Blood donor notification rate in a blood bank in Veracruz, Mexico.

Blood banks are primarily responsible for providing safe blood, but they also indirectly act to prevent the spread of infectious diseases by notifying blood donors of positive screening results. The notification process differs between countries and notifications rates are generally low. This study sought to analyze the notification rate of healthy and infection-positive donors who donated blood at CETS-Veracruz. A total of 41790 donors were analyzed, 1585 (3.79%) were positive for one or more of the screened infection markers. Only 4163 (9.96% of the total) were notified about their serology results. Of the positive donors, 157 were contacted by phone call; of them, 91 (57%) returned to the blood bank for their results. The average notification rate for positive donors was only 17.48%. The highest notification rate was for anti-HBc (26.63%), while the lowest was for HBsAg (4.17%). Age significantly influenced the return of donors: Those aged 18-24 and 25-39 years were 4.71 and 1.64 times less likely, respectively, to return for their results compared to the rate for all ages. The advice received in the pre-donation stage about the risks of transfusion-transmitted infections and the relevance of returning for results did not appear to impact donors, since the rate of notification was lower than those reported internationally. These data indicate that CETS-Veracruz should improve donor data registration and communication mechanisms to increase the notification rate, and that donor notification studies should be carried out in other Mexican blood banks to analyze the return rate at the national level.

Use of Investigator 24plex GO! To analyse allele frequencies of 21 autosomal STRs in the population of Veracruz state, Mexico.

BACKGROUND: Mexican population databases for autosomal STRs are scarce, and no previous studies have been performed with the Qiagen Investigator 24plex GO! AIM: To analyse the frequency of 21 autosomal short tandem repeat (STR) loci and forensic parameters in individuals from Veracruz state, Mexico. SUBJECTS AND METHODS: A total of 234 unrelated individuals were analysed with the Investigator 24plex GO! Kit, which includes the following autosomal STRs: TH01, D3S1358, vWA, D21S11, TPOX, D1S1656, D12S391, SE33, D10S1248, D22S1045, D19S433, D8S133879, D2S1338, D2S441, D18S51, FGA, D16S539, CSF1PO, D13S317, D5S818, and D7S820. Allele frequencies, forensic parameters, and relationships with neighbouring Mexican populations were estimated. RESULTS: The STRs analysed were in Hardy-Weinberg Equilibrium (HWE). The combined matching probability and combined PE were 1.5266 E-24 and 0.999999988711, respectively. The D18S51 and SE33 loci presented the highest Ho (0.8974 and 0.8932) and PE (0.7902 and 0.7815), respectively. The highest PIC (0.9337) and PD (0.9894) values corresponded to SE33. Conversely, D22S1045 had the lowest PIC and PE (0.5533 and 0.3546, respectively). A population cluster among southern Mexican populations, which included non-differentiation between Guerrero and Veracruz states was detected. CONCLUSION: The forensic efficacy of the 21 STRs analysed by the Investigator 24plex GO! Kit was evaluated in the Veracruz state. Moreover, new population clusters that have not yet been described and are related to geographic regions were identified, and these are in agreement with previously reported ancestral differences.

Occult hepatitis B infections and anti-HBc prevalence at a resource-limited blood bank in Mexico.

OBJECTIVES: To identify blood donors with occult hepatitis B infections (OBIs), determine the prevalence of antibody to hepatitis B core antigen (anti-HBc) positivity and estimate the impact of anti-HBc screening on donor deferral at CETS-Veracruz (Mexico). BACKGROUND: Hepatitis B virus infection is a major concern in transfusion medicine. Mexican regulations only mandate screening for hepatitis B surface antigen (HBsAg), and there are no requirements regarding testing for anti-HBc or use of a nucleic acid test (NAT). There is, therefore, limited information about the prevalence of anti-HBc positivity and occult hepatitis B among blood donors in Mexico. METHODS: This retrospective study examined individuals who donated blood to CETS-Veracruz from June 2014 to June 2017. All donors were serologically examined according to Mexican health regulations, and the prevalence of anti-HBc positivity was determined. A NAT was used to identify individuals with OBIs. RESULTS: We analysed the data of 28 016 blood donors. Over 4 years, the average prevalence of anti-HBc positivity was 1.05%. The risk factors for anti-HBc positivity were low education and age over 50 years. There were nine donors with OBIs. CONCLUSION: The presence of donors with OBIs in CETS-Veracruz and other Mexican blood banks highlights the need to mandate the implementation of anti-HBc screening in Mexico.

