Human T-lymphotropic virus type I and type II infections and correlation with risk factors in blood donors from São Paulo, Brazil.
BACKGROUND
Little is known about the prevalence of and risk factors for human T-lymphotropic virus type I and type II (HTLV-I, HTLV-II) infections in Brazil.


METHODS
Sera from 17,063 healthy Brazilian donors were screened by enzyme-linked immunosorbent assay for antibody to HTLV-I/II between August 1991 and July 1993. Repeatedly reactive samples were confirmed by Western blot, and discrimination between HTLV-I and HTLV-II was made by polymerase chain reaction or synthetic peptide enzyme-linked immunosorbent assay. A univariate analysis was performed on demographic and serologic data.


RESULTS
HTLV-I infection was demonstrated in 83 percent of the 30 donors with reactive serologic tests (0.15% of the total tested [17,063]; 95% CI, 0.09-0.20) and HTLV-II infection in 17 percent (0.03% of the total tested [17,063]; 95% CI, 0.01-0.05). HTLV-I-positive donors were more likely than reference groups to be of Asian ethnicity (odds ratio [OR] 15.1; reference group: whites), more than 50 years old (OR 4.2; reference group: 20-29 years old), and positive for antibody to hepatitis C virus (anti-HCV) (OR 21.8) or to hepatitis B core (antigen) (anti-HBc) (OR 5.7). HTLV-II showed a significant association with anti-HCV (OR 75.2) and anti-HBc (OR 21.8). Eleven of the 25 HTLV-I-positive donors were counseled. Family origin in endemic areas of Japan (n = 4), prior blood transfusion (n = 3), or sexual contact with prostitutes (n = 1) were the risk factors reported by 8 donors. In 3 white men, no risk factors could be identified.


CONCLUSIONS
Both HTLV-I and HTLV-II occur among Brazilian blood donors. HTLV-I is associated with Asian ethnicity, greater age, and the presence of anti-HCV and anti-HBc. Three HTLV-I-positive donors had a history of blood transfusion, which emphasizes the need for HTLV-I/II screening in Brazil.
Ferreira Júnior
O C
OC
Hemotherapy Service, Albert Einstein Hospital, São Paulo, Brazil.
Vaz
R S
RS
Carvalho
M B
MB
Guerra
C
C
Fabron
A L
AL
Rosemblit
J
J
Hamerschlak
N
N
D000328:Adult; D000368:Aged; D001208:Asia / Q000208:ethnology; D001483:Base Sequence; D001782:Blood Donors; D015153:Blotting, Western; D001938:Brazil; D004797:Enzyme-Linked Immunosorbent Assay; D015481:HTLV-I Antibodies / Q000097:blood; D015490:HTLV-I Infections / Q000175:diagnosis* / Q000635:transmission; D015482:HTLV-II Antibodies / Q000097:blood; D015491:HTLV-II Infections / Q000175:diagnosis* / Q000635:transmission; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012307:Risk Factors
D015481:HTLV-I Antibodies; D015482:HTLV-II Antibodies