For all people, the drug-resistant strains are hard to fight.

If the government hands out drugs without monitoring the patients, she said, it risks developing drug-resistant strains of the disease.

But breaking off treatment too early can lead to the development and spread of even more lethal, drug-resistant strains.

You have been infected with a drug-resistant strain of the virus.

If you do that, all you've accomplished is to create a new drug-resistant strain.

But the specialists here are alarmed by the emergence of drug-resistant strains.

If treatment is stopped too soon, the infection can linger and be spread as a drug-resistant strain.

With drug-resistant strains those costs rise to more than $6,000.

In such cases, the most drug-resistant strains of the bacteria are allowed to multiply.

The drug-resistant strains killed two health care workers and were suspected in the deaths of four others.