Indeterminate RIBA results were associated with the absence of hepatitis C virus RNA (HCV-RNA) in blood donors

Introduction: Hepatitis C virus (HCV) infection is diagnosed by the presence of antibodies and is supplemented by confirmatory testing methods, such as recombinant immunoblot assay (RIBA) and HCV-RNA detection. This study aimed to evaluate the efficacy of RIBA testing to diagnose HCV infection in blood donors positive for anti-HCV antibodies. Methods: A total of 102 subjects positive for anti-HCV determined by enzyme-linked immunosorbent assay (ELISA) at the Hematology and Hemotherapy Foundation of Bahia (HEMOBA) were later assessed with new samples using the Abbott Architect anti-HCV test (Abbott Diagnostics, Wiesbaden, Germany), the RIBA III test (Chiron RIBA HCV 3.0 SIA, Chiron Corp., Emeryville, CA, USA), the polymerase chain reaction (PCR; COBAS® AMPLICOR HCV Roche Diagnostics Corp., Indianapolis, IN, USA) and line probe assay (LiPA - Siemens, Tarrytown, NY, USA) genotyping for HCV diagnosis. Results: Of these new samples, 38.2% (39/102) were positive, 57.8% (59/102) were negative and 3.9% (4/102) were indeterminate for anti-HCV; HCV-RNA was detected in 22.5% (23/102) of the samples. RIBA results were positive in 58.1% (25/43), negative in 9.3% (4/43) and indeterminate in 32.6% (14/43) of the samples. The prevailing genotypes were 1 (78.3%, 18/23), 3 (17.4%, 4/23) and 2 (4.3%, 1/23). All 14 samples with indeterminate RIBA results had undetectable viral loads (detection limit ≤50 IU/mL). Of these samples, 71.4% (10/14) were reevaluated six months later. Eighty percent (8/10) of these samples remained indeterminate by RIBA, and 20% (2/10) were negative. Conclusions: In this study, individuals with indeterminate RIBA results had no detectable HCV-RNA.

Syphilis seroprevalence estimates of Santa Catarina blood donors in 2010

Introduction Knowledge of blood donor characteristics is essential to better guide clinical and serological screening for hemotherapy. The objective of this study was to determine the syphilis seroprevalence and the associated factors of blood donors in the State of Santa Catarina, Brazil. Methods This population-based study from the State of Santa Catarina used information obtained from blood donation records. We analyzed 83,396 blood donor records generated from donors who were considered eligible to donate between January and August 2010. The aim of the study was to estimate the syphilis seroprevalence and its relationship with educational level, age, gender, geographical region and having donated blood in the past 12 months. We used descriptive analyses and a Poisson regression to calculate the prevalence ratios for the variables of interest. Results We found a 0.14% overall seroprevalence and significant differences among the following: first-time blood donors (0.19%) versus repeat donors (0.03% to 0.08%); low educational levels (0.30%) versus medium and high educational levels (0.08% to 0.19%); and donors who did not report their residence (0.88%) or age (6.94%) versus those who did. Increased syphilis seroprevalence was also significantly associated with increased age. Conclusion High syphilis seroprevalence was associated with lower educational level, age, first-time donation and the failure to provide age or residence information.

Changes in the prevalence, incidence and residual risk for HIV and hepatitis C virus in Southern Brazilian blood donors since the implementation of NAT screening

Introduction Previous studies have shown high residual risk of transfusing a blood donation contaminated by human immunodeficiency virus (HIV) or hepatitis C virus (HCV) in Brazil and motivated the development of a Brazilian platform for simultaneous detection of both viruses by nucleic acid amplification test (NAT) denominated HIV/HCV Bio-Manguinhos/Fundação Oswaldo Cruz (FIOCRUZ). The objective of this study was to verify seroprevalence, incidence and residual risk for both viruses before and after the implementation of NAT. Methods Over 700,000 blood samples from all blood banks in the southern Brazilian State of Santa Catarina were analyzed during the period between January 2007 and July 2013. Results Compared with the period preceding the NAT screening, HIV prevalence increased from 1.38 to 1.58 per 1,000 donors, HIV incidence rate increased from 1.22 to 1.35 per 1,000 donor-years, and HIV residual risk dropped almost 2.5 times during the NAT period. For HCV, seroprevalence increased from 1.22 to 1.35 per 1,000 donors, incidence dropped from 0.12 to 0.06 per 1,000 donor-years, and residual risk decreased more than 3 times after the NAT implementation. Conclusions NAT reduced the duration of the immunologic window for HIV and HCV, thus corresponding to approximately 2.5- and 3-fold respective residual risk reductions.

