Characterization of HIV risks in a Brazilian sickle cell disease population.

BACKGROUND: A low prevalence of HIV in sickle cell disease (SCD) patients has been reported in the literature though mechanisms for this are not understood. METHODS: HIV risk behaviors were compared between SCD cases and non-SCD controls using a self-administered audio computer-assisted self-interview. SCD cases were recruited from a multi-center SCD cohort established in Brazil; controls were recruited from SCD social contacts. Categorical variables were analyzed using Chi-Square or Fisher exact test. Continuous variables were compared using the Mann-Whitney U test. RESULTS: There were 152 SCD cases and 154 age/location matched controls enrolled at three participating Brazilian centers during 2016-17. No significant differences in number of sexual partners (lifetime or previous 12 months), male-to-male sex partners or intravenous drug use were observed. Cases received more transfusions, surgeries, and acupuncture treatment. CONCLUSIONS: Besides the risk of transfusion-transmitted HIV, which is now exceedingly rare, SCD and non-SCD participants demonstrated similar HIV risk behaviors. Causes other than risk behaviors such as factors inherent to SCD pathophysiology may explain the reported low prevalence of HIV in SCD.

Prevalence of Treponema pallidum DNA among blood donors with two different serologic tests profiles for syphilis in São Paulo, Brazil.

The presence of Treponema pallidum DNA was assessed by real-time PCR in samples of blood donors with reactive serologic tests for syphilis. Treponema pallidum DNA was detected in two (1·02%) of 197 samples of VDRL>8, EIA+ and FTA-ABS+ donors, and in no sample from 80 VDRL−, EIA+ and FTA-ABS+ donors. Donors VDRL−, EIA+ and FTA-ABS+ lack demonstrable T. pallidum DNA in their blood and are unlike to transmit syphilis. Donors VDRL>8, EIA+ and FTA-ABS+ carry the risk of syphilis infectivity even in concomitance to antibodies detection. Serologic screening for syphilis may still play a role to prevent its transfusion transmission.

Demographic, risk factors and motivations among blood donors with reactive serologic tests for syphilis in São Paulo, Brazil.

OBJECTIVE: To identify the demographic characteristics, risk factors and motivations for donating among blood donors with reactive serologic tests for syphilis. BACKGROUND: Post-donation interviews with syphilis seropositive blood donors improve recruitment and screening strategies. METHODS: This case-control study compares 75 Venereal Disease Research Laboratory (VDRL) > 8, EIA+ (enzyme immunoassay) and FTA-ABS+ (fluorescent treponemal antibody); 80 VDRL-, EIA+ and FTA-ABS+; and 34 VDRL- and EIA- donors between 2004 and 2009. Donors were assessed by their demographic characteristics, sexual behaviour, history of alcohol and illicit drugs use, and motivations to donate. RESULTS: Donors with VDRL > 8 were more likely to be divorced [AOR = 12·53; 95% confidence interval (CI) 1·30-120·81], to have had more than six sexual partners (AOR=7·1; 95% CI 1·12-44·62) and to report male-male-sex in the past 12 months (AOR=8·18; 95% CI 1·78-37·60). Donors with VDRL-, EIA+ and FTA-ABS+ were less likely to be female (AOR=0·26; 95% CI 0·07-0·96), more likely to be older (AOR=10·2; 95% CI 2·45-42·58 ≥ 39 and <60 years old) and to have had more than six sexual partners in the past 12 months (AOR = 8·37; 95% CI 1·49-46·91). There was no significant difference among groups regarding illicit drugs use; 30·7% (VDRL > 8) and 12·5% (VDRL-, EIA+ and FTA-ABS+) of donors reported that they had been at risk for HIV infection (P = 0·004). One-third of donors came to the blood bank to help a friend or a relative who needed blood. CONCLUSION: Although donors exposed to syphilis reported and recognised some high risk behaviour, most were motivated by direct appeal to donate blood. Monitoring the risk profile of blood donors can benefit public health and improve blood safety.

Knowledge of HIV testing and attitudes towards blood donation at three blood centres in Brazil.

