Interventions for Tuberculosis Control and Elimination 2002

Incidence per 10,000
70
60
50
40
30
20
10
0
Other factors
Reacting to
100 TU only
Tuberculin
negative
0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0
Year of follow-up
Figure 72. Risk of tuberculosis during follow-up of British school children, by initial
tuberculin skin test reaction size, among placebo recipients, BCG trial, Great
Britain. 776
Incidence per 10,000
80
70
50
0
-100
Reacting to
100 TU only
BCG vaccinated
0.0 2.5 5.0 7.5 10.0 12.5 15.0 17.5 20.0
Year of follow-up
Figure 73. Comparative protection from BCG vaccination and presumed infection
with environmental mycobacteria among British school children during follow-up. 776
It has been suggested that infestation with parasites, in particular with
helminths, may affect the human T cell immune responses to mycobacterial
antigens. 836 Treatment of helminths resulted in significant improvement
121