Antibodies to hepatitis E virus among several populations in Greece: increased prevalence in an hemodialysis unit

BACKGROUND: Hepatitis E virus (HEV) has been found to be the causative agent of enterically transmitted non-A, non-B hepatitis in tropical and subtropical countries. Several investigators, however, have indicated that HEV could be endemic in Europe, albeit at a low prevalence. STUDY DESIGN AND METHODS: The purpose of this study was to estimate the prevalence of anti-HEV in various populations in northwestern Greece (Epirus region). Healthy blood donors (2636), refugees from southern Albania (350), children (165), injecting drug users (IDUs) (65), multiply transfused patients (62), patients with chronic viral hepatitis (75), and chronic hemodialysis patients (149) were investigated for anti-HEV by enzyme immunoassay and confirmatory Western blot assay. In addition, 380 consecutive healthy blood donors and 62 hemodialysis patients from a neighboring area (Agrinion, Greece) were investigated. RESULTS: A very low presence of anti-HEV antibody was found among healthy blood donors from Epirus (0.23%) and Agrinion (0.53%). Anti-HEV was not detected in children, IDUs, or multiply transfused patients. In contrast, a low but significant prevalence of anti-HEV was found among refugees (4.85%), patients with chronic viral hepatitis (5.3%), and hemodialysis patients from Epirus (1.34%), as compared with healthy blood donors from Epirus: p < 0.0001, p < 0.00001, and p < 0.10, respectively. A high prevalence (9.7%) of anti- HEV was revealed in patients at the hemodialysis unit of the General Hospital of Agrinion (p < 0.00005, compared to healthy blood donors from Agrinion). No significant association was found between anti-HEV positivity and the age or sex of donors, the duration of hemodialysis, positivity for hepatitis B or C virus infection markers, history of hepatitis, increased alanine aminotransferase, renal transplantation, a history of transfusion, or the number of units transfused. CONCLUSION: This study demonstrated a high prevalence of anti-HEV in a separate hemodialysis unit, without an association with the known routes of transmission of blood-borne viruses. This observation suggests that a still-undefined intra-unit factor or other factors are associated with HEV transmission.     

Results of 1-year screening of donors in The Netherlands for human T− lymphotropic virus (HTLV) type I: significance of Western blot patterns for confirmation of HTLV infection

BACKGROUND: Between January 1993 and January 1994, Dutch blood banks screened approximately 674,000 volunteer donors for the presence of antibodies to human T-lymphotropic virus type I (HTLV-I). STUDY DESIGN AND METHODS: Confirmatory testing was performed on samples from 870 different anti-HTLV-I-reactive donors (0.13% of the total tested). RESULTS: According to the authors' Western blot (WB) interpretation criteria, 15 (0.002%) donors tested HTLV-I-positive in the WB; 201 tested negative, and 654 (75% of donors reacting on enzyme-linked immunosorbent assay) tested indeterminate. Fresh samples from 234 of 870 anti-HTLV-reactive donors were tested for HTLV-I and type II (HTLV- II) DNA by polymerase chain reaction: all 15 WB-positive donors tested positive for HTLV-I DNA; 206 WB-indeterminate and 13 WB-negative donors tested negative for HTLV-I and -II DNA. Application of the manufacturer's (World Health Organization-based) guidelines for WB interpretation would have resulted in the misclassification of 48 (23%) of 206 polymerase chain reaction-negative donors as HTLV-I/II-positive. Risk factors were present in 14 of 15 HTLV-I-infected donors: 8 had a partner from an HTLV-I-endemic area, 4 were from HTLV-I-endemic countries, and 2 had received blood transfusions. CONCLUSION: HTLV-I and -II infection is rare among Dutch blood donors. HTLV screening will prevent few cases of HTLV-related disease, but it will prevent a further spread of the virus by transfusion. In a low-risk population, conservative guidelines for WB interpretation unnecessarily generate an excess of false-positive results.     