BACKGROUND: Reducing risk of HIV window period transmission requires understanding of donor knowledge and attitudes related to HIV and risk factors. STUDY DESIGN AND METHODS: We conducted a survey of 7635 presenting blood donors at three Brazilian blood centres from 15 October through 20 November 2009. Participants completed a questionnaire on HIV knowledge and attitudes about blood donation. Six questions about blood testing and HIV were evaluated using maximum likelihood chi-square and logistic regression. Test seeking was classified in non-overlapping categories according to answers to one direct and two indirect questions. RESULTS: Overall, respondents were male (64%) repeat donors (67%) between 18 and 49 years old (91%). Nearly 60% believed blood centres use better HIV tests than other places; however, 42% were unaware of the HIV window period. Approximately 50% believed it was appropriate to donate to be tested for HIV, but 67% said it was not acceptable to donate with risk factors even if blood is tested. Logistic regression found that less education, Hemope-Recife blood centre, replacement, potential and self-disclosed test-seeking were associated with less HIV knowledge. CONCLUSION: HIV knowledge related to blood safety remains low among Brazilian blood donors. A subset finds it appropriate to be tested at blood centres and may be unaware of the HIV window period. These donations may impose a significant risk to the safety of the blood supply. Decreasing test-seeking and changing beliefs about the appropriateness of individuals with behavioural risk factors donating blood could reduce the risk of transfusing an infectious unit.

Risk factors for human immunodeficiency virus infection among Brazilian blood donors: a multicentre case-control study using audio computer-assisted structured interviews.

BACKGROUND: Although risk factors for HIV infection are known, it is important for blood centres to understand local epidemiology and disease transmission patterns. Current risk factors for HIV infection in blood donors in Brazil were assessed. METHODS: A case-control study was conducted at large public blood centres located in four major cities between April 2009 and March 2011. Cases were persons whose donations were confirmed positive by enzyme immunoassays followed by Western blot confirmation. Audio computer-assisted structured interviews (ACASI) were completed by all cases and controls. Multivariable logistic regression was used to estimate adjusted odds ratios (AORs) and associated 95% confidence intervals (CIs). RESULTS: There were 341 cases, including 47 with recently acquired infection, and 791 controls. Disclosed risk factors for both females and males were sex with an HIV-positive person AOR 11.3, 95% CI (4.1, 31.7) and being an IVDU or sexual partner of an IVDU [AOR 4.65 (1.8, 11.7)]. For female blood donors, additional risk factors were having male sex partners who also are MSM [AOR 13.5 (3.1, 59.8)] and having unprotected sex with multiple sexual partners [AOR 5.19 (2.1, 12.9)]. The primary risk factor for male blood donors was MSM activity [AOR 21.6 (8.8, 52.9)]. Behaviours associated with recently acquired HIV were being a MSM or sex partner of MSM [13.82, (4.7, 40.3)] and IVDU [11.47, (3.0, 43.2)]. CONCLUSION: Risk factors in blood donors parallel those in the general population in Brazil. Identified risk factors suggest that donor compliance with selection procedures at the participating blood centres is inadequate.

Relationship between social capital and test seeking among blood donors in Brazil.

BACKGROUND AND OBJECTIVES: Higher risk of HIV infection could be associated with test seeking, which is one motivation for donating blood. Cognitive social capital is defined as the social support, trust and co-operation that guide community behaviour. Structural social capital refers to an individual's participation in institutions and organizations. The association between social capital and test seeking was assessed. MATERIALS AND METHODS: A survey of over 7500 donors in three Brazilian blood centres was conducted. Test seeking was classified into four non-overlapping categories (non-test seeker, possible, presumed and self-disclosed test seekers) using one direct and two indirect questions. Social capital was summarized into cognitive and structural categorizations. Multivariable logistic regression analysis was performed. RESULTS: Compared with non-test seekers (62% of survey respondents), cognitive social capital was higher for each category of test seeking (OR=1.1, 7.4, 7.1, P<0.05 respectively). Male gender, lower education and lower income were also significantly associated with test seeking. CONCLUSION: As test seekers appear to have strong social networks, blood banks may leverage this to convince them to seek testing at other locations.

