Earlier this month, health officials in Los Angeles confirmed they are treating a patient for extensively drug resistant tuberculosis — a deadly form that does not respond to most of the antibiotics. The United States is one of 100 countries that have reported cases of “XDR-TB” since it was discovered in South Africa less than a decade ago.

Congress is holding public briefings Tuesday and Wednesday to look into the threat posed by tuberculosis, seeking expert recommendations to help develop a U.S. response. To be effective, public health efforts must adapt to the ways TB is evolving.

Tuberculosis is often described as an “ancient” malady, evident in Egyptian mummies. But today’s tuberculosis epidemic, which kills around 1.3 million people a year, is unlike its predecessors genetically, clinically and epidemiologically. Defeating TB 2.0 will require innovative approaches designed to fight this modern epidemic.

Many of the TB strains today come from “modern” genetic lineages rather than the “ancestral” strains common throughout human history. Modern TB strains now predominate in India, which has the world’s highest TB burden, according to recent research published in the International Journal of Tuberculosis and Lung Disease. Some modern strains are more virulent and progress more rapidly, studies suggest, making the disease far more dangerous.

Clinically, today’s TB is “partnering” with a number of modern diseases, creating complex illnesses that are more challenging to treat. While TB has historically been perceived as a lung disease, in people with HIV it often presents elsewhere — lymph nodes, spine, eyeballs, brain — with atypical symptoms. TB kills roughly 320,000 HIV-positive people every year, the leading cause of death for those HIV positive. Yet less than half of the people infected with HIV have been screened for TB, and vice versa.