Tuberculosis Consultant Services

Epidemiologically, we may distinguish between interventions that target a reduction in the incidence of infection with M tuberculosis, that is a reduction in the extent of transmission that occurs in the community. This is the realm of case finding and chemotherapy of sources of infection in the community. Sputum smear-positive cases have been established (see slides on the epidemiology of tuberculosis on this site) to be responsible for the majority of transmissions in the community. Thus, the primoridal and priority task of any tuberculosis control strategy is swift identification of sources of infection and provision of curative chemotherapy for them.

Given the undetermined incubation period between acquisition of infection with M tuberculosis and development of tuberculosis, tuberculosis will continue to emerge as long as the prevalence of infection with M tuberculosis has not decreased to zero. As cases of tuberculosis emerge in a largely unpredictable fashion from among the prevalently infected population but is by and large a rare event, the effort to identify prevalent and asymptomatic infection is much more complex and labor- and resource-intensive than case-finding and treatment of infectious incident cases. However, some countries in which the tuberculosis problem has ceased to be a mjaor public health problem have been embarking on an elimination strategy, targeting in addition to a reduction in the incidence of infection the pool of prevalently infected persons by tuberculin skin testing or interferon-gamma release assay (IGRA) testing and providing those identified and considered to be at particular risk of tuberculosis with preventive therapy.