title: Antiretroviral resistance patterns and HIV-1 subtype in mother-infant pairs after the administration of combination short-course zidovudine plus single-dose nevirapine for the prevention of mother-to-child transmission of HIV.
abstract: BACKGROUND
  World Health Organization guidelines for prevention of mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) recommend administration of zidovudine and single-dose nevirapine (NVP) for HIV-1-infected women who are not receiving treatment for their own health or if complex regimens are not available. This study assessed antiretroviral resistance patterns among HIV-infected women and infants receiving single-dose NVP in Thailand, where the predominant circulating HIV-1 strains are CRF01_AE recombinants and where the minority are subtype B.
  
  
  METHODS
  Venous blood samples were obtained from (1) HIV-infected women who received zidovudine from 34 weeks' gestation and single-dose NVP plus oral zidovudine during labor and (2) HIV-infected infants who received single-dose NVP after birth plus zidovudine for 4 weeks after delivery. HIV-1 drug resistance testing was performed using the TruGene assay (Bayer HealthCare).
  
  
  RESULTS
  Most mothers and infants were infected with CRF01_AE. NVP resistance was detected in 34 (18%) of 190 women and 2 (20%) of 10 infants. There was a significantly higher proportion of NVP mutations in women with delivery viral loads of >50,000 copies/mL (adjusted odds ratio, 8.5; 95% confidence interval, 2.2-32.8, P = .002 for linear trend) and in those with subtype B rather than CRF01_AE infections (38% vs. 16%; adjusted odds ratio, 3.6; 95% confidence interval, 1.1-11.8; P = .038).
  
  
  CONCLUSIONS
  The lower frequency of NVP mutations among mothers infected with subtype CRF01_AE, compared with mothers infected with subtype B, suggests that individuals infected with subtype CRF01_AE may be less susceptible to the induction of NVP resistance than are individuals infected with subtype B.
authors.affiliation: Departments of 1Obstetrics and Gynaecology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Amphan
authors.initials: A
authors.lastname: Chalermchockcharoenkit
authors.forename: Mary
authors.initials: M
authors.lastname: Culnane
authors.forename: Tawee
authors.initials: T
authors.lastname: Chotpitayasunondh
authors.forename: Nirun
authors.initials: N
authors.lastname: Vanprapa
authors.forename: Wanna
authors.initials: W
authors.lastname: Leelawiwat
authors.forename: Philip A
authors.initials: PA
authors.lastname: Mock
authors.forename: Suvanna
authors.initials: S
authors.lastname: Asavapiriyanont
authors.forename: Achara
authors.initials: A
authors.lastname: Teeraratkul
authors.forename: Michelle S
authors.initials: MS
authors.lastname: McConnell
authors.forename: Janet M
authors.initials: JM
authors.lastname: McNicholl
authors.forename: Jordan W
authors.initials: JW
authors.lastname: Tappero
mesh_terms: D000293:Adolescent; D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D001769:Blood / Q000821:virology; D018890:Chemoprevention / Q000379:methods; D024882:Drug Resistance, Viral; D015658:HIV Infections / Q000517:prevention & control* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000187:drug effects / Q000235:genetics; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control*; D008875:Middle Aged; D009035:Mothers; D019829:Nevirapine / Q000627:therapeutic use*; D013785:Thailand; D055815:Young Adult; D015215:Zidovudine / Q000627:therapeutic use*
chemical_list: D019380:Anti-HIV Agents; D015215:Zidovudine; D019829:Nevirapine