Trends in prevalence of HIV and syphilis in a central blood bank of Veracruz, Mexico.

Syphilis and HIV infections continue to threaten the safety of blood banks in countries where altruistic donations are rare. The aim of this study of blood donors to the Centro Estatal de la Transfusion Sanguínea de Veracruz (Mexico) was to determine changes in the prevalence of syphilis and HIV, and to identify factors associated with these infections. A total of 109,054 blood donors were retrospectively analyzed from 2007 to 2014. Serological screening of blood units was performed, and demographic data were collected from clinical records to identify risk factors. The prevalence of Treponema pallidum was 1.4% and that of confirmed HIV was 0.11%. The main risk factors for HIV positivity were age of 18 to 24 years-old, being unmarried, and being an employee or student. The main risk factors for syphilis positivity were being a widow or divorced, being over 35 years-old, having a low level of education, and being a driver, fisherman, or trade worker. There were high prevalences for both infections in southeast Veracruz, where females and males had equal probabilities of each infection. Strengthening of education programs on sexually transmitted diseases for young people may help to prevent new and congenital infections.

Seroprevalence of hepatitis viruses and risk factors in blood donors of Veracruz, Mexico.

INTRODUCTION: Hepatitis B and C are among the most important transfusion-transmitted infections and sources of liver diseases worldwide. In Veracruz, Mexico, liver diseases are important causes of mortality, and the prevalence reports of these viruses are scarce. This study sought to determine the prevalence of these infections in blood donors, in order to increase the safety of blood products in this region. METHODOLOGY: A retrospective study was performed on blood donors who attended the Veracruz State Blood Transfusion Center from 2006 to 2010. All samples were screened for transfusion-transmitted infections. The prevalence rates of hepatitis B virus (HBV) and hepatitis C virus (HCV) were determined, and demographic data obtained from clinical records were used to evaluate risk factors. RESULTS: A total of 56,377 donors were serologically screened; of them, 403 were seropositive for HCV (357 men and 46 women), and 61 were positive for HBsAg (52 men and 9 women). The overall prevalence rates were 0.72% (0.63%-0.76%) for HCV and 0.11% (0.08%-0.14%) for HBsAg. The risk factors for HBsAg positivity were being a cattleman and living in the Huasteca Baja region, whereas those for HCV were being a fisherman, living in the Papaloapan region, and having an elementary-level or lower education. CONCLUSIONS: This is the first study to show that being a fisherman is a risk factor for HCV. The implementation of nucleic acid test technology will help to identify the real risks for transfusion-transmitted hepatitis C in Veracruz.

Prevalence of Trypanosoma cruzi antibodies in blood donors from Veracruz State, Mexico.

BACKGROUND: Trypanosoma cruzi is the causal agent of Chagas disease. Of the Mexican states, Veracruz is among the most affected by this sickness. However, the actual epidemiologic situation of this disease is not well understood. This study sought to determine the prevalence and risk factors for Chagas disease among Veracruzan blood donors. STUDY DESIGN AND METHODS: Blood donors from Centro Estatal de la Transfusion Sanguinea de Veracruz were included. Blood units were serologically scrutinized for T. cruzi antibodies using enzyme-linked immunosorbent assays. To identify risk factors, demographic data were collected from the medical records of positive donors and a representative sample of healthy donors. RESULTS: A total of 87,232 donations were analyzed, and the mean prevalence of T. cruzi was found to be 0.5%. The identified risk factors were living as a couple and in a rural area, having a low level of education, being a farmer, dwelling in a house with earthen or wooden walls and a tile or thatch roof, living with domestic animals, recognition of or exposure to triatomine bugs, and residing in the Huasteca region. An increase of rural-living donors infected with T. cruzi was observed in the past 3 years of the study period. CONCLUSION: The prevalence to Chagas disease has not decreased in the past decade and the disease appears to be spreading in rural areas of Veracruz. This increases the risk of T. cruzi transfusion-transmitted infection, not only in Veracruz and Mexico, but also in other nonendemic countries that receive immigrants from Veracruz State.