Clinical and epidemiological profile of female blood donors with positive serology for viral hepatitis B

ABSTRACTINTRODUCTION:Since women are frequently the minority among blood donors worldwide, studies evaluating this population usually reflect male features. We assessed the features of female blood donors with positive serology for HBV and compared them with those of men.METHODS The study comprised consecutive blood donors referred to a specialized liver disease center to be evaluated due to HBsAg- and/or anti-HBc-positive tests.RESULTS: The study encompassed 1,273 individuals, 219 (17.2%) of whom were referred due to positive HBsAg test and 1,054 (82.8%) due to reactive anti-HBc test. Subjects' mean age was 36.8±10.9 years, and 28.7% were women. Female blood donors referred for positive HBsAg screening tests demonstrated higher prevalence of healthcare workers (9.3% vs 2.5%) and lower prevalence of sexual risk behaviors (15.1% vs 41.1%) and alcohol abuse (1.9% vs 19.8%) compared to men. Women had lower ALT (0.6 vs 0.8×ULN), AST (0.6 vs 0.8×ULN), direct bilirubin (0.2 vs 0.3mg/dL), and alkaline phosphatase (0.5 vs 0.6×ULN) levels and higher platelet count (223,380±50,293 vs 195,020±53,060/mm3). Women also had a higher prevalence of false-positive results (29.6% vs 17.0%). No differences were observed with respect to liver biopsies. Female blood donors referenced for reactive anti-HBc screening tests presented similar clinical, epidemiological, and biochemical characteristics to those reported for positive HBsAg screening tests and similarly had a higher prevalence of false-reactive results.CONCLUSIONS: Compared to men, female blood donors with positive HBsAg and/or anti-HBc screening tests demonstrated higher prevalence of professional risk and false-positive results and reduced alteration of liver chemistry.

Presence of anti-Leishmania (Viannia) braziliensis antibodies in blood donors in the West-Central region of the State of Paraná, Brazil

ABSTRACTINTRODUCTION:Serological screening in blood banks does not include all transmittable diseases. American cutaneous leishmaniasis (ACL) has a high detection rate in the municipalities of the State of Paraná.METHODS:This study analyzed the presence of anti- Leishmania braziliensisantibodies in 176 blood donors who live in these endemic areas. The variables were analyzed with the χ2 test and Stata 9.1 software. RESULTS: Twenty (11.4%) samples were positive for the presence of anti- L. braziliensisantibodies. CONCLUSIONS: The high percentage of donors with anti- Leishmania spp. antibodies indicates the need to study the risk of ACL transmission through blood donors.

Risk factors for Trypanosoma cruzi infection among blood donors in Central Brazil

Characteristics and possible risk factors associated with Trypanosoma cruzi infection among blood donors were assessed within a routine screening programme in blood banks in an endemic area of Chagas disease. 6,172 voluntary blood donors were interviewed and tested for anti-T. cruzi antibodies by Haemagglutination and Complement Fixation tests in six blood banks in Goiânia-Central Brazil from October 1988 to April 1989. An overall prevalence of 2.3% for T. cruzi infection was obtained, being 3.3% for first-time blood donors, and 1.9% for regular ones (p < 0.01). Considering this seropositivity among regular blood donors, selection of candidates relying only on the history of previous donation was found to be inadequate. The risk of infection increased inversely with the degrees of education and monthly income. There was a 9.2 risk of infection (95% CI 3.8-22.6) for those who had lived more than 21 years in an endemic area compared to subjects who had never lived in rural settings, after multivariate analysis. These informations may help to review the criteria of selection of donors in order to improve quality of blood products in endemic areas.

Prevalence and levels of IgG and IgM antibodies against Plasmodium falciparum and P. vivax in blood donors from Rondônia, Brazilian Amazon

Antibodies of IgG and IgM isotopes reacting with Plasmodium falciparum and P. vivax thick-smear antigens were searched for by the indirect fluorescent antibody test (IFAT) in a random sample of 230 blood donors at the transfusion centre of Porto Velho (HEMERON), Rondônia State, western Brazilian Amazon. A high prevalence of IgG seropositivity (32% against P. falciparum, 24% against P. vivax and 37% against either P. falciparum or P. vivax antigens) was detected among them, despite the fact that candidates reporting recent (<12 months) malaria attacks were not elegible. Only a small proportion of them had also detectable IgM antibodies to these antigens. These data suggest an intense, relatively recent exposure to malaria in such an urban population sample. However, parasitaemia (as detected by microscopical examination of Giemsa-stained thick smears) was patent in only one prospective donor. The antibody profile of blood donors was compared with that of healthy subjects of all age groups, living in a close endemic area (Candeias village, 21 km east of Porto Velho). The villagers were classified into two groups according to their history of a recent (<12 months) or a remote (>12 months) past malaria attack due to either P. falciparum or P. vivax. Extensive overlapping was observed when the distribution of antibody titres of healthy subjects from Candeias village with a recent and remote malaria history was compared. In conclusion, subjects with a recent or a remote malaria history could not be distinguished by sorological criteria alone.