Human T-lymphotropic virus type I and type II infections and correlation with risk factors in blood donors from Sao Paulo, Brazil

BACKGROUND: Little is known about the prevalence of and risk factors for human T-lymphotropic virus type I and type II (HTLV-I, HTLV-II) infections in Brazil. STUDY DESIGN AND METHODS: Sera from 17,063 healthy Brazilian donors were screened by enzyme-linked immunosorbent assay for antibody to HTLV-I/II between August 1991 and July 1993. Repeatedly reactive samples were confirmed by Western blot, and discrimination between HTLV-I and HTLV-II was made by polymerase chain reaction or synthetic peptide enzyme-linked immunosorbent assay. A univariate analysis was performed on demographic and serologic data. RESULTS: HTLV-I infection was demonstrated in 83 percent of the 30 donors with reactive serologic tests (0.15% of the total tested [17,063]; 95% CI, 0.09-0.20) and HTLV-II infection in 17 percent (0.03% of the total tested [17,063]; 95% CI, 0.01-0.05). HTLV-I-positive donors were more likely than reference groups to be of Asian ethnicity (odds ratio [OR] 15.1; reference group: whites), more than 50 years old (OR 4.2; reference group: 20–29 years old), and positive for antibody to hepatitis C virus (anti-HCV) (OR 21.8) or to hepatitis B core (antigen) (anti-HBc) (OR 5.7). HTLV-II showed a significant association with anti-HCV (OR 75.2) and anti-HBc (OR 21.8). Eleven of the 25 HTLV-I- positive donors were counseled. Family origin in endemic areas of Japan (n = 4), prior blood transfusion (n = 3), or sexual contact with prostitutes (n = 1) were the risk factors reported by 8 donors. In 3 white men, no risk factors could be identified. CONCLUSION: Both HTLV-I and HTLV-II occur among Brazilian blood donors. HTLV-I is associated with Asian ethnicity, greater age, and the presence of anti-HCV and anti-HBc. Three HTLV-I-positive donors had a history of blood transfusion, which emphasizes the need for HTLV-I/II screening in Brazil.     

Human T-cell lymphotropic virus type I and II DNA amplification in seropositive and seronegative at-risk individuals

To determine the presence or the absence of human T-lymphotropic virus type I and/or II (HTLV-I/II) DNA in at-risk individuals who were persistently negative for specific serologic assays, polymerase chain reaction with two primer pairs in common and conserved regions of HTLV- I and -II genomes was used. Seronegative individuals at risk for HTLV- I/II infection (15 heterosexual partners of seropositive individuals, 17 breastfed children born to HTLV-I-infected mothers, 47 multiply transfused patients, 22 intravenous drug users) were studied (n = 101); 35 seropositive individuals and 25 seronegative low-risk individuals were used as positive and negative controls, respectively. No positive polymerase chain reaction was observed in the seronegative at-risk individuals or in the negative controls. Positive controls gave positive results with at least one primer pair in all cases except one. A latent HTLV-I/II infection with a persistently negative serologic test for HTLV-I/II seems unlikely.     

Evaluation of a new third-generation ARCHITECT rHTLV-I/II assay for blood screening and diagnosis

In comparison to current on-market assays, the ARCHITECT rHTLV-I/II assay is the first fully automated assay that simultaneously detects human T-cell lymphotropic virus type I (HTLV-I) and type II (HTLV-II) in human serum and plasma. Specificity was assessed on 5646 blood donors and 692 clinical specimens. For sensitivity determination, 301 HTLV-I–positive and 105 HTLV-II–positive specimens were tested. Precision was between 3.98% and 4.31% coefficient of variation (CV) for specimens with 1 to 6 sample to cutoff. Specificity was 99.95% and 99.86% on specimens from blood donors and hospitalized patients, respectively. Sensitivity evaluation showed 100% detection on 301 HTLV-I and 105 HTLV-II specimens. HTLV-I and HTLV-II viruses are still circulating among general populations even in the low prevalence areas. To control the further spread of these retroviruses, we need to know that it is important to continue screening of blood. The performance evaluation data from this study demonstrate that the high throughput and fully automated ARCHITECT rHTLV-I/II chemiluminescence immunoassay effectively serves this purpose.     

