In a continuing study in Delhi at several government-run hospitals that has so far included more than 12,000 high-risk newborns, and was made available to The New York Times, about 70 percent of the babies’ infections were found to be immune to multiple powerful antibiotics, confirming the results of earlier and smaller studies.

Doctors interviewed in hospitals across India said that a large number of the infections they found in newborns were resistant to many antibiotics. Awareness of the problem has begun to grow, with Indian medical associations calling for efforts to reduce unnecessary antibiotic use. But there is keen sensitivity here to any alert to the dangers. A 2010 discovery of a New Delhi “superbug” caused intense controversy because of fears that publicity would threaten India’s profitable medical tourism industry. Government officials have stopped some studies of the problem, Dr. Walsh said.

The effects of antibiotic-resistant bacteria on treating disease in India could be enormous. Tuberculosis is just one example of the challenges doctors face. India has the world’s largest number of cases, and recent studies using the latest genetic tests have shown that as many as 10 percent of untreated patients in places as far apart as Mumbai and Sikkim have resistant infections. These patients are catching resistant bugs at home, not hospitals, making the epidemic very difficult to control, Dr. Soumya Swaminathan, director of the National Institute for Research in Tuberculosis, said in an interview.

“It’s startling and very worrying,” Dr. Swaminathan said. Unless the government makes profound and drastic changes, tuberculosis in India may soon become untreatable, she said.

Although resistant bugs are everywhere here, hospitals have become factories for untreatable “superbugs.” A government program that pays women to have babies in hospitals has in 10 years more than doubled the share of hospital-born babies to 82 percent, but the government did little to increase hospital capacity to deal with the crush. Maternity wards often have two and three women in each bed, allowing infections to spread rapidly.

Besides being desperately crowded, many hospitals are unhygienic, allowing the bugs to flourish. A Unicef survey of 94 district hospitals and health centers in Rajasthan last year found that 70 percent had possibly contaminated water and 78 percent had no soap available at hand-washing sinks, while 67 percent of toilets were unsanitary.

Doctors across India have responded to the sanitation crisis in hospitals by giving antibiotics freely.