WOODSTOCK -- The province's chief medical officer of health yesterday ruled out forced vaccinations to contain a rubella outbreak in Oxford and surrounding counties.

Dr. Sheela Basrur said yesterday forcing people to be immunized for their own protection as suggested by some is against the law in the province and contrary to long-standing medical practice.

"There is a general principle in Ontario that people have a right to choose or decline medical treatment if they are legally able to consent," said Basrur during a media briefing outside the Oxford County Board of Health office here.

"That holds true whether the treatment is an injection or surgery," Basrur said.

She came to Woodstock for an update on the outbreak and as a show of support for health workers who've been battling the disease for two weeks.

Confirmed rubella cases jumped to 156 yesterday, up from 145 the previous day.

Three pregnant women, most at risk from rubella, have been infected.

Basrur announced yesterday that Dr. Bryna Warshawsky, associate medical officer of health for Middlesex-London, has been appointed to help manage the outbreak.

Warshawsky will also serve as associate medical officer of health for Oxford.

She is one of a dozen people from health units in surrounding counties called in to help with the outbreak. Four other staff from Middlesex-London are working with Oxford health officials.

The rubella outbreak has been centred at the Rehoboth Christian School in Norwich.

The school draws students from four religious groups and many parents have opted not to have their children vaccinated.

All but one of the people who've contracted rubella have not been immunized. The one exception was an Oxford man, a student at Westervelt College in London, whose immunization did not protect him.

Health officials said it was a rare case of vaccine failure.

Basrur said yesterday that vaccination remains the best defence against rubella, providing safe and effective protection.

The highly contagious disease causes only mild illness in children and adults, although a minority of adults develop joint pain.

Typical symptoms are mild rash, low-grade fever and swollen glands.

Most at risk are non-vaccinated pregnant women because infection in the fetus can lead to birth defects, fetal death or miscarriage.

Basrur said the outbreak is continuing at an expected rate and will continue to grow because of the number of non-immunized people in the hardest-hit community.

The outbreak probably will continue for weeks rather than days, she said. "Hopefully, it will not be for months but time will tell."

Oxford medical officer of health Dr. Doug Sider said the disease will be snuffed out gradually as more people are immunized or contract the disease and develop immunity.

"Eventually, the combination of increased vaccinations and increased infection means the outbreak will be over," Sider said.

"I hope that announcement to the community will be sooner rather than later."

The outbreak has resulted in cancellation of some community events, including a blood donor clinic scheduled for Tuesday at Norwich district secondary school.