Prevalence of viral markers among first-time Arab blood donors in Kuwait

BACKGROUND: The aim of this study was to assess the effect of blood donation modes on the prevalence of viral markers among Arab first-time blood donors in Kuwait. STUDY DESIGN AND METHODS: Donor ethnic background was classified as Kuwaiti nationals and non-Kuwaiti Arabs. A total of 26,874 donors were screened in 2002 for the following viral markers: hepatitis C virus antibody (anti-HCV), hepatitis B surface antigen (HBsAg), anti-hepatitis B core antigen (HBc), human immunodeficiency virus-1 and -2 antibody (anti-HIV-1 and -2), HIV p24, and human T lymphotropic virus-I and -II antibody (anti-HTLVI/II). All samples positive for the presence of anti-HBc were tested for anti-HBs. Among these donors, 12,798 were first-time donors of which 74 percent were replacement and 26 percent were volunteers. RESULTS: The prevalence of HCV among replacement donors was significantly higher than the volunteer group. The difference between the two modes of blood donations, however, was not significant for HBsAg. The prevalence of anti-HCV among Kuwaiti national and non-Kuwaiti Arab first-time donors was 0.8 and 5.4 percent, respectively, whereas the prevalence of HBsAg was 1.1 and 3.5 percent, respectively, with the difference being significant at a p level of <0.0001. The difference observed for prevalence of anti-HBc among Kuwaiti national and non-Kuwaiti Arab donors (17 and 33.3%, respectively) was significant (p < 0.0001). Among first-time donors, 13.7 percent were positive for the presence of anti-HBs, indicating that 13.7 percent of the total Arab donor population might have had a previous infection and possible immunity to hepatitis B virus (HBV). CONCLUSION: A high prevalence of HBV and HCV was found among non-Kuwaiti Arab donors. The prevalence of anti-HCV was only significantly higher among replacement versus volunteer first-time donors. Therefore, there is a need to develop a strategic plan that incorporates the diverse background of the blood donors living in Kuwait.     

Transfusion-associated transmission of human T-lymphotropic virus types I and II: experience of a regional blood center

During a 22-month period, 78,000 blood donors were screened for human T- lymphotropic virus types I and II (HTLV-I/II) at Belle Bonfils Memorial Blood Center (Denver, Colorado). Positive donors and the living recipients of their previously donated blood components were evaluated for risk factors and symptoms related to HTLV-I infection, were screened by enzyme immunoassay, confirmed by Western blot for HTLV- I/II, and subsequently tested by polymerase chain reaction and peptide enzyme immunoassay to distinguish between HTLV-I and -II infection. Six seropositive blood donors (0.008%) were identified; four were typed as having HTLV-I infection and two as having HTLV-II. Of 18 living recipients of components from seropositive donors, none had risk factors for HTLV-I infection prior to transfusion and none had signs or symptoms of HTLV-I infection at follow-up. The mean time from transfusion to testing was 6.4 years. Seven recipients of HTLV-I- infected components were HTLV seropositive; all were typed as having HTLV-I. A possible case of posttransfusion HTLV-I-associated myelopathy was identified in one patient who died before complete evaluation. One possible case of transfusion-associated HTLV-II was identified. These data further support the continued screening of blood donors for HTLV- I/II.     

The prevalence of antibody to HTLV-I/II in United States plasma donors and in United States and French hemophiliacs

Antibody to HTLV-I/II was detected in 19 (0.3%) of 6286 plasma donors from five regions of the United States (US). This seroprevalence rate is approximately 10 times that in whole blood donors. The regional distribution of infection was as follows: Southwest, 0.68 percent; Southeast, 0.45 percent; Midwest, 0.28 percent; Northwest, 0.1 percent; and Northeast, 0.0 percent. Rates of HTLV-I/II infection in blacks (0.74%) and Hispanics (0.66%) were higher (both, p less than 0.001) than those in whites (0.08%). All 19 infected units were donated by subjects aged 30 or older, even though 52.9 percent of the donations came from persons less than 30 years old. Equal rates of HTLV-I/II infection were found in men (0.31%) and women (0.29%). No HTLV-I/II antibody was detected in 154 French and 25 US hemophiliacs who were transfused regularly with noninactivated plasma or its derivatives. This suggests that the transfusion of HTLV-I/II-seropositive plasma products does not transmit the viral infection.     

