ABSTRACT
To investigate the prevalence of drug-resistance mutations, resistance to antiretroviral drugs, and the subsequent virological response to therapy in treatment-naive and antiretroviral-treated patients infected with HIV/AIDS in Henan, China, a total of 431 plasma samples were collected in Queshan county between 2003 and 2004, from patients undergoing the antiretroviral regimen Zidovudine + Didanosine + Nevirapine (Azt+Ddi+Nvp). Personal information was collected by face to face interview. Viral load and genotypic drug resistance were tested. Drug resistance mutation data were obtained by analyzing patient-derived sequences through the HIVdb Program (http://hivdb.stanford.edu). Overall, 38.5% of treatment-naive patients had undetectable plasma viral load (VL), the rate significantly increased to 61.9% in 0 to 6 months treatment patients (mean 3 months) (P＜0.005) but again significantly decrease to 38.6% in 6 to 12 months treatment patients (mean 9 months) (P＜0.001) and 40.0% in patients receiving more than 12 months treatment (mean 16 months) (P＜0.005). The prevalence of drug resistance in patients who had a detectable VL and available sequences were 7.0%, 48.6%, 70.8%, 72.3% in treatment-na(1)ve, 0 to 6 months treatment, 6 to 12 months treatment, and treatment for greater than 12 months patients, respectively. No mutation associated with resistance to Protease inhibitor (PI) was detected in this study. Nucleoside RT inhibitor (NRTI) mutations always emerged after non-nucleoside RT inhibitor (NNRTI) mutations, and were only found in patients treated for more than 6 months, with a frequency less than 5%, with the exception of mutation T215Y (12.8%, 6/47) which occurred in patients treated for more than 12 months. NNRTI mutations emerged quickly after therapy begun, and increased significantly in patients treated for more than 6 months (P＜0.005), and the most frequent mutations were K103N, V106A, Y181C, G190A. There had been optimal viral suppression in patients undergoing treatment for less than 6 months in Queshan,Henan. The drug resistance strains were highly prevalent in antiretroviral-treated patients, and increased with the continuation of therapy, with many patients encountering virological failure after 6 months therapy.
ABSTRACT
<p><b>OBJECTIVE</b>To collect background information on drug-resistant HIV-1 strains in various regions before the start of nation-wide antiretroviral therapy in China.</p><p><b>METHODS</b>Twenty percent of the 2,000 blood samples from antiretroviral therapy naive patients collected for the 2nd national HIV molecular epidemiology survey (NHMES) in 2002 were randomly sampled for this study. The entire protease gene and 20-230 amino acids of the reverse transcriptase gene were amplified by PCR from provirus DNA and sequenced. The results were analyzed with HIV db-Drug Resistance Algorithm and genotypic resistance mutations were determined to particular anti-HIV drugs.</p><p><b>RESULTS</b>Totally 164 protease gene sequences and 138 reverse transcriptase gene sequences were obtained from patients; 0.61% of 164 sequences displayed primary resistance mutations in the protease gene, whereas 99.39% carried 1 or more secondary mutations. Genotypic resistance to at least one nucleoside reverse transcriptase inhibitors (NRTI) was present in 5.80%,and resistance to at least one non-nucleo side reverse transcriptase inhibitors (NNRTI) was present in 1.45% of samples.</p><p><b>CONCLUSION</b>The prevalence of genotypic drug resistance is very low in drug-naive HIV infected patients from 21 provinces of China tested in this study. Laboratories participated in the NHMES have organized a network to provide drug resistance monitoring service in the current nation-wide antiviral treatment program in China.</p>