Decreased CD4 and wide-ranging expression of other immune receptors after HIV-envelope-mediated formation of syncytia in vitro.

In human HIV infection, multinucleated cells (syncytia) are formed by fusion of HIV-infected cells with CD4+ cells. In order to examine possible functional implications of syncytia formation for the immune response, the expression of important surface molecules by T-cell syncytia and surrounding cells that remain unfused (bystander cells) was analyzed in cocultures of HIV-Env- and CD4-expressing E6 Jurkat T cells. Fusion partners were differentially labeled with lipophilic probes, and syncytia and bystander cells were identified by flow cytometry. The cellular phenotype and response to activation stimulus after fusion were analyzed with antibodies coupled to third-party fluorochromes. Cocultured unfused E6 cells showed a marked decrease in CD4 expression, suggesting the selective recruitment of cells strongly expressing CD4 into syncytia. However, the incorporated CD4 was not detected in the syncytia, whereas the range of expression of CD28, ICAM-1, CXCR4 and CD3 was wider than that of unfused cells. Limited expression of CD4 in the bystander unfused population, as well as in the newly formed syncytia, would result in limitation of further viral entry and a failure to identify these cells, and it could partially contribute to functional impairment and a decrease in the number of CD4+ T cells in AIDS. Most of the syncytia were viable and expressed CD25 and IL-2 in response to activation by phorbol myristate acetate (PMA) and ionomicyn. Thus, syncytia populations harboring widely heterogeneous levels of receptors would constitute a potential source of anomalous immune function.

HIV-envelope-dependent cell-cell fusion: quantitative studies.

Interaction in vitro between cells infected with human immunodeficiency virus (HIV) and surrounding, uninfected, target cells often leads to cell fusion and the formation of multinucleated cells, called syncytia. The presence in HIV-infected individuals of virus strains able to induce syncytia in cultures of T cells is associated with disease progression and AIDS. Even in the asymptomatic stage of infection, multinucleated cells have been observed in different organs, indicating that fused cells may be generated and remain viable in the tissues of patients. We used lymphocytic cells transfected for the expression of the HIV-envelope (Env) glycoproteins to develop a method for the direct quantification of fusion events by flow cytometry (Huerta et al., 2006, J. Virol. Methods 138, 17-23; López-Balderas et al., 2007, Virus Res. 123, 138-146). The method involves the staining of fusion partners with lipophilic probes and the use of fluorescence resonance energy transfer (FRET) to distinguish between fused and aggregated cells. We have shown that such a flow-cytometry assay is appropriate for the screening of compounds that have the potential to modulate HIV-Env-mediated cell fusion. Even those syncytia that are small or few in numbers can be detected. Quantitative analysis of the fusion products was performed with this technique; the results indicated that the time of reaction and initial proportion of fusion partners determine the number, relative size, and average cellular composition of syncytia. Heterogeneity of syncytia generated by HIV-Env-mediated cell-cell fusion may result in a variety of possible outcomes that, in turn, may influence the biological properties of the syncytia and surrounding cells, as well as replication of virus. Given the myriad immune abnormalities leading to AIDS, the full understanding of the extent, diverse composition, and role of fused cells in the pathogenesis of, and immune response to, HIV infection is an important, pending issue.

Discriminating in vitro cell fusion from cell aggregation by flow cytometry combined with fluorescence resonance energy transfer.

Expression of fusion proteins in the plasma membrane enables cells to bind and fuse with surrounding cells to form syncytia. Cell fusion can have important functional outcomes for the interacting cells, as syncytia formation does in AIDS pathogenesis. Studies on cell fusion would be facilitated by a quantitative method able to discriminate between cellular aggregates and bona fide fused cells in a cell population. Flow cytometry with fluorescence resonance energy transfer is applied here for analyzing fusion of HIV-1 envelope-expressing cells with CD4+ Jurkat cells. Fusion partners were labeled with the vital lipophilic fluorescent probes DiO (green) and DiI (red) and FRET is manifested by an enhancement of the DiI red fluorescence intensity in double fluorescent cells, thus allowing discrimination between fused and aggregated cells. The inhibitory effect of anti-CD4 monoclonal antibodies and the inhibitory peptide T-20 upon cell fusion were readily quantified by this technique. This method allows the distinction of fused and aggregated cells even when they are at low frequencies.