Prevalence of markers for human immunodeficiency virus types 1 and 2, human T-lymphotropic virus type I, cytomegalovirus, and hepatitis B and C virus in multiply transfused thalassemia patients. The French Study Group On Thalassaemia

The prevalence of markers for human immunodeficiency virus types 1 and 2 (HIV-1, HIV-2), human T-lymphotropic virus type I (HTLV-I), hepatitis B virus (HBV) and hepatitis C virus (HCV), and cytomegalovirus (CMV) was evaluated in a population of 305 multiply transfused thalassemia patients in Belgium, France, and Italy (Sicily). No patients were found positive for HIV-2 antibodies. Two French patients were seropositive for HIV-1, having been infected before systematic blood screening. Antibodies to HTLV-I were found in two Sicilian patients. A positive anti-HCV enzyme-linked immunosorbent assay was found in one-third of the patients and a positive CMV IgG test in two-thirds. Twenty-two percent of the patients in the three countries were uninfected by HBV and were not vaccinated. With the exception of HIV-1, HIV-2, HTLV-I, and anti-hepatitis B surface antigen assays, all markers were encountered more frequently in Sicilian patients than in French or Belgian patients. This study emphasizes the need to improve HBV vaccination coverage in the three countries. At present, data indicate that the introduction of routine screening for HTLV-I should be considered, particularly in Sicily.     

Seroprevalence of human herpes virus 8 antibody in populations at high or low risk of transfusion, graft, or sexual transmission of viruses

BACKGROUND: The routes of transmission of human herpes virus 8 (HHV-8) remain unclear. In particular, HHV-8 transmission by blood components and organ transplantation is still debated and raises public health issues. The objective of this study was to determine the prevalence of anti-HHV-8 in selected populations of persons or patients with or without risk factors for the transmission of viral infections, in order to determine the routes of HHV-8 transmission. STUDY DESIGN AND METHODS: A total of 1431 persons or patients at low or high risk of sexually, blood-, or graft-transmitted viral infections were tested by means of a standardized immunofluorescence serologic assay detecting anti-HHV-8. RESULTS: The persons or patients could be classified into three distinct groups according to anti-HHV-8 prevalence: a low prevalence group (0.0% to 5.0%), including healthy blood donors, healthy pregnant women, multiply transfused patients with thalassemia major, and IV drug users; an intermediate prevalence group (5.0% to 20.0%), including organ donors, kidney transplant recipients, and multiply transfused patients with sickle cell disease; a high prevalence group (>20.0%), including HIV-negative persons at high risk of sexually-transmitted viral infections, and HIV-infected homosexual men and heterosexuals. CONCLUSION: The sexual route appears to be the main route of HHV-8 transmission; bloodborne transmission of HHV-8, if it exists, is rare. In contrast, organ transplantation recipients might be exposed to HHV-8 transmission by the transplanted organ, which raises the issue of systematic screening of organ donors.     

Prevalence and risk factors of hepatitis C virus, hepatitis B virus, and human immunodeficiency virus in multiply transfused recipients in Mexico

