After a female porn star recently tested HIV positive in the San Fernando Valley, Los Angeles County health officials announced June 11 that 16 other unnamed performers have also tested positive, the Los Angeles Times reports. This brings the total number of HIV cases among adult film performers to 22 over the last five years.

According to the article, this data renews safety concerns in the $12 billion industry, which health officials claim has long resisted regulating condom use.

County health officials did not investigate the 16 unpublicized cases at the time because privacy rules before 2006 prevented disclosing HIV-positive people’s names to government agencies. It is unknown whether those adult film stars contracted the virus at work.

The Adult Industry Medical Healthcare Foundation (AIM) did, however, disclose the names of infected performers during one incident in 2004, when porn actor Darren James tested positive and transmitted the virus to three actresses before learning his status. Another unrelated porn actor also tested positive.

Despite a series of public hearings surrounding the James case, no state laws in California require condom use in adult films, and the majority of heterosexual porn still features unprotected, or “bareback,” sexual intercourse.