PHILADELPHIA (AP) --
    As people from around the world head to Philadelphia for the World Meeting of Families and the papal visit, doctors are preparing to treat illnesses that they may not recognize or that normally would be treated at other facilities.
    "Some diseases that are common in other parts of the world aren't regularly seen in the U.S. Our providers know about them but haven't seen them," said Mark Ross, regional manager of emergency preparedness for the Hospital Association of Pennsylvania. "We've made sure our providers know what they look like."
    The Philadelphia Department of Public Health issued a special advisory this week listing some infectious diseases of concern. They include typhoid and yellow fever; the chikungunya virus that produces fevers and joint pain; malaria; polio; and tuberculosis.
    Typically, 0.3 to 1.3 percent of people attending a mass gathering will need some sort of medical care, "from a Band-Aid to heart surgery," said John Wierzbowski, who heads the department of safety and emergency management at Pennsylvania Hospital.
    Papal visit planners have estimated up to 1.5 million people could come to Philadelphia for Sunday's outdoor Mass, the biggest event of Francis' first trip to the U.S. Ahead of the pope's visit, demand for hotels, rail passes and other services was lower than expected. But even an influx of hundreds of thousands of people would put added demand on medical facilities.
    At least 18,000 people from more than 100 countries are attending the Vatican-sponsored World Meeting of Families, which drew Francis to Philadelphia. He will attend the meeting's closing festival Saturday after earlier stops in Washington and New York.
    At Tuesday's opening ceremony, children held up signs showing how far some had traveled: more than 5,000 miles from Argentina and Nigeria and over 8,000 miles from Vietnam and the Philippines.
    The city's Health Department has posted a special World Meeting of Families website with lists of disease symptoms, diagnostics and treatments and instructions on patient isolation and the use of personal protective equipment. It also includes a public health screening tool to aid clinicians in evaluating patients for potential infectious disease.
    The department is instructing health care providers to take a detailed travel history from patients and to report diseases to a special hotline.
    Security and travel restrictions, including the closure of 25 miles of streets and highways during the papal visit this weekend, have also driven medical planning.
    Burn victims would typically go to Temple University Hospital in North Philadelphia. But because of Pennsylvania Hospital's location within the papal safety zone, it has been outfitted with burn carts - containing anti-bacterial dressings, airway management supplies and ointments - to treat people with moderate burns.
    As planners expect a largely older crowd, Wierzbowski said, doctors believe a majority of patients needing medical care will be suffering from dehydration, chest pains or minor cuts, scrapes and burns.
    Still, he knows there will also be visitors with special needs and serious illnesses, some of them hoping for healing from the pope. They'll require more acute care.