Antibodies to human T-cell lymphotropic virus type I (HTLV-I) by particle agglutination (PA) test in Korean blood donors

HTLV-I infection is a recently recognized disease entity that is common in some tropical and subtropical areas, including the southwestern district of Japan. Despite the geographical proximity and frequent cultural exchanges between Korea and Japan, it is understood that Korea is not an endemic area and HTLV-I-associated illnesses are very rare in Korea. This study was des igned to evaluate the positive rate of anti-HTLV-I antibodies in Korean blo od donors and its regional distribution. Sera were obtained from blood dono rs from various districts around Korea. Anti-HTLV-I antibodies were detecte d by using the microtiter particle agglutination test employing an indirect agglutination technique. A total of 9,281 donors were tested and 12 donors (0.13%) were positive for anti-HTLV-I antibodies, 10 (0.11%) our of 8,845 males and 2 (0.46%) out of 436 females, with relative female predominance. A relatively high incidence of anti-HTLV-I positive donors was observed in Cheju Island (0.80%), Kyungnam (0.31%), and Chonnam (0.15%). In conclusion, the positive rate of anti-HTLV-I antibodies seemed to be very low in Korea , but the highest positive rate of anti-HTLV-I antibodies was noticed on Ch eju Island, warranting further research for confirmation.