Assessment of subclinical leprosy infection through the measurement of PGL-1 antibody levels in residents of a former leprosy colony in Thailand.
OBJECTIVE
To investigate the hypothesis that there is continuing subclinical M. leprae infection, contributing to ongoing transmission of leprosy in Phra-Pradaeng Colony.


METHODS
A sero-epidemiological survey was carried out in Phra-Pradaeng Colony, Thailand between May and August 2005. The clinical and serological examinations were conducted in 398 people, aged 3-84 years (average 50 years), comprising 196 males and 202 females.


RESULTS
Measurement of serum anti PGL-I antibodies in eligible contacts and ex-patients showed that 18 people (4.5%) were seropositive, six people (1.5%) were strongly positive and 374 people (94.0%) were seronegative. All six people who were strongly seropositive were ex-patients; five of them had no evidence of active leprosy but the sixth person had relapsed BL leprosy with a reversal reaction.


CONCLUSIONS
This study failed to confirm the hypothesis that there was ongoing subclinical M. leprae infection. More appropriate diagnostic methods and a total survey of the colony should be considered to further clarify this problem.
Kampirapap
Kowit
K
Raj Pracha Samasai Institute, Department of Disease Control, Tiwanon Road, Muang District, Nonthaburi 11000, Thailand. czjth@yahoo.com
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007914:Leper Colonies; D007918:Leprosy / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology / Q000635:transmission*; D008297:Male; D008875:Middle Aged; D009166:Mycobacterium leprae / Q000276:immunology; D016036:Seroepidemiologic Studies; D013785:Thailand / Q000453:epidemiology; D055815:Young Adult
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D006017:Glycolipids; C045169:phenolic glycolipid I, Mycobacterium leprae