ABSTRACT
<p><b>OBJECTIVE</b>To investigate the blood test patterns for blood donors after nucleic acid detection in blood center.</p><p><b>METHODS</b>The collected blood samples after voluntary blood donors first were detected by conventional ELISA, then 31981 negative samples were detected via HBV/HCV/HIV combined nucleic acid test of 6 mixed samples(22716 cases) or single samples(9265 cases) by means of Roche cobas s201 instrument. The combined detection method as follows: the blood samples were assayed by conventional nucleic acid test of 6 mixed samples, at same time, 6 mixed samples were treated with polyethylene glycol precipitation method to concentrate the virus, then the nucleic acid test of blood samples was performed; the single detection method as follows: firstly the conventional nucleic acid test of single sample was performed, then the positive reactive samples after re-examination were 6-fold diluted to simulate the nucleic acid test of 6-mixed samples. The positive rate of positive samples detected by combined nucleic acid test, positive samples detected by nucleic acid test of mixed virus concentration and positive samples detected by single nucleic acid test was statistically analyzed. In addition, for HBVpersons the serological test yet should be performed.</p><p><b>RESULTS</b>In 22 716 samples detected by nucleic acid test of 6 mixed samples (MP-6-NAT) , 9 cases were HBV(0.40‰, 9/22716); at same time, the detection of same samples by nucleic acid test of mixed sample virus concentration showed 29 cases of HBV(1.28‰, 29/22716). In 9265 samples detected by single nucleic acid test(ID-NAT) 12 cases showed HBV(1.30‰, 12/9265), meanwhile the detection of these 12 samples with HBVby 6-fold dilution for virus concentration found only 4 samples with HBV. In serological qualified samples, ID-NAT unqualified rate was 1.28‰, which was higher than that of MP-6-NAT(0.4‰) (χ=8.11, P<0.05); but there was no statistical difference between unqualified rate of ID-NAT and MP-6-NAT(1.3‰ vs 1.28‰)(χ=0.00, P>0.05). In 41 samples with HBsAgHBV DNAdetected by ELISA, 36 samples were confirmed to be occult HBV infective(OBI) by HBsAb, HBcAb test of ELISA; out of these 41 samples, 33 samples showed HBcAb(91.66% of OBI), 5 might be HBV "window period" infective, moreover the HCV RNA and HIV RNA positive samples were not found.</p><p><b>CONCLUSION</b>To avoid the missdiagnosis of donors with low level of virus, the nucleic acid test must be carried out after virus concentration of mixed samples when the blood test pattern of donors is nucleic acid test of mixed samples, otherwise the single nucleic acid test must be performed to obtain more high detected rate of virus nucleic acid. The HBcAb serologic test and physical examination of donors before blood donation must be enhanced on basis of serological test of HBsAg; for high risk people, the persuading no blood donation is simplest pattern.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the application value of chemiluminescence method (CMIA) detection of Treponema pallidum (TP) specific antibodies in the blood test.</p><p><b>METHODS</b>Over the same period the de novo enzyme linked immunosorbent assay (ELISA) and Abbott chemical luminescence method were used to detect the specific antibody of syphilis in a total of 66298 samples; TP-ELISA negative and TP-CMIA positive unpaid blood donation blood samples for syphilis specific antibody were detected and confirmed by Western blot.</p><p><b>RESULTS</b>Blood samples from 66298 blood donors were detected by TP-ELISA, the positive samples was 250 and the positive rate was 0.38%. The positive samples of TP-CMIA was 297, the positive rate was 0.45%, the difference was statistically significant (P<0.05). The blood samples of 47 unpaid blood donors were confirmed by TP-Western blot method, as a result, 32 samples were positive, 15 were negative, and result detected by TP-ELISA method was negative.</p><p><b>CONCLUSION</b>TP-CMIA sensitivity is higher than that of TP-ELISA, and possesses higher sensitivity and specificity, and quick detection, simple operation, easy automation, suggesting greater application value in blood detection of Treponema pallidum.</p>
ABSTRACT
In order to analyze the molecular epidemiology of A (H1N1) influenza virus in 2009, the complete genome sequences of influenza strains from different host sources downloaded from the NCBI were analyzed on genetic evolution by DNAstar software in this research. The results showed that 79 mutation sites of new A (H1N1) influenza virus were observed compared to previous human A (H1N1) influenza strain, including 14 mutation sites new in all A (H1N1) influenza sources and 37 mutation sites only observed in swine strain. A significant difference was represented in antigenic sites between new A (H1N1) influenza strain and the previous human A (H1N1) strain. This phenomenon shows the new A (H1N1) influenza strain is either originated from the recombination of human and swine strain or from the infection in pig populations and gradual mutation to human tansmission, which remains to be further studied.