blood donors who made a previous seronegative donation at 40 United States blood centers were studied. The HIV-1 antibody status was determined for at least one recipient of blood from the seronegative donation preceding the seropositive donation made by 182 of the 701 donors. Results : There were 39 seropositive recipients of blood from these 182 donors. Three donors were excluded from further analysis because the seropositive recipients of their blood had other HIV-1 risk factors or had HIV-1 infection before transfusion. The final study population comprised the remaining 179 donors, of whom 36 (20%) transmitted HIV-1 infection to recipients. When the interval between the seropositive donation and the preceding seronegative donation was less than 180 days, 46 percent of the donors transmitted HIV-1. In contrast, when that interval exceeded 540 days, only 2 percent transmitted HIV-1. A mathematical model was developed to explain the relationship between the probability that the previous seronegative donation occurred during the donor's window period of infectiousness, and hence transmitted HIV-1, as a function of both the window period and the duration between the seropositive and previous seronegative donations. This model indicated that the transmission data were most consistent with an average window period of 45 days. Assuming a log-normal window period distribution, it was estimated with 95 percent certainty that at least 90 percent of persons had a window period of less than 141 days. Conclusion : The window period averages 45 days, with few, if any, donors remaining infectious and seronegative for longer than 6 months.     

Screening of blood donors for idiopathic CD4+ T-lymphocytopenia

BACKGROUND: The recent recognition of idiopathic CD4+ T-lymphocytopenia (ICL) had led to concern that an unknown immunodeficiency virus may be transmissible by transfusion. STUDY DESIGN AND METHODS: To evaluate the prevalence and significance of low CD4+ values among blood donors, CD4+ data on 2030 blood donors who were negative for antibody to human immunodeficiency virus type 1 (HIV-1) were compiled. Those with CD4+ values below ICL cutoffs (< 300 CD4+ T cells/microL, or < 20% CD4+ T cells) were recalled for follow-up investigations. Serial CD4+ data on 55 homosexual men who seroconverted during prospective follow-up and data on 139 anti-HIV-1-positive blood donors initially evaluated in 1986 were reviewed as well. RESULTS: Five seronegative donors (0.25%) had absolute CD4+ counts < 300 cells per microL and/or < 20 percent. On follow-up, all five donors had immunologic findings within normal ranges, lacked HIV risk factors, and tested negative for HIV types 1 and 2 and human T-lymphotropic virus type I and II infections by antibody and polymerase chain reaction assays. Four of five donors reported transient illness shortly after their low CD4+ count donations. The median interval from HIV-1 seroconversion to an initial CD4+ value below ICL CD4+ cutoffs was 63 months for infected homosexual men. Of 139 HIV-1-infected blood donors studied 1 to 2 years after seropositive donations, 34 (24%) had CD4+ counts < 300 cells per microL and/or < 20 percent. CONCLUSION: Low CD4+ counts are rare among anti- HIV-1-negative volunteer blood donors and are generally associated with transient illnesses. If any unknown virus progresses similarly to HIV- 1, CD4+ count donor screening would be a poor surrogate for its detection.     

浙江省宁波市在婚与非在婚男男性接触者性行为特征及艾滋病感染状况比较

目的探讨婚姻状况对男男性接触者(MSM)人群艾滋病相关行为和感染的影响,为在该人群中开展有效的预防控制提供科学依据。方法采用滚雪球招募法,对宁波市744名非在婚MSM和455名在婚MSM进行问卷调查和血清学检测,比较两组间性行为特征及艾滋病、梅毒感染情况。结果在婚MSM艾滋病知识知晓率、同性性行为特征、艾滋病及梅毒感染率与非在婚组比较差异无统计学意义,但两组最近半年异性性行为特征差异有统计学意义,在婚MSM无保护性异性性行为发生率高于非在婚组。结论婚姻并不能制约MSM的同性高危性行为,而且更容易促使艾滋病病毒向普通女性蔓延。针对已婚MSM这一亚人群,有必要采用更有针对性的行为干预措施。     

