Clinical disease associated with HIV-1 subtype B' and E infection among 2104 patients in Thailand.
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.
Amornkul
P N
PN
Epidemic Intelligence Service, Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. pca1@cdc.gov
Tansuphasawadikul
S
S
Limpakarnjanarat
K
K
Likanonsakul
S
S
Young
N
N
Eampokalap
B
B
Kaewkungwal
J
J
Naiwatanakul
T
T
Von Bargen
J
J
Hu
D J
DJ
Mastro
T D
TD
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