The largest outbreak of measles in the United States during 1999: imported measles and pockets of susceptibility.

The largest measles outbreak in the United States during 1999 was traced to a 34-year-old minister with an undocumented history of vaccination, infected while traveling outside the United States. Local health departments in the Central Virginia Health District performed an epidemiological and laboratory investigation that identified 14 additional confirmed cases of measles, including 2 in health care providers and 5 in congregation members. Eight cases (53%) occurred among adults aged 30-35 years and 7 (47%) among children aged 13 months to 8 years.

A Norwalk-like virus outbreak on the Appalachian Trail.

In May and June 1999, an outbreak of acute gastrointestinal illness occurred among long-distance hikers on the Appalachian Trail between Catawba and Troutville, Virginia. An investigation found that 45 out of 70 hikers had become ill within two days of arriving in Catawba, Virginia. Water samples were collected from a general store frequented by the hikers and from several nearby buildings and a popular all-you-can-eat restaurant.