Increasing HIV-1 subtype diversity in seven states, United States, 2006-2013.
The aim of the analysis was to explore HIV-1 subtype diversity in the United States and understand differences in prevalence of non-B subtypes and circulating recombinant forms (CRFs) between demographic/risk groups and over time.



We included HIV-1 polymerase sequences reported to the National HIV Surveillance System for HIV infections diagnosed during 2006-2013 in seven states. We assigned subtype or CRF using the automated subtyping tool COMET, assessed subtype/CRF prevalence by demographic characteristics and country of birth, and determined changes in subtype/CRF by HIV diagnosis year.



Of 32,968 sequences, 30,757 (93.3%) were subtype B. The most common non-B subtypes and CRFs were C (1.6%), CRF02_AG (1.4%), A (0.6%), CRF01_AE (0.5%), and G (0.3%). Elevated percentages of non-B infections occurred among persons aged <13 years at diagnosis (40.9%), Asians (32.1%), persons born outside the United States (22.6%), and persons with infection attributable to heterosexual contact (12.0%-15.0%). Prevalence of non-B infections increased from 5.9% in 2006 to 8.5% in 2013.



Subtype B continues to predominate in the United States. However, the percentage of non-B infections has grown in recent years, and numerous demographic subgroups have much higher prevalence. Subgroups and areas with high prevalence of non-B infections might represent sub-epidemics meriting further investigation.
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA. Electronic address: AOster@cdc.gov.
Alexandra M
AM
Oster
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
William M
WM
Switzer
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
Angela L
AL
Hernandez
ICF International, Atlanta, GA.
Neeraja
N
Saduvala
ICF International, Atlanta, GA; Department of Medicine, University of California, San Diego.
Joel O
JO
Wertheim
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
Ndidi
N
Nwangwu-Ike
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
M Cheryl
MC
Ocfemia
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
Ellsworth
E
Campbell
Division of HIV/AIDS Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
H Irene
HI
Hall
D000293:Adolescent; D000328:Adult; D002648:Child; D003120:Colorado / Q000453:epidemiology; D003237:Connecticut / Q000453:epidemiology; D005260:Female; D014644:Genetic Variation / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D016333:HIV Protease / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000235:genetics; D006801:Humans; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D013022:South Carolina / Q000453:epidemiology; D013781:Texas / Q000453:epidemiology; D014481:United States; D014861:Washington / Q000453:epidemiology; D055815:Young Adult
D054303:HIV Reverse Transcriptase; D016333:HIV Protease
HIV-1; Homosexuality; Intravenous; Molecular epidemiology; Risk factors; Substance abuse; Subtypes; Surveillance