title: HIV-1 drug resistance among newly HIV-1 infected individuals attending tertiary referral center in Chennai, India.
abstract: BACKGROUND
  In the era of free HAART, accessibility and availability of ARV has been dramatically increased in India. However, rates of treatment literacy and adherence appear to be sub-optimal. Therefore, it is essential to monitor the extent of primary drug resistance in such settings.
  
  
  METHODS
  Between July and October 2006, 18 anti-retroviral-naοve individuals were identified as recent infected by the BED-Capture enzyme immunoassay in a VCTC clinic in Chennai. Specimens from these individuals were subjected to genotypic drug resistance testing. Phylogenetic trees were generated using MEGA for Windows version 4.0 using neighbor-joining method. The significant differences in polymorphic mutation frequencies between the study specimens and established subtype C-specific polymorphisms were examined using the Chi-square test.
  
  
  RESULTS
  Amino acid substitution (K103N and V106MV) at drug resistance positions occurred in two (11%) isolates, conferring high-level resistance to the non-nucleoside reverse-transcriptase inhibitors nevirapine (NVP), efavirenz (EFV), delavirdine (DLV) and notably extensive genetic variations were observed. K122E (94.4%) and K49R/KR (11.1%) polymorphisms identified in this study have not been previously described in established subtype-C specific polymorphisms. The rate of polymorphisms showed marked difference at the locations V60, D121, V35, and D123 (P < 0.0001). All the sequences showed maximum homology with Indian HIV-1 subtype C reference strain C.IN.95IN21068.
  
  
  CONCLUSIONS
  The finding of resistance to NNRTIs is of public health importance. There is an urgent need to establish surveillance for primary drug resistance in large scale. Further studies are required to determine the phenotype impact of newer polymorphic mutations in relation to drug resistance and viral fitness.
authors.affiliation: YRG Centre for AIDS Research and Education (YRG CARE), Voluntary Health Services Hospital Campus, Taramani, Chennai, India.
authors.forename: Hussain Syed
authors.initials: HS
authors.lastname: Iqbal
authors.forename: Sunil Suhas
authors.initials: SS
authors.lastname: Solomon
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Saravanan
authors.forename: Madhavan
authors.initials: M
authors.lastname: Vidya
authors.forename: Nagalingeswaran
authors.initials: N
authors.lastname: Kumarasamy
authors.forename: Suniti
authors.initials: S
authors.lastname: Solomon
authors.forename: Pachamuthu
authors.initials: P
authors.lastname: Balakrishnan
mesh_terms: D000480:Alkynes; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D048588:Benzoxazines / Q000627:therapeutic use; D003521:Cyclopropanes; D020008:Delavirdine / Q000627:therapeutic use; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics*; D006801:Humans; D007194:India; D019829:Nevirapine / Q000627:therapeutic use; D011110:Polymorphism, Genetic; D018894:Reverse Transcriptase Inhibitors; D062606:Tertiary Care Centers
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003521:Cyclopropanes; D018894:Reverse Transcriptase Inhibitors; D019829:Nevirapine; D020008:Delavirdine; C098320:efavirenz