| Part OneStudy On Strategy of HIV Exposed Infants Early DiagnosisBackgroundHuman Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome, (AIDS)) is a major public health problem facing the world and it is also a serious threat to women and children’s health and life. Because of the HIV infection mother’s specific antibodies can enter the fetus/baby’s body, usually disappeared until the baby is 12 to 18 months old. The conventional HIV antibody testing (adult HIV infection diagnosis standard methods) can not be accurately diagnosed the HIV infected infants younger than 18 months and the best time to start antiretroviral therapy was delayed. In developed countries, HIV nucleic acid testing which detecting HIV-1 proviral DNA integrated into the human genome or plasma HIV RNA is a conventional detection method for infants younger than 18 months old, especially for the baby who was born a few weeks. In recent years, with the improvement of detection capabilities and application of filter paper as the carrier of dried blood spots (DBS) technology the availability of the HIV nucleic acid detection was enhancing greatly. Infants HIV infection diagnostic test based on HIV DNA Qualitative detection has been widely used in resource-limited countries gradually. In this paper,2575 dry blood spot sample results of HIV exposed infants detected by the Chinese Center for Disease Control and Prevention of STD and AIDS prevention and control center reference laboratory with the qualitative detection of HIV-1 DNA from 2005 to 2015 were grouped by age. By analyzing characteristics of these results provides support for the early infants diagnosis algorithm.ObjectiveTo provide support for the improvement of early infants diagnosis algorithm by analyzing the HIV-1 DNA qualitative detection results of HIV esposed infants over years.Objects and MethodsCollected HIV exposedinfant DBS samples which were sent to Chinese Center for Disease Control and Prevention of STD and AIDS prevention and control center reference laboratory from 2005 to 2015, their HIV infection status have been detected by HIV-1 DNA qualitative testing. There are 2575 samples from 1161 HIV exposed infants grouped by age. Sensitivity, specificity and Youden index of the HIV-1 NDA qualitative testing were calculated different months after birth were analyzed respectively.Results1) For samples of HIV exposure after birth younger than 4 weeks, the sensitivity was 50%(11/22),95% confidence interval (CI):0.288-0.712; specificity was 100%(174/174),95% CI:0.968-1.000; false positive rate: 0; false negative rate of 60%, Youden index was 0.5;2) Older than four weeks 1 than six weeks samples, sensitivity 100%,95% CI (0.699,1.000), specificity 100%(128/128),95%CI(0.963,1.000), false positive 0.000,95%CI(0,0.301), false negative 0,95%CI (0,0.036), Youden index was 1;3) Older than six weeks and younger than three months samples, sensitivity 99.1%(111/112),95% CI:(0.944,1.000) specificity 99.5%(801/805),95% CI:(0.986,0.998), false positive 3.5%,95%CI:(0.011,0.092), false negative 0.1%,95%CI:(0.000,0.008), Youden index was 0.986;4) Older than 3 months:sensitivity 99.1%(112/113),95% CI:(0.945,1.000) specificity 99.7%(1205/1209),95%CI:(0.991,0.999), false positive 0.034, 95% CI:(0.011,0.091), false negative 0.001,95% CI:(0.000,0.005), Youden index was 0.988ConclusionsThe sensitivity of HIV nucleic acid qualitative detection for HIV exposed infants younger than 4 weeks was only 0.5. When 4 weeks later after born with a high sensitivity. In terms of specificity there is no significant difference. It prompt improving early infants diagnosis is feasible.Part TwoPreparation and application of proficiency testing materials for HIV-1 DNA testing on dried blood spots. BackgroundDue to the presence of HIV antibodies from the mother, serological testing is only used to exclude HIV infection in HIV exposed infants, not as a confirmed method for HIV exposed infants early diagnosis. Current methods for early infant diagnosis of HIV exposed infants are mainly qualitative detection of HIV-1 DNA. Up to now, China has established seven regional HIV esposed infants early diagnosis laboratory, which are responsible for HIV exposed infants early diagnosis. All of them were equipped with Abbott m2000 system. It is important for HIV esposed infants to confirm their status through early infants diagnosis and start early antiretroviral therapy. Therefore, Proficiency testing is of great significance. It could find the problem during the testing process which occurred in the lab, ensure the reliability of laboratory test results and improve the overall level of quality control and lab technical capabilities of early infants diagnosis. Proficiency testing materials preparation is very important in the proficiency testing program. The proficiency testing materials should have good characteristics such as content evenly distributed, well stable of physical and chemical properties, without the risk of infection and easy to prepare. This reserch established and evaluated a method to use 8E5 cell preparing proficiency testing materials on filter paper dried blood spots.ObjectiveTo prepare a kind of dried blood spots proficiency testing materials for Human Immunodeficiency Virus Type I DNA proficiency testing, the HIV-1 DNA test would be guaranteed.MethodsHIV-negative whole blood was spiked with a known number of freshly grown 8E5 cells, which contain a single integrated copy of the HIV-1 proviral DNA (defective genome) per cell, prepared as positive samples and HIV-negative whole blood as negative samples using the Abbott RealTime HIV-1 kit under different temperature conditions of preservation of filter paper dried blood spots at different points of time for testing, evaluation of product stability and homogeneity of the DBS proficiency testing materials.ResultsThe sensitivity of the assay did not decrease after storage of the DBS for 1 year at-20℃ or 4℃, for 4 months at room temperature or for 4 days after incubation at 37℃. All the results of 7 laboratories participated in proficiency testing program are consistent with expectations. Filter paper dried blood spots prepared as proficiency testing materials work well.ConclusionsIn this study, the HIV-1 DNA prepared using 8E5 cells is with a well stability and homogeneity and it is an economic and convenient method to prepare for HIV-1 DNA test. |
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