Donation deferral criteria for human immunodeficiency virus positivity among blood donors in northern Thailand

Background: The purpose of this study was to develop human immunodeficiency virus (HIV) infection donation deferral criteria for blood donors in an HIV-epidemic area of northern Thailand, where the predominant means of transmission of HIV is through heterosexual contact. Study Design and Methods: In a preliminary study, 2242 blood donors were interviewed, and their blood was tested for HIV antibodies between September 1993 and April 1994. The risk factors associated with HIV positivity were identified. Criteria to identify HIV-positive persons on the basis of a logistic equation were developed and applied to another group of 5769 prospective blood donors. Results: A multivariate analysis showed the following odds ratios (OR) for traits that were independently associated with HIV positivity: younger age (OR = 0.93 for each additional year of age), male gender (OR = 2.41), having no more than a primary school education (OR = 2.00), being in the military (OR = 1.78), being unsure of one's own blood safety (OR = 2.00), history of injecting drug use (OR = 5.36), diagnosis of syphilis or positive syphilis serologic test in the past 12 months (OR = 2.67), and genital ulcer in the past 12 months (OR = 4.56). On the basis of the model, with a limit of <10 percent loss of uninfected donors, predicted probabilities of HIV positivity alone or of markers of infection with HIV, hepatitis B virus, or Treponema pallidum were calculated. With a cutoff of 6.5-percent estimated probability of HIV infection, derived from the logistic equation, the donor deferral criteria have 33.6-percent sensitivity and 8.3-percent positive predictive value for HIV positivity and 15.5-percent sensitivity and 18.4-percent positive predictive value for markers of infection with one of the three pathogens. Conclusion: The proposed donor deferral system provides a more flexible, sensitive, and predictive tool for averting donation by those who, though HIV antibody-negative, are at a higher risk of being infected with HIV.     

柳州市无偿献血者 HIV 感染流行病学分析

目的：了解柳州市无偿献血者 HIV 感染流行病学特征,为采供血机构献血招募提供依据,降低输血传播 HIV 的风险。方法对2008～2012年无偿献血者 HIV 感染进行流行病学调查,分析其感染特征。结果柳州市无偿献血者 HIV 感染不同年份间差异无统计学意义（P ＞0．05）;5年间男女性别、不同年龄段、已婚与未婚间差异有统计学意义（P ＜0．01）;其中初中以下学历占52．94％;56．21％的感染者为性传播。结论柳州市无偿献血者 HIV 感染以青壮年男性、初中以下文化人员为主,并以异性性传播为主。在献血者招募工作中要有针对性排除有高危行为的人群献血,尽量在低危人群中采集血液。     

Value and cost-effectiveness of screening blood donors for antibody to hepatitis B core antigen as a way of detecting window-phase human immunodeficiency virus type 1 infections. The HIV Blood Donor Study Group

BACKGROUND: The value of screening donors for antibody to hepatitis B core antigen (anti-HBc) for the prevention of posttransfusion hepatitis has declined markedly. However, anti-HBc screening may still be useful as a surrogate marker for the window period (WP) of human immunodeficiency virus type 1 (HIV-1) infection. STUDY DESIGN AND METHODS: First, the relationship between anti-HBc reactivity and HIV-1 WP infections was examined among 225 donors who had seroconverted to anti-HIV-1 positivity between 1987 and 1990. In addition, data from 1654 HIV-1 seropositive donors were analyzed to characterize the relationship among anti-HBc reactivity, donor demographics, and HIV-1- related risk factors. The yield and cost-effectiveness of anti-HBc for HIV-1 prevention were then projected on the basis of a published decision analysis model. RESULTS: Forty (18%) of 225 HIV-1- seroconverting donors tested anti-HBc-reactive on the donation preceding anti-HIV-1 seroconversion; in contrast, 341 (34%) of 1014 HIV- 1-seropositive donors interviewed tested anti-HBc-reactive (chi-square test; p < 0.001). Anti-HBc reactivity was more common among HIV-1- seropositive donors reporting male-to-male sexual contact (169/360, 47%) and injection drug use (44/83, 53%) than among those with heterosexual contacts known to be HIV-1-positive (31/190, 16%) or transfusion exposure (3/21, 14%) or among females with no identified risk factors (21/124, 17%). The estimates of 18 to 34 percent sensitivity for anti-HBc in detecting HIV-1 WP donations and a current rate of 1 in 676,000 HIV-1 WP donations (after p24 antigen screening) suggest that continued use of anti-HBc screening could result in the transfusion of 5 to 12 fewer HIV-1-infected units per year in the United States, which would add 19 to 48 quality-adjusted years of life for the 3.5 million annual transfusion recipients at a cost of $992,020 to $2,345,000 per quality-adjusted life-year saved. CONCLUSION: The low yield and very poor cost-effectiveness of anti-HBc screening indicate that this test is not an effective screening test for HIV-1 WP donations.     

