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.

Detection of Trypanosoma cruzi DNA in blood by PCR is associated with Chagas cardiomyopathy and disease severity.

BACKGROUND: The significance of detection of Trypanosoma cruzi DNA in blood of antibody-positive patients for risk of development of Chagas heart disease is not well established. The objective of this study was to compare detection of T. cruzi DNA with known clinical and laboratory markers of Chagas cardiomyopathy (CC) severity. METHODS: This is a case-control study nested within a retrospective cohort developed in Brazil to understand the natural history of Chagas disease. The study enrolled 499 T. cruzi seropositive blood donors (SP-BD) and 488 frequency matched seronegative control donors (SN-BD) who had donated between 1996 and 2002, and 101 patients with clinically diagnosed CC. In 2008-2010 all enrolled subjects underwent a health questionnaire, medical examination, electrocardiograms and echocardiograms and polymerase chain reaction (PCR) analyses. A blinded panel of three cardiologists adjudicated the outcome of CC. Trypanosoma cruzi kinetoplast minicircle sequences were amplified by real-time PCR using an assay with a sensitivity of one parasite per 20 mL of blood. All testing was performed on coded samples. RESULTS: Rates of PCR detection of T. cruzi DNA were significantly (P = 0.003) higher in CC patients and SP-BD diagnosed with CC (79/105 [75.2 %]) compared with SP-BD without CC (143/279 [51.3%]). The presence of parasitaemia was significantly associated with known markers of disease progression such as QRS and QT interval duration, lower left ventricular ejection fraction, higher left ventricular index mass, and elevated troponin and NTpro-BNP levels. CONCLUSION: Trypanosoma cruzi PCR positivity is associated with presence and severity of cardiomyopathy, suggesting a direct role of parasite persistence in disease pathogenesis.

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.

Human immunodeficiency virus test-seeking motivation in blood donors, São Paulo, Brazil.

BACKGROUND AND OBJECTIVE: Previous studies have shown that volunteer, community-recruited donors have a higher prevalence of human immunodeficiency virus (HIV) infection in São Paulo, Brazil, than replacement donors. One hypothesis which may explain this unexpected finding is that some individuals donate blood because they are seeking HIV testing. The objective of this study was to characterize test-seeking blood donors and to determine whether they are at higher risk for HIV infection compared with other donors. MATERIALS AND METHODS: Subjects presenting for blood donation were asked to participate in a study assessing their motivations (including test seeking) to donate, as measured by perceiving donation as a means to obtain infectious disease test results. Participants completed the standard blood bank predonation screening questions plus our additional survey, and were tested for HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell lymphocytotrophic virus (HTLV) I/II, syphilis and Chagas' disease. As a result of anticipated low statistical power to directly measure the association between test-seeking motivation and HIV infection, we tested for herpes simplex virus type 2 (HSV-2) as a marker of sexual risk for HIV. Our survey includes accepted donors as well as persons whose risk-behaviour histories would result in their exclusion from donation according to routine screening procedures. RESULTS: Of 1,720 potential blood donors randomly selected and approached, 1,600 (93.0%) participated. Overall, 141 (8.8%) were classified as test seekers; 15.6% of these were HSV-2 positive. The proportion of test seekers was the same among community-recruited and replacement donors. Test seekers had a higher prevalence of HSV-2 [adjusted odds ratio (AOR) 1.66; 95% confidence interval (CI): 1.06-2.59] adjusting for age, gender and prior donation. The association was significant among community-recruited blood donors whose previous donation was more than 1 year ago (i.e. 'lapsed donors') (AOR 2.55; 95% CI: 1.20-5.44). Test seekers were not more likely to be rejected from blood donation as a result of health reasons, self-reported HIV risk-related behaviour, or by their own confidential unit exclusion. We found no difference in HSV-2 prevalence between persons accepted for donation (15.7%) and those rejected because of self-reported sexual risk (16.7%). CONCLUSIONS: We did not detect a difference in the proportion of test seekers across different types of blood donors; however, we did detect an association between HSV-2 infection and test seeking, especially among community-recruited lapsed blood donors. Of note, questions on test-seeking behaviour detected donors with increased prevalence of HSV-2, but the self-reported sexual risk behaviours currently used for deferral criteria did not. Incentives to get tested at sites other than blood banks may decrease the residual risk of HIV in the blood supply.