BACKGROUND: Transfusion-transmitted viral infection (TTI) is a major problem in patients receiving blood products. Monitoring high-risk patients is essential for assessing the epidemiology of blood-borne infections.
STUDY DESIGN AND METHODS: A 1-year, cross-sectional seroprevalence study in patients with a history of multiple transfusions was conducted. Peripheral blood samples were titered to detect serologic markers of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). The presence of these viruses and demographic, behavioral, and medical traits were assessed.
RESULTS: A total of 300 male and female multiply transfused patients with a mean age of 30.7 (±17.5) years were studied. The prevalence was 13.7% for HCV, 7% for HBV, and 1.7% for HIV. Patients with hemophilia had the highest prevalence for HCV and HIV infections, and hemodialyzed patients, for HBV infection. The risk factors related to acquired HCV were hemophilia (odds ratio [OR], 5.6; 95% confidence interval [CI], 2.5-12.6), more than five hospitalizations (OR, 3.8; 95% CI, 1.6-8.9), and having received a transfusion before mandatory screening in 1993 (OR, 8.4; 95% CI, 2.0-34.6), and for HIV, having received a transfusion before 1987 (OR, 19.0; 95% CI, 2.0-177.7). The main risk factors for HBV were having end-stage renal disease and being treated with hemodialysis (OR, 3.7; 95% CI, 1.4-9.9) and transplantation (OR, 4.2; 95% CI, 1.4-12.1).
CONCLUSIONS: This study showed that HCV infection was more frequently identified than HBV and HIV infections in multiply transfused Mexican patients. Additionally, several risk factors are associated with TTI such as mandatory screenings before 1987 and 1993, which were the most important for HIV and HCV infections but not for HBV.     

Transfusion transmission of human T-lymphotropic virus types I and II: serologic and polymerase chain reaction results in recipients identified through look-back investigations

To determine the transmissibility of human T-lymphotropic virus types I and II (HTLV-I and HTLV-II) via transfusion, persons who, from 1983 to 1989, received blood components donated by persons who subsequently tested anti-HTLV-I-positive were evaluated. It was found that 16 (30%) of 54 evaluable recipients of transfused cellular components became infected with one of the HTLVs: 8 had HTLV-I and 8 had HTLV-II. Forty percent of platelet recipients and 28 percent of red cell recipients acquired infection. The rate of transmission of HTLV-I and HTLV-II was significantly correlated with storage age of red cell units prior to transfusion: 47 percent for red cells stored < or = 14 days and 0 for red cells stored > 14 days (p < 0.01). Multiple confirmatory serologic tests performed in 46 anti-HTLV-I enzyme immunoassay-negative recipients revealed that HTLV infection could not be excluded in 3 recipients of blood components from HTLV-II-infected donors. Polymerase chain reaction established HTLV-II infection in one recipient, and the other two recipients could not be classified with respect to HTLV infection status. It appears that some HTLV-II-infected transfusion recipients will not be detected by existing HTLV-I antigen-based reagents. If it is deemed necessary to initiate or continue look-back programs to detect transfusion transmission of HTLV-II infection, it is suggested that the current testing algorithm be modified in selected cases.     

Prevalence of GB virus type C/hepatitis G virus RNA and of anti-E2 in individuals at high or low risk for blood-borne or sexually transmitted viruses: evidence of sexual and parenteral transmission

BACKGROUND: The first epidemiologic evidence of GB virus type C (GBV- C)/hepatitis G virus (HGV) infection showed a high prevalence of asymptomatic carriers in blood donors and in populations at risk for blood-borne viruses. However, by using only viral RNA polymerase chain reaction, those studies underestimated the true spread of GBV-C/HGV infection. The combined detection of GBV-C/HGV RNA and of anti-E2 (which reflects recovery from infection) is necessary to define accurately the prevalence of GBV-C/HGV. STUDY DESIGN AND METHODS: The presence of both anti-E2 and GBV-C/HGV RNA was searched for in 1438 serum samples collected from various groups of individuals at low or high risk for blood-borne or sexually transmitted viruses (blood donors, organ donors, unselected pregnant women, immunocompetent or immunodepressed multiply transfused patients, HIV-positive or HIV- negative homosexual men, intravenous drug addicts). RESULTS: The presence of GBV-C/HGV RNA and/or anti-E2 (exposure to GBV-C/HGV) was frequent in populations at risk for blood-borne or sexually transmitted viruses. GBV-C/HGV appeared also to be sexually transmitted, with transmission from male to female more efficient than vice versa. A particularly elevated level of exposure to GBV-C/HGV was observed in homosexual men. In immunocompetent individuals, the prevalence of anti- E2 was about twice that of GBV-C/HGV RNA, which suggests the frequency of recovery from GBV-C/HGV infection. Most of the GBV-C/HGV RNA- positive individuals had no biochemical evidence of liver damage. CONCLUSIONS: GBV-C/HGV is frequent in populations at risk for blood- borne or sexually transmitted viruses. GBV-C/HGV is not a hepatitis virus, and it seems appropriate to rename it.     