Issues concerning women and AIDS: sexuality.

In the US and globally women are contracting the human immunodeficiency virus (HIV) and developing the acquired immunodeficiency syndrome (AIDS) the fastest. Worldwide, HIV is transmitted primarily through heterosexual intercourse. In the US, the proportion of women who have contracted AIDS by heterosexual transmission has increased from 11% in 1984 to 34% in 1990. Women are at a greater risk than men for transmission by heterosexual intercourse as the ratio of women to men who acquire AIDS by heterosexual transmission is 3 to 1. Furthermore, 25% of AIDS cases caused by heterosexual transmission or iv drug use occurs in women. Although women often develop HIV-related serious gynecologic problems, including cervical cancer and refractory vaginal candidiasis, these conditions do not fall within the Centers for Disease Control definition of AIDS. Women who have gynecologic symptoms are not diagnosed as having AIDS, are not eligible for AIDS benefits, and live half as long as men do once they are diagnosed as being HIV infected. Little is known about the characteristics of HIV infection or AIDS in women. Sexually transmitted diseases (STDs) seem to act as cofactors for HIV infection. The human papilloma virus or genital warts, the herpes simplex virus, syphilis, chancroid, recurrent vaginal candidiasis, abnormal Pap smears, cervical neoplasias, and pelvic inflammatory disease have been associated with HIV infection in women. HIV infection should be considered in all women with symptoms of any of these disorders. Nurses must first become aware of the clinical manifestations of HIV infection specific to women. Nursing interventions should educate about safer-sex including condom use with nonoxynol 9, and the risks of sharing needles. Strategies must be developed that provide empowerment skills and are sensitive to the women's cultural, religious, and ethnic background, beliefs, and values.     

The global distribution of human immunodeficiency virus type 2 (HIV-2) infection

We reviewed published reports of infection with human immunodeficiency virus type 2 (HIV-2) to provide a picture of its geographic distribution, pathogenicity, modes of transmission, and risk to the blood supply. Since the first reports in 1986, 627 HIV-2-seropositive persons have been reported; 604 of these were in natives of West Africa. Acquired immunodeficiency syndrome (AIDS) had developed in 42 patients, while 8 patients had AIDS-related complex. Transmission by sexual intercourse was the usual reported mode of spread. The modes of transmission of HIV-2 are thought to be the same as those for HIV-1, but perinatal transmission and transmission by sharing of needles among intravenous drug abusers have not yet been reported. The virus has not been identified in blood donors in the United States or West Germany, but two HIV-2-infected blood donors were reported in France. Further epidemiologic studies are needed to define the spectrum of disease, modes of transmission, and risk of HIV-2 to the blood supply.     

