Objective To analyze the positive results of HIV antibody screening in the laboratory of AIDS confirmation center of Hubei Provincial Center for Disease Control and Prevention from 2014 to 2020, and to provide a basis for improving detection strategies. Methods A total of 2 728 primary screening positive specimens received by the laboratory of Hubei confirmation center from 2014 to 2020 were retested with two reagents. Specimens with at least one reactive result were confirmed with western blot (WB). The samples with uncertain or negative WB results were further confirmed by nucleic acid quantitative detection. The test results were analyzed retrospectively. Results A total of 2 297 specimens with positive retest results were confirmed by WB, with a positive rate of 93.47%. The highest proportion of patients was from medical institutions. The positive rate detected by 4 diagnostic kits was apparently higher in S/CO＞10 cases than that in S/CO≤10, and the difference was statistically significant (P < 0.05). Of the 19 samples with inconsistent results in ELISA, 1 was confirmed as positive by WB, while 12 were negative both by WB and nucleic acid detection. Among 68 samples with uncertain WB results, 49 cases had nucleic acid quantitative results > 5 000cps / ml, and 12 cases were TND. 13 of the 30 WB negative samples had nucleic acid test results＞5 000CPs/mL . Conclusions The coverage of HIV screening laboratories in hospitals at all levels should be further increased to find more HIV infected persons. The anti-HIV ELISA S/CO ratio is correlated with the positive results confirmed by western blot. Therefore, ELISA S/CO ratio can be used to predict anti-HIV antibody positivity. For samples with uncertain or negative WB detection, supplemental nucleic acid test should be carried out timely for early diagnosis.

Objective To explore the application of nucleic acid test in the diagnosis of HIV western blotting (WB) indeterminate and negative samples. Methods A total of 2 518 HIV samples to be confirmed were collected from the Hubei HIV Confirmation Center Laboratory from 2014 to 2022. The results of follow-up antibody test and nucleic acid test of WB indeterminate and negative samples were analyzed, and the diagnostic rate, sensitivity, specificity and coincidence rate of the two detection strategies were compared. Results There were totally 133 indeterminate or negative samples by WB test. Of the 99 indeterminate samples , 76 (76.77%) had nucleic acid test results >5000 copies/mL. 40 cases were followed up, of which 33 cases (82.50%) turned positive and 7 (17.50%) were still uncertain. Of the 7 samples with 20~5000 copies /mL (7.07%), 2 cases were followed up and both turned positive during the follow-up. 1 case (1.01%) with nucleic acid <20 copies/mL turned positive during follow-up. Among the 34 WB negative samples, 15 cases (45.45%) were > 5 000 copies/mL, 9 of which were seroconversion. The diagnostic rates of ^“antibody confirmation^” and ^“nucleic acid test^” were 96.78% (2 437/2 518) and 99.60% (2 508/2 518), respectively. The sensitivities were 98.02% (2 430/2 479) and 99.88% (2476/2 479), and the specificities were 78.13% (25/32) and 100.00 % (32/32), respectively. The coincidence rates were 97.77% (2 455/2 511) and 99.88% (2 508/2 511), respectively. Conclusion Nucleic acid supplemental test strategy has high diagnostic rate, sensitivity, specificity and coincidence rate. WB indeterminate and negative samples can be diagnosed as early as possible through nucleic acid supplemental testing.

Objective To investigate the prevalence of primary drug resistance among HIV-1 patients in Hubei Province from 2020 to 2022, and to provide corresponding basis and data support for HIV antiviral therapy (ART) in Hubei Province. Methods During 2020-2022, plasma samples of HIV-1 infected patients before ART were collected., Patients’ demographic data and baseline laboratory test data were also collected. HIV-1 pol region was amplified by in-house method for sub-type typing and drug-resistant mutation site analysis. Results The pol gene sequence was successfully amplified in 242 of 285 cases, with a success rate of 84.9%. CRF07_BC was the predominant HIV-1 sub-type, accounting for 47.11% (114/242), followed by CRF01_AE, accounting for 25.21% (61/242), sub-type B, accounting for 14.16% (35/242), and CRF55_01B, accounting for 4.13% (10/242). The primary resistance rate was 6.20% (15/242). The mutation site of nucleoside reverse transcriptase inhibitors (NRTIs) was mainly M184V, and the mutation sites of non-nucleoside reverse transcriptase inhibitors (NNRTIs) were mainly E138A/G/EG and V179E. These different mutation sites led to different degrees of drug resistance to 12 drugs. The incidence of drug resistance mutation of CRF55_01B sub-type was significantly higher than that of other sub-types. Conclusion The primary drug resistance rate of HIV-1 infected patients is at a slightly high level in Hubei Province, and close monitoring of primary drug resistance and mutation sites should be strengthened before ART, especially for CRF55_01B sub-type.