A man traveling the country to fund-raise for charity in Orthodox Jewish communities is responsible for 38 cases of measles in Michigan after driving from Brooklyn to Detroit for a business trip full of community meetings.

The Israeli traveler, dubbed 'Michigan's Patient Zero' by the Washington Post, arrived in New York in November, when the measles outbreak was starting to take hold in Brooklyn, and he stayed until March.

It took Michigan authorities a week to realize he might be the source - by which time, the Post reported, he had interacted with 'hundreds of people', visiting synagogue three times a day, kosher markets, and staying in people's homes.

The man, who had gone to a doctor with a fever, cough and rash when he first arrived in Detroit but was given the all-clear, was 'devastated' when he realized he was the source of a fresh outbreak, Michigan health authorities said.

The Israeli traveler arrived in New York in November, when the measles outbreak was starting to take hold in Brooklyn. He went to Michigan in early March and was there for a week before diagnosis (file image)

On the night that he set off for his overnight drive from New York to Michigan, the man, who has not been identified, had a fever and a heavy cough - two classic symptoms of measles - so he went straight to a doctor when he arrived, the Post reported.

His concerns were dismissed. The doctor gave him antibiotics for bronchitis.

The next day, the man called the doctor's office saying he'd developed a rash. The doctor said it must be an allergic reaction and nothing to worry about.

With the doctor's vote of confidence, the man went ahead with his jam-packed schedule of events across Oakland County, in which Detroit sits, including daily synagogue visits, and staying in people's homes.

But shortly after their phone call, the doctor had a moment of realization: it could be measles.

He called back. The man's phone, which wasn't working, went straight to voicemail, so he called the authorities.

According to the Post, his call was answered by the perfect person: Steve McGraw, not only head of emergency medical services but also part of Oakland County's Orthodox Jewish community, who immediately contacted all the rabbis in the area.

His contacts in the community knew exactly who he was talking about and directed him to the neighborhood the man was scheduled to be in that day.

McGraw told the Post he felt confident that he could find the man because he knew the man was driving a blue sedan and he knew 'it would stand out among the minivans used by virtually every family'.

They tracked him down in a matter of hours and told him what had happened, to his shock.

The antibiotics he'd been given were futile for his illness, though it can help for measles sufferers who develop bacterial infections like pneumonia, which is common.

There is no treatment for measles, bar a post-exposure vaccine.

The only thing doctors can advise is to stay away from others.