Potential deferral criteria predictive of human immunodeficiency virus positivity among blood donors in Thailand

Background: To develop deferral criteria to prevent human immunodeficiency virus (HIV) transmission by recently infected blood donors in the seronegative “window” phase, routine data on donors at a university hospital were examined for factors predicting seropositivity. Study Design and Methods: Records of all 281 HIV- positive blood donors from August 1987 through September 1991 were retrospectively compared with those of 1076 randomly selected control donors matched only by year of donation. Four controls were selected for each HIV-positive donor. Results: The prevalence of HIV in 102,684 donor units during the period rose from 0.02 percent in 1987 to 0.52 percent in 1991. Multivariable analysis revealed that male sex (odds ratio [OR] = 26.4), VDRL test positivity (OR = 3.0), age 21 to 30 years (OR = 2.2; referent: 16–20-year-old group), and replacement donorship (OR = 1.4; referent: voluntary donors) were independent factors significantly associated with HIV positivity among these donors (p < 0.05). Since replacement donorship cannot be avoided, only male sex, age 21 to 30 years, and VDRL test positivity were considered as potential criteria. When these findings were extrapolated to all donors in 1990 and 1991, those with all three or only two (excluding VDRL test, because the results are known only after donation) of these high- risk factors had HIV positivity probabilities of 2.2 and 1.0 percent, respectively. These probabilities were, respectively, 4.9 times (95% CI: 2.9 8.3) and 4.1 times (3.1, 5.4) the risk among other donors. However, applying such criteria would have eliminated 1.5 and 31.2 percent, respectively, of all HIV-negative donors in 1990 and 1991. The latter deferral proportion is too high to be acceptable. Conclusion: In Thailand, improved donor deferral criteria addressing sexual risk factors could lead to decreased probability of window-period donation, with an acceptable rate of deferral. Additional p24 antigen testing may be indicated for donors at increased risk for HIV infection, specifically, men aged 21 to 30.     

Surveillance of HIV-1 genetic subtypesand diversity in the US blood supply

BACKGROUND: Recent reports of variant (non-subtype B) HIV infections in US populations have raised concerns about the sensitivity of subtype B virus-based donor screening and diagnostic assays. This study was designed to determine the prevalence and genetic diversity of HIV subtypes in US blood donors over the last two decades. STUDY DESIGN AND METHODS: Three groups were studied: hemophiliacs infected by clotting factor concentrates in the early 1980s (n = 49), blood donors retrospectively identified as being seropositive in 1985 (n = 97), and blood donors identified as seropositive between 1993 and 1996 (n = 405). Subtype assignment was based primarily on heteroduplex mobility analysis (HMA) of HIV-1 env, with DNA sequence confirmation of selected specimens. HIV peptide-based EIA serotyping was used to rule out HIV-2 and group O infections and to serotype HMA-refractory specimens. RESULTS: Of 551 specimens, 535 (97%) were assigned subtypes; 532 (99%) of these were subtype B. Three postscreening donations (1%) were assigned non-B subtypes (2 A, 1 C). Two of these three donors were born in Africa; the third was born in the United States and reported no risk factors other than heterosexual activity. HMA distribution plots showed an increase in env diversity among HIV-1 group B strains over time. CONCLUSION: The results support the need for continued surveillance of HIV subtype diversity and ongoing validation of the sensitivity of HIV diagnostic assays to non-B subtype infections.     

No evidence of frequent human immunodeficiency virus type 1 infection in seronegative at-risk individuals

The possible existence of human immunodeficiency virus type 1 (HIV-1) infection in asymptomatic seronegative at-risk individuals was investigated in a prospective study of 55 seronegative high-risk individuals (42 homosexual men and 13 heterosexual individuals) and 32 seronegative hemophiliacs treated with factor VIII or IX concentrates before viral inactivation by heat treatment and systematic screening of blood donations. Tests used include the polymerase chain reaction assay with three primer pairs (one in the gag region and two in the pol region) and tests for serum p24 antigen, anti-nef serology (Western blot), and five biologic markers frequently altered by HIV infection (CD4 lymphocyte count, serum beta 2-microglobulin and neopterin concentration, and serum IgG and IgA concentration). Although 91 of 92 HIV-1-seropositive persons were positive in testing with at least one primer pair, no positive result was observed in seronegative at-risk individuals or in 117 seronegative low-risk controls. No nef antibody was found in seronegative at-risk individuals or seronegative controls, but 44 (47%) of 92 HIV-1-seropositive persons had nef antibodies. These findings do not support the existence of frequent HIV-1 infection in seronegative at-risk individuals.