Public health officials in Sudbury say a local rise in drug resistant strains of HIV should be a wakeup call.

A study by the Ontario HIV Epidemiologic Monitoring Unit shows Sudbury has an alarming number of patients who don't respond to the most commonly used medications for the virus.

A total of 50 per cent of HIV patients in Sudbury show resistance to common medications, a number significantly higher than the 5 per cent of drug-resistant HIV patients across the rest of Ontario.

"I think what this tells us is that it is incredibly important to prevent HIV, to get tested, to know your status, to go on effective medications, and to stay on those medications," said Dr. Penny Sutcliffe, Sudbury's medical officer of health.

The drug resistant strains were found most often in injection drug users and women.          

Sudbury doctor Robert Remis said for those patients who have an HIV strain that is resistant to at least one treatment drug,  treatment can be difficult.

"The problem is … if there are further mutations, it could make the virus very untreatable," he said.

"So it takes away your margin of safety in terms of having drugs that really can suppress the multiplying of HIV."

Each year, an average of 11 people are diagnosed with HIV in the city.