A single window-period donation detected by human immunodeficiency virus p24 antigen after 5 years of routine screening in a group of Brazilian blood banks.

BACKGROUND AND OBJECTIVES: The purpose of this article was to describe the experience of screening for human immunodeficiency virus (HIV) p24 antigen (p24Ag) in blood donors, in four Brazilian Blood Banks, and to report the detection of the first window-period donation. MATERIALS AND METHODS: During 61 months (May 96 to June 01), 103 470 consecutive donations were screened for HIV p24Ag using commercially available enzyme-linked immunosorbent assay (ELISA) kits. Testing was carried out in accordance with the instructions supplied with the kits. RESULTS: Fifty-eight repeatedly reactive samples were identified [0.056% of the total; 95% confidence interval (95% CI): 0.042-0.070]. Ten of the 58 were confirmed as p24Ag positive after neutralization (0.010%; 95% CI: 0.004-0.016), nine of the 10 (0.009%; 95% CI: 0.003-0.014) were also HIV antibody positive and only one (0.001%; 95% CI: 0-0.003) was HIV antibody negative. CONCLUSIONS: In this setting the rate of sole p24Ag-positive donations was one in 103 740. This figure corresponds closely with the previously estimated yield of one in 87 796 donations. The yield of HIV p24Ag+ : Ab- has been previously estimated in our centres to be 1 : 87 796 donations, a value similar to that observed in actual practice.

Significance of isolated hepatitis B core antibody in blood donors from São Paulo.

The clinical significance of isolated anti-HBc is still a challenge. To elucidate the real importance of this finding in our blood donors, an investigation algorithm was tested. One hundred and twelve isolated anti-HBc seropositive blood donors underwent clinical evaluation and retesting of HBV markers. Those who presented repeatedly reactive isolated anti-HBc, received a single dose of hepatitis B recombinant vaccine to verify anti-HBs early response. A HBV-DNA determination by PCR was done for those who did not test positive to anti-HBs after vaccine. The level of anti-HBc was recorded as a ratio of the sample-to-cut-off values (S:C ratio) in 57 candidates at donation. Comparing true and false-positive anti-HBc results, the different S:C ratios of them were statistically significant and when less than 2, implying in a false-positive result probability over 80%. A high percent of false-positive results (16.07%) was verified after anti-HBc retesting. HBV immunity was characterized in 49.11%, either by anti-HBs detection in retesting (15.18%), or after a single dose HBV vaccination (33.93%). HBV-DNA was negative in all tested donors. In conclusion, this algorithm was useful to clarify the meaning of isolated anti-HBc in most of our blood donors.

Risk of exposure to Chagas' disease among seroreactive Brazilian blood donors.

BACKGROUND: Screening of blood donors for Chagas' disease by using currently available serologic tests is complicated by the lack of adequate sensitivity, discordant results between tests, and the absence of a gold standard. STUDY DESIGN AND METHODS: The study was designed to evaluate the serologic tests by using epidemiologic data relating to the risk of exposure to Trypanosoma cruzi in the urban centers of Brazil. The serologic results obtained from screening 411,617 voluntary blood donations in São Paulo during 1993 and 1994 were reviewed, as well as follow-up results on 1,267 donors who initially were repeatably reactive in at least one of three screening tests. Epidemiologic data were obtained from 321 individuals who on follow-up remained reactive in at least one test and who returned for medical counseling. Controls included 119 screen-negative blood donors and 45 blood donors who were repeatably reactive in at least one screening test but were negative on follow-up. RESULTS: Of the individuals who reacted in three screening tests, 94.6 percent remained reactive on follow-up. Of the individuals who were repeatably reactive in only one screening test, 70.8 percent were negative in all three tests on follow-up. Most individuals who reacted in two or three tests on follow-up had epidemiologic evidence of a risk of exposure to Chagas' disease. A significant proportion (29.1%) of those who were reactive in only one test on follow-up had epidemiologic evidence of exposure to the Chagas' disease vector as compared to 14.6 percent of controls (p = 0.007). This suggests that some of these individuals truly were infected. CONCLUSION: No single test for Chagas' disease is sufficiently sensitive to prevent transfusion transmission of the disease in the urban centers of Brazil.