[Tuberculosis in a pair of twins--the use of molecular biology methods for the detection of the source of infection].

Tuberculosis is still one of the most prevalent infectious diseases worldwide with a high annual morbidity and mortality rate. Its mode of spread necessitates prompt investigation to identify those with active disease, possible carriers and as many contacts as possible. This article describes a pair of twins with endobronchial tuberculosis following close contact with a family relative who had active disease. Mycobacterium tuberculosis was isolated from the family relative and the two children. Laboratory diagnosis of the mycobacterial strain and epidemiologic follow-up were performed using a molecular biology tool, the restriction fragment length polymorphism method. Treatment was successful due to the close cooperation between the medical staff of the hospitals, the community clinics and the Center for Diagnosis and Treatment of Tuberculosis. Treatment was administered by the directly observed therapy (DOT) method recommended by the World Health Organization. This article describes the clinical course and treatment of the patients and reviews the new molecular biology methods currently being used for the diagnosis of tuberculosis and their important clinical applications.