Hepatitis B and C prevalences among blood donors in the south region of Brazil

The prevalence of hepatitis B and C infection has been determined in a seroepidemiological survey among blood donors from the south of Brazil (Florianópolis, State of Santa Catarina). These markers has also been correlated with the levels of alanine aminotransferase (ALT), a surrogate marker to prevent post-transfusion hepatitis. Sera from 5000 donors were randomly collected in the period of April to November 1991. The prevalences of HBsAg, anti-HBs and anti-HBc were respectively 0.78, 7.02 and 13.98. The anti-HCV prevalence after confirmation testing with line immunoassay (LIA), was 1.14. Normal values of ALT ( < = 32 U/ml) were found in 59.78, values slightly above the mean (ALT between 32-70 U/ml) in 37.74 and high values of ALT ( > = 70 U/ml) in 2.48. The positivity of anti-HCV antibodies increased with the elevation of ALT levels. This correlation was not observed in relation to HBsAg. There exists a diversity in the recognition of HCV epitopes among HCV positive donors. Via the confirmation test used, we could observe that 94.7 of donors recognize the structural core antigen. Besides that, we observed that 5.26 of the HCV reactive sera recognized only epitopes located in the NS4 and/or NS5 region, indicating the importance of these epitopes for the improvement of assays.

Coinfection by Strongyloides stercoralis in blood donors infected with human T-cell leukemia/lymphoma virus type 1 in São Paulo city, Brazil

The frequency of coinfection with Strongyloides stercoralis and human T-cell leukemia/lymphoma virus type 1 (HTML-1) was determined in 91 blood donors examined at the blood bank of a large hospital in São Paulo city, Brazil. As control group 61 individuals, not infected by HTLV-1, were submitted to the same techniques for the diagnosis of S. stercoralis infection. In HTLV-1 infected patients the frequency of S. stercoralis infection was 12.1%; on the other hand, the control group showed a frequency significantly lower of S. stercoralis infection (1.6%), suggesting that HTLV-1 patients shoud be considered as a high risk group for strongyloidiasis in São Paulo city.

Prevalence of antibodies to hepatitis B core antigen in blood donors in the middle west region of Brazil

The prevalence of antibodies to hepatitis B core antigen in 552 prime blood donors was of 9.4%. The majority (71.2%) has antibodies to hepatitis B surface antigen. The hepatitis B surface antigen was present in 0.7%, all of them antibodies to hepatitis B core antigen positive.

High prevalence anti-Trypanosoma cruzi antibodies, among blood donors in the State of Puebla, a non-endemic area of Mexico

Blood transfusion is the second most common transmission route of Chagas disease in many Latin American countries. In Mexico, the prevalence of Chagas disease and impact of transfusion of Trypanosoma cruzi-contaminated blood is not clear. We determined the seropositivity to T. cruzi in a representative random sample, of 2,140 blood donors (1,423 men and 647 women, aged 19-65 years), from a non-endemic state of almost 5 millions of inhabitants by the indirect hemagglutination (IHA) and enzyme linked immunosorbent assay (ELISA) tests using one autochthonous antigen from T. cruzi parasites, which were genetically characterized like TBAR/ME/1997/RyC-V1 (T. cruzi I) isolated from a Triatoma barberi specimen collected in the same locality. The seropositivity was up to 8.5% and 9% with IHA and ELISA tests, respectively, and up to 7.7% using both tests in common. We found high seroprevalence in a non-endemic area of Mexico, comparable to endemic countries where the disease occurs, e.g. Brazil (0.7%), Bolivia (13.7%) and Argentina (3.5%). The highest values observed in samples from urban areas, associated to continuous rural emigration and the absence of control in blood donors, suggest unsuspected high risk of transmission of T. cruzi, higher than those reported for infections by blood e.g. hepatitis (0.1%) and AIDS (0.1%) in the same region.

Prevalence and genotypes of GB Virus C/Hepatitis G virus among blood donors in Central Brazil

A survey was conducted in a blood donor population of Central Brazil aiming to investigate the prevalence of GB virus C (GBV-C)/hepatitis G virus (HGV) infection and also to analyze the virus genotypes distribution. A total of 241 voluntary blood donors were interviewed at the State Blood Bank in Goiânia, State of Goiás, Brazil. Blood samples were collected and serum samples tested for GBV-C/HGV RNA by polymerase chain reaction. Genotypes were determined by restriction fragment length polymorphism (RFLP) analysis. Seventeen samples were GBV-C/HGV RNA-positive, resulting in a prevalence of 7.1% (95% CI: 4.2-11.1). A significant trend of GBV-C/HGV RNA positivity in relation to age was observed, with the highest prevalence in donors between 29-39 years old. Ten infected individuals were characterized by reporting parenteral (30%), sexual (18%), both (6%) and intrafamiliar (6%) transmission. However, 7 (40%) GBV-C/HGV RNA-positive donors did not mention any potential transmission route. RFLP analysis revealed the presence of genotypes 1 and 2 of GBV-C/HGV; more precisely, 10 (58.9%) samples were found belonging to the 2b subtype, 4 (23.5%) to the 2a subtype, and 3 (17.6%) to genotype 1. The present data indicate an intermediate endemicity of GBV-C/HGV infection among this blood donor population, and a predominant circulation of genotype 2 (subtype 2b) in Central Brazil.