Infectious disease markers in blood donors in northern Thailand.
BACKGROUND
A major epidemic of human immunodeficiency virus type 1 (HIV-1) infections that are primarily due to heterosexual transmission has developed in Thailand since 1988. The epidemic has been most severe in northern Thailand. The blood banks in Chiang Mai began screening donors for HIV-1 antibodies in February 1988 and for p24 antigen in April 1992.


METHODS
The trends of HIV-1 antibody prevalence were analyzed by type of donor (i.e., paid, replacement, and voluntary) for the period of 1988 through 1993. In addition, the prevalence of HIV-1 p24 antigen and of antibodies to syphilis, hepatitis B surface antigen, and hepatitis C virus was evaluated among blood donors at Chiang Mai University Hospital and the Thai Red Cross blood banks in Chiang Mai.


RESULTS
The prevalence of HIV-1 antibodies increased from 0.84 percent in 1988 to 4.04 percent in 1991. Seropositivity was highest in paid professional donors. After discontinuation of the use of paid donors in 1993, HIV-1 antibody prevalence decreased to 3.34 percent. Antibody prevalence in replacement donors increased from 0.56 percent in 1988 to 5.82 percent in 1991. Among 44,446 donors tested, 7 (0.016%) were HIV-1 p24 antigen positive but antibody negative.


CONCLUSIONS
The exclusion of paid donors and the use of p24 antigen testing are justified in northern Thailand. Additional strategies to exclude donors at very high risk and to attract those at low risk for infection should be developed and evaluated to increase blood transfusion safety in this and other, similar populations.
Mundee
Y
Y
Blood Bank, Faculty of Medicine, Maharaj Nakorn Chiang Mai Hospital, Thailand.
Kamtorn
N
N
Chaiyaphruk
S
S
Nantachit
N
N
Ness
P M
PM
Nelson
K E
KE
D000163:Acquired Immunodeficiency Syndrome / Q000635:transmission; D001771:Blood Banks; D001782:Blood Donors; D015483:HIV Antibodies / Q000097:blood*; D016655:HIV Core Protein p24 / Q000097:blood; D015497:HIV-1 / Q000276:immunology; D016174:Hepacivirus / Q000276:immunology; D006508:Hepatitis Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006801:Humans; D013588:Syphilis Serodiagnosis; D013785:Thailand
D015483:HIV Antibodies; D016655:HIV Core Protein p24; D006508:Hepatitis Antibodies; D006514:Hepatitis B Surface Antigens