CHICAGO (CBS) — In the face of increasing measles cases in Illinois and elsewhere, U.S. Sen. Dick Durbin said politicians need “to stop playing doctor,” and encouraging parents who choose not to vaccinate their children.

The senator said it used to be only a few parents – for religious or other reasons – would opt out of school requirements for vaccinations against the measles, and other diseases; but, because of unfounded fears about the vaccine, many now claim exemptions.

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Durbin said that’s one reason measles cases are on the rise.

“I think the politicians in Washington, and around this country, have got to stop playing doctor. Some of the loose comments they’ve made about these measles vaccinations just make the situation worse,” he said. “It is a safe vaccine. Parents should use this vaccine, protecting themselves and their children.”

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New Jersey Gov. Chris Christie has said parents have the right to choose whether their children are vaccinated for measles or other preventable diseases. U.S. Sen. Rand Paul, an opthamologist, also has said vaccines should be voluntary, and said he’s heard cases of children suffering “profound mental disorders after vaccines,” a view strongly disputed by the medical community.

Speaking at the Institute of Health Sciences Career Academy, Durbin said parents who don’t want to vaccinate their children should be challenged more. He pointed out Illinois requires all children to be vaccinated before attending school, unless their parents can prove a religious or medical objection – such as an allergy to a vaccine.

Cook County and Illinois public health officials announced Thursday that five infants who attend a daycare in Palatine have been diagnosed with measles. Lab tests have confirmed measles in two of the babies, while doctors for three others have diagnosed measles based on clinical and epidemiological criteria.

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However, health officials have not confirmed the source of the outbreak, or said whether it can be traced to a child whose parents opted not to vaccinate him or her.