The International Dimension of the U.S. HIV Transmission Network and Onward Transmission of HIV Recently Imported into the United States

AIDS Res Hum Retroviruses. 2016 Oct/Nov;32(10-11):1046-1053. doi: 10.1089/AID.2015.0272. Epub 2016 May 19.


The majority of HIV infections in the United States can be traced back to a single introduction in late 1960s or early 1970s. However, it remains unclear whether subsequent introductions of HIV into the United States have given rise to onward transmission. Genetic transmission networks can aid in understanding HIV transmission. We constructed a genetic distance-based transmission network using HIV-1 pol sequences reported to the U.S. National HIV Surveillance System (n = 41,539) and all publicly available non-U.S. HIV-1 pol sequences (n = 86,215). Of the 13,145 U.S. persons clustered in the network, 457 (3.5%) were genetically linked to a potential transmission partner outside the United States. For internationally connected persons residing in but born outside the United States, 61% had a connection to their country of birth or to another country that shared a language with their country of birth. Bayesian molecular clock phylogenetic analyses indicate that introduced nonsubtype B infections have resulted in onward transmission within the United States.

Keywords: HIV; cluster; molecular clock; surveillance; transmission network.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • Cluster Analysis
  • Female
  • Genotype*
  • HIV Infections / epidemiology*
  • HIV Infections / transmission*
  • HIV Infections / virology
  • HIV-1 / classification*
  • HIV-1 / genetics*
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Molecular Epidemiology
  • Phylogeny
  • Sequence Analysis, DNA
  • United States
  • Young Adult
  • pol Gene Products, Human Immunodeficiency Virus


  • pol Gene Products, Human Immunodeficiency Virus