Comparative Test Of Two Dengue NS1 Antigen Detection Kits

Objective:1. Evaluate the sensitivity and specificity as well as the advantages and disadvantages of a dengue NS1 antigen detection kit(colloidal gold) produced by Blue Cross BioMedical(Beijing) Co., Ltd.(henceforth referred to as the Blue Cross NS1 kit) and a dengue NS1 antigen test kit(henceforth referred to as ELISA method) produced by Beijing Wantai Biological Pharmacy Enterprise Co., Ltd..2. Analyze the influence of the interferential samples on the test results.3. Provide scientific basis for the homemade test kit to pass national registration and be used for the early rapid diagnosis of dengue fever in order to advance the early rapid diagnosis system for dengue fever.Methods:With One Step Dengue NS1 Rapi DipTM Insta Test(Serum) produced by US Corte Z(henceforth referred to as US NS1 kit) as the reference group, Blue Cross NS1 kit and ELISA method were used to detect the sera from dengue patients(positive by US NS1kit) and health people respectively. The positive coincidence rate(true positive rate), negative coincidence rate(true negative rate), false positive rate, false negative rate, and total coincidence rate were calculated based on the detection results. Their sensitivity and specificity as well as the advantages and disadvantages were also evaluated. The paired ??2 test was used to evaluate whether the difference between the two methods and the US NS1 kit has statistical significance.Results:1. Results from Blue Cross NS1 kit:120 serum samples from dengue patients were tested, with 120 positives and no negative. The positive coincidence rate(true positive rate) is 100% and the false negative rate 0%.232 negatives and 1 positive were detected from the 233 negative samples. The negative coincidence rate is 99.57% and the false positive rate 0.43%. 16 negatives and 2 positives were detected from the 18 interferential samples. The coincidence rate is 88.89%.The total coincidence rate of the Blue Cross method is 99.72%.2. Results from ELISA method:108 serum samples from dengue patients were tested, with 108 positives and no negative. The positive coincidence rate(true positive rate) is 100% and false negative rate 0%.127 negatives and 12 positives were detected from the 139 negative samples. The negative coincidence rate is 91.37% and the false positive rate 8.63%. 15 negatives and no positive were detected from the 15 interferential samples. The coincidence rate is 100%.The total coincidence rate of the ELISA method is 95.14%.3. Results from US NS1 kit:120 serum samples from dengue patients were tested, with 120 positives and no negative. The positive coincidence rate(true positive rate) is 100% and the false negative rate 0%.104 pure negative samples and 18 interferential samples were tested, the results are all negatives. The negative coincidence rate is 100% and the false positive rate 0%. The coincidence rate of the interferential sample is 100%.The total coincidence rate of the US NS1 kit is 100%.4. Results from nucleic acid detection:15 serum samples(negative by US NS1 kit, but positive by Blue Cross NS1 kit or ELISA method) from healthy people were tested, including 3 samples with positive using Blue Cross NS1 kit and 12 samples with positive using ELISA method. The results are all negatives, indicating that the results from Blue Cross NS1 kit and ELISA method are false positive.Conclusions:1. The sensitivity of the Blue Cross NS1 kit is on the same level with that of ELISA method. But the specificity of the former is better than that of the latter.2. Blue Cross NS1 detection kit is easier to implement than the ELISA method and the US NS1 detection kit(samples can be plasma, whole blood, or serum). The results can be shown more rapidly(in 15 min). In the experimental process, Blue Cross NS1 kit could save more manpower, materials resources and financial resources. It is relatively safer and more environment-friendly. These advantages make the Blue Cross NS1 kit more suitable for extensive field usage.3. According to the paired ??2 test, the difference between Blue Cross NS1 detection kit and US NS1 kit has no statistical significance. The difference between ELISA method and US NS1 kit has statistical significance, indicating that the ELISA method is not as good as the US NS1 kit. The difference between Blue Cross NS1 kit and ELISA method has statistical significance. It therefore can be considered that the Blue Cross NS1 detection kit is better than ELISA method.4. Compared with other interferential samples, hemolytic samples have greater influence on the results of the Blue Cross NS1 detection kit. Therefore, the hemolysis should be avoided when collecting samples.