Prevalence of tuberculosis infection in Melbourne secondary school students.
OBJECTIVE
To estimate the prevalence of asymptomatic Mycobacterium tuberculosis infection in Melbourne secondary school students.


METHODS
Cross-sectional Mantoux testing of a partly random and partly targeted sample of secondary school students, designed to enable estimation of prevalence by region of birth.


METHODS
Fifty-one State and Catholic secondary schools in metropolitan Melbourne during 1995.


METHODS
Australian and overseas-born students in Years 9 and 10.


METHODS
Proportions of students with positive Mantoux reactions (defined as induration at 48 hours of > or = 5 mm with a history of recent exposure; > or = 10 mm and no prior BCG vaccination; > or = 15 mm and prior BCG vaccination).


RESULTS
Of 2586 students potentially eligible for testing, evaluable results were obtained from 1274 (49%). The overall prevalence of infection for Melbourne students in Years 9 and 10 was 2.5% (95% CI, 1.1-3.9%). Main predictors of a positive test were birth overseas and number of years residing overseas. Prevalence varied considerably by region of birth, and was very low in students born in Australia (0.7%), "other developed countries" (0.7%), and Southern Europe (0). The highest rates were observed in students born in Indochina (15.9%), other countries in South East Asia (10.2%), and Eastern Europe (10.2%).


CONCLUSIONS
The risk of a young person becoming infected with M. tuberculosis while living in Melbourne is very low. Our results do not indicate a need for the reintroduction of mass screening in Victorian schools. If targeted screening were to be considered, the group most likely to benefit would be recently arrived migrants from Indochina.
Johnson
P D
PD
Clinical Epidemiology and Biostatistics Unit, Royal Children's Hospital, Melbourne, VIC. Paul.Johnson@med.monash.edu.au
Carlin
J B
JB
Bennett
C M
CM
Phelan
P D
PD
Starr
M
M
Hulls
J
J
Nolan
T M
TM
D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000293:Adolescent; D000995:Antitubercular Agents / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D001500:BCG Vaccine / Q000008:administration & dosage; D002648:Child; D003430:Cross-Sectional Studies; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D015995:Prevalence; D011897:Random Allocation; D012189:Retrospective Studies; D012574:Schools; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology* / Q000517:prevention & control
D000276:Adjuvants, Immunologic; D000995:Antitubercular Agents; D001500:BCG Vaccine