Adult T-cell leukemia/lymphoma in the Middle East: first report of two cases from Lebanon

BACKGROUND: Adult T-cell leukemia/lymphoma (ATL) is an aggressive lymphoproliferative disorder caused by human T-cell leukemia virus type I (HTLV-I). HTLV-I is endemic in southern Japan, the Caribbean, Central and South America, certain areas of Africa, and the southeastern United States. In the Middle East, North East Iran, particularly the region of Mashhad, has been recognized as an endemic region.
CASE REPORTS: In this report, the first two cases of ATL diagnosed in Lebanon are described. The first patient of Lebanese origin presented with acute ATL. The second patient of Romanian origin developed acute ATL in early relapse after autologous transplantation for ATL. Both patients had lymphocytosis, severe hypercalcemia, and CD25+ T-cell immunophenotype on peripheral blood. In both patients, HTLV-I serology was positive by enzyme-linked immunosorbent assay and confirmed by Western blot and HTLV-I oncoprotein Tax expression was documented in the leukemic cells. Upon screening, seven direct family members of the first patient were HTLV-I positive; four of them were regular blood donors.
CONCLUSIONS: Screening blood donors for HTLV-I seropositivity is not currently performed in Lebanon. A large screening study in Lebanon is needed to confirm whether South Lebanon is a new endemic region for HTLV-I infection and to recommend mandatory screening of blood donors for HTLV-I infection.     

Efficacy of donor screening for HTLV-I and the natural history of transfusion-transmitted infection

BACKGROUND: It has been 10 years since the implementation in Japan of donor blood screening for human T-cell lymphotropic virus type I (HTLV-I). This report reviews the effectiveness of screening in preventing transmission of HTLV-I through blood transfusion and the current status of patients with confirmed seroconversion due to transfusions given before the implementation of screening. STUDY DESIGN AND METHODS: Patients who received blood at Kyushu University Hospital from 1990 to 1997 were followed. Serum samples were collected before transfusion and 60 days or more after transfusion. Seroconversion was determined by a second-generation particle agglutination test. Confirmation tests were an immunofluorescence assay, enzyme-linked immunosorbent assay, and immunoblotting. Confirmed seroconverted patients were followed by a search of hospital records. RESULTS: Seroconversion was found in one of 4672 transfused patients, but the donor was identified and confirmed to be negative for anti-HTLV-I and virus genome by nested polymerase chain reaction. A total of 23,323 red cell concentrates and 17,237 platelet concentrates were transfused to these 4672 patients. Therefore, the anti-HTLV-I prevalence in blood for transfusion after screening was estimated at 1 in 45,560 (0.0022%; the upper 95% CI was 0.0080%). One hundred two seroconverted patients who were transfused before donor screening for HTLV-I were followed. One patient developed HTLV-I-associated myelopathy, diagnosed 18 weeks after seroconversion, and another patient developed uveitis 1 month after seroconversion. No patients developed adult T-cell lymphoma, and the survival rate of seroconverted patients was 92.5 percent 15 years after transfusion. CONCLUSION: This study confirmed that the present donor screening program for HTLV-I by the new particle agglutination test can almost completely prevent virus transmission by transfusion. Complications of HTLV-I transmission were at lower rates than expected.     

