title: Clinical disease associated with HIV-1 subtype B' and E infection among 2104 patients in Thailand.
abstract: BACKGROUND
  Two HIV-1 envelope subtypes have accounted for virtually all infections in Thailand: subtype B' (Thai B), found mainly in injection drug users (IDU), and subtype E, found in over 90% of sexually infected persons and an increasing proportion of IDU in recent years. It remains unclear whether there are differences in pathogenesis associated with these HIV-1 subtypes.
  
  
  METHODS
  From November 1993 to June 1996, demographic, risk, clinical, and laboratory data were collected by enhanced surveillance from HIV-infected inpatients (> or =14 years) at an infectious disease hospital near Bangkok. HIV-1 subtype was determined by V3-loop peptide enzyme immunoassay (EIA). Because of confounding, multivariate analyses were stratified by risk category and controlled for sex and age.
  
  
  RESULTS
  The infecting HIV-1 subtype was determined for 2104 (94.9%) of 2217 HIV-infected patients with complete data: 284 (13.5%) were subtype B', 1820 (86.5%) were E. Specimens from 113 (5.1%) patients were non-reactive or dually reactive on peptide EIA and were excluded. Among IDU, 199 (67.2%) had subtype B', and 97 (32.7%) had E. IDU accounted for 70.1% (199/284) of patients with subtype B' and 5.3% (97/1820) of those with E. Patients infected with HIV-1 subtypes B' or E had similar spectrums of opportunistic infections (OI), levels of immunosuppression, and in-hospital mortality rates. Of patients who did not inject drugs, more patients infected with subtype E had extrapulmonary cryptococcosis than those with subtype B' (adjusted odds ratio, 2.6; 95% confidence interval, 1.28-5.37).
  
  
  CONCLUSIONS
  HIV-1 subtypes B' and E seem to be associated with similar degrees of immunosuppression and, with one exception, with similar OI patterns. These data do not suggest an association between HIV-1 subtype and differences in pathogenicity.
authors.affiliation: Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. pca1@cdc.gov
authors.forename: P N
authors.initials: PN
authors.lastname: Amornkul
authors.forename: S
authors.initials: S
authors.lastname: Tansuphasawadikul
authors.forename: K
authors.initials: K
authors.lastname: Limpakarnjanarat
authors.forename: S
authors.initials: S
authors.lastname: Likanonsakul
authors.forename: N
authors.initials: N
authors.lastname: Young
authors.forename: B
authors.initials: B
authors.lastname: Eampokalap
authors.forename: J
authors.initials: J
authors.lastname: Kaewkungwal
authors.forename: T
authors.initials: T
authors.lastname: Naiwatanakul
authors.forename: J
authors.initials: J
authors.lastname: Von Bargen
authors.forename: D J
authors.initials: DJ
authors.lastname: Hu
authors.forename: T D
authors.initials: TD
authors.lastname: Mastro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000276:immunology / Q000503:physiopathology* / Q000821:virology*; D015497:HIV-1 / Q000145:classification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D013785:Thailand