Scientific American [feedly], India—On a drizzly Monday afternoon here a few weeks ago, patients crowded around a door in a hallway in P. D. Hinduja Hospital—a private, nonprofit facility that caters to around 350,000 people per year. There is a loud, steady roar of voices, and patients and nurses have to shoulder past one another to get through the door, which leads to the office of lung specialist Zarir Udwadia. The walls are clean and white, and the air carries the tangy smell of disinfectant.
Against one of those white walls a grizzled old man with a breathing tube in his nose lies moaning on a stretcher. Nearby, clutching a sheaf of prescriptions, the father of a sick college student tries to catch the attention of one of Udwadia's assisting physicians. Several families have traveled thousands of kilometers to be here. Many of these patients, like 19-year-old Nisha, an engineering student from the central state of Madhya Pradesh, have tuberculosis (TB). Nisha, who asked that her real name be withheld, has been treated for lung problems for more than a year, only to learn that inaccurate diagnoses and prescription errors have supercharged the disease rather than curing it. "My doctors kept on changing the drugs," says Nisha. Dressed in jeans and a floral-print blouse and black Buddy Holly–style horn-rimmed glasses, she speaks in a bright, optimistic voice, although her battle with TB has left her anorexic-thin.
By exposing Nisha's TB to various drugs without wiping it out, her doctors just made it stronger, a problem that Udwadia—the doctor who first identified extreme drug resistance in the germ—and other health experts say is becoming increasingly widespread in India. Too few diagnostic laboratories, too many poorly-trained health practitioners and thousands of infected people living in crowded, unsanitary conditions has made India home to the world's largest epidemic of drug-resistant TB. More than two million Indians every year get the highly contagious disease, and a patient dies every two minutes. Around 62,000 of these people harbor TB that is immune to at least four types of drugs, according to the World Health Organization, and as many as 15,000 may have an even more dangerous type called "extensively drug-resistant" TB that fights off almost every antibiotic in the medical arsenal.
Now, difficult-to-kill TB is no longer just India's nightmare. In June U.S. health authorities confirmed that an Indian patient carried this extreme form of the infection, called XDR-TB, across the ocean to Chicago. The patient drove from there to visit relatives as far away as Tennessee and Missouri. Health officials in several states are tracking down everyone with whom the patient—who is now quarantined and being treated at the National Institutes of Health in Maryland—had prolonged contact. The disease can be cured in only 30 percent of patients and sometimes requires surgery to remove infected parts of lungs. Although TB's slow rate of infection makes explosive epidemics unlikely, the Chicago episode shows how easy it might be for the illness to become a worldwide export.