title: Evaluation of postpartum HIV superinfection and mother-to-child transmission.
abstract: OBJECTIVE
  This study examined HIV superinfection in HIV-infected women postpartum, and its association with mother-to-child transmission (MTCT).
  
  
  METHODS
  Plasma samples were obtained from HIV-infected women who transmitted HIV to their infants after 6 weeks of age (transmitters, n = 91) and HIV-infected women who did not transmit HIV to their infants (nontransmitters, n = 91). These women were originally enrolled in a randomized trial for prevention of MTCT of HIV in Malawi (Post-Exposure Prophylaxis of Infants trial in Malawi).
  
  
  METHODS
  Two HIV genomic regions (p24 and gp41) were analyzed by next-generation sequencing for HIV superinfection. HIV superinfection was established if the follow-up sample contained a new, phylogenetically distinct viral population. HIV superinfection and transmission risk were examined by multiple logistic regression, adjusted for Post-Exposure Prophylaxis of Infants study arm, baseline viral load, baseline CD4 cell count, time to resumption of sex, and breastfeeding duration.
  
  
  RESULTS
  Transmitters had lower baseline CD4 cell counts (P = 0.001) and higher viral loads (P < 0.0001) compared with nontransmitters. There were five cases of superinfection among transmitters (rate of superinfection = 4.7/100 person-years) compared with five cases among the nontransmitters (rate of superinfection = 4.4/100 person-years; P = 0.78). HIV superinfection was not associated with increased risk of postnatal MTCT of HIV after controlling for maternal age, baseline viral load, and CD4 cell count (adjusted odds ratio = 2.32, P = 0.30). Longer breastfeeding duration was independently associated with a lower risk of HIV superinfection after controlling for study arm and baseline viral load (P = 0.05).
  
  
  CONCLUSIONS
  There was a significant level of HIV superinfection in women postpartum, but this was not associated with an increased risk of MTCT via breastfeeding.
authors.affiliation: aLaboratory of Immunoregulation, NIAID, NIH bJohns Hopkins School of Medicine, Johns Hopkins University cJohns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland dGenomics Unit, Division of Intramural Research, Research Technologies Branch, Rocky Mountain Laboratories, NIAID, NIH, Hamilton, Montana, USA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Redd
authors.forename: Sarah K J
authors.initials: SK
authors.lastname: Wendel
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Longosz
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Fogel
authors.forename: Sufia
authors.initials: S
authors.lastname: Dadabhai
authors.forename: Newton
authors.initials: N
authors.lastname: Kumwenda
authors.forename: Jin
authors.initials: J
authors.lastname: Sun
authors.forename: Michael P
authors.initials: MP
authors.lastname: Walker
authors.forename: Daniel
authors.initials: D
authors.lastname: Bruno
authors.forename: Craig
authors.initials: C
authors.lastname: Martens
authors.forename: Susan H
authors.initials: SH
authors.lastname: Eshleman
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Porcella
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Quinn
authors.forename: Taha E
authors.initials: TE
authors.lastname: Taha
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D001942:Breast Feeding; D018791:CD4 Lymphocyte Count; D002675:Child, Preschool; D005260:Female; D005838:Genotype; D060005:Genotyping Techniques; D016655:HIV Core Protein p24 / Q000235:genetics; D015700:HIV Envelope Protein gp41 / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission*; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008295:Malawi / Q000453:epidemiology; D056990:Post-Exposure Prophylaxis; D049590:Postpartum Period; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic; D017422:Sequence Analysis, DNA; D012725:Sexual Behavior; D015163:Superinfection / Q000453:epidemiology* / Q000821:virology*; D019562:Viral Load; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents; D016655:HIV Core Protein p24; D015700:HIV Envelope Protein gp41