SHILOH, Ohio — Visitors from around the world to two upcoming events in Ohio’s Amish country could come away with more than they bargained for, health officials fear – a case of measles from the nation’s largest outbreak in two decades.

The outbreak, with more than 360 cases, started after Amish travelers to the Philippines contracted measles this year and returned home to rural Knox County, where it spread thanks to a lower rate of vaccination among the Amish and the difficulty public health authorities had in getting the word out to largely rural communities where phones are few and the Internet is nonexistent.

Health officials believe the outbreak is slowing in Ohio thanks to vaccination clinics and door-to-door visits by public health nurses. But Horse Progress Days, an international showcase of horse-drawn equipment scheduled for Friday and Saturday, is expected to draw more than 20,000 Amish and others from around the globe. And a large annual auction that raises money to help Amish families pay medical bills for children with birth defects is scheduled for Saturday.

Symptoms of measles, which is caused by a virus, include fevers, coughs, rashes and pinkeye. Before widespread vaccinations in the U.S. beginning in the 1950s, 450 to 500 people died each year, 48,000 were hospitalized and nearly a thousand people suffered brain damage or deafness. Though nearly eradicated in the United States, measles remains common in many parts of Asia, the Pacific and Africa.

The Amish eschew many conveniences of modern life. Their religion does not prevent them from seeking vaccinations, but because their children don’t attend traditional public schools, vaccinations are not required and therefore not routine.

For Amish who aren’t vaccinated, Ohio health officials say, reasons include religious objections, unwillingness to shoulder the cost because they don’t have insurance, and not seeing the need for a disease that isn’t common.

Outreach efforts have been hampered by communication – few Amish have phones.