Tuberculosis, the world's foremost killer, has made a comeback in Russia, ravaging the country's population at a rate of 250,000 a year and developing lethal strains not seen since World War II.Speaking at a special government meeting called last week to discuss the problem, Ms. Tatyana Dmitrieva, Russian Health Minister, said the incidence of tuberculosis had more than doubled since 1991, reaching 68 cases per every 100,000 Russians, 18 cases above the epidemic threshold as defined by the World Health Organisation.