Serologic distinction between human T-lymphotropic virus (HTLV) type I and HTLV type II

In November 1988, the Food and Drug Administration approved reagents for serologic screening for human T-lymphotropic virus type I (HTLV-I) infection in blood donors and patients suspected of having HTLV-I-related illnesses. These reagents are able to detect HTLV type II (HTLV-II), a close relative of HTLV-I with no known pathologic effect. The distinction between the two forms of HTLV is important to the donor and to any recipient of blood containing HTLV. The application to sera from 38 seropositive blood donors and 2 recipients (37 "confirmed" positive and 3 indeterminate by Western blot) of two methods (Western blot and peptide enzyme immunoassay) for serologic distinction between HTLV-I and -II is described. These results were compared to those from polymerase chain reaction (PCR) analysis of HTLV proviral DNA obtained from donor peripheral blood mononuclear cells. The peptide enzyme immunoassay was found to be less sensitive than the Western blot, but completely concordant with PCR results when differential reactivity could be established. The Western blot pattern showed complete diagnostic concordance with the samples with confirmed-positive serologic tests, but was incorrect in two HTLV-II-infected donors with indeterminate serologic tests. Thirty-three (89%) of the 37 individuals from this predominantly Native American and Hispanic group of blood donors were found to have HTLV-II. These findings confirm and extend previous reports that HTLV-I infection may be less common, and HTLV-II infection more common, than previously believed. The peptide enzyme immunoassay can provide most individuals who have positive results with the HTLV-I/II screening test with serologic distinction between HTLV-I and HTLV-II.     

Human T-lymphotropic virus type I among blood donors from Guadeloupe: donation, demographic, and biologic characteristics

BACKGROUND: Epidemiologic data on human T-lymphotropic virus type I (HTLV-I) in Guadeloupe (French West Indies) are scant. STUDY DESIGN AND METHODS: From January 1989 to December 1996, 59,426 blood donors were screened by enzyme immunoassay for antibodies to HTLV-I. All repeatedly reactive samples were confirmed by Western blot. Temporal trends in HTLV-I seropositivity rates were examined during the study period. A multivariate analysis of donation, demographic, and biologic characteristics was performed. RESULTS: Of the screened blood donors, 195 were confirmed as seropositive, for an overall prevalence of 0.33 percent (95% CI 0.28-0.38). A marked decrease in overall HTLV-I prevalence with time (from 0.47% in 1989 to 0.13% in 1996) was observed, which can be explained mainly by the decreasing percentage of recruited new donors during the study period. Four independent risk factors for HTLV-I were identified: new donor status (odds ratio [OR] 12.5), female sex (OR 1.7), increasing age (30-39 years: OR, 2.4; 40-49 years: OR, 3.7; >50 years: OR 6.6), and positive antibodies to hepatitis B virus core antigen (OR, 1.7). Selection of specific locations for blood collection was inversely associated with HTLV-I (OR 0.5). CONCLUSION: New donor status, advancing age, female sex, and positivity for hepatitis B virus core antibodies were the major factors associated with HTLV-I infection in Guadeloupe.     

Serologic evidence of hepatitis A and B virus infections in thalassemia patients: a retrospective study

To determine the current risk of hepatitis B virus (HBV) infection in multiply transfused thalassemia patients, we tested sera from such patients in New York City for the hepatitis B surface antigen (HBsAg) and its antibody (anti-HBs) using radioimmunoassay techniques. Altogether 48 per cent of the patients had either HBsAg (4.5%) or anti- HBs (43.9%) positive sera. The prevalence of these HBV markers was related to both the number of units transfused and the year blood transfusion therapy was begun, although evidence suggested that the latter factor had the greatest influence. Donor HBsAg screening began in New York in 1969, and only one patient first transfused since that time had HBV marker positive serum. Thus, multiply-transfused thalassemia patients now appear to be at little risk of HBV infection from transfusions. Sera were also tested for antibody to the hepatitis A virus (anti-HA) using immune adherence hemaglutination. Anti-HA prevalence was only 4.9 per cent, no greater than rates reported among nontransfused children, providing evidence against a significant role for blood transfusions in hepatitis A virus transmission.     

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.