Prevalence and trends of transfusion-transmittable infections among blood donors in Southwest China.

BACKGROUND: The high prevalence of transfusion-transmitted infections (TTIs) is causing serious harm to human health worldwide. The aim of this research was to assess the prevalence and influencing factors of TTIs in Southwest China. METHODS: A retrospective study of blood donor records from January 2008 to December 2015 was conducted. All samples were screened for HBV, HCV, HIV and syphilis. The donor's data was recorded and analyzed statistically using SPSS software. RESULTS: We revealed that the prevalence of TTIs showed a decreasing trend from 2.39 to 1.98%, and this was slightly lower than that in other regions of China. Syphilis infection was the most serious issue among blood donors in Southwest China, which demonstrated a significantly higher rate than that in other areas of China. The high infection rate of the female and farmer groups in rural regions is worth noting. The logistic regression model showed that age, occupation and donor category was the influential factors for TTIs. CONCLUSIONS: The overall prevalence of TTIs demonstrated a decreasing trend from 2008 to 2015 in Southwest China, but there is still a sufficient threat to blood safety, and more efforts are needed to further guarantee blood safety in China.

Quantitative and multiplexed detection for blood typing based on quantum dot-magnetic bead assay.

BACKGROUND: Accurate and reliable blood grouping is essential for safe blood transfusion. However, conventional methods are qualitative and use only single-antigen detection. We overcame these limitations by developing a simple, quantitative, and multiplexed detection method for blood grouping using quantum dots (QDs) and magnetic beads. METHODS: In the QD fluorescence assay (QFA), blood group A and B antigens were quantified using QD labeling and magnetic beads, and the blood groups were identified according to the R value (the value was calculated with the fluorescence intensity from dual QD labeling) of A and B antigens. The optimized performance of QFA was established by blood typing 791 clinical samples. RESULTS: Quantitative and multiplexed detection for blood group antigens can be completed within 35 min with more than 105 red blood cells. When conditions are optimized, the assay performance is satisfactory for weak samples. The coefficients of variation between and within days were less than 10% and the reproducibility was good. The ABO blood groups of 791 clinical samples were identified by QFA, and the accuracy obtained was 100% compared with the tube test. Receiver-operating characteristic curves revealed that the QFA has high sensitivity and specificity toward clinical samples, and the cutoff points of the R value of A and B antigens were 1.483 and 1.576, respectively. CONCLUSION: In this study, we reported a novel quantitative and multiplexed method for the identification of ABO blood groups and presented an effective alternative for quantitative blood typing. This method can be used as an effective tool to improve blood typing and further guarantee clinical transfusion safety.

HCV infection in voluntary donors and its influence on recruitment of donors in Chongqing area.

Blood donor recruitment models have changed from paid donors to employer-organized donors and to voluntary donors in China. Reports on the hepatitis C virus (HCV) infection among voluntary blood donors in China have been rarely found at present. The prevalence of anti-HCV and genotypes among the first-time voluntary blood donors was investigated in Chongqing area of China. A total of 13,620 serum samples were collected from the first-time voluntary blood donors in Chongqing, China. Anti-HCV antibody was tested by ELISA. The Core/E2 region of HCV RNA from HCV seropositive samples was amplified by RT-PCR for genotyping. The results indicated that the prevalence of anti-HCV averaged 0.49% (67/13,620), and the highest rate (0.86%) was obtained in the group aged 40 to 49. A higher prevalence was observed among the more educated donors, and metropolitan donors. The ratios of following genotypes 1b, 2a, 3a and 3b were 4 (18%), 5 (23%), 9 (41%) and 4 (18%) in all the 22 samples respectively. Genotype 3 (3a and 3b) was the predominant genotype. In conclusion, the prevalence of anti-HCV was low among the population of voluntary blood donors in Chonqing area. The genotyping results showed the possibility of presence of druggies among the voluntary blood donors. Therefore, more attention should be paid to exclude those high-risk persons from the volunteers.

[Report on difficulty in blood group identification due to anti-H antibody in three cases].

Anti-H antibody belongs to IgM type cold antibody, which often induces the unconformity of positive and reverse typing and leads to the difficulty in clinical blood typing. Anti-H antibody was found during identification of the counter blood group in 3 cases. The antibody was found to be active at 37 degrees C, room temperature and 4 degrees C when determined by blood group serology, and was finally analyzed to be IgM. It is suggested that not to give erythrocytes of O group unreasoningly to blood recipient of AB group during emergent moment, but instead, to give same type of blood. If there was no same type of blood during urgent events, O type erythrocytes could be employed after being matched by saline centrifuging with host side coincidence and screened by incomplete method. In this case, anti-H antibody leading to adverse-reaction in blood transfusion should be prevented.