More than 17 percent of positive people in China possess a drug-resistant strain of HIV, Chinese researchers announced at the XVII International AIDS Conference in Mexico City, Reuters reports.

Positive people can run out of options quickly as only seven of the more than 20 HIV drugs are available in China. The virus usually mutates into a drug-resistant form only after people have been on medication for some time. The mutant strain was found in Chinese families with low and unstable incomes.

The Chinese government estimated last year about 700,000 people are infected with HIV.