This paper presents mathematical models for tuberculosis and its dynamics under the
implementation of the direct observation therapy strategy (DOTS) in Nigeria. The models establish
conditions for the eradication of tuberculosis in Nigeria based on the fraction of detected
infectious individuals placed under DOTS for treatment. Both numerical and qualitative analysis
of the models were carried out and the effect of the fraction of detected cases of active TB on the
various epidemiological classes is investigated. The results showed that, provided that the fraction
of detected infectious individuals exceeded a critical value, there exists a globally stable disease
free equilibrium. However, if this critical detection level is not reached, the disease-free equilibrium
will be unstable even with the very high probability successful treatment under DOTS. The
results showed that DOTS expansion in Nigeria must include significant increase in the detection
rate of infectious individuals; otherwise the effect in reducing the incidence in Nigeria will not
be achieved disregarding the tremendous efforts in any other direction, and the huge number of
undetected cases will make DOTS insignificant with respect to tuberculosis control.